Tumor necrosis factor-alpha and interleukin 6 synergistically induce T cell growth.
T cells stimulated with phytohemagglutinin are dependent on monocyte-derived helper signals (e.g. interleukin (IL) 6 and IL 1) for their proliferation. In the present study the effect of recombinant tumor necrosis factor alpha (rTNF-alpha) as a helper signal for growth of highly purified peripheral blood human T cells stimulated with phytohemagglutinin was examined. TNF-alpha alone had a weak co-stimulatory effect, while a combination of TNF-alpha and IL 6 provided highly effective synergistic helper signals for T cell proliferation. The effect of TNF-alpha could not be ascribed to secondary induction of IL 1 production. The effect of TNF-alpha on T cell proliferation was also found to be independent of the autocrine T cell growth factors IL 2 and IL 4. This latter points to dissimilarity between IL 1 and TNF-alpha in the mechanism by which each of these two cytokines in combination with IL 6 promotes T cell proliferation. TNF-alpha, IL 6 and IL 1 thus seem to follow different pathways in their function as helper signals in T cell activation.
Kuhweide
R
R
Department of Medicine, University of Leuven, Belgium.
Van Damme
J
J
Ceuppens
J L
JL
D000328:Adult; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis / Q000502:physiology; D007376:Interleukin-2 / Q000502:physiology; D015847:Interleukin-4 / Q000502:physiology; D015850:Interleukin-6 / Q000096:biosynthesis / Q000502:physiology*; D008213:Lymphocyte Activation / Q000187:drug effects / Q000502:physiology; D008875:Middle Aged; D010835:Phytohemagglutinins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000166:cytology*; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*
D007375:Interleukin-1; D007376:Interleukin-2; D015850:Interleukin-6; D010835:Phytohemagglutinins; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4