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A J Teale

Publications and source records attributed to A J Teale.

66 records · Page 4Linked to original sources
PubMed1986

Bovine cytotoxic T-cell clones specific for cells infected with the protozoan parasite Theileria parva: parasite strain specificity and class I major histocompatibility complex restriction.

We present information on the specificity of three bovine cytotoxic T-cell clones reactive with lymphoblasts infected with the protozoan parasite Theileria parva. The clones were derived from peripheral blood mononuclear cells of an animal immunized with T. parva (Muguga stock), after five stimulations in vitro with an autologous parasitized cell line. The three clones belonged to the BoT8+ subset of T cells, which is similar to the human CD8+ T-cell subset. On the basis of analysis on a panel of infected target cells originating from cattle of different major histocompatibility complex (MHC) phenotypes, killing by all three clones was found to be restricted to targets bearing the class I MHC specificity KN104, which is defined by alloantiserum KNA104 and monoclonal antibody IL-A4. This class I MHC restriction was confirmed by blocking of target cell lysis with these antibodies and monoclonal antibody w6/32, which reacts with a nonpolymorphic determinant on bovine class I MHC molecules. The three clones were parasite strain specific, in that they did not kill cells of the appropriate MHC type infected with T. parva (Marikebuni stock). These findings, taken together with previous observations that immunization of cattle with T. parva (Muguga) does not provide protection against challenge with T. parva (Marikebuni), suggest that the cytotoxic T cells recognize a cell surface antigen that may be important in induction of immunity to the parasite.

Animals↗
PubMed1986

Characterization by a monoclonal antibody and functional analysis of a subset of bovine T lymphocytes that express BoT8, a molecule analogous to human CD8.

Monoclonal antibody (mAb) IL-A17 characterizes a subset of bovine T lymphocytes. IL-A17 recognizes a 34,000-35,000 MW doublet, designated BoT8, which is expressed on the surface of approximately 20% of peripheral blood mononuclear leucocytes (PBM), a subpopulation of lymphocytes in T-dependent areas of lymph nodes and spleen, and about 70% of thymocytes. This molecule is not expressed on B lymphocytes, monocytes/macrophages or granulocytes. Double labelling of PBM showed that the BoT8+ population is distinct from the T lymphocyte subset expressing BoT4. BoT8+ lymphocytes purified with a fluorescence-activated cell sorter (FACS) proliferated poorly in response to mitogenic and alloantigenic stimulation in the absence of exogenous growth factors. IL-A17 had no inhibitory effect on proliferation of PBM to mitogens (Con A and PHA) or alloantigens and no measurable effect on the in vitro generation of cytolytic effector cells. However, in some experiments IL-A17 was found to block partially allospecific cytolytic function mediated by bulk effector cell populations when included in 51Cr-release assays. Fractionation of effector cells generated in an allogeneic mixed leucocyte culture (MLC) demonstrated that cytotoxic cells specific for class I major histocompatibility complex (MHC) antigens reside within the BoT8+ population. Based on these data, and information reported elsewhere on alloreactive bovine T-cell clones, BoT8 is considered to be analogous to CD8 in humans and equivalent molecules in other species.

Animals↗
PubMed1985

Bovine alloreactive cytotoxic cells generated in vitro: target specificity in relation to BoLA phenotype.

Cytotoxic cells of bovine origin were generated in primary MLC using stimulator cells of BoLA w8/w11 phenotype. Bovine lymphoblasts transformed by the protozoan parasite Theileria parva parva acted as target cells in studies of the specificity of cytotoxicity. When responder cells in MLC did not share w8 or w11 with stimulator cells, cytotoxicity was evident with all targets bearing w8 or w11, or both, and was almost entirely restricted to these products of the BoLA-A locus. When responder and stimulator cells shared both w8 and w11, cytotoxicity was also generated. Whether this was specific for the products of other putative Class I loci in cattle, or for the products of a Class II region, remains to be determined. These results suggest that the determinants recognized by appropriately generated bovine alloreactive cytotoxic cells are identical with, or closely related to, determinants characterized by BoLA w8 and w11 defining alloantisera.

Animals↗
PubMed1985

De novo expression of T cell markers on Theileria parva-transformed lymphoblasts in cattle.

We describe monoclonal antibodies that detect two new membrane antigens on bovine T cells. One molecule is only expressed on activated T cells and has a m.w. of 100,000. The other antigen is a glycoprotein that is precipitated as two bands of m.w. 150,000 and 158,000 and is expressed on a subpopulation of T cells and all myeloid cells. We show that when bovine lymphocytes are transformed by the protozoan parasite Theileria parva, both antigens become expressed on the cell surface. The infected cell acquires the phenotype of a proliferating T cell, irrespective of its precursor cell phenotype.

Animals↗
PubMed1984

Detection of antibody to Theileria parva schizonts and cell surface membrane antigens of infected lymphoblastoid cells by immunoperoxidase techniques.

