| cloning and sequences of primate cd4 molecules: diversity of the cellular receptor for simian immunodeficiency virus/human immunodeficiency virus. | to study the interaction between the primate lentiviruses simian immunodeficiency virus (siv) and human immunodeficiency virus (hiv) and the cd4 receptor we have cloned and sequenced the cd4 molecule from six non-human primate species: african green monkeys (three subspecies: sabeus, pytherethrus, aethiops), sooty mangabeys, patas monkeys, chimpanzees, rhesus macaques, and pig-tail macaques. molecular cdna clones representing cd4 mrna were generated from total rna from peripheral blood mononucle ... | 1992 | 1425921 |
| functional classification of simian immunodeficiency virus isolated from a chimpanzee by transactivators. | in reporter-based transient expression systems, we characterized simian immunodeficiency virus from a chimpanzee (sivcpz), with special reference to the human immunodeficiency virus type 1 (hiv-1). sivcpz was not equally activated by tat and rev transactivators derived from representative primate lentiviruses. hiv-1 alone activated sivcpz to the full extent in both tat and rev assays. the tat and rev gene products of sivcpz, as well as those of hiv-1, efficiently transactivated the other viruses ... | 1992 | 1604820 |
| vaccine protection of chimpanzees against challenge with hiv-1-infected peripheral blood mononuclear cells. | because human immunodeficiency virus (hiv) can be transmitted as cell-free virus or as infected cells (cell-associated virus), vaccines must protect against infection by both viral forms. vaccine-mediated protection of nonhuman primates against low doses of cell-free hiv-1, hiv-2, or simian immunodeficiency virus (siv) has been demonstrated. it is now shown that multiple immunizations of chimpanzees with hiv-1 antigens protected against infection with cell-associated virus. protection can persis ... | 1992 | 1609280 |
| isolation and characterization of a new chimpanzee lentivirus (simian immunodeficiency virus isolate cpz-ant) from a wild-captured chimpanzee. | to assess the prevalence of infection with simian immunodeficiency virus (siv) isolate cpz, a lentivirus closely related to hiv-1, in chimpanzees, and to obtain new sivcpz isolates. | 1992 | 1616649 |
| neutralization and enhancement of in vitro and in vivo hiv and simian immunodeficiency virus infections. | over the past year significant progress has been made in mapping those regions of the hiv-1 envelope glycoproteins involved in virus neutralization and virus enhancement. these functional, antigenic domains of the gp160 are illustrated in fig. 1. the role of neutralization in vaccine development is still unresolved, although high-titer antibody to the v3 loop of hiv-1 appears to be correlated with the ability to prevent hiv-1 infection by the homologous strain in chimpanzees. therefore, the mech ... | 1990 | 2152561 |
| report of a who informal consultation on animal models for evaluation of drugs and vaccines for hiv infection and aids. w.h.o., geneva, 14-15 september 1989. | the use of animal models in the preclinical evaluation of anti-hiv drugs and vaccines was discussed at an informal consultation at world health organization headquarters in geneva, 14-15 september 1989. the consultation was attended by six experts from four countries. hiv animal models, other lentivirus/animal models and oncornavirus/animal models were discussed, and their advantages and disadvantages were compared to hypothetical ideal hiv/animal models for preclinical evaluation of anti-hiv dr ... | 1990 | 2175206 |
| isolation and partial characterization of an hiv-related virus occurring naturally in chimpanzees in gabon. | two cases of wild-born chimpanzees which were positive for hiv-1 antibodies were observed in gabon. these animals were never experimentally exposed to hiv-1 and had no history of inoculation with human blood products. a retrovirus was isolated from one of these chimpanzees. several of the viral proteins from this virus, designated sivcpz-gab-1 (simian immunodeficiency virus from chimpanzee), differed in molecular weight from the known corresponding hiv/siv proteins. the major gag protein of sivc ... | 1989 | 2512955 |
| animal models of aids. | animal models of aids are essential for understanding the pathogenesis of retrovirus-induced immune deficiency and encephalopathy and for development and testing of new therapies and vaccines. aids and related disorders are etiologically linked to members of the lentivirus subfamily of retroviruses; these lymphocytopathic lentiviruses are designated human immuno-deficiency virus type 1 (hiv-1) and human immuno-deficiency virus type 2 (hiv-2). the only animals susceptible to experimental hiv-1 in ... | 1989 | 2556312 |
| identification and biologic characterization of an acutely lethal variant of simian immunodeficiency virus from sooty mangabeys (siv/smm). | a virus pool isolated from lymphoid tissue of a macaque (pbj) infected for 14 months with siv/smm was found to be associated with acute disease and death. six of six pig-tailed macaques, one of three rhesus macaques, and three of four siv/smm-seronegative mangabeys developed acute disease within 5 days and died from 7 to 13 days postinoculation; however, neither of two siv/smm-infected mangabeys died or developed disease. the virus associated with acute disease and death was shown by electron mi ... | 1989 | 2765298 |
| sequence of simian immunodeficiency virus from macaque and its relationship to other human and simian retroviruses. | because of the growing incidence of aids (acquired immune deficiency syndrome), the need for studies on animal models is urgent. infection of chimpanzees with the retroviral agent of human aids, the human immunodeficiency virus (hiv), will have only limited usefulness because chimpanzees are in short supply and do not develop the disease. among non-human primates, both type d retroviruses and lentiviruses can be responsible for immune deficiencies. the d-type retroviruses, although important pat ... | 1987 | 3649576 |
| phenotypic and functional parameters of cellular immunity in a chimpanzee with a naturally acquired simian immunodeficiency virus infection. | the cellular immunologic and virologic status of a chimpanzee, naturally infected with a human immunodeficiency virus type 1 (hiv-1)-like lentivirus (sivcpz-ant), was compared longitudinally with those of 3 hiv-1-infected and 5 uninfected chimpanzees for a period of 49 months. evidence of immune deficiency was not observed in the hiv-1-infected chimpanzees, nor could virus be isolated from plasma. virus could be isolated from plasma of the sivcpz-ant-infected chimpanzee, but clinical signs of im ... | 1995 | 7561216 |
| construction of human immunodeficiency virus 1/simian immunodeficiency virus strain mac chimeric viruses having vpr and/or nef of different parental origins and their in vitro and in vivo replication. | we constructed a series of human immunodeficiency virus 1 (hiv-1)/simian immunodeficiency virus strain mac (sivmac) chimeric viruses having vpr and/or nef genes of either hiv-1 or sivmac based on a chimeric virus with ltrs, gag, pol, vif and vpx derived from sivmac and tar, rev, vpu and env from hiv-1. all of the chimeric viruses replicated in human and macaque peripheral blood mononuclear cells (pbmcs) and in several cd4+ human cell lines, though their growth potentials were slightly different ... | 1995 | 7561755 |
| a new subtype of human immunodeficiency virus type 1 (mvp-5180) from cameroon. | a new subtype (mvp-5180) of human immunodeficiency virus type 1 (hiv-1) was isolated from a cameroonian aids patient. mvp-5180 was grown in several human t-cell lines and the monocytic u937 line. mvp-5180 dna could not be amplified by nested primer pcr with conventional env primers and could be only very faintly amplified with gag and pol primers. most german, ivoirian, and malawian anti-hiv-1 sera reacted faintly or moderately with env proteins in an mvp-5180 immunoblot, whereas some cameroonia ... | 1994 | 8107219 |
