Multiple cytokine secretion by IL-7-stimulated human T cells.
The induction of cytokine secretion by human peripheral blood (PB) T cells was examined. Highly purified T cells stimulated with interleukin 7 (IL-7), in the absence of co-mitogen, secreted IL-2, IL-4, IL-6 and interferon gamma (IFN-gamma) upon restimulation with phorbol ester and ionomycin. In contrast, induction of T-cell cultures initiated with IL-2 or IL-4 yielded only low levels of IL-6 and virtually undetectable levels of IL-4 or IFN-gamma, while IL-2 secretion was reduced. No difference was seen in the ability of CD4+ and CD8+ subpopulations, grown in IL-7, to produce cytokines. In contrast, subdivision of T cells into memory and naive populations using the CD45RO monoclonal antibody (mAb) UCHL1, revealed that almost all of the potential to secrete IL-4 and IL-6 in response to IL-7 resided in the CD45RO+ memory population. Stimulation of cytokine-secreting cells appeared to be a direct effect of IL-7 as neutralizing antibodies directed against IL-2 and IL-4 had no effect on the levels of cytokines produced. The differences observed in the ability of IL-2, IL-4, and IL-7 to potentiate cytokine production was supported by measurement of cytokine mRNA levels by PCR. The elevated levels of cytokine secretion seen in cells cultured with IL-7 was not due simply to increased viability in these cultures compared with those containing IL-2 or IL-4, as these populations showed comparable cloning frequencies in phytohemagglutinin (PHA) + IL-2. These results demonstrate that IL-7, in the absence of co-mitogen, is a potent initial stimulus for multiple cytokine production by human T cells upon restimulation.
Armitage
R J
RJ
Immunex Research and Development Corporation, Seattle, Washington 98101.
Macduff
B M
BM
Ziegler
S F
SF
Grabstein
K H
KH
D016207:Cytokines / Q000235:genetics / Q000378:metabolism*; D004247:DNA / Q000235:genetics; D015342:DNA Probes; D015870:Gene Expression; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000378:metabolism; D007376:Interleukin-2 / Q000378:metabolism / Q000494:pharmacology; D015847:Interleukin-4 / Q000378:metabolism / Q000494:pharmacology; D015850:Interleukin-6 / Q000378:metabolism; D015851:Interleukin-7 / Q000494:pharmacology*; D007700:Kinetics; D008969:Molecular Sequence Data; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism
D016207:Cytokines; D015342:DNA Probes; D007376:Interleukin-2; D015850:Interleukin-6; D015851:Interleukin-7; D015847:Interleukin-4; D007371:Interferon-gamma; D004247:DNA