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proliferation of theileria annulata and theileria parva macroschizont-infected bovine cells in scid mice.theileria annulata and theileria parva macroschizont-infected bovine cells formed tumours at the inoculation site when injected subcutaneously into c.b.-17 scid mice. t. annulata tumours showed more vigorous growth than t. parva tumours. the tumours did not regress and infected cells spread to other tissues. intraperitoneal injection of high doses of t. annulata-infected cells resulted in the development of ascites: the infected cells colonized abdominal organs, in particular mesenteric tissue. ...19938468139
production of interferon by theileria annulata- and t. parva-infected bovine lymphoid cell lines.theileria annulata and t. parva-infected lymphoblastoid cells were examined for their capacity to produce interferon (ifn). supernatants of such cells were tested in biological assay for their antiviral activity. only t. parva-infected cells of t-cell origin were capable of producing ifn-gamma. supernatants of some but not all t. annulata-infected cells showed also antiviral activity, which was greatly reduced after exposure to a ph of 2. northern-blot analysis of the cells using an ifn-gamma cd ...19938493239
factors influencing the transmission and incidence of tropical theileriosis (theileria annulata infection of cattle) in morocco.a longitudinal epidemiological investigation of tropical theileriosis was carried out in an endemic region of morocco during the 1991 disease season. this involved approximately 220 cross-bred cattle on 15 farms. data were collected on the frequency of existing infections, the size of the vector tick population and the incidences of new infections and clinical disease, and these were then analysed using statistical models. the prevalence of subclinically infected carriers of theileria annulata, ...19958533276
t cell activation by theileria annulata-infected macrophages correlates with cytokine production.a major feature of the pathology induced by theileria annulata is acute lymphocytic proliferation, and this study investigates the mechanisms underlying the intrinsic ability of t. annulata-infected monocytes to induce naive autologous t cells to proliferate. different t. annulata-infected clones expressed different but constant levels of mhc class ii, varying from < 1.0 x 10(5) to 1.5 x 10(6) molecules/cell, as measured by saturation binding. however, no correlation was found between the level ...19958536365
selection of diversity at putative glycosylation sites in the immunodominant merozoite/piroplasm surface antigen of theileria parasites.the immunodominant merozoite/piroplasm surface antigen of theileria parasites has potential as a diagnostic reagent and as a component of a sub-unit vaccine. this molecule is known to be antigenically diverse, and it is important to determine the nature and extent of this heterogeneity. in the present study nucleotide sequences, representing alleles of the gene (tams1) encoding this molecule in theileria annulata were compared to each other and to sequences of homologous genes in theileria serge ...19958538686
detection of theileria annulata in blood samples of carrier cattle by pcr.we report the detection of theileria annulata, the causative agent of tropical theileriosis, by pcr in blood samples obtained from carrier cattle. the assay employs primers specific for the gene encoding the 30-kda major merozoite surface antigen of t. annulata. a 721-bp fragment was amplified from blood samples taken monthly from calves experimentally infected with one of four different stocks of t. annulata originating in either mauritania, portugal, spain, or turkey. at the end of the experim ...19958567902
theileria annulata sporozoite antigen fused to hepatitis b core antigen used in a vaccination trial.a c terminal fragment (sr1) of spag-1, a sporozoite surface antigen of theileria annulata, has been expressed as a fusion protein in the e1 loop of hepatitis b core antigen (hbcag). this recombinant antigen (hbcag-sr1) is produced in the form of self-assembling polyhedral particles which have been visualised under the electron microscope. cattle immunised with hbcag-sr1 produced high titres of neutralising antibodies. a significant t cell response to both the hbcag and sr1 determinants was obser ...19958578798
conservation of neutralizing determinants between the sporozoite surface antigens of theileria annulata and theileria parva.the sporozoite surface antigens spag-1 of theileria annulata and p67 of theileria parva are postulated to contain determinants necessary for host cell invasion and/or recognition and are both being considered as candidates for inclusion in subunit vaccines. preliminary data suggest that these are related molecules. in this paper we describe the investigation of the relationship between these sporozoite antigens further by analysis of the immunological cross-reactivity using mabs and sera raised ...19968631374
theileria annulata: altered gene expression and clonal selection during continuous in vitro culture.kept in continuous in vitro culture, the protozoan parasite theileria annulata gradually loses virulence when inoculated into cattle. these attenuated cell lines form the basis of the in vitro live vaccines which have been used successfully to control tropical theileriosis in several endemic regions. in the study reported here, events occurring during in vitro culture of an indian (hisar) cell line, which may be associated with the reduction in virulence, have been investigated. hybridization wi ...19968654541
expression of genes encoding two major theileria annulata merozoite surface antigens in escherichia coli and a salmonella typhimurium aroa vaccine strain.the genes, tams1-1 and tams1-2, encoding the 30-and 32-kda major merozoite surface antigens of theileria annulata (ta), have recently been cloned and characterized. both genes encode a protein of 281 amino acids (aa) containing a putative hydrophobic n-terminal signal peptide. another hydrophobic stretch is predicted at the c terminus which probably functions to anchor the protein in the membrane of the merozoite and piroplasm. here, we report the successful expression of both tams1-1 and tams1- ...19968654987
piroplasms of domestic animals in the macedonia region of greece. 1. serological cross-reactions.during a serological survey on haemoparasites in macedonia, serum samples were collected from cattle, sheep and goats. all sera were tested by the indirect immunofluorescence test (ifat); the cattle sera against theileria orientalis, t. annulata, babesia bigemina, b. bovis, b. divergens and b. major antigens; the sheep and goat sera against t. ovis, b. ovis, b. motasi and b. crassa antigens. parallel tests of negative and positive control sera against all the antigens showed the existence of cro ...19968792579
piroplasms of domestic animals in the macedonia region of greece. 2. piroplasms of cattle.a study was carried out on piroplasms of cattle in the macedonia region of greece. during 1984-1986, 602 serum samples were collected from cattle in 33 localities. blood smears were also prepared from 50 of the animals in 13 localities. the indirect fluorescent antibody (ifa) test revealed that 41.4% of cattle sera were positive to theileria orientalis, 2.0% to theileria annulata, 21.6% to babesia bovis, 15.2% to babesia bigemina, 5.1% to babesia major and 2.7% to babesia divergens. some of the ...19968792580