| where are we now with vaccines against aids? | extensive studies in experimental animal models and phase i and ii clinical trials in humans provide some grounds for optimism about developing a vaccine for aids. over 200 monkeys have been protected by simple inactivated vaccines against infection with a lethal challenge dose of simian immunodeficiency virus (siv). passive transfer of the antibody to siv has been shown to prevent infection. recent vaccination with attenuated, live siv protected against a challenge with 1000 monkey infectiou ... | 1993 | 8490466 |
| cyclophilin a is required for the replication of group m human immunodeficiency virus type 1 (hiv-1) and simian immunodeficiency virus siv(cpz)gab but not group o hiv-1 or other primate immunodeficiency viruses. | the human immunodeficiency virus type 1 (hiv-1) gag polyprotein binds to cyclophilin a and incorporates this cellular peptidyl prolyl-isomerase into virions. disruption of cyclophilin a incorporation, either by gag mutations or by cyclosporine a, inhibits virion infectivity, indicating that cyclophilin a plays an essential role in the hiv-1 life cycle. using assays for packaging of cyclophilin a into virions and for viral replication sensitivity to cyclosporine a, as well as information gleaned ... | 1996 | 8676442 |
| resistance of previously infected chimpanzees to successive challenges with a heterologous intraclade b strain of human immunodeficiency virus type 1. | to test whether the protective effects of attenuated simian immunodeficiency virus vaccines in macaques were applicable to the human immunodeficiency virus type 1 (hiv-1)-chimpanzee system, two groups of animals, previously infected with hiv-1(iiib) or hiv-1(sf2) were each challenged with a heterologous clade b virus, hiv-1(dh12). following challenge, the parameters measured included virus isolation (from plasma, peripheral blood mononuclear cells, and lymph node tissue); quantitative dna pcr us ... | 1996 | 8676459 |
| the nef gene from a long-term hiv type 1 nonprogressor. | we examined the nef gene of hiv-1 in a long-term nonprogressor to look for evidence suggesting an attenuated virus. the nef gene was previously shown to be required for induction of aids. simian immunodeficiency virus (siv) deleted in nef, while infectious, fails to sustain the high viral loads necessary for the induction of aids in infected adult rhesus monkeys. the human subject of this report was found to harbor virus (hiv-1 sur25) encoding open-nef reading frames. however, the nef genes of t ... | 1996 | 8906995 |
| the neutralization relationship of hiv type 1, hiv type 2, and sivcpz is reflected in the genetic diversity that distinguishes them. | neutralizing antibody (na) patterns in the sera of individuals naturally infected with human immunodeficiency virus (hiv) type 1, hiv-2, and the simian immunodeficiency virus (sivcpz) to their homologous and heterologous isolates were determined in a peripheral blood mononuclear cell-based neutralization assay. we examined the role of the v3 loop of hiv-1 and sivcpz in neutralization and the cross-reactivities among them. cross-neutralization by sera of humans and chimpanzees naturally infected, ... | 1997 | 8989422 |
| study of the dynamics of neutralization escape mutants in a chimpanzee naturally infected with the simian immunodeficiency virus sivcpz-ant. | here we report on the use of spectral map analysis of time-paired sequential neutralization data of 11 serum samples of a chimpanzee naturally infected with a simian immunodeficiency virus (sivcpz-ant) and 8 primary consecutive sivcpz-ant isolates, taken at about 4-month intervals. the analysis reveals the existence of three sivcpz-ant isolate and serum neutralization clusters. each cluster groups virus isolates and/or sera based on similarities of their neutralization spectra. on average, neutr ... | 1997 | 9032368 |
| an hiv-1 infection-related idiotype/clonotype (1f7) is expressed on antibodies directed to envelope glycoprotein in simian immunodeficiency virus- and chimeric simian/human immunodeficiency virus-infected rhesus monkeys. | an antiidiotypic/clonotypic marker, designated 1f7, is restricted to antibodies directed to human immunodeficiency virus type 1 (hiv-1) envelope, core, and reverse transcriptase proteins. 1f7-id is shared by more than 70% of hiv-infected individuals, arising early and persisting throughout all disease stages. to study the specificity and biological function of this cross-reactive idiotypic marker, and to explore its potential in therapeutics, we have sought an appropriate animal model. 1f7-id+ a ... | 1997 | 9085123 |
| relation between phylogeny of african green monkey cd4 genes and their respective simian immunodeficiency virus genes. | an apparent species-specific relatedness of sivagm suggests a coevolution with their natural hosts. however, the exact species or subspecies classification of african green monkeys, agm, is uncertain because current classification schemes rely on phenotype markers, while more definitive genetic data are lacking. in this study, the cd4 protein involved in tissue type recognition was genetically cloned and sequenced from pbmc rna from all agm species, including barbados green monkeys (bgm). phylog ... | 1997 | 9379478 |
| primary sivsm isolates use the ccr5 coreceptor from sooty mangabeys naturally infected in west africa: a comparison of coreceptor usage of primary sivsm, hiv-2, and sivmac. | genetically divergent strains of simian immunodeficiency virus (siv) from macaques (mac), chimpanzees, and sooty mangabeys (sm) efficiently used rhesus and human ccr5 (r5), but not cxcr4 (xr4), for cell entry. thus far, however, no studies have characterized primary sivsm strains for their use of coreceptors derived from their own natural host. coreceptor usage of two primary, blood-derived sivsm isolates, sivsmsl92b and sivsmfns from naturally infected sooty mangabeys, was determined. primary s ... | 1998 | 9656999 |
| a novel simian immunodeficiency virus (sivdrl) pol sequence from the drill monkey, mandrillus leucophaeus. | the drill monkey has been shown by serology and pcr to harbor a unique simian immunodeficiency virus (sivdrl). a pol sequence, amplified from uncultured peripheral blood cells, is most closely related to the equivalent siv sequences from the red-capped mangabey (sivrcm), the sabaeus african green monkey (sivagmsab), and the chimpanzee (sivcpz) and to the human immunodeficiency virus type 1 (hiv-1) sequence of humans. it is as yet unclear whether sivdrl has a mosaic genome like sivrcm and sivagms ... | 1998 | 9811781 |
| origin of hiv-1 in the chimpanzee pan troglodytes troglodytes. | the human aids viruses human immunodeficiency virus type 1 (hiv-1) and type 2 (hiv-2) represent cross-species (zoonotic) infections. although the primate reservoir of hiv-2 has been clearly identified as the sooty mangabey (cercocebus atys), the origin of hiv-1 remains uncertain. viruses related to hiv-1 have been isolated from the common chimpanzee (pan troglodytes), but only three such sivcpz infections have been documented, one of which involved a virus so divergent that it might represent a ... | 1999 | 9989410 |
| postexposure immunoprophylaxis of primary isolates by an antibody to hiv receptor complex. | mab b4 is a monoclonal antibody directed against hiv receptor complex. the antibody had broad neutralizing activity against hiv and provided postexposure prophylaxis to hu-peripheral blood leukocyte (pbl)-severe combined immunodeficient mice and chimpanzees. b4 recognized a complex receptor site for hiv on the t cell surface that includes cd4 and also may be influenced by interaction with hiv coreceptors. mab b4 preferentially neutralized primary hiv-1 isolates compared with t cell line-adapted ... | 1999 | 10468614 |
