Generation of rat Th2-like cells in vitro is interleukin-4-dependent and inhibited by interferon-gamma.
Differentiation of naive T cells into effector cells producing T helper type 1 (Th1) and Th2 cytokines is regulated by the presence of specific cytokines in the T-cell microenvironment. The effect of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) on Th1- and Th2-like cell development was investigated in cultures of mixed rat spleen cells. These cells were cultured for 4 days in medium containing concanavalin A (Con A) with or without additional IL-2, IFN-gamma or IL-4. The cells were then washed and their capacity to produce IL-4, IL-5 and IFN-gamma determined following stimulation with phorbol 12-myristate 13-acetate (PMA) and ionomycin. Freshly isolated cells stimulated with PMA and ionomycin expressed detectable levels of IL-4 and IL-5 mRNA as measured by a quantitative polymerase chain reaction (PCR) procedure and much higher levels of IFN-gamma mRNA. Cells cultured with Con A for 4 days, washed, and restimulated with PMA + ionomycin were unable to express detectable levels of IL-4 and IL-5 mRNA, but produced high levels of IFN-gamma mRNA. Addition of IL-4, or anti-IFN-gamma antibody, to Con A-driven splenocyte cultures restored the ability of restimulated cells to express IL-4 and IL-5. CD4+ T cells isolated from these cultures also showed an increased capacity to secrete IL-4 and IL-5 when anti-IFN-gamma and IL-4 were present in the culture medium. When cultured for 4 days with Con-A, IL-4 and anti-IFN-gamma splenocytes showed an increased capacity to proliferate in response to recombinant IL-2 and proliferated in response to IL-4 alone. IL-2 had no effect on cytokine production by cultured splenocytes. These results indicate that: (1) IL-4 is essential for the generation of Th2-like cells; (2) IFN-gamma inhibits IL-4 production by mixed spleen cells and suppresses generation of IL-4 responsive T cells; (3) in mixed spleen cell cultures mitogenic stimulation favours differentiation of naive rat T cells into effector cells expressing a Th1, and not Th2, cytokine profile.
Noble
A
A
Department of Allergy and Allied Respiratory Disorders, United Medical School, Guy's Hospital, London, U.K.
Staynov
D Z
DZ
Kemeny
D M
DM
D000818:Animals; D001483:Base Sequence; D002455:Cell Division; D002478:Cells, Cultured; D003208:Concanavalin A / Q000276:immunology; D016207:Cytokines / Q000276:immunology*; D005260:Female; D016898:Interferon-alpha / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology*; D015847:Interleukin-4 / Q000276:immunology*; D015848:Interleukin-5 / Q000276:immunology; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats
D016207:Cytokines; D016898:Interferon-alpha; D015848:Interleukin-5; D012333:RNA, Messenger; D003208:Concanavalin A; D015847:Interleukin-4; D007371:Interferon-gamma