Publications

antimalarial antibodies of the immunoglobulin g2a isotype modulate parasitemias in mice infected with plasmodium yoelii.	previous studies have demonstrated the importance of antibodies in mediating immunity to malaria, but the relative contribution of the different immunoglobulin isotypes has not been assessed. in this study, hyperimmune plasma was generated against plasmodium yoelii and separated by protein a-sepharose chromatography into fractions containing immunoglobulin g1 (igg1), igg2a, igg2b, or igg3 antibodies and the remaining nonbinding plasma proteins, including igm. following concentration, the antimal ...	1991	1894361
plasmodium yoelii: antibody response in resistant and susceptible mouse strains.	the numbers of antigen-reactive antibody-secreting cells, levels of parasite antigen-specific serum antibodies and numbers of red blood cells staining positive for surface immunoglobulin were determined for susceptible and resistant mouse strains following infection with plasmodium yoelii 17x. as a control, these parameters also were measured using antigen prepared from normal red blood cells. the relatively susceptible c57bl/6 mice produced more antigen-specific antibody-secreting cells and had ...	1991	1915739
antibody recognition and isoelectrofocusing of antigens of the malaria parasite plasmodium yoelii.	inbred balb/c mice were either immunized with triton x-100-extracted antigens of blood-stage plasmodium yoelii or infected with p. yoelii and cured in three successive schedules. whereas the immunized balb/c became only partially protected from subsequent challenge infection with blood-stage p. yoelii, the convalescent mice acquired total immunity. when total p. yoelii antigen extract was resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, transferred to nitrocellulose, and im ...	1991	1937750
lysozyme is an inducible marker of macrophage activation in murine tissues as demonstrated by in situ hybridization.	this study demonstrates the induction of lysozyme mrna expression in situ in tissue macrophages (m phi) of mice following in vivo stimulation. the resting resident tissue m phi of most tissues do not contain enough lysozyme mrna to be detected by in situ hybridization using 35s-labeled rna probes. following bacille calmette guerin or plasmodium yoelli infection, however, m phi recruited to liver and spleen hybridize strongly to the lysozyme probe. within 24 h of infection, cells found in the mar ...	1991	1940787
tissue schizontocidal effect of trifluoroacetyl primaquine in plasmodium yoelii infected mice and plasmodium cynomolgi infected monkeys.	trifluoroacetyl primaquine oxalate (m8506) was compared with primaquine phosphate for tissue schizontocidal action in rodent and simian malaria. in plasmodium yoelii sporozoites infected mice, the causal prophylactic effects of m8506 at 5, 10 and 20 mg(base)/kg were 56.7%, 87.2% and 100%, respectively, comparable to those of primaquine (54.4%, 90.8% and 100%). in p. cynomolgi sporozoites infected rhesus monkeys 4 dosage regimens of the two agents were compared for radical curative effect. on the ...	1991	1948265
[effect of poly i:c on the sporozoite invasion and the development of exoerythrocytic forms of plasmodium yoelii yoelii in rats].	when wistar rats were given intravenously with poly i:c 5 mg/kg 18 h before sporozoite inoculation, the density of exoerythrocytic forms (eef) in the rat liver 42 h after inoculation was markedly decreased, the sporozoite viability being only 5-12% of that of the controls. however, the size and maturation rate of eef were all normal. when poly i:c was given 2 h after sporozoite inoculation, the sporozoite viability and the size and the maturation rate of eef were similar to those of the controls ...	1991	1959171
plasmodium yoelii: oral delivery of 5-fluoroorotate to treat malaria in mice.		1991	1959576
monoclonal, but not polyclonal, antibodies protect against plasmodium yoelii sporozoites.	one of the primary strategies for malaria vaccine development has been to design subunit vaccines that induce protective levels of antibodies against the circumsporozoite (cs) protein of malaria sporozoites. in the plasmodium yoelii mouse model system such vaccines have been uniformly unsuccessful in protecting against sporozoite-induced malaria. to demonstrate that antibodies to p. yoelii cs protein could provide protection we established a passive transfer model. passive transfer of navy yoeli ...	1991	1988490
plasmodium yoelii: quantification of the exoerythrocytic stages based on the use of ribosomal rna probes.		1991	1993458
a spleen is not necessary to resolve infections with plasmodium yoelii.	the role of the spleen in resistance to infections with nonlethal plasmodium yoelii 17x is dependent upon the genotype of the host. thus, dba/2 (d2) mice infected with p. yoelii 17x were not adversely affected by removal of the spleen, while splenectomized c57bl/6 (b6) or balb/c mice failed to resolve their infections and eventually died. the levels of parasitemia were lower in splenectomized mice compared to intact controls; however, splenectomized mice became as anemic as did spleen-intact con ...	1991	1996740
immunization and protection against malaria during murine pregnancy.	normal and immune mice were evaluated for their ability to resist infection to the rodent malaria parasite, plasmodium yoelii, during pregnancy. parasitemia levels were slightly higher and time-to-death shorter in the nonimmunized pregnant group infected with virulent parasites relative to virgin controls. subinoculation experiments revealed that numerous virulent organisms were present in the placentas of unprotected gravida but were absent from the fetal livers of their conceptuses. it was als ...	1991	2012261
primary structure of the merozoite surface antigen 1 of plasmodium vivax reveals sequences conserved between different plasmodium species.	merozoite surface antigen 1 (msa1) of several species of plasmodia has been shown to be a promising candidate for a vaccine directed against the asexual blood stages of malaria. we report the cloning and characterization of the msa1 gene of the human malaria parasite plasmodium vivax. this gene, which we call pv200, encodes a polypeptide of 1726 amino acids and displays features described for msa1 genes of other species, such as signal peptide and anchoring sequences, conserved cysteine residues ...	1991	2023952
evaluation of merocyanine 540-sensitized photoirradiation as a method for purging malarially infected red cells from blood.	the photosensitizing dye merocyanine 540 (mc 540) was evaluated as a means for purging malarially infected red cells from murine blood using the rodent malarial pathogens, plasmodium yoelii and plasmodium berghei, as models of human malaria. malarially infected red cells bound more mc 540 and were more sensitive to mc 540-sensitized photoirradiation than were noninfected erythroid cells. extracorporeal exposure of infected red cells to the dye and white light prevented the transmission of the di ...	1991	2037797
mitochondria of mammalian plasmodium spp.	highly purified mitochondrial fractions have been isolated from the intraerythrocytic stages of two mammalian plasmodium spp., plasmodium yoelii of rodents and plasmodium falciparum of man. mitochondria of the former parasite are cristate whereas those of the latter are essentially acristate. isolated mitochondria from both parasite species were heterogeneous with respect to size, shape, density of matrix staining and extent of internal structure. respiratory assay, by reduction of exogenous cyt ...	1991	2038500