[epidemiologic status of theileria annulata bovine theileriasis in tunisia]. 19948801842
[phenotypic and molecular analysis of isolates of theileria annulata]. 19948801843
a preliminary study on the attenuation of tunisian schizont-infected cell lines of theileria annulata.four theileria annulata cell lines were characterised at low passage levels using two polymorphic markers and then used to infect calves. their virulence seemed to be related to the number of genotypes present within the cell line. in all, 3 of the 4 cell lines were cultured up to passage 100 or 200 and inoculated into calves. their characterisation using the same markers indicated that the attenuation was related to a reduction in the parasite polymorphism down to a single genotype. the immunog ...19968875574
a stage regulated cyclophilin gene from theileria annulata. 19968892310
matrix metalloproteinases mediate the metastatic phenotype of theileria annulata-transformed cells.theileria annulata infects and reversibly transforms bovine leucocytes. the parasite-transformed cells are immortalized, metastatic and express a number of metalloproteinases including matrix metalloproteinase 9 which they secrete. all the metalloproteinases observed on substrate gels are inhibited by tissue inhibitor of metalloproteinase 1 and 4 synthetic inhibitors bb94, gm6001, brl29808ai and ro31-4724. we have adapted an in vitro assay for metastatic behaviour that measures the ability of pa ...19968893530
theileria annulata: in vitro cultivation of schizont-infected bovine lymphocytes.experimental parameters of optimization of the in vitro growth conditions for theileria annulata schizont-infected bovine lymphoid cells are presented. of the nine different media tested in the course of 14 successive passages, leibovitz l-15 (l-15) and a combination of mccoy and leibovitz l-15 (ml) were preferable to mccoy, dulbecco (dmem), rpmi 1640 or eagles's minimum essential medium (mem) based on either hank's or earle's salts. the lowest multiplication rate was obtained with m-199 medium ...19968916396
the isolation and characterization of genomic and cdna clones coding for a cdc2-related kinase (thcrk2) from the bovine protozoan parasite theileria.the tick-transmitted protozoan parasites theileria annulata and theileria parva are important intracellular pathogens of domestic cattle in tropical and subtropical regions. proliferative phases take place within both lymphocytes and erythrocytes. the lymphocyte is stimulated to enter the cell cycle by the parasite and the multinucleate parasite can establish a state in which karyokinesis and cytokinesis occur in phase with the host cell. the link between parasite nuclear division and cytokinesi ...19968930914
bovine gamma/delta tcr+ t lymphocytes are stimulated to proliferate by autologous theileria annulata-infected cells in the presence of interleukin-2.an in vitro model system has been developed in which freshly isolated resting wc1+ gamma/delta tcr+ t cells proliferate in response to cells transformed by the protozoan parasite theileria annulata, providing a strategy in which the basis of activation of naive gamma/delta t cells can be investigated. irradiated parasite-transformed cells stimulate the proliferation, but not cytolytic activity, of autologous peripheral blood mononuclear cells (pbmc) from non-immune animals. the proliferating cel ...19968947595
diagnosis of theileria annulata infection of cattle in tunisia: comparison of serology and blood smears.the immunofluorescent antibody test (ifat) using schizont and piroplasm antigens was compared with the microscopic examination of giemsa-stained blood smears for the diagnosis of theileria annulata infection in experimentally and naturally infected cattle. the results obtained on 100 naive cattle showed that non-specific fluorescence disappeared at serum dilution levels of 1/40 and 1/160 for the piroplasm and schizont antigens, respectively. these levels were therefore retained as the starting d ...19968956476
theileria annulata schizonts found in calf kidney cell culture.mononuclear cells infected with theileria annulata schizonts were isolated at 4 different times from monolayer cultures of primary kidney cells derived from apparently healthy, 2 to 6 weeks old zebu calves. the presence of such an organism could interfere with the manufacturing procedure of rinderpest tissue culture vaccine if it is to be carried out in calf kidney cell culture.19968983133
epidemiology of tropical theileriosis (theileria annulata infection of cattle) in an endemic region of tunisia: characterisation of endemicity states.a serological survey on tropical theileriosis was conducted on a sample of 54 farms in a region within the semi-arid bioclimatic zone of tunisia. screening of cattle sera at a dilution of 1/160 using the indirect immunofluorescent antibody test with the schizont antigen of theileria annulata, revealed the presence of animals with positive sera in 92.15% of the sampled farms. the exposure of calves to infection in the first season was shown to be significantly lower than in older cattle. three en ...19968983146
macrophage-parasite relationship in theileriosis. reversible phenotypic and functional dedifferentiation of macrophages infected with theileria annulata.theileria annulata is a tick-transmitted protozoan parasite of cattle, which transforms cells of macrophage (mphi) or b cell lineage. bone marrow cells, bone marrow cell-derived, and monocyte-derived mphi were infected with t. annulata sporozoites, and the resulting cell lines were assessed for surface marker expression and function. transformed lines expressed histocompatibility complex (mhc) class-i and ii, cd44, cd45, and the myeloid marker dh598-surface markers cd14, cd11b, m-m7, th57a, and ...19979103233
isolation and establishment in in vitro culture of a theileria annulata--infected cell line from spain.the isolation of theileria annulata-infected lymphocytes using blood from an animal suffering from mediterranean theileriosis as a source of parasites is described. the present work reports the first isolation and establishment in in vitro culture of a t. annulata-infected cell line from southwestern europe, where mediterranean theileriosis causes important economic losses, especially in southern spain. the parasite was identified by staining of cells from culture with giemsa, by immunofluoresce ...19979134566
bovine cells infected in vivo with theileria annulata express cd11b, the c3bi complement receptor.bovine cells from cattle infected with theileria annulata were phenotyped with monoclonal antibodies recognizing bovine leukocyte antigens. macroschizont-infected, transformed cell lines prepared from peripheral blood mononuclear cells of cattle, infected with sporozoites, were assessed by flow cytometry; parasitized cells in tissues from infected cattle were examined by immunocytochemical techniques. co-expression of markers for different cell lineages by the cell lines precluded a definite con ...19979151409
