Activation of rat T lymphocytes by anti-CD2 monoclonal antibodies (original) (raw)
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European Journal of Immunology, 1989
Previously we described a monoclonal antibody (mAb 12-15) that reacted with murine Fc receptor proteins (betal, beta2 and alpha) and an undefined molecule of 37 kDa (beta3) on certain types of cells. Here we present serological and biochemical evidence that the beta3 chain is expressed on mouse thymocytes and that it is identical to the CD2 antigen. By immunofluorescence staining and cytofluorographic analysis > 95% of thymocytes were positive. Brightly staining cells coincided with cortisonresistant thymocytes suggesting that mature thymocytes ex ressed higher levels of the antigen. Biosynthetic labeling of DBN2 thymocytes with ['Slmethionine showed that the size of the CD2 precursor molecule was 43 kDa which was processed to approximately 55-65 kDa in the mature molecule. mAb12-15 was also reactive with the tunicamycin-treated form of the CD2 antigen suggesting that the cross-reactive epitope was of protein nature. Comparison of different mouse strains indicated that two molecular forms of CD2 exist. On BALB/c thymocytes, the relative mass of the native molecule was approximately 60-70 kDa (CD2.1) and slightly larger than in DBN2 (CD2.2). Following endoglycosidase F treatment both proteins still showed a slight difference in electrophoretic mobility. Several inbred mouse strains were analyzed for expression of CD2 forms. When mAb 12-15 was used in cyotoxic T lymphocyte inhibition experiments using specific CTL and tumor target cells it was found that the antibody could specifically inhibit CTL-mediated lysis presumably by interfering with CD2 function.
The effects of anti-CD2 antibodies on the differentiation of mouse thymocytes
European Journal of Immunology, 1989
Using a rat monoclonal antibody against mouse CD2, we determined the expression of this marker on thymocytes during ontogeny. CD2 expression becomes detectable at day 15 and reaches adult levels (-95% positivity) by day 19. Furthermore, the effect of anti-CD2 antibodies on T cell differentiation was analyzed by addition of antibodies to thymus organ cultures or repeated injection into newborn mice. Anti-CD2 antibodies inhibit CD2 expression in organ cultures and drastically reduce its expression on thymocytes and peripheral lymphocytes in vivo. In either situation, suppression of CD2 expression does not significantly alter the generation of T cells expressing CD3, CD4, CD8 and T cell receptor Vp8. These results do not support a role for CD2 in early steps of thymocyte differentiation.
Molecular Immunology, 1987
Mouse monoclonal antibodies (MAbs) have been prepared against rat T cell blasts. One MAb called MRC OX-40 recognized an antigen that differed from any previously described in that its expression was detected only on T blasts that also expressed the CD4 antigen. The OX-40 MAb did not detect an activation determinant of CD2 or CD4 molecules but recognized a distinct chain of mol. wt 50.000. The OX-40 MAb augmented T cell proliferation at late stageson in vitro responses. Other MAbs without obvious counteroarts in other soecies were MRC OX-48 and MRC 0X-49.50 which recognized cell surface molecules of mol. wts of abo;t 95,000 and 90,000, respectively. The Ox-48 antigen was not expressed on resting lymphocytes but was found on a subset of T and B blasts and also on other leucocytes. The 0X-49,50 antigen was found on most haemopoietic cells but was expressed at greatly increased levels after lymphocyte activation and this was also the case for MRC OX-47 antigen which is of unknown M,. The MRC OX-39 MAb was found to bind the rat IL-2 receptor; expression of this antigen was detected on thymic dendritic cells as well as on T blasts. The phenotype of rat T blasts compared to resting cells was also examined and changes in expression of L-CA, Thy-l, OX-2 and CD8 antigens were seen in addition to the changes found with the above MAbs.