penetration of the mosquito midgut wall by the ookinetes of plasmodium yoelii nigeriensis.	the penetration route of ookinetes of plasmodium yoelii nigeriensis in the midgut of a mosquito, anopheles omorii, was investigated by electron microscopy. within 15-18 h after an infective blood meal, ookinetes could be seen in the midgut lumen, in the process of entering the midgut wall, or lodged between the basement membrane and the basal lamina. the morphology of the ookinetes and their transformation into early oocysts were found to be similar to those previously reported. ookinetes penetr ...	1991	2047369
inhibitory activity of il-6 on malaria hepatic stages.	addition of recombinant interleukin-6 (il-6) to plasmodium yoelii hepatic cultures resulted in a specific dose-dependent inhibition of parasite development. time course experiments showed that, without any direct effect on free sporozoites, il-6 exerts its action during both the early phase of infection and during the subsequent maturation of the schizonts. elicitation of the oxidative burst appears to be one mechanism by which il-6 interferes with the development of hepatic phase. catalase and ...	1991	2052407
[observation on interleukin-2 in mice infected with plasmodium yoelii].	c57bl/6j, nih and icr mice were inoculated with nonlethal p. yoelii (by 265 strain) and nih mice which had recovered from primary infection were reinoculated with the same parasite. the parasitemia of the mice was observed and il-2 production by spleen lymphocytes of the mice upon con a or p. yoelii antigen stimulation was detected at different intervals throughout primary infection and reinfection. the il-2 level was measured by the microassay based on incorporation of h-tdr into ctll2. the mai ...	1991	2065455
in vitro activity of cd4+ and cd8+ t lymphocytes from mice immunized with a synthetic malaria peptide.	in previous work, a t-helper epitope was mapped within the circumsporozoite protein of the murine malaria parasite plasmodium yoelii. a 21-mer synthetic peptide corresponding to this epitope (amino acid positions 59-79; referred to as py1) induced a specific t-cell proliferation in balb/c and c57bl/6 mice and provided help for the production of antibodies to peptides from the repetitive region, (gln-gly-pro-gly-ala-pro)n, of the p. yoelii circumsporozoite protein when mice were immunized with th ...	1991	1680235
il-6 induced by il-1 inhibits malaria pre-erythrocytic stages but its secretion is down-regulated by the parasite.	the capacity of il-6 to mediate the antiparasitic activity of il-1 on intrahepatic development of malaria parasite was demonstrated. the comparisons of il-6 levels in infected and noninfected hepatocyte cultures, either purified or enriched with nonparenchymal cells and stimulated by il-1 or il-6, indicate that subtle interactions exist between intrahepatocytic development of plasmodium yoelii and liver synthesis of il-6. during its intrahepatic multiplication, the parasite causes a decline in i ...	1992	1727866
kinetics of antigen specific and non-specific polyclonal b-cell responses during lethal plasmodium yoelii malaria.	in order to study the kinetics and composition of the polyclonal b-cell activation associated to malaria infection, antigen-specific and non-specific b-cell responses were evaluated in the spleens of mice infected with plasmodium yoelii 17xl or injected with lysed erythrocytes or plasma from p. yoelii infected mice or with p. falciparum culture supernatants. spleen/body weight ratio, numbers of nucleated spleen cells and immunoglobulin-containing and immunoglobulin-secreting cells increased prog ...	1992	1284989
the chemotherapy of rodent malaria. xlvii. studies on pyronaridine and other mannich base antimalarials.	the activities of mannich base antimalarials, including pyronaridine, have been explored against drug-sensitive (plasmodium berghei n) and chloroquine-resistant (plasmodium yoelii ns) rodent malaria parasites in vivo. lines of these parasites have been developed with resistance to pyronaridine, amodiaquine, or wr 228,258. the responses and patterns of cross-resistance of these lines to mannich bases and other blood schizontocides are inconsistent. it is concluded that some mannich bases may prov ...	1992	1288426
[effect of sodium artesunate on plasmodium yoelii analysed by flow cytometry].	the effect of sodium artesunate on plasmodium yoelii-infected mouse erythrocytes was analysed by flow cytometry. the results showed that malarial dna content in experimental group was obviously decreased 2-5 hours after the drug was administered, fluorescence distribution of malarial dna almost disappeared within 24 hours after the administration. thus we deem that sodium artesunate can inhibit the dna synthesis in p. yoelii.	1992	1307277
"antimalarial" medicinal plants and their impact on cell populations in various organs of mice.	we have investigated the effects of leaf and bark decoctions of ocimum gratissimum, azadirachta indica, morinda lucida and enantia chlorantha on (a) the course of plasmodium yoelii nigeriensis malaria (b) reticulocyte and haematocrit values and (c) nucleated cell numbers in the spleen, bone marrow, peritoneum, liver and peripheral blood of swiss albino mice. results obtained showed that normal mice infected with the parasite (10(4)/mouse) suffered fulminant parasitaemia which resulted in death, ...	1992	1308080
recombinant pseudorabies virus carrying a plasmodium gene: herpesvirus as a new live viral vector for inducing t- and b-cell immunity.	in balb/c mice, the sterile protective immunity induced by immunization with radiation-attenuated plasmodium yoelii sporozoites is eliminated by in vivo depletion of cd8+ t lymphocytes, suggesting that cytotoxic t lymphocytes (ctl) against malaria antigens expressed on infected hepatocytes are required for mediating this protective immunity. to produce a vaccine that would induce ctl against the p. yoelii circumsporozoite protein (cs), we constructed an attenuated pseudorabies virus (prv) contai ...	1992	1323900
aberrations in cerebral vascular functions due to plasmodium yoelii nigeriensis infection in mice.	plasmodium yoelii nigeriensis infection in mice caused an increase in uptake of 125i-labeled bovine serum albumin, 51cr-labeled erythrocytes and evans blue dye from peripheral circulation into the brain. isolated cerebral microvessels which were characterized in terms of their morphology under scanning electron microscope and enhancement of the specific activities of biochemical markers, viz. alkaline phosphatase, gamma-glutamyl transpeptidase, and monoamine oxidase, showed significant decrease ...	1992	1356826
cerebral ammonia levels and enzyme changes during plasmodium yoelii infection in mice.	ammonia, lactate and glutamate levels and the activities of glutamine synthetase (gs), glutamate dehydrogenase (gdh), glutaminase (gln), aspartate transaminase (ast), phosphofructokinase (pfk) and monoamine oxidase (mao) were compared in the brain tissue of normal and p. yoelii infected mice. the brain lactate increased by 96% at peak parasitaemia. cerebral ammonia also exhibited an increase in infected mice which was parasitaemia dependent, while glutamate remained almost unchanged. the brain g ...	1992	1361009
