Two regions of the H-2 Dd promoter are responsive to dimethylsulfoxide in line 1 cells by a mechanism distinct from IFN-gamma.
The line 1 lung carcinoma is a spontaneous BALB/c tumor deficient in class I Ag expression at the protein and mRNA levels. Exposure of line 1 cells to 3% DMSO or IFN-gamma increases class I Ag protein and mRNA dramatically. We have examined the regulation of class I Ag induction by DMSO in line 1 cells. We found DMSO induces class I Ag expression in line 1 cells by a mechanism distinct from IFN, because the kinetics of class I Ag induction by these agents were dramatically different, 7 days vs 3 days, and DMSO did not act through an IFN second messenger. At the molecular level, class I H chain transcription in line 1 cells was low. Treatment with 3% DMSO or IFN-gamma increased H chain transcription four-fold and sevenfold, respectively, indicating that class I H chain expression is regulated at the level of transcription in line 1 cells. Using reporter gene constructs, we mapped the regions in the Dd H chain promoter that increase H chain expression after DMSO treatment of line 1 cells. Two regions of the Dd promoter, D1, from -210 to -133 bp, and D2, from -125 to -61 bp, were found to be independently responsive to DMSO. These regions were also responsive to IFN-gamma in line 1 cells. However, consistent with our cellular results, DMSO and IFN induction of class I H chain expression differed at the molecular level as determined by D1 point mutations that diminished IFN-gamma responsiveness but did not alter induction by DMSO. Thus, DMSO appears to regulate class I transcription through multiple regions of the class I H chain promoter in line 1 cells by a mechanism distinct from IFN-gamma.
Cerosaletti
K M
KM
Cancer Center Immunology Unit, University of Rochester School of Medicine and Dentistry, NY 14642.
Woodward
J G
JG
Lord
E M
EM
Frelinger
J G
JG
D000818:Animals; D001483:Base Sequence; D015500:Chloramphenicol O-Acetyltransferase / Q000032:analysis / Q000235:genetics; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D006183:H-2 Antigens / Q000096:biosynthesis / Q000235:genetics*; D064532:Histocompatibility Antigen H-2D; D007371:Interferon-gamma / Q000494:pharmacology*; D008175:Lung Neoplasms / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic / Q000187:drug effects; D014407:Tumor Cells, Cultured
D006183:H-2 Antigens; D064532:Histocompatibility Antigen H-2D; D007371:Interferon-gamma; D015500:Chloramphenicol O-Acetyltransferase; D004121:Dimethyl Sulfoxide