altered expression of class i major histocompatibility antigens on bovine cells infected with the protozoan parasite theileria annulata.theileria annulata infection is controlled by mhc class i restricted cytotoxic t cell killing of infected cells. the long term persistence of parasite suggests that it employs a mechanism to avoid immune surveillance. in this paper we describe the modification of bola class i antigens on the surface of theileria annulata transformed lymphoblastoid cells. the extent of modification is different between individuals varying from extensive to undetectable.19969157682
a non-protective t helper 1 response against the intra-macrophage protozoan theileria annulata.theileria annulata is a protozoan parasite which infects and transforms bovine macrophages. infected macrophages possess augmented antigen presentation capabilities, as they are able to activate the majority of t cells from unexposed animals. in vivo, t cells in the draining lymph node (principal site of parasite development) are activated 'non-specifically' by the parasite. this event is followed by failure of the immune response to control the infection. protective immune responses against int ...19979182893
the indirect fluorescent antibody test based on schizont antigen for study of the sheep parasite theileria lestoquardi.an indirect fluorescent antibody test (ifat), based on schizont-infected lymphoblastoid cells, was applied to study the course of antibody production in adult sheep inoculated with attenuated, in vitro grown, theileria lestoquardi (theileria hirci) infected cells. bright fluorescence of the intracellular schizonts could first be demonstrated 15 days after inoculation. a 32-64-fold rise in antibody titres was recorded 1 month after infection, and substantial titres were still observed 90 days aft ...19979187025
theileria annulata "superantigen" activity--tcb usage by responding bovine cd4+ cells from uninfected donors. 19979191321
a general review on the prevention and treatment of theileria annulata in china.a review is given of the prevention and treatment of theileria annulata infection of cattle in china. primaquine phosphate has been shown to be an effective drug for the elimination of gametocytes of t. annulata and an attenuated strain of virulent parasites is used as a vaccine. this vaccine has proved to be 100% safe and over 90% effective. since the use of these two methods of control, the disease caused by t. annulata in cattle in china has been controlled.19979195712
detection of theileria annulata by the pcr in ticks (acari:ixodidae) collected from cattle in mauritania.we report on the detection of theileria annulata in infected hyalomma ticks by the pcr using primers derived from the gene encoding the 30 kda major merozoite surface antigen (tamsi-1). no inhibition of the pcr was observed and as little as 0.1 pg of parasite dna, corresponding to 12 sporozoites, could be detected in non-infected tick dna samples, spiked with t. annulata genomic dna. hyalomma dromedarii ticks, fed on a calf experimentally infected with t. annulata, were used to validate the pcr ...19979203350
theileria-mediated constitutive expression of the casein kinase ii-alpha subunit in bovine lymphoblastoid cells.theileria-infected cells are induced to undergo a transformation that is reversible, since their proliferation is inhibited after elimination of the schizonts by the theilericidal drug buparvaquone. the molecular mechanisms of the transformation remain unknown. the experiments described in the present report deal with the role of casein kinase (ck) ii, a serine/threonine protein kinase, in the permanent proliferation of the parasitized cells and show that the ck ii-alpha subunit is expressed in ...19979211502
modulation of protein synthesis relative to dna synthesis alters the timing of differentiation in the protozoan parasite theileria annulata.the control of differentiation through time is critical for the correct ordering of sequential developmental events. a timing mechanism based on the number of mitotic divisions has been proposed for both higher eukaryote and protozoan parasite cellular differentiation. however, the mitotic clock model has not been validated by experiments which altered the proliferation rate of cells in vitro. this study has used the drugs aphidicolin and oxytetracycline to investigate the modulation of differen ...19979224762
field trial of immunization with an experimental vaccine against mediterranean theileriosis in spain.vaccines against mediterranean theileriosis have been developed in several countries where this disease is of economic concern. until recently, tissue culture vaccines were a suitable method for immunizing cattle and they have been widely applied with success. in spain, mediterranean theileriosis is an obstacle to the improvement of dairy cattle productivity. no vaccines against this disease have been applied until recently. this report concerns the field trial of an available experimental tissu ...19979257447
allograft responses can interfere with the development of immunity against theileria annulata following vaccination with parasite infected cell lines.theileria annulata macroschizont-infected cell lines are successfully used as vaccines in several countries. the inoculated animals produce a strong allogeneic response against the mhc antigens of the immunizing cell line followed by an anti-parasite response. immunity against the parasite wanes in the absence of challenge and re-immunization is sometimes recommended. however, it is not known if allogeneic responses generated by the first immunization with a t. annulata infected cell line will i ...19979364559
induction of protective immunity to theileria annulata using two major merozoite surface antigens presented by different delivery systems.allelic forms (tams1-1 and tams1-2) of the major merozoite surface antigen gene of theileria annulata have recently been expressed in escherichia coli and in salmonella typhimurium aroa vaccine strain sl3261. to test the potential of subunit vaccines against t. annulata infection, we immunized four groups of three calves with either recombinant (re-) (tams1-1 and tams1-2) proteins or naked dna encoding these antigens. group i was immunized intramuscularly with both re-proteins incorporated into ...19979364686
cattle theileriosis in china.amongst the piroplasmoses of livestock in china, the commonest theilerioses are caused by theileria annulata, t. sergenti and t. mutans. research carried out over many years has shown these to be distributed mainly in northern china but they also occur in southern china. t. annulata and t. sergenti are the most troublesome, affecting large numbers of cattle, especially those of exotic breeds. the incident rate and numbers of fatalities vary widely between areas and breeds of cattle. t. annulata ...19979512736
observations on the treatment of natural haemosporidia infections by total alkaloid of peganum harmala l. in cattle.eighty two cattle naturally infected with haemosporidians were treated with total alkaloid hydrochloride of peganum harmale l. (0.5 mg/kg/day). fifty eight cases with theileria sergenti showed a cure rate of 86%; thirteen cases with theileria annulata showed a cure rate of 85%; eight cattle infected with babesia bigemina showed a cure rate of 88% and three cases of anaplasma marginale were completely cured. the results suggested that the curative effect of total alkaloid of p. harmale was better ...19979512749