| env sequences of simian immunodeficiency viruses from chimpanzees in cameroon are strongly related to those of human immunodeficiency virus group n from the same geographic area. | human immunodeficiency virus type 1 (hiv-1) group n from cameroon is phylogenetically close, in env, to the simian immunodeficiency virus (siv) cpz-gab from gabon and sivcpz-us of unknown geographic origin. we screened 29 wild-born cameroonian chimpanzees and found that three (cam3, cam4, and cam5) were positive for hiv-1 by western blotting. mitochondrial dna sequence analysis demonstrated that cam3 and cam5 belonged to pan troglodytes troglodytes and that cam4 belonged to p. t. vellerosus. gen ... | 2000 | 10590144 |
| natural infection of chimpanzees with new lentiviruses related to hiv-1/sivcpz. | to determine newly identified lentiviruses, termed simian immunodeficiency virus (siv)cpz97cg4 and sivcpz97cg6, from two wild-captured juvenile brother chimpanzees in the republic of congo, subgenomic pol (integrase, 288 bp), 5'tat/rev-env cl (including vpu, 354 bp) and env (c2-c4, 544 bp) gene fragments were amplified and sequenced. the analysis revealed significantly discordant phylogenetic positions of sivcpz97cg in each genomic region. in the trees derived from partial env sequences (v3), bo ... | 1999 | 10593482 |
| new prospects for the development of a vaccine against human immunodeficiency virus type 1. an overview. | during the past few years, definite progress has been made in the field of human immunodeficiency virus type 1 (hiv-1) vaccines. initial attempts using envelope gp120 or gp140 from t-cell line-adapted (tcla) hiv-1 strains to vaccinate chimpanzees showed that neutralizing antibody-based immune responses were protective against challenge with homologous tcla virus strains or strains with low replicative capacity, but these neutralizing antibodies remained inactive when tested on primary hiv-1 isol ... | 1999 | 10646090 |
| aids as a zoonosis: scientific and public health implications. | evidence of simian immunodeficiency virus (siv) infection has been reported for 26 different species of african nonhuman primates. two of these viruses, sivcpz from chimpanzees and sivsm from sooty mangabeys, are the cause of acquired immunodeficiency syndrome (aids) in humans. together, they have been transmitted to humans on at least seven occasions. the implications of human infection by a diverse set of sivs and of exposure to a plethora of additional human immunodeficiency virus-related vir ... | 2000 | 10649986 |
| analysis of genetic variability within the immunodominant epitopes of envelope gp41 from human immunodeficiency virus type 1 (hiv-1) group m and its impact on hiv-1 antibody detection. | the serodiagnosis of human immunodeficiency virus type 1 (hiv-1) infection primarily relies on the detection of antibodies, most of which are directed against the immunodominant regions (idr) of hiv-1 structural proteins. among these, the n-terminal region of gp41 contains cluster i (amino acids [aa] 580 to 623), comprising the cytotoxic t-lymphocyte epitope (averylkdqqll) and the cysteine loop (csgklic), and cluster ii (aa 646 to 682), comprising an ectodomain region (eldkwa). to delineate the ... | 2000 | 10655384 |
| serological detection of infection with diverse human and simian immunodeficiency viruses using consensus env peptides. | cross-species transmission has been shown to play an important role in the emergence of human retroviruses. we developed a generic enzyme immunoassay using synthetic peptides from gp41 and c2v3 consensus sequences (human immunodeficiency virus [hiv] type 1 [hiv-1] groups m, o, and n and the homologous region of simian immunodeficiency virus [siv] strains from chimpanzees [sivcpz], sivcpzgab1 and sivcpzant) to detect divergent hiv and siv. a cocktail of peptides from gp41 and c2v3 (m-o) detected ... | 2000 | 10882678 |
| the chimpanzee and other non-human-primate models in hiv-1 vaccine research. | animal models are of great importance for the study of disease pathogenesis, particularly non-human-primate models of infectious diseases. the role of non-human primates in hiv-1 research is continually discussed and debated. here, we examine three primate models: chimpanzee-hiv-1, rhesus macaque-simian immunodeficiency virus and rhesus macaque-shiv, and discuss immunological similarities and differences, safety and monetary issues, and ethical concerns. | 2000 | 10989311 |
| identification of gp120 regions targeted by a highly potent neutralizing antiserum elicited in a chimpanzee inoculated with a primary human immunodeficiency virus type 1 isolate. | we have previously reported that a chimpanzee infected with a primary human immunodeficiency virus type 1 (hiv-1) isolate (hiv-1(dh12)) developed an extremely potent virus-neutralizing antibody. immunoglobulin g purified from this animal conferred sterilizing immunity following passive transfer to macaques which were subsequently challenged with simian immunodeficiency virus/hiv-1 chimeric virus strain dh12. in addition to being highly strain specific, the chimpanzee antiserum did not bind to th ... | 2000 | 11000249 |
| sivcpz from a naturally infected cameroonian chimpanzee: biological and genetic comparison with hiv-1 n. | thus far, simian immunodeficiency virus from chimpanzees (sivcpz) genomes have been characterized as pan troglodytes troglodytes and show a strong relation with human immunodeficiency virus (hiv)-1 n in their env genes. we fully characterized another sivcpz from p. t. troglodytes. this chimpanzee (cam5) was, as was also the host of sivcpz-cam3, wild born in cameroon, a region where all three groups of hiv-1 (m, n and o) co-occur. in contrast to other sivcpz, sivcpz-cam5 was isolated immediately ... | 2000 | 11085579 |
| chat oral polio vaccine was not the source of human immunodeficiency virus type 1 group m for humans. | a book published in 1999 hypothesized that the scientists who worked with the chat type 1 attenuated poliomyelitis strain, tested in the former belgian congo in the late 1950s, had covertly prepared the vaccine in chimpanzee kidney cells contaminated with a simian immunodeficiency virus, which evolved into human immunodeficiency virus type 1 group m. this article summarizes the results of the investigation conducted by the author to determine the legitimacy of the accusation. testimony by eyewit ... | 2001 | 11264036 |
| molecular analyses of oral polio vaccine samples. | it has been suggested that the human immunodeficiency virus (hiv), and thus the acquired immunodeficiency syndrome (aids) it causes, was inadvertently introduced to humans by the use of an oral polio vaccine (opv) during a vaccination campaign launched by the wistar institute, philadelphia, pa, usa, in the belgian congo in 1958 and 1959. the "opv/aids hypothesis" suggests that the opv used in this campaign was produced in chimpanzee kidney epithelial cell cultures rather than in monkey kidney ce ... | 2001 | 11326104 |
| origin of aids discovered. | during the 6th conference on retroviruses and opportunistic infections (croi), researchers at the university of alabama reported that they have traced the origin of aids to a subspecies of chimpanzees (pan troglodytes) found in africa. studies of simian immunodeficiency virus (siv), which is harmless in chimpanzees, may facilitate understanding about hiv transmission and the immune system response. unfortunately the chimpanzees are being eradicated by hunters and the logging trade. scientists sp ... | 1999 | 11367166 |
