Identification of a cord blood T cell subset of CD3+4-8-45R+ suppressing interleukin 2 production in the autologous mixed lymphocyte reaction and the mode of action of exogenous IL2 in the induction of IL2 production.
As previously reported, the inability of cord blood T cells to produce IL2 in the autologous mixed lymphocyte reaction (AMLR) could be recovered by the treatment of stimulator non-T cells with interferon-gamma (IFN-gamma) and of the AMLR with exogenous IL2. In the present study, we showed that addition of untreated autologous cord blood T cells to the above-mentioned AMLR abrogated the IL2 production in a dose-dependent manner, suggesting active suppression by the untreated T cells because untreated cord blood T cells did not consume IL2. Suppressor activity was abrogated by the treatment of cord blood T cells with monoclonal anti-CD3 antibody plus complement or with monoclonal anti-CD45R (Leu 18) antibody, but not by the treatment with monoclonal anti-CD4 antibody and/or anti-CD8 antibody plus complement. These data showed that the cord blood suppressor T cells were CD3+4-8-45R+. This suppressor activity also disappeared by culturing with rIL2 for 8 hr. As the frequency of CD45R+ cord blood T cells was comparable to that of CD45R+ adult T cells and was minimally affected by the IL2 treatment, functional modulation of CD45R+ suppressor T cells by IL2 is suggested. Moreover, in spite of the inhibitory effect of anti-CD45R antibody on the suppressor activity, IL2 production was not induced merely by addition of anti-CD45R antibody directly to the responder cells in AMLR. Taken together, these data suggest the requirement of exogenous IL2 for IL2 production in that IL2-producing-precursor T cells themselves should be stimulated by IL2 in addition to the modulation of CD45R+ suppressor T cells by IL2.
Kawano
Y
Y
Department of Pediatrics, Saitama Medical School.
Noma
T
T
Yata
J
J
D000328:Adult; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000032:analysis; D000943:Antigens, Differentiation / Q000032:analysis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D017252:CD3 Complex; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens; D005312:Fetal Blood / Q000166:cytology* / Q000276:immunology; D006649:Histocompatibility Antigens / Q000032:analysis; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis* / Q000494:pharmacology; D017493:Leukocyte Common Antigens; D007959:Lymphocyte Culture Test, Mixed; D011948:Receptors, Antigen, T-Cell / Q000032:analysis; D016176:T-Lymphocyte Subsets / Q000502:physiology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D050378:T-Lymphocytes, Regulatory / Q000502:physiology*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D015704:CD4 Antigens; D016827:CD8 Antigens; D006649:Histocompatibility Antigens; D007376:Interleukin-2; D011948:Receptors, Antigen, T-Cell; D017493:Leukocyte Common Antigens