vaccines against hemoparasitic diseases in israel with special reference to quality assurance.four vaccines against hemoparasitic diseases (anaplasmosis, babesiosis and theileriosis) and a vaccine against besnoitiosis are currently used in israel. these vaccines contain live attenuated parasites derived from cell culture (theileria annulata and besnoitia besnoiti) or from blood of infected, splenectomized calves (babesia bigemina, b. bovis and anaplasma centrale). cryopreserved master seed is used to initiate production of the vaccines. quality control performed during the preproduction ...19979512751
research on the schizont cell culture vaccine against theileria annulata infection in xinjiang, china.theileria annulata infection (tai) is one of the most serious diseases of cattle in xinjiang autonomous region of uigur minority nationality. it has been recorded in 14 prefectures, except the tulufan prefecture, but the enzootic areas are mainly distributed around the zhunger basin and talim basin. according to the records collected in the ten years before vaccination with the schizont cell culture vaccine was carried out, the average incidence rate of tai in enzootic areas was 7.22% and the mo ...19979512753
lowered vaccine dose for immunisation of calves against tropical theileriosis using theileria annulata lymphoblasts.bovine tropical theileriosis is of high incidence in calves below 2 months old in india. the theileria cell culture vaccine evolved by the punjab agricultural university (pau) was evaluated previously for its efficiency and safety in younger calves, both experimentally and in the field. the dose of cells used for vaccination was regulated at 1.75 to 2 x 10(6) cells. this study, which was undertaken to assess the minimum number of cells which would be effective and safer for vaccination, showed t ...19979512754
responses in animals vaccinated with the theileria annulata (hisar) cell culture vaccine.bovine tropical theileriosis caused by theileria annulata is an economically important disease of cattle in india. the disease has assumed paramount importance with the intensification of cross-breeding programmes aimed at enhancing milk production in the country. to control this disease, a cell culture vaccine was developed in this department by continuous passaging of t. annulata (hisar) schizonts in vitro. current work in this department has concentrated on the epidemiology of theileriosis: d ...19979512755
revaccination with the same theileria annulata infected cell line may not be feasible for boosting immunity against tropical theileriosis.a model for studying re-immunisation using skin grafting was developed as the allogeneic responses produced by t. annulata cell lines were similar to those produced by skin grafting. appearance of schizonts and piroplasms post-immunisation was either delayed or prevented by already existing allogeneic responses. isolation of parasite infected cell lines from lymph node biopsies and peripheral blood after cell line immunisation was also delayed or prevented by already existing allogeneic response ...19979512756
macroschizonts of theileria annulata as vaccine and diagnostic tools.t. annulata-infected cells present infection-associated peptides. these peptides represent target molecules of the cytotoxic acting cells. their preparation and characterization may help to develop a sub-unit vaccine. our studies show that macroschizont-infected bovine cells can be used as parasite antigen in serology for the detection of parasite-specific antibodies in serum of infected animals. primers derived from the macroschizont of t. annulata can be used as molecular tools for the detecti ...19979512759
parasite-mediated steps in immune response failure during primary theileria annulata infection."exotic" european cattle are highly susceptible to t. annulata infection. in immunised animals, several effective anti-parasite responses can be demonstrated, such as anti-macroschizont cytotoxic t cells (ctl), and nitric oxide killing of parasites. the failure of infected animals to mount an effective primary immune response suggests that the presence of the parasite directly interferes with the development of immunity. when the activation pathways of cd4+ t cells in draining lymph nodes were e ...19979512760
protective immune responses to theileria annulata of relevance to vaccine development.a series of projects on theileria annulata funded by the european union (std1/std2/std3) have provided convincing evidence that macrophage and natural killer (nk) cell-dependent immune mechanisms may directly control the proliferation of different stages of t. annulata in cattle. the evidence for this conclusion and the implications for vaccine development are discussed in the following paper.19979512761
development of an experimental tissue culture vaccine against mediterranean theileriosis in spain.vaccines against mediterranean theileriosis have been developed in several countries where the disease is an economic problem. tissue culture vaccines have been widely and successfully used to immunize cattle. although mediterranean theileriosis represents a constraint to dairy cattle production in spain, no vaccines against this disease have been developed previously. the successful development of a tissue culture vaccine consisting of attenuated theileria annulata schizont infected cells from ...19989529992
nitric oxide causes the macroschizonts of theileria annulata to disappear and host cells to become apoptotic.the proliferation of theileria annulata macroschizont-infected cell lines in vitro was significantly inhibited by nitric oxide (no) generated by s-nitroso-n-acetyl-dl-penicillamine (snap). incubation with snap caused the macroschizonts to disappear and host cells to become apoptotic. snap-derived no also significantly inhibited the incorporation of tritiated thymidine by cultures of cells in which the schizonts had been induced to differentiate into merozoites by maintenance at 41 degrees c inst ...19989541988
metastasis of theileria annulata macroschizont-infected cells in scid mice is mediated by matrix metalloproteinases.theileria annulata (ta)-infected leucocytes are able to disseminate in scid mice. the dose of virulent parasites of the ta-ode line required to achieve quantifiable dissemination was found to be 2 x 10(6) cells given i.p. dissemination was higher on day 11 post-inoculation than on day 18. the attenuated ta-ode cells were found to disseminate very poorly compared to their virulent progenitors, which correlates with a marked reduction in matrix metalloproteinase (mmp) expression. a daily i.p. inje ...19989550215
in vitro propagation of theileria annulata infected schizonts in different media supplemented with heterologous sera.efficacy of medium rpmi-1640 (supplied by gibco usa, centron and hi-media) supplemented with horse, donkey, sheep and goat sera was evaluated for in vitro propagation of theileria annulata (hisar) infected bovine mononuclear cells. the results were compared with the growth rate in rpmi-1640 supplemented with foetal bovine serum (gibco). rpmi-1640 (gibco) proved to be the best medium for in vitro cultivation of the parasite infected cells. foetal bovine serum could be easily, safely and reliably ...19979567745