structure and expression of the gene for pv200, a major blood-stage surface antigen of plasmodium vivax.	molecular cloning and structure analysis of the gene encoding the pv200 protein of the sal-1 strain of plasmodium vivax revealed an overall identity of 34-37% when the deduced amino acid sequence was compared with the sequences of various major merozoite surface antigens of plasmodium falciparum, plasmodium yoelii and plasmodium chabaudi. when the sal-1 pv200 sequence was compared with the corresponding sequence from the belèm strain of p. vivax, it was found that the two merozoite surface antig ...	1992	1371329
the in vivo cytotoxic activity of cd8+ t cell clones correlates with their levels of expression of adhesion molecules.	cd8+ t cell clones specific for a defined epitope present in the circumsporozoite protein of plasmodium yoelii display striking differences in their in vivo antiplasmodial activity. the adoptive transfer of certain clones (ya23 and ya26) into naive mice inhibits by 90% or more the development of liver stages of malaria parasites and protects against malaria infection. the adoptive transfer of two other t cell clones (yb8 and ya15) results, respectively, in partial or no inhibitory activity on pa ...	1992	1372647
[localization of the antigen in erythrocytic stages of plasmodium yoelii by immuno-electron microscopy].	in this study, the antigen recognized by the protective mcab m26-32 in erythrocytic stages of p. yoelii was localized by immuno-electron microscopy with lr whithe resin embedding and colloidal gold probe cytochemical techniques. the results indicated that the antigen which reacts specifically to mcab m26-32 was mainly localized within the cytoplasm of early and late trophozoites, schizonts and merozoites, being the common antigen of asexual blood stages of the plasmodium. the amount of the antig ...	1992	1394891
[roles of t cell subsets in the protective immunity of mice against plasmodium yoelii].	balb/c mice which had developed protective immunity against plasmodium yoelii (p. y.) challenge were injected with anti-cd4 or anti-cd8 monoclonal antibody, and were then challenged again with p. yoelli. no impairment of protection was observed. cd8+t cells obtained from spleens of these mice were transferred to balb/c nude mice and induced partial protection, while transfer of cd4+t cells did not so. in p. yoelli-mouse model, the parasites invaded reticulocytes in the early infection, and the i ...	1992	1394892
phospholipid-containing toxic malaria antigens induce hypoglycaemia.	hypoglycaemia is associated with severe malaria and is an important prognostic indicator. molecules liberated during overnight incubation of erythrocytes infected with plasmodium yoelii induce marked hypoglycaemia in normal mice, with a delayed time course compared with insulin; some, though weaker, activity could also be obtained by overnight incubation of uninfected erythrocytes. the active component shares many properties with the phospholipid-containing molecules which we have previously sho ...	1992	1395089
malarial toxic antigens synergistically enhance insulin signalling.	hypoglycaemia is a major complication of severe malaria [(1990) trans. roy. soc. trop. med. 84 (suppl. 2) 1-65], especially cerebral malaria, in which it is associated with increased mortality [(1990) lancet 336, 1039-1043; (1989) quart. j. med. (new series) 71, 441-459]; however, the mechanisms responsible have not been fully explained. preparations containing toxic malaria antigens (tma) released by blood stage plasmodium yoelii malaria parasites have been shown to induce hypoglycaemia in mice ...	1992	1397320
characterization of plasmodium falciparum sporozoite surface protein 2.	immunization of mice with plasmodium yoelii sporozoite surface protein 2 (pyssp2) and circumsporozoite protein protects completely against p. yoelii. the amino acid sequence of pyssp2 suggested that the thrombospondin-related anonymous protein (trap) [robson, k. j. h., hall, j. r. s., jennings, m. w., harris, t. j. r., marsh, k., newbold, c. i., tate, v. e. & weatherall, d. j. (1988) nature (london) 335, 79-82] is the plasmodium falciparum homolog of pyssp2. we report data confirming that trap i ...	1992	1409621
[studies on the tissue schizonticide of malaria parasite: synthesis of derivatives of 2-substituted phenoxyprimaquine, 4-methylprimaquine and quinoxaline].	2-substituted phenoxy-, 4-methyl-6-methoxy-8-aminoquinolines and 7-methoxy-5-aminoquinoxaline were condensed with 1-phthalimido-bromo-alkane to yield 2-substituted phenoxy-, 4-methyl-6-methoxy-8-(1-phthalimidoalkyl)-aminoquinolines (compounds 7-10 and 15-20) and 7-methoxy-5-(1-phthalimidoalkyl)aminoquinoxalines (28-30) which were subsequently reacted with hydrazine hydrate to give 2-substituted phenoxy-, 4-methyl-6-methoxy-8-(1-aminoalkyl)-aminoquinolines (11-14 and 22-27) and 7-methoxy-5-(1-ami ...	1992	1442068
trials to infect anopheles stephensi with plasmodium yoelii nigeriensis by the membrane feeding technique.	the aim of this study was to find optimal conditions for the membrane feeding technique to obtain maximum infection rates of mosquitoes with plasmodium yoelii nigeriensis. the results show that the malaria parasite plasmodium yoelii nigeriensis is most infective to anopheles stephensi mosquitoes on day 3 of the infection in the mice, 1 day before the peak of parasitaemia. the mortality rate of the mosquitoes fed on mice on day 3 after infection was the highest as compared to mosquitoes fed on ot ...	1992	1456466
specific inflammatory cell infiltration of hepatic schizonts in balb/c mice immunized with attenuated plasmodium yoelii sporozoites.	we compared immunization of balb/c mice with radiation-attenuated versus killed sporozoites of the rodent malaria parasite, plasmodium yoelii. we employed a suboptimal schedule of only two immunizations, in expectation that some parasites might break through the resultant low level immunity and that it might thus be possible to study the response of the host against these 'breakthrough' schizonts. as a measure of protective immunity, we used histological means to determine the percentages of cha ...	1992	1498082
characterization of the gene encoding sporozoite surface protein 2, a protective plasmodium yoelii sporozoite antigen.	sporozoite surface protein 2 (ssp2) is a 140-kda, protective sporozoite surface protein from plasmodium yoelii distinct from the circumsporozoite protein (csp). a genomic clone containing the ssp2 gene was isolated and sequenced to determine its size, structural organization and deduced primary amino acid sequence. the coding sequence consists of a single, long open reading frame encoding 826 amino acids. the overall structure of ssp2 is similar to that of the csp, consisting of a central region ...	1992	1501644
a t cell clone directed at the circumsporozoite protein which protects mice against both plasmodium yoelii and plasmodium berghei.	clone b is a cytotoxic t cell clone induced by immunization with plasmodium yoelii sporozoites which recognizes an epitope on both the p. yoelii and plasmodium berghei circumsporozoite proteins. it is cd8, uses the v beta 8.1 tcr, and is kd restricted. when adoptively transferred, it protects mice against infection by both species of malaria sporozoites, and this protection is dependent on ifn-gamma. clone b cells are more broadly reactive and protective than previously described murine t cell c ...	1992	1517574
