Differential induction of cytokine-specific mRNA in human PBL after in vitro culture with either IL2 or IL4.
The present study was designed to investigate whether human equivalents of murine T helper cell subsets can be demonstrated by propagation of peripheral blood lymphocytes (PBL) with either recombinant human (rh) interleukin (IL) 2 or rhIL4 in the presence of neutralising antibodies. Cells of both cultures, termed T-IL2 or T-IL4, respectively, were challenged on day 8 using a combination of phorbol-12-myristate-13-acetate (PMA) and the Ca2(+)-ionophore A23187 (Io). Total cellular RNA was isolated at different time points after PMA/Io-stimulation and the expression of 7 distinct cytokine genes was assessed by Northern analysis. Whereas maximal accumulation of mRNA species for IL2, GM-CSF, TNF alpha and TNF beta did not reveal major differences between cells of T-IL2 and T-IL4 cultures, substantial differences emerged for the induction of IFN gamma and IL3 messages. Accumulation of IFN gamma-mRNA consistently was 2- to 13-fold higher in T-IL2 than in T-IL4 cells, depending on the time point of RNA harvest. In contrast, IL3-specific mRNA levels induced in T-IL4 cells were 2-5 times greater than those in T-IL2. If PBL cultured with IL2 for 7-8 days were subsequently shifted to IL4 and further propagated until day 14, the mRNA induction pattern seen for IFN gamma and IL3 was similar to that obtained if cells had continuously been propagated with IL2. Collectively, these results indicate a selective outgrowth of distinct responder phenotypes by IL2 or IL4 rather than a direct modulation of cytokine expression by these factors.
Kalthoff
F S
FS
Sandoz Research Institute Ges.m.b.H., Department of Immunopharmacology, Vienna, Austria.
Rossiter
H
H
Liehl
E
E
D015152:Blotting, Northern; D002478:Cells, Cultured; D016207:Cytokines / Q000235:genetics*; D015342:DNA Probes; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D016130:Immunophenotyping; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000235:genetics; D007376:Interleukin-2 / Q000235:genetics / Q000276:immunology*; D007377:Interleukin-3 / Q000235:genetics; D015847:Interleukin-4 / Q000235:genetics / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D012333:RNA, Messenger / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology
D016207:Cytokines; D015342:DNA Probes; D007376:Interleukin-2; D007377:Interleukin-3; D012333:RNA, Messenger; D011994:Recombinant Proteins; D015847:Interleukin-4; D007371:Interferon-gamma