phenotypic and genotypic alterations associated with the attenuation of a theileria annulata vaccine cell line from turkey.attenuated vaccines, produced by prolonged in vitro culture of the macroschizont stage of the life-cycle, are the main method of controlling theileria annulata infections. little is known about the mechanism(s) of attenuation. here we present data from a turkish cell line demonstrating that attenuation is associated with reduced ability to differentiate into microschizonts and a reduction in matrix metalloproteinase activity. we also show that attenuation results in a change in the structure of ...19989569467
interferon production by theileria annulata-transformed cell lines is restricted to the beta family.theileria are tick-transmitted protozoans causing often fatal diseases in ruminants. theileria sporozoites immortalize and transform host cells of haematopoietic origin. transformation is associated with profound functional alterations. for example, bovine cells infected by theileria annulata or t. parva. constitutively produce interferon (ifn). in this study, the type and family of ifn produced by a panel of t. annulata-transformed cell lines and a t. parva-transformed cell line was investigate ...19989618728
theileria annulata: the expression of two novel macroschizont antigens on the surface of infected mononuclear cells differs during in vitro attenuation of a virulent cell line.the first part of this study of the biological mechanisms underlying attenuation of virulent theileria annulata macroschizont-infected cell lines screened four pairs of t. annulata (hisar) in vivo- and in vitro-derived macroschizont-infected cell lines (lines) and identified a single in vivo-derived line, which induced lethal tropical theileriosis. the other seven lines were relatively avirulent. analysis of the clinical, hematological, and parasitological responses of cattle immunized with diff ...19989635447
delayed type hypersensitivity theilerin test in cattle vaccinated against theileria annulata infection.theilerin was prepared and its total nitrogen was determined at level of 1 mg/ml. seventy-two holstein friesian cattle recovered from acute theileriosis or vaccinated received 0.1 ml of theilerin intradermally at normal concentration of total nitrogen or other dilutions (1 / 10 and 1 / 100). some 60(% of calves and 66.67% of milking cows receiving normal theilerin showed more than 1 mm increase in skin thickness at the site of inoculation (mean value of 1.86 mm for calves and 3.46 mm for milking ...19989637228
differences between b cell and macrophage transformation by the bovine parasite, theileria annulata: a clonal approach.theileria annulata, a tick-transmitted protozoan parasite, infects and transforms cells of the hemopoietic system, particularly those of the b cell and monocyte/macrophage lineages. here, the effect of infection/transformation on the resulting phenotype was studied using a clonal approach. three phenotypes of transformed cell lines could be discerned. the first is characterized by surface expression of igm, cd21, and the b cell epitopes, b-b2 and b-b8, ig heavy chain gene rearrangement, and mrna ...19989647241
theileria lestoquardi and t. annulata in cattle, sheep, and goats. in vitro and in vivo studies.theileria annulata, causing bovine tropical theileriosis, and t. lestoquardi (syn t. hirci), the agent of malignant ovine theileriosis, are both transmitted by ticks of the genus hyalomma. their distribution is thus very similar and, should these parasites infect more than one ruminant species, the difficulty in interpreting epidemiological studies is magnified considerably. a pilot series of experiments was thus conducted in which cattle, sheep and goats were infected with sporozoites of a sing ...19989668448
detection and differentiation of theileria annulata and theileria parva using macroschizont-derived dna probes.a lamda gt11 expression library based on t.annulata-infected cells was screened with an antiserum raised in rabbits against partially purified schizonts of t.annulata. two clones were detected, sequenced and designated as sa288 and sb288 (shayan et al., submitted for publication). from the sequences of these two genes oligonucleotide primers were designed for specific amplification of parasite dna by polymerase chain reaction (pcr). we could show that these genes are of parasitic origin and do o ...19989668454
selection for antigenic diversity of tams1, the major merozoite antigen of theileria annulata.tams1, the major merozoite/piroplasm surface antigen of theileria annulata has the potential to be a component of a diagnostic elisa test and be included in a recombinant subunit vaccine. however, the observation that this antigen displays diversity could constrain these applications. in this paper we have extensively characterized tams1 diversity at the dna level, using a pcr/sequencing strategy. up to 44 alleles have been cloned and sequenced. the comparison of these alleles has identified reg ...19989668455
theileria annulata: carrier state and immunity.recovery from primary infection of theileria annulata results in the development of a persistent carrier state in the vertebrate host. the carrier state is of great importance in the maintenance of the life cycle by alternate tick/cattle challenge and both contributes to and may be necessary for maintenance of immunity. therefore, an accurate determination of carrier animals could be useful in determining immune status and may allow the necessary control measures to be implemented. detailed info ...19989668456
a stage-specific, parasite-induced, "window" of in vivo interferon-gamma production is associated with pathogenesis in theileria annulata infection.the tick-borne protozoan parasite theileria annulata causes tropical theileriosis, a severe leukoproliferative disease of cattle, which naive susceptible animals fail to control. the parasite infects and transforms macrophages, developing in the local draining lymph node. ifn gamma has been shown to block parasite development in newly infected cells, and inhibits the growth of fully differentiated macroschizont stage-infected cells in vitro. however, the parasite has been found to specifically i ...19989668460
different vaccine strategies used to protect against theileria annulata.spag-1, a sporozoite surface antigen of t. annulata, has previously been shown to elicit partial protection when used, as an hepatitis b core antigen fusion, to immunize cattle. the objective of this study was to try and improve the protective capacity of this antigen by enlisting different vaccine strategies. cattle were immunized with spag-1, as a fusion protein with a his6 tag, either incorporated into iscoms, with or without the merozoite antigens tams 1-1 and 1-2, or with rwl as adjuvant th ...19989668470
in vitro infectivity and in vivo cross-protectivity of theileria lestoquardi and t. annulata in sheep and cattle. 19989668499
cytokine production/t-cell-stimulatory ability of theileria annulata-infected cells and post-vaccinal reactions. 19989668500