| epidemiology and the emergence of human immunodeficiency virus and acquired immune deficiency syndrome. | although acquired immune deficiency syndrome (aids) was first described in the usa in 1981, there is evidence that individual cases occurred considerably earlier in central africa, and serological and virological data show human immunodeficiency virus (hiv) was present in the democratic republic of congo (drc) as far back as 1959. it is likely that hiv-1 infection in humans was established from cross-species transmission of simian immunodeficiency virus of chimpanzees, but the circumstances surr ... | 2001 | 11405922 |
| experimental oral polio vaccines and acquired immune deficiency syndrome. | the simian immunodeficiency virus (siv) of the common chimpanzee is widely acknowledged as the direct ancestor of hiv-1. there is increasing historical evidence that during the late 1950s, kidneys were routinely excised from central african chimpanzees by scientists who were collaborating with the polio vaccine research of dr hilary koprowski, and sent - inter alia - to vaccine-making laboratories in the usa and africa, and to unspecified destinations in belgium. while there is no direct evidenc ... | 2001 | 11405924 |
| untruths and consequences: the false hypothesis linking chat type 1 polio vaccination to the origin of human immunodeficiency virus. | a book published in 1999 hypothesized that the scientists who worked with the chat type 1 attenuated polio strain tested in the former belgian congo in the late 1950s had covertly prepared the vaccine in chimpanzee kidney cells contaminated with a simian immunodeficiency virus, which evolved into hiv-1 group m. this paper summarizes the results of the investigation conducted by the author to determine the legitimacy of the accusation. testimony by eyewitnesses, documents of the time, epidemiolog ... | 2001 | 11405925 |
| the jezierski papers: live polio vaccine development in colobus monkey cells but not chimpanzee cells in the belgian congo, 1952-1958. | a reading of ten relevant papers by alexandre jezierski provides evidence for the only attempt in central africa to develop a live oral polio vaccine (opv) from growing reference wild polio strains to 210 passages in colobus monkey tissue culture, and experimental administration to about 25 humans. chimpanzees were used as a human model, but their tissues or kidneys were absent from the passage and production line of the proposed vaccine. thus, the implication published by hooper that jezierski ... | 2001 | 11405928 |
| natural and iatrogenic factors in human immunodeficiency virus transmission. | in the light of the evidence and discussion presented during the royal society discussion meeting it seems to me that the oral polio vaccine (opv) hypothesis for the origins of human immunodeficiency virus (hiv) and the acquired immune deficiency syndrome epidemic is less tenable now than one year earlier. the opv hypothesis does not accord with hiv phylogenetic studies: the geographical correlation has been challenged; the testimony of those directly involved with opv trial vaccines denies the ... | 2001 | 11405945 |
| wild mandrillus sphinx are carriers of two types of lentivirus. | mandrillus sphinx, a large primate living in cameroon and gabon and belonging to the papionini tribe, was reported to be infected by a simian immunodeficiency virus (siv) (sivmndgb1) as early as 1988. here, we have identified a second, highly divergent sivmnd (designated sivmnd-2). genomic organization differs between the two viral types; sivmnd-2 has the additional vpx gene, like other sivs naturally infecting the papionini tribe (sivsm and sivrcm) and in contrast to the other sivmnd type (here ... | 2001 | 11435589 |
| simian immunodeficiency virus from mandrill (mandrillus sphinx) sivmnd experimentally infects human and nonhuman primate cells. | this study set out to characterize the features of experimental infection by simian immunodeficiency virus in mandrill (sivmnd) (mandrillus sphinx), cynomolgus macaque (macaca fascicularis), rhesus macaque (macaca mulatta), chimpanzee (pan troglodytes), african green monkey (cercopithecus pygerythrus), baboon (papio cynocephalus) and human cells. purified cells were exposed to a primary isolate of sivmnd grown in the infected mandrill peripheral blood mononuclear cells, and viral p27 gag antigen ... | 2001 | 11445446 |
| complement-dependent control of viral dynamics in pathogenesis of human immunodeficiency virus and simian immunodeficiency virus infection. | since the first contact with the host, human immunodeficiency virus (hiv) exploits the complement system to reach maximal spread of infection. hiv has adapted many strategies to avoid complement-mediated lysis and uses the opsonization with complement fragments for attachment to complement receptors (cr). from the pathogen's perspective, binding to cr-expressing cells is remarkably beneficial, bringing together virus and activated target cells that are highly susceptible to infection. moreover, ... | 2001 | 11532285 |
| characterization of novel simian immunodeficiency viruses from red-capped mangabeys from nigeria (sivrcmng409 and -ng411). | two novel simian immunodeficiency virus (siv) strains from wild-caught red-capped mangabeys (cercocebus torquatus torquatus) from nigeria were characterized. sequence analysis of the fully sequenced siv strain rcmng411 (sivrcmng411) and gag and pol sequence of sivrcmng409 revealed that they were genetically most closely related to the recently characterized sivrcm from gabon (sivrcmgb1). thus, red-capped mangabeys from distant geographic locations harbor a common lineage of siv. sivrcmng411 carr ... | 2001 | 11711592 |
| sivcpz in wild chimpanzees. | | 2002 | 11799233 |
| development of anti-cd4 mab hu5a8 for treatment of hiv-1 infection: preclinical assessment in non-human primates. | the anti-cd4 mab 5a8 is a potent inhibitor of cd4-mediated infection of hiv-1. cd4 is obligatory for infection with primary hiv-1 isolates. humanized 5a8 (hu5a8) was constructed to reduce the potential immunogenicity and enhance the in vivo half-life when used in humans. hu5a8 is a molecularly engineered human igg4 antibody retaining the binding and functional properties of the murine version of 5a8 (mu5a8). this humanized mab has been shown to be very effective in inhibiting hiv-1 infection of ... | 2002 | 11893418 |
| in vitro replication of sivcpz is suppressed by beta-chemokines and cd8+ t cells but not by natural killer cells of infected chimpanzees. | unlike humans, chimpanzees are relatively resistant to aids after infection with hiv-1 or simian immunodeficiency virus of chimpanzee (sivcpz). we hypothesized that resistance to disease progression is associated with efficient suppression of virus replication possibly by beta-chemokines secreted by cd8+ lymphocytes and especially natural killer (nk) cells. in vitro suppression of virus replication can be easily studied in sivcpz-infected chimpanzees because they produce high infectious virus ti ... | 2002 | 11897039 |
| longitudinal comparison of virus load parameters and cd8 t-cell suppressive capacity in two sivcpz-infected chimpanzees. | in a longitudinal study we address the hypothesis that resis tance to disease progression in lentivirus-infected chimpanzees is related to potent non-cytotoxic suppression of virus replication. in a long-term follow-up, the viral suppressive capacity in two simian immunodeficiency virus (siv)cpz-infected chimpanzees was correlated with two polymerase chain reaction (pcr)- and two culture-based virus load measurements. in both animals, quantitative virus isolation (qvi) tended to decline slowly, ... | 2001 | 11990239 |
