Increased cell surface expression of histocompatibility class II I-A(d) in c-fos transfected clones of the P388D1 murine macrophage cell line.
Numerous biological functions of the monocyte-macrophage lineage are affected by the presence of immunomodulators. Enhancement in transcription of c-fos has been shown in the murine P388D1 macrophage line treated by LPS, TPA, Ca++ ionophore or dibutyryl cAMP. In order to study the effects of an increased c-Fos protein level on macrophage functions, we previously have established stable c-fos-overexpressing clones in the P388D1 cell line. Here we report that the expression of class II MHC antigens (I-A(d) antigen) is increased in these clones, particularly after IFN-gamma treatment. No variation in the cell surface expression of IFN-gamma receptor was observed. The increase of I-A(d) cell surface expression was well correlated with the level of I-A(d) mRNA. No inducible NO synthase activity and no increase of TNF-alpha release were observed in c-fos transfected cells. A slight increase of the basal expression of the main class II MHC transcription factor CIITA which is further amplified by IFN-gamma treatment, was observed in the c-Fos overexpressing clones. This suggests that the increased I-A(d) expression in clones could result from a transactivating action of the c-Fos protein on the CIITA factor.
Laboratoire d'histologie cytogénétique, CHU Cochin-Port-Royal, 24, rue du Faubourg-Saint-Jacques, 75014 Paris, France.
Y
Y
Le Garrec
E
E
Rouer
F
F
Conti
P
P
Michel
A
A
Pompidou
D000818:Animals; D015152:Blotting, Northern; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D016762:Genes, fos; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000378:metabolism*; D008264:Macrophages / Q000201:enzymology / Q000378:metabolism*; D051379:Mice; D019001:Nitric Oxide Synthase / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017471:Receptors, Interferon / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D000096743:Interferon gamma Receptor
D000949:Histocompatibility Antigens Class II; D019001:Nitric Oxide Synthase; D012333:RNA, Messenger; D017471:Receptors, Interferon; D000096743:Interferon gamma Receptor; C111389:I-Ad antigen