evidence for strain specificity in cytotoxic t-lymphocyte-mediated, major histocompatibility complex class i-dependent killing of theileria annulata-infected cells.cattle immunised against theileria annulata with one parasite strain have been found to be immune to re-challenge with different strains of the parasite. however, recent evidence of apparent strain specificity has been documented in cattle immunised with attenuated parasite-infected cells. in this study the strain specificity of major histocompatibility complex class i-restricted cytotoxic t-lymphocytes (ctl), a major anti-parasite effector mechanism, was examined. ctl generated following challe ...19989694379
chemoprophylaxis of theileria annulata and theileria parva infections of calves with buparvaquone.a clinical trial testing the prophylactic effect of a 5 mg kg-1 dose of buparvaquone on either theileria annulata or theileria parva experimental infections of calves demonstrated its efficacy for periods of at least seven days. the drug given 1 h or seven days before 50% lethal t. annulata sporozoite infection protected all eight calves, but prophylaxis was insufficient after 14 days to protect two out of four calves from severe reaction. when immunity was challenged by a lethal second parasite ...19989703615
identification of a theileria annulata antigen expressed in multiple stages of the parasite life cycle.in order to identify sporozoite surface molecules which may be involved in invasion and could act as potential vaccine candidates, a number of mabs were raised in mice against t. annulata sporozoites. these were assayed for their ability to block sporozoite invasion of bovine peripheral blood mononuclear (pbm) cells in vitro. one of these, mab 4b11, was found to neutralize sporozoite invasion to a high degree and to recognize a group of sporozoite antigens on western blots. a t. annulata lambdag ...19989709037
immunization of cattle with nymphal hyalomma anatolicum anatolicum extracts: effects on tick biology.antigens derived from partially engorged nymphs of hyalomma anatolicum anatolicum were used in immunizing crossbred (bos indicus x bos taurus) cattle against larval, nymphal and adult h. a. anatolicum and h. dromedarii. the cattle were either infected with theileria annulata at low parasitaemia or were uninfected. whole nymphal extract (wne), nymphal membrane antigens (nma) and nymphal soluble antigens (nsa) were used for immunization. the group immunized with wne showed significant and better r ...19989719836
recent development in control of theileria annulata in iran.during 1973-1990 cattle immunization, in iran, was induced by two strains within an interval of one month: first the milder and then the mild strain. although this method of vaccination rendered satisfactory results in the field, yet production, maintenance in deep-freezers and transportation in liquid nitrogen particularly to remote areas of the country proved to be uneconomical and time consuming. therefore, in order to reduce cost and save time, a new method involving only one local and live ...19989754318
sequence analysis of the major piroplasm surface protein gene of benign bovine theileria parasites in east asia.relatively benign theileria parasites are widespread among cattle in east asia. although the parasites are presumed to be of the theileria sergenti/theileria buffeli/theileria orientalis group, their taxonomic status and epidemiology have not been well defined. in the present study, theilerial dna samples were collected from various east asian countries, including japan, korea, taiwan, and china. dna sequences encoding a major piroplasm surface protein were amplified by polymerase chain reaction ...19989762568
haematological and biochemical studies on experimental theileria annulata infection in crossbred calves.administration of ground-up tick tissue stabilate (0.75 tick equivalent) by the subcutaneous route to crossbred calves aged 1 week to 1 month led to the development of acute theileriosis. haematological studies revealed significant progressive decreases in haemoglobin concentration, packed cell volume and red blood cell count, whereas the total leukocyte count showed an initial non-significant leukocytosis followed by a significant leukopenia. analysis of serum revealed significant increases in ...19989778780
successful long-term in vitro cultivation of theileria annulata schizonts in media supplemented with homologous and heterologous sera.the efficacy of medium rpmi-1640 supplemented with either foetal bovine, normal bovine, goat or sheep sera was compared for prolonged in vitro propagation of theileria annulata (hisar) schizonts. medium rpmi-1640 supplemented with 20% foetal bovine serum (standard growth medium) resulted in optimum growth of t. annulata (hisar) schizonts in vitro. comparable viability and non-viability counts were observed in growth media supplemented with normal bovine or goat sera. however, viability counts in ...19989806493
directing differentiation in theileria annulata: old methods and new possibilities for control of apicomplexan parasites.apicomplexan parasites are major pathogens of humans and domesticated animals. the ability of these organisms to evade the host immune response and the emergence of drug-resistant parasites indicates a need for the identification of novel control strategies. ideally, selected targets should be shared by a range of apicomplexans and fundamental to parasite biology. one process of apicomplexan biology which may provide this type of target is the molecular regulation of stage differentiation. this ...19989846602
stage-specific activity in vitro on the theileria infection process of serum from calves treated prophylactically with buparvaquone.an in vitro method for testing activity of buparvaquone in serum on the infection and development of theileria in its bovine host mononuclear cells is described and results compared with the effect exhibited in vivo. serum samples were collected over a time course from calves in a clinical trial of 5 mg kg(-1) buparvaquone prophylaxis on theileria annulata or t. parva experimental infection. to evaluate drug levels and persistence in each animal for a period of 14 days and its effect on the earl ...19989870365
nested polymerase chain reaction for detection of theileria annulata and comparison with conventional diagnostic techniques: its use in epidemiology studies.in this work we studied the ability of a nested polymerase chain reaction (pcr) to detect theileria annulata, the causative agent of mediterranean theileriosis, in blood samples obtained from cattle on farms in different spanish regions and its possible use in epidemiology studies. of the 214 samples analyzed, 78.04%, 69.86%, and 62.26% were found to be positive by nested pcr, indirect immunofluorescent antibody test, and optical microscopy of giemsa-stained smears, respectively. the three techn ...19999951969
susceptibility to tropical theileriosis of calves born to dams immunized with theileria annulata (hisar) cell culture vaccine.the susceptibility/immune status to tropical theileriosis of calves born of immunized dams was evaluated. six cows were vaccinated with the theileria annulata cell culture vaccine in the eighth month of pregnancy. sera from the immunized dams exhibited very high post-vaccination antibody titres as determined by the indirect fluorescent antibody (ifa) test. the calves born to these dams did not show antibodies against t. annulata at the time of birth (ifa titres of < 1:20). the new-born calves we ...19989974207