| characterization of a novel simian immunodeficiency virus with a vpu gene from greater spot-nosed monkeys (cercopithecus nictitans) provides new insights into simian/human immunodeficiency virus phylogeny. | in the present study, we describe a new simian immunodeficiency virus (siv), designated sivgsn, naturally infecting greater spot-nosed monkeys (cercopithecus nictitans) in cameroon. together with sivsyk, sivgsn represents the second virus isolated from a monkey belonging to the cercopithecus mitis group of the cercopithecus genus. full-length genome sequence analysis of two sivgsn strains, sivgsn-99cm71 and sivgsn-99cm166, revealed that despite the close phylogenetic relationship of their hosts, ... | 2002 | 12134035 |
| evidence for an ancient selective sweep in the mhc class i gene repertoire of chimpanzees. | mhc class i molecules play an essential role in the immune defense against intracellular infections. the hallmark of the mhc is its extensive degree of polymorphism at the population level. however, the present comparison of mhc class i gene intron variation revealed that chimpanzees have experienced a severe repertoire reduction at the orthologues of the hla-a, -b, and -c loci. the loss of variability predates the (sub)speciation of chimpanzees and did not effect other known gene systems. there ... | 2002 | 12186979 |
| amplification of a complete simian immunodeficiency virus genome from fecal rna of a wild chimpanzee. | current knowledge of the genetic diversity of simian immunodeficiency virus (sivcpz) infection of wild chimpanzees (pan troglodytes) is incomplete since few isolates, mostly from captive apes from cameroon and gabon, have been characterized; yet this information is critical for understanding the origins of human immunodeficiency virus type 1 (hiv-1) and the circumstances leading to the hiv-1 pandemic. here, we report the first full-length sivcpz sequence (tan1) from a wild chimpanzee (pan troglo ... | 2003 | 12525658 |
| human and simian immunodeficiency virus-infected chimpanzees do not have increased intracellular levels of beta-chemokines in contrast to infected humans. | this study was undertaken to explain why chimpanzees infected with hiv-1 (human immunodeficiency virus type 1) or siv(cpz) (simian immunodeficiency virus of chimpanzee) are relatively resistant to aids (acquired immunodeficiency syndrome). the numbers of beta-chemokine-positive cells were compared between uninfected and infected humans and chimpanzees using three-color cytofluorometry. in humans, the percentage of beta-chemokine-positive cells was significantly higher in cd8(+) t and natural kil ... | 2003 | 12526038 |
| simian immunodeficiency viruses from multiple lineages infect human macrophages: implications for cross-species transmission. | zoonotic transfer of simian immunodeficiency virus (siv) from chimpanzees and sooty mangabeys to humans has been documented on at least seven occasions. several recently identified siv isolates have also been shown to replicate efficiently in human peripheral blood mononuclear cells (pbmcs) in vitro, indicative of the potential for additional cross-species transmission via t cell infection. although siv predominantly uses the macrophage-tropic hiv chemokine coreceptor ccr5, little is known about ... | 2003 | 12640192 |
| characterization of a novel simian immunodeficiency virus (sivmonng1) genome sequence from a mona monkey (cercopithecus mona). | a novel simian immunodeficiency virus (siv) sequence has been recovered from rna extracted from the serum of a mona monkey (cercopithecus mona) wild born in nigeria. the sequence was obtained by using novel generic (degenerate) pcr primers and spans from two-thirds into the gag gene to the 3' poly(a) tail of the sivmonng1 rna genome. analysis of the open reading frames revealed that the sivmonng1 genome codes for a vpu protein, in addition to gag, pol, vif, vpr, tat, rev, env, and nef proteins. ... | 2003 | 12768007 |
| foci of endemic simian immunodeficiency virus infection in wild-living eastern chimpanzees (pan troglodytes schweinfurthii). | simian immunodeficiency virus of chimpanzees (sivcpz) is the immediate precursor to human immunodeficiency virus type 1 (hiv-1), yet remarkably, the distribution and prevalence of sivcpz in wild ape populations are unknown. studies of sivcpz infection rates in wild chimpanzees are complicated by the species' endangered status and by its geographic location in remote areas of sub-saharan africa. we have developed sensitive and specific urine and fecal tests for sivcpz antibody and virion rna (vrn ... | 2003 | 12805455 |
| identification of a new simian immunodeficiency virus lineage with a vpu gene present among different cercopithecus monkeys (c. mona, c. cephus, and c. nictitans) from cameroon. | during a large serosurvey of wild-caught primates from cameroon, we found 2 mona monkeys (cercopithecus mona) out of 8 and 47 mustached monkeys (cercopithecus cephus) out of 302 with human immunodeficiency virus (hiv)-simian immunodeficiency virus (siv) cross-reactive antibodies. in this report, we describe the full-length genome sequences of two novel sivs, designated sivmon-99cmcml1 and sivmus-01cm1085, isolated from one mona (cml1) and one mustached (1085) monkey, respectively. interestingly, ... | 2003 | 14610175 |
| frequent simian foamy virus infection in persons occupationally exposed to nonhuman primates. | the recognition that aids originated as a zoonosis heightens public health concerns associated with human infection by simian retroviruses endemic in nonhuman primates (nhps). these retroviruses include simian immunodeficiency virus (siv), simian t-cell lymphotropic virus (stlv), simian type d retrovirus (srv), and simian foamy virus (sfv). although occasional infection with siv, srv, or sfv in persons occupationally exposed to nhps has been reported, the characteristics and significance of thes ... | 2004 | 14990698 |
| origin of aids: contaminated polio vaccine theory refuted. | despite strong evidence to the contrary, speculation continues that the aids virus, human immunodeficiency virus type 1 (hiv-1), may have crossed into humans as a result of contamination of the oral polio vaccine (opv). this 'opv/aids theory' claims that chimpanzees from the vicinity of stanleyville--now kisangani in the democratic republic of congo--were the source of a simian immunodeficiency virus (sivcpz) that was transmitted to humans when chimpanzee tissues were allegedly used in the prepa ... | 2004 | 15103367 |
| what can natural infection of african monkeys with simian immunodeficiency virus tell us about the pathogenesis of aids? | the simian immunodeficiency viruses are a diverse group of viruses that naturally infect a wide range of african primates, including chimpanzees, african green monkeys (agm) and sooty mangabey monkeys (sm). although natural infection is widespread in feral populations of agms and sms, this infection does not result in immunodeficiency. however, experimental inoculation of asian macaque species results in an immunodeficiency syndrome that is remarkably similar in pathogenesis to human aids. thus, ... | 2004 | 15168740 |
| nef proteins from simian immunodeficiency virus-infected chimpanzees interact with p21-activated kinase 2 and modulate cell surface expression of various human receptors. | the accessory nef protein allows human immunodeficiency virus type 1 (hiv-1) to persist at high levels and to cause aids in infected humans. the function of hiv-1 group m subtype b nef alleles has been extensively studied, and a variety of in vitro activities believed to be important for viral pathogenesis have been established. however, the function of nef alleles derived from naturally simian immunodeficiency virus (siv)-infected chimpanzees, the original host of hiv-1, or from the hiv-1 n and ... | 2004 | 15194762 |
