IL-4 (B cell stimulatory factor 1) exhibits thymocyte growth factor activity in the presence of IL-2.
The proliferative activity of thymocytes cultured with IL-2 and submitogenic concentrations of PHA is increased by 3- to 10-fold in the presence of IL-4. In contrast, IL-4 alone is unable to induce proliferative activity in thymocyte cultures and its synergistic activity is only apparent to concentrations of IL-2 above 1 U/ml. The costimulatory activity of IL-4 is abrogated by the monoclonal anti-IL-4 antibody 11B11. Furthermore, potentiation of the IL-2-mediated thymocyte proliferation is not seen with IL-1, IL-3, IFN-gamma, and granulocyte-macrophage CSF. Thymocytes are at least as responsive to IL-4 as B cells and the IL-4 costimulatory activity in fractionated thymocytes appears to be restricted mainly to the Lyt-2+/L3T4- population. In contrast, purified resting mature T cells do not respond to IL-4 plus IL-2, although they did proliferate in response to IL-4 in combination with PMA. These findings indicate that thymocytes and mature T cells are responsive to the costimulatory activity of IL-4 under quite different conditions, and that IL-4 may play an important role in thymocyte maturation in the thymus.
Carding
S R
SR
Department of Pathology, Howard Hughes Medical Institute, New Haven, CT 06510.
Bottomly
K
K
D000818:Animals; D000911:Antibodies, Monoclonal / Q000502:physiology; D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly; D001402:B-Lymphocytes / Q000276:immunology; D002454:Cell Differentiation / Q000187:drug effects; D002470:Cell Survival; D004306:Dose-Response Relationship, Immunologic; D004357:Drug Synergism; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D007166:Immunosuppressive Agents / Q000502:physiology; D007376:Interleukin-2 / Q000494:pharmacology*; D015847:Interleukin-4; D007378:Interleukins / Q000276:immunology / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000145:classification / Q000166:cytology* / Q000276:immunology
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000950:Antigens, Ly; D000949:Histocompatibility Antigens Class II; D007166:Immunosuppressive Agents; D007376:Interleukin-2; D007378:Interleukins; D015847:Interleukin-4