Deficits in T helper cells after total lymphoid irradiation (TLI): reduced IL-2 secretion and normal IL-2 receptor expression in the mixed leukocyte reaction (MLR).
Spleen cells from BALB/c mice treated with total lymphoid irradiation (TLI) and from normal, unirradiated mice were compared in the mixed leukocyte reaction (MLR). Although the percentage of CD4+ cells in the spleen was close to normal, 4 to 6 weeks after TLI, the MLR of unfractionated spleen cells from irradiated mice was more than 10-fold lower than controls. A similar reduction was observed when purified CD4+ cells were used as responders in the MLR. Secretion of IL-2 by cells from irradiated mice was also about 10-fold lower than controls. However, the percentage of CD4+ and CD8+ cells which expressed IL-2 surface receptors during the MLR was similar using spleen cells from irradiated and control mice. Addition of an exogenous source of IL-2 restored the proliferative capacity of the irradiated cells and suggests that the lack of IL-2 secretion is the likely explanation of the marked deficit in the MLR of CD4+ spleen cells after TLI.
Bass
H
H
Department of Medicine, Stanford University School of Medicine, California 94305.
Strober
S
S
D000818:Animals; D015704:CD4 Antigens / Q000032:analysis; D007376:Interleukin-2 / Q000378:metabolism* / Q000494:pharmacology; D007959:Lymphocyte Culture Test, Mixed; D008221:Lymphoid Tissue / Q000528:radiation effects*; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D015375:Receptors, Interleukin-2 / Q000032:analysis*; D011994:Recombinant Proteins / Q000494:pharmacology; D013154:Spleen / Q000276:immunology / Q000528:radiation effects; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology / Q000528:radiation effects*
D015704:CD4 Antigens; D007376:Interleukin-2; D015375:Receptors, Interleukin-2; D011994:Recombinant Proteins