| readily acquired secondary infections of human and simian immunodeficiency viruses following single intravenous exposure in non-human primates. | accumulating evidence suggests that exposed individuals may acquire multiple human immunodeficiency virus (hiv) infections more frequently than originally believed. as a result, circulating recombinant forms of hiv are emerging that are of particular concern in the aids epidemic and hiv vaccine development efforts. the aim of this study was to determine under what conditions secondary or superinfections of hiv or simian immunodeficiency virus (siv) may be acquired under controlled settings in we ... | 2004 | 15557247 |
| the potential significance of adaptive evolution and dimerization in chimpanzee intercellular cell adhesion molecules (icams). | cell adhesion molecules are involved in a diverse array of cellular processes. recent data suggests that human immunodeficiency virus (hiv-1) co-opts their functions, in particular the properties of the intercellular cell adhesion molecules (icams), to enhance viral infection and transmission. to investigate mechanisms that may underlie the non-progression that occurs in immunodeficiency virus-infected chimpanzees, we amplified the protein coding regions of multiple non-human primate icams 1-5 a ... | 2005 | 15572059 |
| simian immunodeficiency virus infection in wild-caught chimpanzees from cameroon. | simian immunodeficiency viruses (sivcpz) infecting chimpanzees (pan troglodytes) in west central africa are the closest relatives to all major variants of human immunodeficiency virus type 1 ([hiv-1]; groups m, n and o), and have thus been implicated as the source of the human infections; however, information concerning the prevalence, geographic distribution, and subspecies association of sivcpz still remains limited. in this study, we tested 71 wild-caught chimpanzees from cameroon for evidenc ... | 2005 | 15613358 |
| contrasting effects of natural selection on human and chimpanzee cc chemokine receptor 5. | human immunodeficiency virus type 1 (hiv-1) evolved via cross-species transmission of simian immunodeficiency virus (sivcpz) from chimpanzees (pan troglodytes). chimpanzees, like humans, are susceptible to infection by hiv-1. however, unlike humans, infected chimpanzees seldom develop immunodeficiency when infected with sivcpz or hiv-1. sivcpz and most strains of hiv-1 require the cell-surface receptor cc chemokine receptor 5 (ccr5) to infect specific leukocyte subsets, and, subsequent to infect ... | 2004 | 15625621 |
| mitochondrial dna and retroviral rna analyses of archival oral polio vaccine (opv chat) materials: evidence of macaque nuclear sequences confirms substrate identity. | inoculation of live experimental oral poliovirus vaccines (opv chat) during the 1950s in central africa has been proposed to account for the introduction of hiv into human populations. for this to have occurred, it would have been necessary for chimpanzee rather than macaque kidney epithelial cells to have been included in the preparation of early opv materials. theoretically, this could have led to contamination with a progenitor of hiv-1 derived from a related simian immunodeficiency virus of ... | 2005 | 15705467 |
| simian immunodeficiency virus infection of chimpanzees. | | 2005 | 15767392 |
| retrovirus restriction by trim5alpha variants from old world and new world primates. | the trim5alpha proteins of humans and some old world monkeys have been shown to block infection of particular retroviruses following virus entry into the host cell. infection of most new world monkey cells by the simian immunodeficiency virus of macaques (sivmac) is restricted at a similar point. here we examine the antiretroviral activity of trim5alpha orthologs from humans, apes, old world monkeys, and new world monkeys. chimpanzee and orangutan trim5alpha proteins functionally resembled human ... | 2005 | 15767395 |
| the epidemiology of simian immunodeficiency virus infection in a large number of wild- and captive-born chimpanzees: evidence for a recent introduction following chimpanzee divergence. | simian immunodeficiency virus (sivcpz) from the chimpanzee subspecies pan troglodytes troglodytes has been linked phylogenetically to the origin of hiv-1. related but distinct sivcpz strains have also been found in p. t. schweinfurthii , suggesting that sivcpz may have coevolved among the four chimpanzee subspecies. however, sivcpz strains from p. t. verus and p. t. vellerosus have not yet been identified. to better understand the epidemiology and natural history of sivcpz among chimpanzees, we ... | 2005 | 15929695 |
| characterization of a novel vpu-harboring simian immunodeficiency virus from a dent's mona monkey (cercopithecus mona denti). | we report the identification of a new simian immunodeficiency virus (siv), designated sivden, in a naturally infected dent's mona monkey (cercopithecus mona denti), which was kept as pet in kinshasa, capital of the democratic republic of congo. sivden is genetically distinct from the previously characterized primate lentiviruses. analysis of the full-length genomic sequence revealed the presence of a vpu open reading frame. this gene is also found in the virus lineage of human immunodeficiency v ... | 2005 | 15956597 |
| antiretroviral drug studies in nonhuman primates: a valid animal model for innovative drug efficacy and pathogenesis experiments. | several nonhuman primate models are used in hiv and aids research. in contrast to hiv-1 infection of chimpanzees, infection of macaque species with simian immunodeficiency virus (siv) isolates results in a disease (simian aids) that shares many similarities with hiv infection and aids in humans. although each animal model has its limitations and can never completely mimic hiv infection of humans, a carefully designed study allows experimental approaches, such as the control of certain variables, ... | 2005 | 16092501 |
| structure of the zinc finger domain encompassing residues 13-51 of the nucleocapsid protein from simian immunodeficiency virus. | the ncps (nucleocapsid proteins) of hiv-1 (hiv type 1), hiv-2 and siv (simian immunodeficiency virus) are small highly basic proteins, characterized by the presence of two cchc zf (zinc finger) domains. ncps, closely associated with the dimeric rna genome in the core of the virus particle, were shown to promote the specific encapsidation of the viral rna and are implicated in reverse transcription. solution structure of the hiv-1 ncp7 and complexes of ncp7 with rna or dna showed the critical rel ... | 2006 | 16229684 |
| a simplified method for the rapid fluorometric assessment of antibody-dependent cell-mediated cytotoxicity. | we demonstrate that the fatal cytolysis assay can be adapted into a rapid and fluorometric antibody-dependent cellular cytotoxicity assay (rfadcc). the rfadcc relies on double-staining target cells with a membrane dye (pkh-26) and a viability dye (cfse) prior to the addition of antibody and effector cells. we used the rfadcc to assess dose-dependent and envelope-specific anti-human immunodeficiency virus (hiv) adcc responses mediated by monoclonal antibody-2g12 and human sera. using the assay, w ... | 2006 | 16343526 |
| chimpanzee reservoirs of pandemic and nonpandemic hiv-1. | human immunodeficiency virus type 1 (hiv-1), the cause of human acquired immunodeficiency syndrome (aids), is a zoonotic infection of staggering proportions and social impact. yet uncertainty persists regarding its natural reservoir. the virus most closely related to hiv-1 is a simian immunodeficiency virus (siv) thus far identified only in captive members of the chimpanzee subspecies pan troglodytes troglodytes. here we report the detection of sivcpz antibodies and nucleic acids in fecal sample ... | 2006 | 16728595 |
