Tac antigen-positive T cells activated in autologous mixed lymphocyte reaction regulate the generation of killer T cells against hapten-modified autologous cells.
T cells that proliferate in the autologous mixed lymphocyte reaction (auto-MLR) have been shown to acquire some suppressor or regulatory activities. In the present study, we examined the suppressive effects of T cells activated in the auto-MLR on the induction of hapten-specific cytotoxic T cells. NRFT (depletion of ARFT from UT) were used as the responder cells of TNP-MLR. After primary and secondary TNP-MLR, the cells were harvested and tested for their cytotoxic activities against TNP-modified autologous cells by 51Cr-release assay. When UT cells cultured for 1 wk in auto-MLR were added to primary TNP-MLR at the beginning of culture, the cytotoxic activity tested at the end of the culture was suppressed from 15.6% +/- 2.7 to 5.8% +/- 1.1 (percent cytotoxicity, mean +/- SE). However, these auto-MLR-activated UT cells had little suppressive activity against cytotoxic T cells when they were added to the final assay of TNP-CTR. Suppressive activities of these cells on the generation of cytotoxic T cells during secondary TNP-MLR were also tested. The addition of auto-MLR-activated UT cells to the secondary TNP-MLR at the beginning of the culture reduced the cytotoxic activities of NRFT from 23.8% +/- 2.3 to 9.7% +/- 1.7 after secondary TNP-MLR. Allo-activated T cells, PHA blasts, and fresh autologous T cells were used as the controls, but none of the cells had suppressive effects on the generation of CTL. Characteristics of these suppressor cells were examined. Auto-MLR-activated cells from ARFT fractions exhibit very powerful suppressor activity. Treatment of the auto-MLR-activated T cells with mitomycin C eliminated their suppressive effects on the generation of CTL; 21.2% +/- 6.3 of UT cells became anti-Tac positive after 1 wk of auto-MLR. Treatment of auto-MLR-activated UT cells with anti-Tac antibody plus complement eliminated their suppressive activities on the induction of CTL. Thus, T cells stimulated in auto-MLR were shown to have suppressive effects on the induction of cytotoxic T cells against TNP-modified autologous cells. These cells were mitomycin C sensitive. Because anti-Tac antibody is reactive to activated T cells, activation of T cells during auto-MLR was thought to be necessary for the acquisition of the suppressive activity.
Kumagai
S
S
Namiuchi
S
S
Ozaki
S
S
Sano
H
H
Tsubata
T
T
Suginoshita
T
T
Imura
H
H
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000276:immunology*; D002469:Cell Separation; D003165:Complement System Proteins / Q000502:physiology; D003602:Cytotoxicity, Immunologic; D005434:Flow Cytometry; D006241:Haptens / Q000276:immunology*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014302:Trinitrobenzenesulfonic Acid / Q000276:immunology; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D006241:Haptens; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D014302:Trinitrobenzenesulfonic Acid; D003165:Complement System Proteins