TCR- and IL-1-mediated co-stimulation reveals an IL-4-independent way of Th2 cell proliferation.
Previously, it has been shown that Th1 cells, when triggered solely via their TCR, are blocked from proliferation in response to IL-2. Herein, we describe a similar characteristic for Th2 cells in that immobilized mAb directed to the TCR blocked proliferation of Th2 cells in response to IL-4. This "proliferative block' was observed in all four Th2 cell clones tested, but not in a subline of one of the clones which has been cultured in vitro for several years. Addition of IL-1 neutralized the proliferative block in all four Th2 cell clones. Surprisingly, blocking experiments with sIL-4R and anti-IL-4 mAb revealed that in three out of four Th2 cell clones this effect of IL-1 was IL-4-independent and could also not be blocked by cyclosporin A (CsA). In contrast, the proliferation of one Th2 cell clone in response to the TCR- and IL-1-mediated signals was indeed inhibited by sIL-4R, anti-IL-4 mAb and CsA. Thus, our data illustrate that in addition to the well-known IL-4-dependent proliferation, there also exists an IL-4-independent, IL-1-mediated way of Th2 cell proliferation.
Huber
M
M
Institute of Clinical Microbiology and Immunology, University of Erlangen-Nürnberg, Germany.
Rutherford
A
A
Meister
W
W
Weiss
A
A
Röllinghoff
M
M
Lohoff
M
M
D000818:Animals; D002455:Cell Division; D002999:Clone Cells; D016572:Cyclosporine / Q000494:pharmacology; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D015847:Interleukin-4 / Q000494:pharmacology*; D008213:Lymphocyte Activation; D051379:Mice; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D011994:Recombinant Proteins / Q000494:pharmacology; D015398:Signal Transduction; D018418:Th2 Cells / Q000166:cytology / Q000276:immunology*
D007375:Interleukin-1; D011948:Receptors, Antigen, T-Cell; D011994:Recombinant Proteins; D015847:Interleukin-4; D016572:Cyclosporine