| transmission of simian immunodeficiency virus sivcpz and the evolution of infection in the presence and absence of concurrent human immunodeficiency virus type 1 infection in chimpanzees. | current data suggest that the human immunodeficiency virus type 1 (hiv-1) epidemic arose by transmission of simian immunodeficiency virus (siv) sivcpz from a subspecies of common chimpanzees (pan troglodytes troglodytes) to humans. sivcpz of chimpanzees is itself a molecular chimera of sivs from two or more different monkey species, suggesting that recombination was made possible by coinfection of one individual animal with different lentiviruses. however, very little is known about sivcpz trans ... | 2006 | 16809326 |
| paucity of cd4+ccr5+ t cells is a typical feature of natural siv hosts. | in contrast to lentiviral infections of humans and macaques, simian immunodeficiency virus (siv) infection of natural hosts is nonpathogenic despite high levels of viral replication. however, the mechanisms underlying this absence of disease are unknown. here we report that natural hosts for siv infection express remarkably low levels of ccr5 on cd4+ t cells isolated from blood, lymph nodes, and mucosal tissues. given that this immunologic feature is found in 5 different species of natural siv h ... | 2007 | 17003371 |
| generation of infectious molecular clones of simian immunodeficiency virus from fecal consensus sequences of wild chimpanzees. | studies of simian immunodeficiency viruses (sivs) in their endangered primate hosts are of obvious medical and public health importance, but technically challenging. although siv-specific antibodies and nucleic acids have been detected in primate fecal samples, recovery of replication-competent virus from such samples has not been achieved. here, we report the construction of infectious molecular clones of sivcpz from fecal viral consensus sequences. subgenomic fragments comprising a complete pr ... | 2007 | 17494082 |
| human and simian immunodeficiency virus-mediated upregulation of the apoptotic factor trail occurs in antigen-presenting cells from aids-susceptible but not from aids-resistant species. | human immunodeficiency virus (hiv) and simian immunodeficiency virus (siv) infections lead to aids in humans and rhesus macaques (rm), while they are asymptomatic in species naturally infected with siv, such as chimpanzees, sooty mangabeys (sm), and african green monkeys (agm). differential cd4(+) t-cell apoptosis may be responsible for these species-specific differences in susceptibility to disease. to identify factors that influence the different apoptotic responses of these species, we analyz ... | 2007 | 17494085 |
| adaptation of hiv-1 to its human host. | human immunodeficiency virus type 1 (hiv-1) originated from three independent cross-species transmissions of simian immunodeficiency virus (sivcpzptt) infecting chimpanzees (pan troglodytes troglodytes) in west central africa, giving rise to pandemic (group m) and non-pandemic (groups n and o) clades of hiv-1. to identify host-specific adaptations in hiv-1 we compared the inferred ancestral sequences of hiv-1 groups m, n and o to 12 full length genome sequences of sivcpzptt and four of the outly ... | 2007 | 17545188 |
| the origins of hiv and implications for the global epidemic. | hiv type 1 (hiv-1) and type 2 (hiv-2) are the result of several cross-species transmissions from primates to humans. recently, the ancestral strains of hiv-1 groups m and n were shown to still persist in today's wild chimpanzee populations (pan troglodytes troglodytes) in south cameroon. lately, hiv-1 group o-related viruses have been identified in western gorillas (gorilla gorilla), called sivgor, but chimpanzees are most likely the original reservoir of this simian immunodeficiency virus (siv) ... | 2007 | 17618555 |
| prevalence and genetic diversity of simian immunodeficiency virus infection in wild-living red colobus monkeys (piliocolobus badius badius) from the taï forest, côte d'ivoire sivwrc in wild-living western red colobus monkeys. | numerous african primates are infected with simian immunodeficiency viruses (sivs). it is now well established that the clade of sivs infecting west-central african chimpanzees (pan troglodytes troglodytes) and western gorillas (gorilla gorilla gorilla) represent the progenitors of human immunodeficiency virus type 1 (hiv-1), whereas hiv-2 results from different cross-species transmissions of sivsmm from sooty mangabeys (cercocebus atys atys). we present here the first molecular epidemiological ... | 2008 | 17916449 |
| pinpointing a selective sweep to the chimpanzee mhc class i region by comparative genomics. | chimpanzees experienced a reduction of the allelic repertoire at the major histocompatibility complex (mhc) class i a and b loci, which may have been caused by a retrovirus belonging to the simian immunodeficiency virus (siv) family. extended mhc haplotypes were defined in a pedigreed chimpanzee colony. comparison of genetic variation at microsatellite markers mapping inside and outside the mhc region was carried out in humans and chimpanzees to investigate the genomic extent of the repertoire r ... | 2008 | 18346126 |
| molecular ecology and natural history of simian foamy virus infection in wild-living chimpanzees. | identifying microbial pathogens with zoonotic potential in wild-living primates can be important to human health, as evidenced by human immunodeficiency viruses types 1 and 2 (hiv-1 and hiv-2) and ebola virus. simian foamy viruses (sfvs) are ancient retroviruses that infect old and new world monkeys and apes. although not known to cause disease, these viruses are of public health interest because they have the potential to infect humans and thus provide a more general indication of zoonotic expo ... | 2008 | 18604273 |
| the quality of chimpanzee t-cell activation and simian immunodeficiency virus/human immunodeficiency virus susceptibility achieved via antibody-mediated t-cell receptor/cd3 stimulation is a function of the anti-cd3 antibody isotype. | while human immunodeficiency virus type 1 (hiv-1) infection is associated with hyperimmune activation and systemic depletion of cd4(+) t cells, simian immunodeficiency virus (siv) infection in sooty mangabeys or chimpanzees does not exhibit these hallmarks. control of immune activation is thought to be one of the major components that govern species-dependent differences in the disease pathogenesis. a previous study introduced the idea that the resistance of chimpanzees to sivcpz infection-induc ... | 2008 | 18667496 |
| genetic subspecies diversity of the chimpanzee cd4 virus-receptor gene. | chimpanzees are naturally and asymptomatically infected by simian immunodeficiency virus (siv). pathogenic properties of siv/hiv vary and differences in susceptibility and pathogenicity of siv/hiv depend in part on host-specific factors such as virus-receptor/co-receptor interactions. since cd4 plays a primary role in virus binding and since sivcpz have been found only in two african chimpanzee subspecies, we characterized the genetic diversity of cd4 receptors in all four recognized subspecies ... | 2008 | 18718520 |
| an assessment of the role of chimpanzees in aids vaccine research. | prior to simian immunodeficiency virus (siv)-infected macaques becoming the 'model of choice' in the 1990s, chimpanzees were widely used in aids vaccine research and testing. faced with the continued failure to develop an effective human vaccine, some scientists are calling for a return to their widespread use. to assess the past and potential future contribution of chimpanzees to aids vaccine development, databases and published literature were systematically searched to compare the results of ... | 2008 | 18826331 |
| origin and biology of simian immunodeficiency virus in wild-living western gorillas. | western lowland gorillas (gorilla gorilla gorilla) are infected with a simian immunodeficiency virus (sivgor) that is closely related to chimpanzee and human immunodeficiency viruses (sivcpz and hiv-1, respectively) in west central africa. although existing data suggest a chimpanzee origin for sivgor, a paucity of available sequences has precluded definitive conclusions. here, we report the molecular characterization of one partial (bq664) and three full-length (cp684, cp2135, and cp2139) sivgor ... | 2009 | 19073717 |
