Selective stimulation of human thymocyte subpopulations by recombinant IL-4 and IL-3.
Human thymocytes and thymocyte subsets were examined for their proliferative response to recombinant interleukin-4 (IL-4) and interleukin-3 (IL-3) in serum-free cultures. IL-4 induced marked proliferation of thymocytes after PHA and TPA stimulation, in contrast to the marginal response of T cells from adult peripheral blood. However, depletion of thymocytes bearing the CD3 antigen diminished the IL-4-induced proliferation of thymocytes, indicating that the response of thymocytes to IL-4 is mainly mediated by the CD3-positive cells. Phenotypic changes after culture with IL-4 showed an increase in the percentage of total thymocytes expressing mature T cell antigens (CD3, CD5, and TCR-1) and a decrease in CD1-positive cells. In addition there was an increase in the percentage of CD4+8- cells in both nylon wool-separated thymocytes and CD3-depleted cells with the disappearance of most of the CD4+8+ cells. However, an increase in the percentage of CD4-8- cells was also observed. The IL-4-responding cells do, however, express the mature T cell antigen, CD5, in high density. The effect of IL-3 on the proliferation of human thymocytes was very low and detected only when the thymocytes were cultured in serum-free medium. Depletion of CD3-positive cells did not diminish the IL-3-mediated proliferation of thymocytes, indicating that IL-3-responsive thymocytes are more immature than the subset of thymocytes which responds to IL-4. These results suggest that IL-4 and IL-3 play different roles in the development of human T cells.
Department of Microbiology, UCLA School of Medicine 90024.
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Ueno
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Boone
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Uittenbogaart
D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D002675:Child, Preschool; D003470:Culture Media; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000494:pharmacology; D007377:Interleukin-3 / Q000494:pharmacology*; D015847:Interleukin-4; D007378:Interleukins / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000145:classification* / Q000166:cytology; D013950:Thymus Gland / Q000166:cytology*
D000945:Antigens, Differentiation, T-Lymphocyte; D003470:Culture Media; D007376:Interleukin-2; D007377:Interleukin-3; D007378:Interleukins; D015847:Interleukin-4