subcellular fractionation of the two organelle dnas of malaria parasites.	malaria parasites contain two extrachromosomal dnas, a 6 kb repetitive linear molecule which is assigned on the basis of its genetic content to the mitochondria, and a 35 kb transcriptionally active circular molecule whose intracellular location is not known. we used the polymerase chain reaction to detect and estimate the numbers of both molecules in sub-cellular fractions derived from the rodent parasite plasmodium yoelii. the two dna molecules were not coordinately partitioned by the fraction ...	1992	1525866
serological relationship of tumor necrosis factor-inducing exoantigens of plasmodium falciparum and plasmodium vivax.	exoantigens of plasmodium vivax-parasitized erythrocytes stimulated macrophages to secrete tumor necrosis factor, and antisera raised against the exoantigens inhibited this secretion. the antisera also inhibited the activity of plasmodium falciparum and plasmodium yoelii exoantigens, and conversely, antisera against the latter cross-reacted with the exoantigens of p. vivax.	1992	1541540
immunization with synthetic peptides containing a defined malaria epitope induces a highly diverse cytotoxic t lymphocyte response. evidence that two peptide residues are buried in the mhc molecule.	in the present study, we have explored ways of inducing a ctl response to a previously defined h-2kd mhc class i restricted epitope in the circumsporozoite (cs) protein of plasmodium berghei, and studied in detail the fine specificity of the response. we found that the s.c. injection of a variety of synthetic peptides emulsified in freund's adjuvant efficiently induced a specific ctl response in (balb/c x c57bl/6)f1 (h-2d x h-2b) mice. in contrast, balb/c mice responded only marginally, consiste ...	1992	1541825
detoxified exoantigens and phosphatidylinositol derivatives inhibit tumor necrosis factor induction by malarial exoantigens.	we have previously shown that malaria parasites liberate exoantigens which, through a phospholipid component, stimulate mouse macrophages to secrete tumor necrosis factor (tnf), which are toxic to d-galactosamine-sensitized mice, and which therefore might be involved in pathology. plasmodium yoelii exoantigens detoxified by dephosphorylation or digestion with lipases do not induce tnf production. however, these partial structures inhibited its production in response to the exoantigens, although ...	1992	1563780
the effects of nosema algerae on the development of plasmodium yoelii nigeriensis in anopheles stephensi.	experimental simultaneous infections of anopheles stephensi (diptera: culicidae) with nosema algerae (microsporida: nosematidae) and plasmodium yoelii nigeriensis under standardized laboratory conditions showed partial suppression of the malaria parasite. at 9 days after an infective bloodmeal, the oocysts in the midgut were counted; 12.1%-66.6% of the double-infected mosquitoes exhibited no oocysts, whereas only 4.5%-12% of the control group showed no oocysts. the mean reduction in oocyst numbe ...	1992	1584748
comparison of the carboxy-terminal, cysteine-rich domain of the merozoite surface protein-1 from several strains of plasmodium yoelii.		1992	1620166
antibodies against phosphatidylinositol and inositol monophosphate specifically inhibit tumour necrosis factor induction by malaria exoantigens.	the active component of the exoantigens of malarial parasites which stimulates macrophages to secrete tumour necrosis factor (tnf) has been shown to depend upon a phospholipid, the activity of which was blocked by phosphatidylinositol (pi) and inositol monophosphate (imp) in competitive inhibition studies. antisera made against the exoantigens of plasmodium yoelii, which inhibited their induction of tnf, were found by an elisa assay to contain antibody against several other phospholipids. howeve ...	1992	1628898
are antibodies important in mice infected with plasmodium yoelii?	it is unwise to extrapolate results, even from one mouse strain to another, when attempting to define the mechanisms that control and effect anti-malaria immunity. it is important to better characterize the broad range o f possible responses that are likely to occur when individuals in an outbred population are infected. here, peter sayles and donald wossom discuss briefly their views on the role of antibody in murine and human malaria infections, based on their work on mice infected with plasmo ...	1992	15463543
are antibodies important in mice infected with plasmodium yoelii?		1993	15463719
effector functions of circumsporozoite peptide-primed cd4+ t cell clones against plasmodium yoelii liver stages.	previously, cd4+ t cell lines and clones were isolated after immunization of balb/c and c57bl/6 mice with the py1 peptide, a 21-mer synthetic peptide corresponding to a n-terminal segment of the circumsporozoite protein of plasmodium yoelii. the clones were separated into the th1 and th2 subsets on the basis of lymphokine production. it was observed that immunization with the py1 peptide induced preferentially th1 cells in balb/c and th2 cells in c57bl/6 mice. these clones were then tested for t ...	1993	7679428
synthetic peptides based on conserved plasmodium falciparum antigens are immunogenic and protective against plasmodium yoelii malaria.	two synthetic polypeptides containing multiple b- and t-cell epitopes derived from the conserved regions of two vaccine candidate antigens namely msa-1 and resa of human malarial parasite p. falciparum were studied for immunogenicity and protectivity. both constructs elicited strong antibody and lymphocyte proliferation responses in balb/c mice immunized with the carrier-free peptides. in an elisa, these peptides also bound antibodies present in the sera from the p. vivax infected humans as well ...	1993	7685076
priming with recombinant influenza virus followed by administration of recombinant vaccinia virus induces cd8+ t-cell-mediated protective immunity against malaria.	live vectors expressing foreign antigens have been used to induce immunity against several pathogens. however, for the virulent rodent malaria parasite plasmodium yoelii, the use of recombinant vaccinia virus, pseudorabies virus, or salmonella, expressing the circumsporozoite protein of this parasite, failed to induce protection. we generated a recombinant influenza virus expressing an epitope from the circumsporozoite protein of p. yoelii known to be recognized by cd8+ t cells and demonstrated ...	1993	7685119
the relative contribution of antibodies, cd4+ and cd8+ t cells to sporozoite-induced protection against malaria.	protective immunity against plasmodium yoelii, induced by sporozoite immunization, was investigated using a quantitative method based on the measurement of plasmodial ribosomal rna in the liver of sporozoite-challenged mice. the relative importance of the different immune mechanisms induced by sporozoite immunization was determined by evaluating quantitatively the anti-parasite activity of antibodies, cd4+ and cd8+ t cells. the role of antibodies was determined by passive transfer of immune sera ...	1993	7902331
[effects of four drugs on intraerythrocytic plasmodium yoelii of early and late stages].	erythrocytes of mice infected with plasmodium yoelii of early stage (esp) were separated from those infected with late stage (lsp), by a single density-gradient centrifugation in 19% diatrizoate meglumine. after centrifugation, the differential counts of esp and lsp were 84.9% and 87.4%, respectively. the stage-dependent effects of nitroquine (nq), pyrimethamine (pyr), perphenazine (per) and metronidazole (met) were studied with [3h]adenosine incorporation into esp and lsp in vitro using chloroq ...	1993	8010072
