Interferon gamma upregulates its own gene expression in mouse peritoneal macrophages.
Interferon gamma (IFN-gamma) exerts a variety of immunoregulatory effects on several cell targets. It is generally assumed that IFN-gamma is specifically produced by T and large granular lymphocytes. In this study, we show that IFN-gamma is constitutively expressed in resting mouse peritoneal macrophages (PM). Treatment of PM with cycloheximide results in a significant accumulation of IFN-gamma mRNA, suggesting that a short-lived IFN-gamma mRNA accumulates when protein synthesis is inhibited. Moreover, treatment of PM with IFN-gamma also results in a clear-cut accumulation of this mRNA. This effect is not observed in murine lymphocytes from mesenteric lymph nodes (which instead produce IFN-gamma after phytohemagglutinin treatment) and in mouse cell lines. The treatment of PM with IFN-gamma also results in secretion of IFN-gamma after 24-48 h. The upregulation of IFN-gamma expression is also found in PM from anti-asialo GM1-treated nude mice. We suggest that the ability of PM to produce this IFN-gamma is indicative of an autocrine mechanism. The macrophage IFN-gamma may play a role in the regulation of cell differentiation and immune response.
Di Marzio
P
P
Department of Virology, Istituto Superiore di Sanita, Rome, Italy.
Puddu
P
P
Conti
L
L
Belardelli
F
F
Gessani
S
S
D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D004247:DNA; D005786:Gene Expression Regulation; D007371:Interferon-gamma / Q000235:genetics* / Q000502:physiology; D017737:Macrophages, Peritoneal / Q000166:cytology / Q000378:metabolism*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D008819:Mice, Nude; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D015854:Up-Regulation
D007371:Interferon-gamma; D004247:DNA