Peroxidase-labeled antibody procedures were described for detecting bovine antibodies reactive with intracellular Theileria parva schizonts and cell surface membrane antigens of infected lymphoblastoid cells. Indirect tests were performed where the reacting bovine antibodies were localized with affinity purified rabbit-anti-bovine IgG coupled to horseradish peroxidase. A 4- to 8-fold increase in sensitivity for detecting bovine antibodies was obtained with unlabeled rabbit-anti-bovine IgG which in turn was detected with peroxidase labeled goat-anti-rabbit IgG. The T. parva infected cells used as antigen were attached to poly-l-lysine treated glass slides and all reaction steps were performed on the slides. The intracellular schizonts and cell surface staining reactions were dependent upon the status of the cells; acetone-fixed cells were required for schizont reactions and viable unfixed cells for cell surface membrane reactions. Sera from cattle stimulated in various ways with T. parva were examined by the techniques. Cattle infected by stabilate inoculation or inoculated with infected autologous lymphoblastoid cells developed relatively high levels of antibody to schizonts, but no detectable antibody to cell surface membrane antigens. This would indicate that parasite antigens do not occur on the surface of infected lymphoblasts. Cattle inoculated with infected allogeneic lymphoblasts developed low-levels of antibody to schizonts and readily demonstrable antibody to cell surface antigens. The immunoperoxidase procedures have certain advantages over immunofluorescence in that light microscopy is used; therefore, the reactions do not fade which permits a more detailed examination and provides a relatively permanent record, the preparations can be counterstained, and the reagents may be used for immunoelectron-microscopy. The procedures could provide suitable alternatives to immunofluorescence methods for East Coast fever investigations and other systems having intracellular and/or cell surface membrane antigens.

Animals↗
PubMed1984

A histocompatibility barrier to immunization against East Coast fever using Theileria parva-infected lymphoblastoid cell lines.

Histocompatibility may be a barrier to the infection of cattle when Theileria parva parva-infected tissues or in vitro cultured macroschizont-infected lymphoblastoid cell lines are used for immunization. By inoculating 10(3) and 10(5) infected cells into autologous recipients infection was achieved and immunity engendered. Cell lines inoculated into BoLA matched recipients did not produce patent infections but some recipients developed antibodies to the parasite and 3/5 were immune to challenge. No evidence of infection or immunity was found in BoLA half matched or mismatched cattle. This result suggests that there is an histocompatibility barrier to infection using T. p. parva-infected lymphoblastoid cells.

Animals↗
PubMed1982

Toxoplasmosis in rams: possible significance of venereal transmission.

Three rams were infected with tick-borne fever eight months after infection with toxoplasma. There was no clinical evidence of reactivation of the latent toxoplasma infection and semen samples from the rams were not infective to mice. Semen samples from 77 apparently normal rams were tested for toxoplasma infection by passage through mice; none of the samples produced patent infections in mice. Two rams with chronic toxoplasma infection were repeatedly mated with seronegative ewes. None of the ewes showed serological evidence of acquired infection and all lambed satisfactorily.

Animals↗
PubMed1982

Experimentally induced toxoplasmosis in young rams: the clinical syndrome and semen secretion of toxoplasma.

Six rams were inoculated subcutaneously with 2000 toxoplasma tissue cysts. Semen samples from these rams, and from three uninfected controls, were screened for the presence of infective forms of toxoplasma. Three of the infected rams produced infective semen, each on two occasions, between 14 and 26 days post infection (pi). Five of the infected rams showed a febrile response from the fourth to 10th days pi and their indirect haemagglutination titres rose sharply from 10 days pi; the sixth ram was seropositive before infection and showed no clinical or serological response. In the experimental infection studied there were no symptoms or haematological changes of possible diagnostic value. The production of infective semen was restricted to a brief period shortly after infection although observations were continued for over 90 days. It was concluded that venereal transmission was unlikely to be significant in the spread of ovine toxoplasmosis.

Animals↗
PubMedDate not supplied

A male linkage map of the cattle (Bos taurus) genome.

A male linkage map of the cattle (Bos taurus) genome was constructed using nine large half-sib families. The map consists of 269 loci, of which 249 are microsatellites and 20 are structural genes. Among the 249 microsatellites, 140 are markers selected from other maps and 98 are new assignments. Chromosome assignment were established for 35 new markers by somatic cell hybrid analysis, of which 26 were confirmed by linkage analysis. Genome coverage is 1975 cM contained within terminal markers on all 29 autosomes. The average distance between adjacent loci is 9.7 cM, with 72.1% of the map intervals < or = 15 cM and 4.9% of the intervals > or = 25 cM. The inclusion of mapped markers permitted integration and comparisons with other maps, facilitating the identification of discrepancies in chromosome assignment, gene order, and map distance. The inclusion of Type I and blood group markers in the map was useful for comparative mapping, revealing possible blood group orthologies between humans and cattle. The map generated will serve as a useful tool for comparative mapping, mapping of quantitative trait loci and marker assisted selection.

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