plasmodium yoelii in mice: antigen reactivity of cd4- and cd8-bearing t cells.	mice infected with plasmodium yoelii (265 by, a nonlethal strain) after recovering from parasitemia become resistant to reinfection. in the present study, we have attempted to define the role of t cell subsets in primary vs secondary p. yoelii infection. we have evaluated the in vivo effects of selective depletion of each subset of t cells on the course of infection and also investigated the in vitro expansion of each subset in response to homologous antigen. depletion of cd4- or cd8-bearing t c ...	1993	8102089
the role of cd4+ t cells in immunity to malaria sporozoites.	balb/c mice are strongly protected against malaria after immunization with plasmodium yoelii (py) sporozoites, and this is an important model for malaria vaccine development in humans. this paper explores the role of cd4+ cells in the induction of the antimalarial immune response. the method used has been to treat animals with anti-cd4 mab before immunization, resulting in a profound depletion of cd4+ t cells. the primary finding is that mice are not protected by sporozoite immunization after de ...	1993	8103069
t-cell recognition of a cross-reactive antigen(s) in erythrocyte stages of plasmodium falciparum and plasmodium yoelii: inhibition of parasitemia by this antigen(s).	in the current study, we investigated the presence of a cross-reactive antigen(s) in the erythrocyte stage from plasmodium yoelii (265 by strain) and plasmodium falciparum through recognition by t cells primed in vivo with antigens from each of these parasites. balb/c mice are naturally resistant to p. falciparum but are susceptible to p. yoelii infection. mice that had recovered from p. yoelii primary infection became resistant to a second infection. a higher in vitro proliferative response to ...	1993	8104901
anti-thy-1 treated and irradiated spleen cells from (balb/c x c57bl/6) f1 mice infected with plasmodium chabaudi chabaudi can transfer protection into irradiated hosts.	the transfer of spleen cells from (balb/c x c57bl/6) f1 mice recovered from a plasmodium chabaudi chabaudi as infection into irradiated syngeneic recipients conferred protection. neither elimination of thy-1+ cells nor in vitro irradiation of immune cells before transfer affected protection while both anti-thy-1 treatment and irradiation abolished the appearance of anti-p. c. chabaudi antibodies in the recipients. superinfection of immune spleen cell donors did not improve their capability to tr ...	1993	8316408
immunotoxicity of cephalosporins in mice.	this study was performed in female b6c3f1 mice to confirm previously observed effects of selected cephalosporin antibiotics on nonspecific immunity, and to determine possible effects on specific acquired immunity and host resistance. mice were treated intravenously with dq-2556, ceftizoxime or ceftezole at 800 mg/kg/day for 3, 5, or 7 consecutive days. all three compounds increased total serum igm levels from day 3, but had no effects on total serum igg levels and the thymus weight. all three ce ...	1993	8325130
structure and expression of a post-transcriptionally regulated malaria gene encoding a surface protein from the sexual stages of plasmodium berghei.	the sexual stage-specific protein pbs21 of the rodent malaria parasite plasmodium berghei, expressed on the surface of zygotes and ookinetes, has been shown to induce an effective and long-lasting transmission blocking immunity. the gene encoding pbs21 was cloned by screening a cdna library prepared from enriched zygotes and ookinetes using the monoclonal antibody 13.1.15, which is capable of blocking subsequent parasite sexual development in the mosquito vector. the pbs21 gene encoded a protein ...	1993	8341324
a recombinant 15-kilodalton carboxyl-terminal fragment of plasmodium yoelii yoelii 17xl merozoite surface protein 1 induces a protective immune response in mice.	since the developmental stages of malarial parasites which replicate within erythrocytes are responsible for the morbidity and mortality associated with this disease, antigens produced by these stages have been proposed as candidates for a vaccine. one surface protein of merozoites (msp-1) has been shown to immunize both rodents and primates against virulent challenge infection in experimental systems. however, little is known of relevant epitopes on the molecule, and attempts to obtain recombin ...	1993	8363656
plasmodium falciparum sporozoite immunization protects against plasmodium berghei sporozoite infection.	irradiated sporozoites are generally thought to elicit protective immune responses that are parasite stage and species specific. but immunization with plasmodium falciparum sporozoites delivered by the bite of infected mosquitoes protects an average of 60% mice from plasmodium berghei sporozoite infection. protection appears to be specific as p. falciparum sporozoite-immunized mice protected against p. berghei remain susceptible to plasmodium yoelii sporozoite infection. passively transferred im ...	1993	8375482
resolution of blood-stage malarial infections in cd8+ cell-deficient beta 2-m0/0 mice.	we utilized a definitive model of cd8+ t cell deficiency, the beta 2-microglobulin-deficient (beta 2-m0/0) mouse, to determine whether cd8+ t cells are required in the resolution of blood-stage malaria. in a parallel experiment, c57bl/6 mice treated with anti-cd8 mab showed significantly higher levels of parasitemia than untreated c57bl/6 control mice at several points during the infection. this finding suggests some role for cd8+ cells in containing malaria. however, the beta 2-m0/0 mice, which ...	1993	8376774
induction of hepatic inflammatory response by plasmodium berghei sporozoites protects balb/c mice against challenge with plasmodium yoelii sporozoites.	balb/c mice are about 2,000 times less susceptible to sporozoites of plasmodium berghei than to plasmodium yoelii. associated with this is the innate cellular response mounted after injection with p. berghei. host inflammatory cells do not normally attack p. yoelii during their development as exoerythrocytic forms (eefs) in the liver. we used p. berghei sporozoites to induce host inflammation that might act against developing p. yoelii eefs. mice injected with p. berghei sporozoites followed 1 h ...	1993	8410550
transgenic mice expressing c-reactive protein are susceptible to infection with plasmodium yoelii sporozoites.	human and rat c-reactive proteins, major acute-phase reactants, bind to sporozoites and inhibit their in vitro development in hepatocytes (a. nussler, s. pied, m. pontet, f. miltgen, l. renia, m. gentilini, and d. mazier, exp. parasitol. 72:1-7, 1991, and s. pied, a. nussler, m. pontet, f. miltgen, h. matile, p.-h. lambert, and d. mazier, infect. immun. 57:278-282, 1989). we show here that rabbit c-reactive protein has identical properties. nevertheless, infection by plasmodium yoelii sporozoite ...	1993	8418060
monoclonal antibodies of three different immunoglobulin g isotypes produced by immunization with a synthetic peptide or native protein protect mice against challenge with plasmodium yoelii sporozoites.	passive transfer of monoclonal antibodies (mabs) against malaria circumsporozoite (cs) proteins protects animals against malaria. active immunization with synthetic or recombinant peptides induces a level of polyclonal antibodies to sporozoites comparable to those found after passive immunization but does not provide comparable protection. in the plasmodium yoelii system, synthetic or recombinant peptide-induced antibodies have never been shown to protect. the current studies were designed to de ...	1993	8500885
