J.A. Ellis

Bio: J.A. Ellis is an academic researcher from University of Wyoming. The author has contributed to research in topics: Antigen & Monoclonal antibody. The author has an hindex of 18, co-authored 24 publications receiving 862 citations.

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

Abstract: 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.

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.

The Nervous System

Abstract: Experimental Neurology By Prof Paul Glees Pp xii + 532 (Oxford: Clarendon Press; London: Oxford University Press, 1961) 75s net

Role of antioxidants and trace elements in health and immunity of transition dairy cows.

Abstract: A number of antioxidants and trace minerals have important roles in immune function and may affect health in transition dairy cows. Vitamin E and β-carotene are important cellular antioxidants. Selenium (Se) is involved in the antioxidant system via its role in the enzyme glutathione peroxidase. Inadequate dietary vitamin E or Se decreases neutrophil function during the perpariturient period. Supplementation of vitamin E and/or Se has reduced the incidence of mastitis and retained placenta, and reduced duration of clinical symptoms of mastitis in some experiments. Research has indicated that β-carotene supplementation may enhance immunity and reduce the incidence of retained placenta and metritis in dairy cows. Marginal copper deficiency resulted in reduced neutrophil killing and decreased interferon production by mononuclear cells. Copper supplementation of a diet marginal in copper reduced the peak clinical response during experimental Escherichia coli mastitis. Limited research indicated that chromium supplementation during the transition period may increase immunity and reduce the incidence of retained placenta.