Cellular Immunology, 1987
Monoclonal antibody 3A35 (MA 3A35) has previously been shown to be an activation marker of macrophages and T lymphocytes. It immunoprecipitated from macrophages a 200-kDa molecule belonging to the T200 family and from T cells a 85kDa antigen. In the present work, the factors controlling the expression of the epitope identified by MA 3A35 on polyclonal activated T cells and T-cell clones, as well as the ability of 3A35 alone or together with complement to interfere with T-cell functions, were investigated. Corticoresistant thymocytes unreactive with MA 3A35 became fully reactive after 2 days of in vitro stimulation by PMA and IL-2 and the level of reactivity per cell declined to a low level thereafter, In helper and cytolytic T-cell clones, the expression ofthe epitope defined by MA 3A35 was also maximal soon after antigenic stimulation then declined. In helper-T-cell clones, the epitope remained detectable during the entire culture period, whereas in cytolytic clones its expression was markedly reduced at the end of the culture. The lineage of cytotoxic T lymphocytes (CTL) as studied in a bulk culture of spleen cells primed in vivo against a syngeneic tumor exhibited similar regulation by antigenic stimulation. The CTL precursors were resistant to lysis by MA 3A35 plus complement; after 3 days of culture with the stimulatory antigen, they became highly sensitive but their sensitivity then diminished and mature CTL were completely resistant. MA 3A35 plus complement also killed the activated T cells which responded to macrophage-presented antigens and were thought to be mainly Lyt-l+. Therefore, the epitope identified by MA 3A35 was expressed predominantly at an early stage of T-cell activation. At a late stage, it persisted almost exclusively on helper and Lyt-1' cells. In addition, MA 3A35 plus complement Iysed NK cells, AK cells, and their precursors present in normal spleen. In the absence ofcomplement, MA 3A35 had no detectable effect on T-cell functions. 0 1987 Academic PXSS, IX. ' This work was supported by the F&&ration Nationale des Centres de Lutte contre le Cancer.
Similarities in sequences and cellular expression between rat CD2 and CD4 antigens
Journal of Experimental Medicine, 1987
The MRC OX-34 mouse mAb was raised against rat T blasts and was found to label all T lymphocytes and most thymocytes but not B lymphocytes (1) . The OX-34 antigen had an apparent mol wt of 50,000 (1), and it seemed possible that it was the rat equivalent of human CD2 (T11) antigen (2-4). However, 0X-34 mAb labeled many more cells in rat spleen than could be accounted for by T lymphocytes (1), a property not described for human CD2 (2-4).
Immunology
We produced three murine monoclonal antibodies (mAb) directed against the human T-cell differentiation antigen CD2 (formerly T11) and analysed their epitope specificity by E-rosette inhibition, cross-blocking and proliferation-induction experiments. When added together, two mAb (both IgG1 kappa) were able to induce proliferation in peripheral blood T cells. This proliferation was found to be strictly dependent on the presence of monocytes. The polymorphism of Fc receptors (FcR) expressed on human monocytes for murine IgG1 antibodies, which is readily demonstrable in anti-CD3-induced T-cell activation, was not found in the anti-CD2-driven system. Moreover, mAb directed against the 40,000 MW FcRII were unable to inhibit proliferation induced by the mitogenic anti-CD2 combination. Still, F(ab')2 fragments of the mitogenic anti-CD2 antibody combination could not initiate T-cell mitogenesis, despite their ability to induce a rise in the free intracellular [Ca2+]. The contributions of...
A monoclonal antibody to human B lymphoblastoid cells activates human and murine T lymphocytes
Cellular immunology, 1989
A B lymphoblastoid cell line can provide a comitogenic, accessory signal for mitogen-treated T cells. In a study evaluating the antigenic determinant of such cells that mediate this effect, a monoclonal antibody (I57) was raised against the Daudi cell line. This antibody was found to interact with a 30-kDa protein on these cells and had agonistic properties. It enhanced the B lymphoblastoid accessory cell and interleukin 1 (IL-1)-dependent stimulation of PHA-treated murine thymocytes. The stimulatory effect of I57 on PHA-treated thymocytes was more pronounced at high, supraoptimal concentrations of the lectin. This was in contrast with the effect of IL-1 that failed to stimulate these cells treated with PHA at high concentrations. I57 also enhanced stimulation of thymocytes treated with IL-2 alone or with both PHA and IL-2. I57 exhibited by itself mitogenic activity for human T cells. These cells, treated with IL-2, were further stimulated by I57. I57 seems to be different from othe...
Expression and ontogeny of murine CD2
European Journal of Immunology, 1989
Expression and ontogeny of murine CD2* CD2 was first defined as the erythrocyte rosetting protein on the surface of human T cells. Recently, the rat and murine homologues have been identified by cDNA cloning. In this report we demonstrate that CD2 is expressed on the surface of most adult murine peripheral lymphocytes and thymocytes by indirect immunofluorescence using an anti-murine CD2 antiserum. The expression of CD2 on murine B cells was unexpected since in rat and human species it has been defined as a T cell-specific marker. Furthermore, CD2 appears very early on fetal thymocytes during development. The level of surface expression increases from day 13 of gestation to day 17, after which the surface density appears to reach a steady state. Thus, CD2 is expressed on day-13 thymocytes at the same stage that Thy-1, Pgpl and the TcRy/6/ CD3 complex have been shown to be expressed.