plasmodium yoelii: splenectomy alters the antibody responses of infected mice.	the antibody response to plasmodium yoelii is altered in splenectomized mice. sera were obtained from sham-operated or splenectomized dba/2 and c57bl/6 mice on days 11, 18, and 24 after infection with nonlethal p. yoelii 17x and used to precipitate metabolically radiolabeled parasite antigens. mice of both strains responded to many antigens. however, only splenectomized dba/2 mice made strong antibody responses to antigens of approximately 110, 56, 50, 40, 35, and 20 kda. metabolically radiolabe ...	1993	8513875
plasmodium yoelii: cellular immune responses in splenectomized and normal mice.	spleen and lymph node cells from plasmodium yoelii 17x-infected, c57bl/6 (b6), and dba/2 (d2) mice were cultured in vitro with parasite antigens. the ability of these cells to proliferate was quantified by uptake of [3h]thymidine and elisa was used to measure secretion of ifn-gamma and il-5. b6 mice are relatively susceptible to p. yoelii 17x infection compared to d2 mice. susceptible mouse strains develop higher levels of parasitemia, become more anemic, and take longer to resolve their infecti ...	1993	8513876
[fluidity of red blood cell membrane from mouse infected with malaria parasite].	the fluidity of membrane lipid regions of plasmodium berghei- or plasmodium yoelii-infected red blood cells has been determined by the fluorescence polarization technique using 1,6-diphenyl-1,3,5-hexatriene (dph) as a probe. the results showed that the fluidity of plasmodium (berghei or yoelii)-infected red blood cell membranes was increased significantly as compared with that of normal controls judging from the degree of polarization and the microviscosity. its mechanism was discussed briefly.	1993	8174215
[effect of some factors on the development of exoerythrocytic stage of plasmodium yoelii].	using orthogonal design, the effect of environmental temperature, photoperiod, splenectomy and oestrogen levels upon the development of exoerythrocytic forms (eef) of p. yoelii was observed. the results indicated that a significant number of viable sporozoites were cleared in the spleen, since the eef density was much higher in the livers of splenectomized rats (1.73/mm3) than in sham-operated counterparts (0.55/mm3). the effect of high level oestrogen on eef density was also evident since there ...	1993	8174223
[schizogony of plasmodium yoelii nigeriensis. role of latent merozoites].	several procedures were employed to try to specify the schizogonic cycle of plasmodium yoelii nigeriensis. the percoll-glucose gradient technique for concentrating the very young stages (rings and young trophozoites), allowing a very precise follow up of the development of the parasitaemia during the first schizogonic cycles. a method for studying the prepatencies, providing an approximation of the number of merozoites inoculated. a comparison between the numbers of merozoites present in the blo ...	1993	8154783
role of adjuvants in the modulation of antibody isotype, specificity, and induction of protection by whole blood-stage plasmodium yoelii vaccines.	mice were immunized with whole killed blood stage plasmodium yoelii parasites in 15 adjuvant formulations then boosted and challenged with parasitized blood. five of six groups immunized with the ag in oil-in-water emulsions or formulations without oil were protected. formulations that induced protection contained saponin, pertussis, copolymer p1004, and detoxified ralps. in contrast, none of nine groups of animals immunized with ag in water-in-oil emulsions were protected. ineffective adjuvants ...	1993	8258712
ntp technical report on the toxicity studies of a chemical mixture of 25 groundwater contaminants administered in drinking water to f344/n rats and b6c3f(1) mice.	toxicity studies were performed with a chemically defined mixture of 25 groundwater contaminants, using dose levels considered to have environmental relevance. the mixture contained 19 organic compounds and six metals (shown below); the selection of these compounds was based primarily on the frequency of their occurrence in united states environmental protection agency surveys of groundwater contamination in the vicinity of hazardous waste disposal sites. this report focuses primarily on 26-week ...	1993	12209189
gamma delta t cells contribute to immunity against the liver stages of malaria in alpha beta t-cell-deficient mice.	the functional role of gamma delta t cells (expressing the gamma delta heterodimeric t-cell receptor for antigen) in infectious diseases remains largely unknown. we have therefore attempted to define the possible role of these t cells in the immune response against the various developmental stages of malaria parasites. for this purpose, we monitored the immune response and the development of liver and blood stages of plasmodium yoelii, a rodent malaria parasite, in immunized and nonimmunized alp ...	1994	8278391
cerebral malaria in mice: demonstration of cytoadherence of infected red blood cells and microrheologic correlates.	to understand the microcirculatory events during cerebral malaria, we have studied the lethal strain of rodent plasmodia, plasmodium yoelii 17xl, originally described by yoeli and hargreaves in 1974. the virulence of p. yoelii 17xl is caused by intravascular sequestration of infected red blood cells (irbcs), especially in the brain vessels and capillaries. this mouse model resembles human p. falciparum infection more closely than p. berghei anka infection since it shows little, if any, inflammat ...	1994	8166359
copolymer adjuvants in malaria vaccine development.	protection against virulent challenge with murine plasmodium yoelii malaria was induced by immunization with whole killed blood-stage parasites in copolymer p1004 and detoxified lipopolysaccharide as adjuvant. similar immunization with freund's complete adjuvant and other water-in-oil emulsions failed to protect. protection was associated with the production of antibody of the igg2a isotype against epitopes measured by immunofluorescence. several formulations that did not protect elicited high a ...	1994	8172332
serum antibody immunoglobulin g of mice convalescent from plasmodium yoelii infection inhibits growth of plasmodium falciparum in vitro: blood stage antigens of p. falciparum involved in interspecies cross-reactive inhibition of parasite growth.	we demonstrated that antibodies in the serum of balb/c mice convalescent from plasmodium yoelii infection inhibit the in vitro growth of plasmodium falciparum. blood stage p. falciparum antigens that cross-react with the convalescent-phase mouse serum antibodies were identified and partially characterized. convalescent-phase mouse serum immunoglobulin g (igg) reacted with p. falciparum lysates at up to a 1:15,000 dilution of the immune sera and bound to p. falciparum-parasitized erythrocytes at ...	1994	8188358
synchronization of plasmodium yoelii nigeriensis and p. y. killicki infection in the mouse by means of percoll-glucose gradient stage fractionation: determination of the duration of the schizogonic cycle.	the youngest (rings and young trophozoites) erythrocytic stages of plasmodium yoelii nigeriensis and p. yoelii killicki, two rodent malaria subspecies developing very asynchronously in the blood, were separated from the other stages using a discontinuous percoll-glucose gradient. they were inoculated into mice and the subsequent infection remained synchronous for two generations. the duration of the asexual cycle was found to be 18 h.	1994	8202457