effects of experimentally induced theileria annulata infection on the pharmacokinetics of oxytetracycline in cross-bred calves.the effects of an experimental theileria annulata infection on the intravenous (10 mg kg-1) pharmacokinetics of oxytetracycline (otc) were investigated in crossbred calves. the serum concentration-time curve of oxytetracycline before and after the experimental infection was best described by an open two-compartment model. the experimental infection was induced by a subcutaneous administration of ground-up tick supernate (guts) equivalent to 30 hyalomma anatolicum anatolicum ticks infected with t ...199910081114
tissue damage in cattle infected with theileria annulata accompanied by metastasis of cytokine-producing, schizont-infected mononuclear phagocytes.the distribution of schizont-infected cells in six calves undergoing acute, lethal sporozoite-induced infections with theileria annulata was examined, the calves being killed in the early, middle or late stages of disease. a combination of histological and immunocytochemical techniques showed that schizont-infected cells became disseminated rapidly through the lymphoid tissues from the prescapular lymph node draining the site of inoculation to distant lymph nodes (e.g., precrural, mesenteric and ...199910098015
is interleukin 2 necessary for the autocrine proliferation of theileria-infected bovine cells?theileria-infected bovine lymphoblastoid cells are induced to proliferate permanently such that the division of the parasites and that of their host cells occur synchronously. the mechanism by which the parasites induce the transformation of their host cells is unknown. we investigated the growth-factor dependency of a number of theileria-infected cell lines. supernatants of the majority of the cell lines tested in our study showed no growth-enhancing activity. however, supernatants of a limited ...199910227059
macrophages behaving badly: infected cells and subversion of immune responses to theileria annulata.the protozoan parasite theileria annulata is the causative agent of the tick-borne disease tropical theileriosis, responsible for morbidity and mortality of cattle in many developing countries. here, john campbell and roger spooner discuss how the parasite might evade immune destruction during an acute primary infection. theileria annulata macroschizont-infected macrophages act as over-efficient antigen-presenting cells within the infected draining lymph node. infected cells activate cd4+ and cd ...199910234172
simultaneous detection of bovine theileria and babesia species by reverse line blot hybridization.a reverse line blot (rlb) assay was developed for the identification of cattle carrying different species of theileria and babesia simultaneously. we included theileria annulata, t. parva, t. mutans, t. taurotragi, and t. velifera in the assay, as well as parasites belonging to the t. sergenti-t. buffeli-t. orientalis group. the babesia species included were babesia bovis, b. bigemina, and b. divergens. the assay employs one set of primers for specific amplification of the rrna gene v4 hypervari ...199910325324
theileria annulata: genetic characterization of spanish isolates by isoenzyme electrophoresis and random amplified polymorphic dna.isoenzyme electrophoresis and rapd techniques were used to study the genetic polymorphism of different spanish isolates of theileria annulata in the schizont and piroplasm stages. enzyme activity attributable to the parasite was detected in only 5 of the 13 loci studied with isoenzyme electrophoresis. of these, differences between the cell lines studied were found only in the loci gpi, icd, and fh. only 6 of the 11 primers used in the rapd generated reproducible genomic dna fingerprints. none of ...199910329366
diminished il-2 responses and alteration of cd2 expression on cd8+ t cells are associated with a lack of cytotoxic t cell responses during theileria annulata infection.theileria annulata is a tick-borne protozoan parasite which causes the disease bovine tropical theileriosis. in immunized or drug-treated animals, the pathogenic macroschizont stage of the parasite is destroyed by mhc class i-restricted cytotoxic t lymphocytes (ctl). here we show that although cd8+ t cells increase greatly in number and display activation markers during an acute infection, they exhibit no killing of infected cells. during the ineffectual response, efferent lymph cells' ability t ...199910337024
in vivo development of theileria annulata: major changes in efferent lymph following infection with sporozoites or allogeneic schizont-infected mononuclear cells.the object of these experiments was to study the pathogenesis and kinetics of theileria annulata infection in the efferent lymph of the draining lymph nodes of calves. efferent lymphatics of calves were cannulated prior to infection with t. annulata sporozoite or an allogeneic schizont cell line. potentially lethal sporozoite challenge induced cell shut-down from days 4-6 and then a massive increase in output of blasting cells (both infected and non-infected) in the efferent lymph. the rate of l ...199910340321
infectivity and cross-immunity studies of theileria lestoquardi and theileria annulata in sheep and cattle: i. in vivo responses.in a series of experiments, sporozoite stabilates of a theileria lestoquardi (lahr) and a t. annulata (ankara) stock prepared from hyalomma anatolicum anatolicum ticks, were used to examine the infectivity of both parasite species for sheep and cattle and to study the development of cross-immunity between these parasite species. in the first experiment sheep and cattle were inoculated with t. lestoquardi sporozoites. surviving animals and naive sheep and cattle were, in the second experiment, in ...199910348097
infectivity and cross-immunity studies of theileria lestoquardi and theileria annulata in sheep and cattle: ii. in vitro studies.in the studies previously reported, the tick-borne protozoan parasites theileria lestoquardi and theileria annulata were shown to differ in their capacity to infect sheep and cattle. in the studies presented here, these findings were further supported. in vitro infectivity of t. lestoquardi and t. annulata sporozoites for peripheral blood mononuclear cells of sheep and cattle were determined by analysis of cell cultures for cell proliferation, the detection of parasites in giemsa-stained cytospi ...199910348098
should i stay or should i go now? a stochastic model of stage differentiation in theileria annulata.the events that initiate and determine stage differentiation of protozoan parasites are not fully understood. in this article, brian shiels suggests that for differentiation to the merozoite in theileria annulata the process is predetermined by the parasite, but can be initiated and modulated by changes to the extracellular environment. shiels proposes a mechanism operating on the basis of factors that regulate gene expression reaching a commitment threshold. similarities across protozoan and hi ...199910366832
