Effect of total lymphoid irradiation on natural killer cells and cytotoxic and primed T lymphocytes.
Total lymphoid irradiation (TLI), which results in prolonged depression of the number and function of T and B cells, augments the natural killer (NK) cell activity. Small doses of irradiation (200-400 cGy) in vitro did not reduce the lytic activity of TLI-induced NK cells, whereas irradiation with 1,500 and 3,000 cGy decreased NK function by 50-70%. Addition of TLI spleen cells, containing a high proportion of large mononuclear cells, to cytotoxic T lymphocytes (CTL), generated in vitro by one-way mixed lymphocyte reaction and tested against 51Cr labeled target cells, suppressed the lytic activity 27-57% of that observed following the addition of normal spleen cells. The suppressive effect induced by spleen cells of TLI-treated mice was H2 nonrestrictive. Primed T lymphocytes (PTL) stimulated with irradiated allogeneic cells were inhibited by cocultured TLI spleen cells, causing inhibition of 57% as measured by secondary proliferative response and 86% inhibition by primary response to a third strain of cells. Our results, together with previously published data, indicate that TLI-induced suppressor cells inhibit the generation of PTL and CTL. Secondary proliferative responses of T cells primed to alloantigens are suppressed, as is the lysis of target cells by CTL. All suppressive phenomena presented here are antigen nonspecific.
Weiss
L
L
Department of Bone Marrow Transplantation, Hadassah University Hospital, Jerusalem, Israel.
Slavin
S
S
D000818:Animals; D001853:Bone Marrow / Q000528:radiation effects; D001854:Bone Marrow Cells; D003602:Cytotoxicity, Immunologic / Q000528:radiation effects*; D007694:Killer Cells, Natural / Q000528:radiation effects*; D008221:Lymphoid Tissue / Q000528:radiation effects*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D011829:Radiation Dosage; D013154:Spleen / Q000166:cytology / Q000528:radiation effects; D013602:T-Lymphocytes, Cytotoxic / Q000528:radiation effects*; D014407:Tumor Cells, Cultured