in vitro and in vivo chloroquine-potentiating action of strychnos myrtoides alkaloids against chloroquine-resistant strains of plasmodium malaria.	crude alkaloids of strychnos myrtoides gilg & busse, empirically used as an adjuvant to chloroquine (cq) in malagasy herbal remedies, were practically devoid of intrinsic in vitro and in vivo antimalarial activity. however, when combined with cq at a dose level much lower than their ic50 value, they markedly enhanced in vitro the effectiveness of the synthetic drug against a cq-resistant strain of plasmodium falciparum. they also enhanced in vivo cq activity against a resistant strain of plasmod ...	1994	8134408
alterations of uninfected red blood cells in malaria.	red blood cell (rbc) negative charges and resistance to linoleic acid (lna)-induced lysis were studied in plasmodium yoelii-infected mice and in malaria (p. falciparum)-affected individuals. rbcs from mice infected with p. yoelii showed a progressive decrease in the net surface negative charges at 24 h after infection, reaching a minimal value on day 3, followed by a second phase that was characterised by a recovery to normal levels on day 6. resistance to linoleic acid follows similar kinetics. ...	1994	8153129
immunization against malaria with a recombinant protein.	we have expressed in bacteria the c-terminal part of plasmodium yoelii merozoite surface protein-1 (msp1) containing the two epidermal growth factor-like domains. the protein, either alone or fused to glutathione s-transferase, was highly effective as a vaccine and protected mice against challenge infection. reduction and alkylation abolished the protection obtained with the protein. this shows for the first time the absolute requirement of the disulphide-bonded conformation for immunogenicity. ...	1994	8015856
neuropathological studies on plasmodium yoelii nigeriensis-induced malaria in mice.	malaria infection in mice was produced by intraperitoneal inoculation of 10(6) erythrocytes parasitized with plasmodium yoelii nigeriensis, a virulent strain of murine malaria. about one week after infection parasitaemia ranged between 60 and 80%, and 100% mortality was observed. infected animals were killed 6 days after infection to allow the examination of brain tissue. electron microscopical observations revealed marked damage to cerebral vascular vessel walls with separation of muscular laye ...	1994	8040397
nitric oxide-mediated antiplasmodial activity in human and murine hepatocytes induced by gamma interferon and the parasite itself: enhancement by exogenous tetrahydrobiopterin.	expression of inducible nitric oxide (no) synthase has been shown to inhibit the development of several pathogens, including fungi, bacteria, parasites, and viruses. however, there is still controversy as to whether this effector mechanism can inhibit the development of human pathogens. we now report that gamma interferon (ifn-gamma) induces the elimination of plasmodium falciparum-infected primary human hepatocytes from cultures and that the antimalarial activity is dependent on no. infection w ...	1994	8063424
immunity to erythrocytic stages of malarial parasites.	in those individuals who live in endemic areas, immunity to malaria is slow to develop and stage-specific. the nature and antigenic specificity of this response, which may involve components of both cell-mediated and humoral immunity, is not well understood. rodent models provide useful systems to explore the spectrum of host responses that may contribute to resolution of erythrocytic-stage infection or possibly to pathogenesis. moreover, these models allow identification of plasmodial molecules ...	1994	7909653
intrasplenic immunization with infected hepatocytes: a mouse model for studying protective immunity against malaria pre-erythrocytic stage.	malaria liver forms are the target of antibody or t-cell-mediated immune mechanisms induced by previous or subsequent developmental stages of the parasite. the potential for vaccine development of antigens expressed exclusively in the liver stages has not been fully explored partly because of the lack of an experimental animal model. here we show that protective immunity against sporozoite-induced infection with plasmodium yoelii and p. berghei can be obtained by intrasplenic injection of a smal ...	1994	7913914
sporogonic development of plasmodium yoelii in five anopheline species.	sporogonic development of plasmodium yoelii yoelii 17xnl was examined in 5 species of anopheles mosquitoes; a. albimanus, a. dirus, a. freeborni, a. gambiae, and a. stephensi. the kinetics of ookinete formation differed among species. in a. freeborni, a. gambiae, and a. stephensi, mature ookinetes formed synchronously at 8 hr, then quickly subsided. in a. albimanus and a. dirus, ookinete formation was more protracted, and ookinete densities peaked from 12 to 24 hr. losses in parasite abundance d ...	1994	7931901
in vitro survival and retention of infectivity of plasmodium yoelii sporozoites over extended periods of time.	the ability to maintain sporozoites in vitro should render the biological mechanism of sporozoite infectivity amenable to experimental analysis. with this in mind, plasmodium yoelii py17x(nl) clone 1.1 sporozoites were incubated at 4, 24, or 37 c for 0, 8, or 24 hr in tissue culture medium m199 with 5% normal mouse serum and penicillin-streptomycin. balb/c mice were challenged intravenously with 5,000 in vitro-incubated sporozoites and then evaluated daily for parasitemia beginning on day 3 post ...	1994	7931920
a gene coding for a high-molecular mass rhoptry protein of plasmodium yoelii.	we describe the deduced amino acid sequence for a gene encoding a high molecular mass rhoptry protein of plasmodium yoelii. the sequence was obtained from an ecori genomic clone that overlaps a short drai fragment isolated previously. the open reading frame consists of 2294 codons and putative hydrophobic signal and membrane anchor sequences were identified. similarity with sequence from a clone coding for part of a plasmodium vivax reticulocyte-binding protein was noted. based on the sequence a ...	1994	7935623
protection against malaria by immunization with plasmid dna encoding circumsporozoite protein.	immunization with irradiated sporozoites protects animals and humans against malaria, and the circumsporozoite protein is a target of this protective immunity. we now report that adjuvant-free intramuscular injection of mice with plasmid dna encoding the plasmodium yoelii circumsporozoite protein induced higher levels of antibodies and cytotoxic t lymphocytes against the p. yoelii circumsporozoite protein than did immunization with irradiated sporozoites. mice immunized with this vaccine had an ...	1994	7937907
interleukin 12 induction of interferon gamma-dependent protection against malaria.	intraperitoneal injection of recombinant interleukin 12 (ril-12) at 30 ng/day for 5 days beginning 1 to 2 days before sporozoite challenge or administration of a single dose of 150 ng of ril-122 days before challenge protected 100% of balb/c mice against challenge with 10(2) plasmodium yoelii sporozoites. ril-12-induced protection was eliminated in all mice by administration of a monoclonal antibody against interferon gamma and in 50% of mice by administration of ng-monomethyl-l-arginine, a comp ...	1994	7938013
