In situ hybridization of interferon-gamma producing peripheral blood mononuclear cells.
Individual interferon-gamma (IFN-gamma) producing cells in activated human peripheral blood mononuclear cells (PBMC) were characterized by in situ hybridization using [35S]-labelled antisense RNA probes. The proportion of positive cells expressing IFN-gamma mRNA varied according to the substances used for stimulation. IFN-gamma mRNA expressed a relatively low percentage of 1-8% PBMC after a single stimulus with mitogens or OKT-3 antibody and 20-30% of the cells were identified to synthesize IFN-gamma mRNA after stimulation with PHA + P-MA + OKT-3 antibody. The expression of IFN-gamma mRNA and production of the lymphokine was dependent on accessory cells. If accessory cells were replaced by recombinant interleukin-1 (IL-1) plus interleukin-6 (IL-6), then T-cell proliferation to phytohaemagglutinin (PHA) could be partially restored and measurable amounts of IFN-gamma were detected. The addition of interleukin-2 (IL-2) or phorbol-12-myristate-13-acetate to T cells stimulated with PHA, IL-1 and IL-6 did not restore the production of IFN-gamma to an extent comparable to that produced by T cells stimulated in the presence of accessory cells. In further studies, depletion of T-cell subsets showed that CD3+, CD4+, CD8+, CD29+ and CD45RA+ cells were involved in IFN-gamma production after mitogenic stimulation. In conclusion, our data demonstrate that IFN-gamma production is dependent on signals from accessory cells and IFN-gamma is synthesized by only a small proportion of T cells, that did not belong to a unique population, characterized by conventional cellular surface antigens.
Rutenfranz
I
I
Institute of Experimental Immunology, University of Marburg, Germany.
Kruse
A
A
Kirchner
H
H
D015152:Blotting, Northern; D002469:Cell Separation; D016207:Cytokines / Q000494:pharmacology; D004768:Enterotoxins / Q000494:pharmacology; D015870:Gene Expression; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000235:genetics; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D010835:Phytohemagglutinins / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D016207:Cytokines; D004768:Enterotoxins; D010835:Phytohemagglutinins; D012333:RNA, Messenger; C031818:enterotoxin B, staphylococcal; D007371:Interferon-gamma; D013755:Tetradecanoylphorbol Acetate