| passive immunization with human neutralizing monoclonal antibodies against hiv-1 in macaque models: experimental approaches. | after more than 20 years of intense research, a safe and effective vaccine against hiv-1/aids has not been developed. passive immunization has been used as a tool to demonstrate the role of neutralizing antibodies in conferring protection against hiv-1 challenge in chimpanzees. because these animals are endangered and studies are difficult to conduct with this species, chimeric viruses, termed simian-human immunodeficiency viruses (shivs), have been generated that encode the hiv-1 envelope gene ... | 2009 | 19252837 |
| dating the age of the siv lineages that gave rise to hiv-1 and hiv-2. | great strides have been made in understanding the evolutionary history of simian immunodeficiency virus (siv) and the zoonoses that gave rise to hiv-1 and hiv-2. what remains unknown is how long these sivs had been circulating in non-human primates before the transmissions to humans. here, we use relaxed molecular clock dating techniques to estimate the time of most recent common ancestor for the sivs infecting chimpanzees and sooty mangabeys, the reservoirs of hiv-1 and hiv-2, respectively. the ... | 2009 | 19412344 |
| hepatitis b virus infection in non-human primates. | hepatitis b viruses (hbvs) represent a serious public health problem affecting 350 to 400 million hbv carriers worldwide. the virus does not exclusively infect humans, but can also be found in non-human primates as in the families hominidae (chimpanzee, gorilla, orangutan) and hylobatidae (gibbon), which are distributed over africa (chimpanzee and gorilla) and southeast asia (orangutan and gibbon), the endemic areas of human hbv. the prevalence of asymptomatic hbv carriers reaches in gibbons 23- ... | 2009 | 19537907 |
| increased mortality and aids-like immunopathology in wild chimpanzees infected with sivcpz. | african primates are naturally infected with over 40 different simian immunodeficiency viruses (sivs), two of which have crossed the species barrier and generated human immunodeficiency virus types 1 and 2 (hiv-1 and hiv-2). unlike the human viruses, however, sivs do not generally cause acquired immunodeficiency syndrome (aids) in their natural hosts. here we show that sivcpz, the immediate precursor of hiv-1, is pathogenic in free-ranging chimpanzees. by following 94 members of two habituated c ... | 2009 | 19626114 |
| modification of a loop sequence between alpha-helices 6 and 7 of virus capsid (ca) protein in a human immunodeficiency virus type 1 (hiv-1) derivative that has simian immunodeficiency virus (sivmac239) vif and ca alpha-helices 4 and 5 loop improves replication in cynomolgus monkey cells. | human immunodeficiency virus type 1 (hiv-1) productively infects only humans and chimpanzees but not cynomolgus or rhesus monkeys while simian immunodeficiency virus isolated from macaque (sivmac) readily establishes infection in those monkeys. several hiv-1 and sivmac chimeric viruses have been constructed in order to develop an animal model for hiv-1 infection. construction of an hiv-1 derivative which contains sequences of a sivmac239 loop between alpha-helices 4 and 5 (l4/5) of capsid protei ... | 2009 | 19650891 |
| simian immunodeficiency virus envelope glycoprotein counteracts tetherin/bst-2/cd317 by intracellular sequestration. | tetherin is an ifn-inducible restriction factor that inhibits hiv-1 particle release in the absence of the hiv-1 countermeasure, viral protein u (vpu). although ubiquitous in hiv-1 and simian immunodeficiency viruses from chimpanzees, greater spot nosed monkeys, mustached monkeys, and mona monkeys, other primate lentiviruses do not encode a vpu protein. here we demonstrate that siv from tantalus monkeys (sivtan) encodes an envelope glycoprotein (sivtan env) able to counteract tetherin from tanta ... | 2009 | 19864625 |
| molecular epidemiology of simian immunodeficiency virus infection in wild-living gorillas. | chimpanzees and gorillas are the only nonhuman primates known to harbor viruses closely related to hiv-1. phylogenetic analyses showed that gorillas acquired the simian immunodeficiency virus sivgor from chimpanzees, and viruses from the sivcpz/sivgor lineage have been transmitted to humans on at least four occasions, leading to hiv-1 groups m, n, o, and p. to determine the geographic distribution, prevalence, and species association of sivgor, we conducted a comprehensive molecular epidemiologi ... | 2010 | 19906908 |
| anti-retroviral activity of trim5 alpha. | human immunodeficiency virus type 1 (hiv-1) shows a very narrow host range limited to humans and chimpanzees. experimentally, hiv-1 does not infect old world monkeys, such as rhesus (rh) and cynomolgus (cm) monkeys, and fails to replicate in activated cd4 positive t lymphocytes obtained from these monkeys. in contrast, simian immunodeficiency virus isolated from a macaque monkey (sivmac) can replicate well in both rh and cm. in 2004, tripartite motif 5 alpha (trim5 alpha) was identified as a hos ... | 2010 | 20049904 |
| high prevalence, coinfection rate, and genetic diversity of retroviruses in wild red colobus monkeys (piliocolobus badius badius) in tai national park, cote d'ivoire. | simian retroviruses are precursors of all human retroviral pathogens. however, little is known about the prevalence and coinfection rates or the genetic diversity of major retroviruses-simian immunodeficiency virus (siv), simian t-cell lymphotropic virus type 1 (stlv-1), and simian foamy virus (sfv)-in wild populations of nonhuman primates. such information would contribute to the understanding of the natural history of retroviruses in various host species. here, we estimate these parameters for ... | 2010 | 20484508 |
| fundamental difference in the content of high-mannose carbohydrate in the hiv-1 and hiv-2 lineages. | the virus-encoded envelope proteins of human immunodeficiency virus (hiv) and simian immunodeficiency virus (siv) typically contain 26 to 30 sites for n-linked carbohydrate attachment. n-linked carbohydrate can be of three major types: high mannose, complex, or hybrid. the lectin proteins from galanthus nivalis (gna) and hippeastrum hybrid (hha), which specifically bind high-mannose carbohydrate, were found to potently inhibit the replication of a pathogenic cloned siv from rhesus macaques, sivm ... | 2010 | 20610711 |
| impact of simian immunodeficiency virus infection on chimpanzee population dynamics. | like human immunodeficiency virus type 1 (hiv-1), simian immunodeficiency virus of chimpanzees (sivcpz) can cause cd4+ t cell loss and premature death. here, we used molecular surveillance tools and mathematical modeling to estimate the impact of sivcpz infection on chimpanzee population dynamics. habituated (mitumba and kasekela) and non-habituated (kalande) chimpanzees were studied in gombe national park, tanzania. ape population sizes were determined from demographic records (mitumba and kase ... | 2010 | 20886099 |
| vaccine-induced t cells provide partial protection against high-dose rectal sivmac239 challenge of rhesus macaques. | despite enormous efforts by the scientific community, an effective hiv vaccine remains elusive. to further address to what degree t cells in absence of antibodies may protect against simian immunodeficiency virus (siv) disease progression, rhesus macaques were vaccinated intramuscularly with a chimpanzee-derived ad vector (adc) serotype 6 and then boosted intramuscularly with a serologically distinct adc vector of serotype 7 both expressing gag of sivmac239. animals were subsequently boosted int ... | 2010 | 21081905 |