Showing papers by "Cynthia L. Baldwin published in 1988"

Bovine T cells, B cells, and null cells are transformed by the protozoan parasite Theileria parva

Abstract: The target cells for infection and transformation by Theileria parva were investigated. Peripheral blood mononuclear cells were reacted with monoclonal antibodies specific for bovine leukocyte differentiation antigens, sorted into subpopulations with a fluorescence-activated cell sorter, and infected in vitro with T. parva sporozoites. Infected cells were cultured at limiting dilution, and transformed clones were screened with monoclonal antibodies. The results indicated that B cells, T cells (including BoT4+ and BoT8+ cells), and null cells but not monocytes or neutrophils were transformed in vitro after infection with T. parva. After transformation, peripheral blood T cells and T-cell clones retained expression of most or all of the T-cell differentiation antigens including the mature T-cell marker recognized by monoclonal antibody IL-A27, BoT2, and BoT4 or BoT8, and some cells acquired a low level of expression of BoT4, BoT8, or the null cell marker recognized by monoclonal antibody IL-A29. T. parva-transformed null cells retained expression of the IL-A29 determinant and acquired expression of BoT2 and BoT8 but not the IL-A27 determinant or BoT4. T. parva-transformed B cells in most instances lost expression of surface immunoglobulin and never acquired expression of the IL-A27 determinant, BoT2, BoT4, or BoT8, although some cells acquired a low level of expression of the null cell marker recognized by monoclonal antibody IL-A29. Further studies on cell lines and clones grown in vitro from populations isolated from T. parva-infected cattle suggested that the majority of the in vivo T. parva-transformed cells were of T-cell origin.

Monoclonal antibodies which react with bovine T-lymphocyte antigens and induce blastogenesis: tissue distribution and functional characteristics of the target antigens.

Abstract: In this study we report on the tissue distribution and functional characteristics of bovine T-cell differentiation antigens recognized by the monoclonal antibodies (mAbs) IL-A26, IL-A27, and IL-A28. All three mAbs are able to stimulate proliferation of peripheral blood mononuclear cells (PBM) and inhibit proliferation of responder cells in mixed leucocyte cultures (MLC). MAbs IL-A27 and IL-A28 are believed to react with the same molecule, which is different to that recognized by IL-A26 as determined by a number of criteria. MAbs IL-A27 and IL-A28 inhibit binding of one another, but not of IL-A26. MAbs IL-A27 and IL-A28 react with 25% of thymocytes confined to the medulla, whereas IL-A26 reacts with approximately 80% of thymocytes, including medullary and cortical populations. MAbs IL-A27 and IL-A28 react with thymocytes which express BoT4 or BoT8 singularly, whereas IL-A26 reacts with all cells which express BoT4 or BoT8, either singularly or dually, in addition to all thymocytes which react with IL-A27/28. Only IL-A26 inhibits spontaneous sheep erythrocyte (E)-rosette formation by bovine T cells. Based on tissue distribution and functional characteristics, IL-A26 is believed to recognize the bovine homologue of CD2, designated BoT2, whereas IL-A27/28 reacts with a mature T-cell antigen. Cells reactive with the mAbs constitute approximately 60% of bovine PBM. Using these mAbs in dual immunofluorescence analyses, at least three populations of bovine T cells are demonstrable in PBM. The majority of T cells are BoT4+ or BoT8+ and also react with IL-A26/27/28. A second small population of PBM is negative for BoT4 and BoT8 but is IL-A26/27/28+. A third population (less than 5%) is BoT4-/BoT8-/ILA27/28- but reacts with IL-A26.

Bovine pan T-cell monoclonal antibodies reactive with a molecule similar to CD2

Abstract: Monoclonal antibodies (mAb) CH128A and CH61A react with molecules of 50,000-60,000 MW. They are expressed by all T cells in cattle, comprising 44-69% of peripheral blood mononuclear leucocytes (PBM), the majority of lymphocytes in T-dependent areas of lymph node, and 75-80% of cells derived from the thymus including both cortical and medullary thymocytes. The molecule recognized by these mAbs is not expressed on B lymphocytes, monocytes/macrophages, or granulocytes. Both mAb inhibit spontaneous rosette formation by sheep erythrocytes and bovine lymphocytes. We postulate that these mAb see the bovine homologue of the human sheep red blood cell receptor CD2 and has been named BoT2.

Bovine TCells, B Cells, andNullCells AreTransformed bythe Protozoan Parasite Theileria parvat

Abstract: cell sorter, andinfected invitro withT.parva sporozoites. Infected cells werecultured atlimiting dilution, andtransformed clones werescreened with monoclonal antibodies. Theresults indicated that Bcells, Tcells (including BoT4+andBoT8+cells), andnull cells butnotmonocytes orneutrophils weretransformed invitro after infection withT.parva. After transformation, peripheral blood T cells andT-cell clones retained expression ofmostoralloftheT-cell differentiation antigens including themature T-cell markerrecognized bymonoclonal antibody IL-A27, BoT2, andBoT4orBoT8,andsomecells acquired alowlevel ofexpression ofBoT4, BoT8, orthenull cell marker recognized bymonoclonal antibody IL-A29. T.parva-transformed null cells retained expression oftheIL-A29 determinant andacquired expression ofBoT2andBoT8butnottheIL-A27determinant orBoT4.T. parva-transformed B cells inmostinstances lost expression ofsurface immunoglobulin andneveracquired expression oftheIL-A27determinant, BoT2,BoT4, orBoT8,although somecells acquired alowlevel of expression ofthenull cell marker recognized bymonoclonal antibody IL-A29. Further studies oncell lines and clones growninvitro frompopulations isolated fromT.parva-infected cattle suggested that themajority ofthe invivoT.parva-transformed cells wereofT-cell origin.