The effect of IL-18 on IL-12-induced CD30 expression and IL-4 and IFN-gamma production by allergen and PPD specific T cells.
CD30 is expressed on activated T cells that, as has been suggested, preferentially produce IFN-gamma. Interleukin 12 increases antigen-induced CD30 expression on T cells and IFN-gamma production. Synthesis of IFN-gamma can be augmented further by IL-18. The aim of our study was to investigate whether IL-18 affects the IL-12 induced CD30 expression and cytokine production by allergen or PPD specific T cells. Mononuclear cells of healthy or atopic volunteers were stimulated with PPD or allergen, respectively, to obtain specific T cell lines. T cells were restimulated with appropriate antigen and antigen-presenting cells in the presence of IL-12, IL-18 or a combination of these cytokines. After 3 days, expression of CD30 was investigated on CD4 and CD8 T cells and IFN-gamma and IL-4 cytokine production was estimated in the culture supernatants. Flow cytometric analyses showed no effect of IL-18 on CD30 expression during IL-12 co-stimulation. At the same time after the optimal stimulation for CD30 expression, the levels of IFN-gamma were high in PPD-stimulated cell lines but have not been up-regulated by IL-18. IFN-gamma levels were much lower in allergen-stimulated T cells and although they were up-regulated by IL-12 there was no additional or synergistic effect from IL-18. IL-18, however, increased production of IL-4 in allergen-stimulated cell lines. Our studies provide new information about IL-18 activity on human cells and question its exclusive role in Th1 mediated responses.
Tarkowski
M
M
Institute of Occupational Medicine, Department of Immunotoxicology, Lodz and Institute of Paediatrics, Medical University of Lodz, Poland. maciekt@excite.com
Chrul
S
S
Bodalski
J
J
D000485:Allergens / Q000276:immunology; D002478:Cells, Cultured; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology* / Q000378:metabolism; D018664:Interleukin-12 / Q000276:immunology* / Q000494:pharmacology; D020382:Interleukin-18 / Q000276:immunology* / Q000494:pharmacology; D015847:Interleukin-4 / Q000276:immunology* / Q000378:metabolism; D017730:Ki-1 Antigen / Q000096:biosynthesis / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D009504:Neutrophils / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D014373:Tuberculin / Q000276:immunology
D000485:Allergens; D020382:Interleukin-18; D017730:Ki-1 Antigen; D014373:Tuberculin; D018664:Interleukin-12; D015847:Interleukin-4; D007371:Interferon-gamma