the theileria annulata sporozoite and macroschizont polypeptide encoded by the spm1 gene shares phenylalanine-glycine motifs with nuclear pore proteins. 199910377002
innate and adaptive immune responses co-operate to protect cattle against theileria annulata.for many years it was assumed that theileria annulata resembled t. parva, parasitizing lymphocytes and causing lymphoproliferative disease, with the two species being controlled by similar protective immune responses. patricia preston et al. here review the evidence that has led to a different view of t. annulata. it is now thought that the schizonts of t. annulata inhabit macrophages and b cells, and that tropical theileriosis is not a lymphoproliferative disease. both innate and adaptive respo ...199910377528
the effect of buparvaquone treatment on the levels of some antioxidant vitamins, lipid peroxidation and glutathione peroxidase in cattle with theileriosis.plasma levels of vitamins a, e, beta carotene, both plasma and erythrocyte glutathione peroxidase (gshpx), lipid peroxidation (lpo) and reduced glutathione (gsh) were investigated in cattle naturally infected with theileria annulata and treated with buparvaquone. there were two groups each containing 30 cattle. naturally infected cattle were used in the second group. buparvaquone (2.5 mg/kg body weight) was administered to animals in the second group. blood samples were taken from control animal ...199910379233
review: theileria schizonts induce fundamental alterations in their host cells.the sporozoites of theileria annulata and t. parva invade bovine leukocytes, where they differentiate into schizonts. the latter can immortalize and induce fundamental changes in their host cells. t. annulata infects mainly major histocompatibility complex class ii cells, whereas t. parva preferentially transforms t-lymphocytes, which proliferate continuously without the need for exogenously added growth factors. most of the cell lines appear to be independent of a growth factor but may express ...199910382602
review: the cellular basis of the immunity to and immunopathogenesis of tropical theileriosis.the intracellular protozoan parasite theileria annulata causes a severe and often fatal disease of pure and crossbred cattle in tropical and subtropical countries. animals that recover from the infection are immune against challenge with homologous parasite strains. in the present review we refer to the role of immunocompetent cells and their products in containing the infection or in facilitating the progress of the disease. parasite-infected host cells produce cytokines, which, depending on th ...199910382603
molecular phylogenetic studies on theileria parasites based on small subunit ribosomal rna gene sequences.classification of theileria parasites of south-east asian countries is still ambiguous due to the lack of basic studies, especially their molecular genetic information. in this study, we included 6 known species and 14 unclassified theileria parasite isolates: theileria annulata, theileria parva, theileria taurotragi, theileria sergenti, theileria buffeli, theileria types sable, theileria types a, b, b1, b2, c, d, e, f, g, g1, theileria type medan (indonesia), theileria type ipoh (malaysia) and ...199910392966
evidence for localisation of a theileria parasite at hook dna-binding protein to the nucleus of immortalised bovine host cells.immortalisation of bovine leukocytes by the macroschizont stage of the tick transmitted protozoan parasite, theileria annulata, results in the clonal expansion of infected cells and dissemination throughout the bovine host. the parasite-encoded factors which induce this unique transformation event have not been defined to date. in this study, a gene family (tashat) has been characterised that encodes polypeptides with homology to known dna-binding proteins. expression of tashat genes occurs at t ...199910413048
the proliferation-associated nuclear protein ki-67 in the bovine system: partial characterisation and its application for determination of the proliferation of theileria-infected bovine cells.theileria annulata-infected bovine cells as well as mitogen-stimulated bovine peripheral blood mononuclear cells (pbmc) express a proliferation-associated nuclear protein equivalent to the human ki-67 protein. in analogy to the human system, the expression of the bovine ki-67 protein is restricted to proliferating cells only, since (a) ki-67 expression paralleled [3h]-thymidine incorporation in concanavalin a (con a)-stimulated bovine pbmc, (b) ki-67 was not detectable in quiescent bovine cells, ...199910431723
generation of theileria annulata-specific cytotoxic t lymphocytes coincides with the control of tropical theileriosis. 199910494818
direct and sensitive detection of trypanosoma evansi by polymerase chain reaction.the mechanically transmitted haemoflagellate, trypanosoma evansi causes 'surra', a wasting disease of domestic animals and is highly endemic in distribution in southeast asia. the detection of t. evansi is important for improving the epizootiological and animal health status of the region. the specificity and sensitivity of polymerase chain reaction (pcr) using oligonucleotide primers constructed from t. evansi repetitive dna sequences were studied in the present investigation. using the assay, ...199910497829
evaluation of recombinant sporozoite antigen spag-1 as a vaccine candidate against theileria annulata by the use of different delivery systems.the major sporozoite surface antigen of theileria annulata (spag-1) is a candidate for inclusion in a subunit vaccine. in this paper we summarize the results of 4 vaccination experiments using recombinant spag-1 expressed in different systems and presented in different adjuvants. the antigen has been presented as either a c terminal 108 amino acid peptide (called sr1) expressed as both beta-galactosidase and hepatitis b core antigen fusions or as a full-length form expressed as a gst fusion with ...199910540314
mechanism(s) of attenuation of theileria annulata vaccine cell lines.attenuated vaccines are an important means of controlling theileria annulata infection of cattle. production is by prolonged cultivation of macroschizont-infected cells. the mechanism of attenuation remains unclear. there are three general nonmutually exclusive possibilities: selection of avirulent subpopulations, genome rearrangements and alterations in gene expression. several groups, including ours, have provided evidence that the population structure usually tends to simplify during attenuat ...199910540315
transformation of leukocytes by theileria parva and t. annulata.theileria parva and t. annulata provide intriguing models for the study of parasite-host interactions. both parasites possess the unique property of being able to transform the cells they infect; t. parva transforms t and b cells, whereas t. annulata affects b cells and monocytes/macrophages. parasitized cells do not require antigenic stimulation or exogenous growth factors and acquire the ability to proliferate continuously. in vivo, parasitized cells undergo clonal expansion and infiltrate bot ...199910547684
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