plasmodium yoelii: brefeldin a-sensitive processing of proteins targeted to the rhoptries.	we have shown that a family of high-molecular-mass proteins can be detected in lysates of parasitized erythrocytes using antibodies specific for a plasmodium yoelii rhoptry protein. when these polypeptides are biosynthetically labeled in the presence of brefeldin a or at 15 degrees c, their electrophoretic mobility on polyacrylamide gels is decreased. removal of the drug restores the size of the polypeptides to that in the absence of the drug. these results indicate that the proteins undergo a p ...	1994	7957749
in vitro development of infectious liver stages of p. yoelii and p. berghei malaria in human cell lines.	the preerythrocytic stages of the malaria parasite are the focus of intense efforts to identify new immunological and pharmacological methods for the control of the malaria parasite. the study of the malaria hepatic stages requires an in vitro system to facilitate the analysis of parasite/host cell interactions and the characterization of exoerythrocytic form (eef) antigens. at the present time, only the rodent malaria, plasmodium berghei, and the human malaria, plasmodium vivax, develop into ma ...	1994	7957756
anaemia and resistance to malaria in transgenic mice expressing human tumour necrosis factor.	transgenic mice carrying a modified human tumour necrosis factor (hutnf)/beta-globin gene construct linked to the t-cell-specific locus control region of the human cd2 gene express hutnf in their t cells which is released into the circulation and causes the development of a wasting syndrome. we now report that the mice develop anaemia, probably through enhanced erythrophagocytosis rather than inhibition of reticulocyte production. thus autologous erythrocytes, as well as sheep erythrocytes, were ...	1994	7959874
efficacy of azithromycin as a causal prophylactic agent against murine malaria.	the efficacy of the newly marketed azalide azithromycin was compared with that of the clinical agent doxycycline in a murine model of sporozoite-induced malaria. drug was administered once; plasmodium yoelii sporozoites were administered 2 h later; survival at day 60 was determined. for parenterally administered drug, 160 mg of azithromycin or doxycycline per kg of body weight was 100% effective; 40 mg of azithromycin per kg was 80% effective, but 40 mg of doxycycline per kg was 40% effective. o ...	1994	7986022
immunotoxicity of mono-nitrotoluenes in female b6c3f1 mice: i. para-nitrotoluene.	para-nitrotoluene (p-nitrotoluene) is used primarily as an intermediate in the production of various dyes, explosives, pharmaceuticals, and in the production of rubber and agricultural products. previous investigations indicated that p-nitrotoluene was mutagenic in the ames test and that other mono-substituted nitrotoluenes bound covalently to hepatic macromolecules. the objective of these studies was to evaluate the potential immunotoxicity of p-nitrotoluene in mice exposed by the oral route. m ...	1994	7988386
immunotoxicity of mono-nitrotoluenes in female b6c3f1 mice: ii. meta-nitrotoluene.	the nitrotoluenes are chemicals used in dyes, agricultural products, pharmaceuticals and explosives. in the present studies, the toxicology and immunotoxicity of meta-nitrotoluene (m-nitrotoluene) were evaluated. mice, exposed to m-nitrotoluene at dose levels of 200, 400 and 600 mg/kg/body weight for 2 weeks by gastric gavage, gained body weight over the treatment period to a slightly greater extent than the control groups. of the selected organs weighed, the liver and kidney of mice exposed to ...	1994	7988387
complete protection against plasmodium yoelii by adoptive transfer of a cd8+ cytotoxic t-cell clone recognizing sporozoite surface protein 2.	balb/c mice immunized with irradiated plasmodium yoelii sporozoites produce antibodies and cytotoxic t lymphocytes against the circumsporozoite protein and against a 140-kda protein, sporozoite surface protein 2 (pyssp2). approximately 50% of mice immunized with p815 cells transfected with the gene encoding pyssp2 are protected against malaria, and this protection is reversed by in vivo depletion of cd8+ t cells. to determine if cd8+ t cells against pyssp2 are adequate to protect against malaria ...	1994	8005684
induction of murine cytotoxic t lymphocytes against plasmodium falciparum sporozoite surface protein 2.	sporozoite surface protein 2 has been identified as a target of malaria vaccines designed to produce protective cd8+ cytotoxic t lymphocytes (ctl) because mice immunized with mastocytoma cells expressing a fragment of plasmodium yoelii sporozoite surface protein 2 (pyssp2) are protected against malaria by an immune response that requires cd8+ ctl. to define ctl epitopes in the plasmodium falciparum sporozoite surface protein 2 (pfssp2), spleen cells (sc) from mice immunized with irradiated sporo ...	1994	7517870
influenza and vaccinia viruses expressing malaria cd8+ t and b cell epitopes. comparison of their immunogenicity and capacity to induce protective immunity.	we compared the effectiveness of several recombinant influenza and vaccinia viruses to induce a malaria-specific immune response. the cd8+ t cell epitope of the circumsporozoite (cs) protein of plasmodium yoelii, a rodent malaria parasite, was expressed in two distinct influenza virus proteins, the hemagglutinin and the neuraminidase. these recombinant viruses were found to be equally efficient at inducing cs-specific cd8+ t cells in mice. a third recombinant virus, which expresses a b cell epit ...	1994	7525709
sequence of the gene encoding the n-terminal portion of the plasmodium yoelii yoelii 17xl merozoite surface protein-1 (msp-1).	the nucleotide (nt) sequence of the 5' portion of the gene encoding the plasmodium yoelii yoelii (pyy) 17xl merozite surface protein-1 (msp-1) was determined by direct sequencing of both strands of the polymerase chain reaction (pcr) product. this report completes the entire coding region of the pyy 17xl msp-1 gene which we have found to be identical to the nt sequence of the pyy ym msp-1 [lewis, mol. biochem. parasitol. 36 (1989) 271-282], despite independent selection of parasite clones, passa ...	1994	7828902
characterization of liver lymphomyeloid cells in mice infected with plasmodium yoelii sporozoites.	we have isolated, characterized and quantified the immunocompetent cells present in the extravascular hepatic compartment at various stages after plasmodium yoelii malaria infection with sporozoites. cytological analyses revealed a predominantly lymphoid population. in mice with a primary infection, the predominant cells were cd4+, cd8+ and b lymphocytes. in fully protected mice, cd3+ cd4- cd8- and polymorphonuclear cells, particularly eosinophils, were most common. the significance of changes i ...	1994	7835930
estimation of the time required by the malaria parasites to cross the digestive tract to reach blood in mice inoculated by the oral route.	in a previous report we described the transmission of the malaria parasites by the oral route in a murine model. later, we performed some experiments to demonstrate the transmission of malaria infection by cannibalism. now we commence to look for the site, mechanism and stages of the parasite involved in crossing the alimentary canal to reach blood and start the infection. to know the invasive stage of the parasite and the way it penetrates, we wanted first to find the level of the digestive tra ...	1994	7637998