The Pmed1 gene promoter of human Fc gamma RIIIA can function as a NK/T cell-specific restriction element, which involves binding of Sp1 transcription factor.
The low-affinity receptor for IgG (human FcgammaRIIIA) is selectively expressed by a subset of T lymphocytes, NK cells, and macrophages. To understand the mechanisms underlying this pattern of cell type-specific expression, we initially identified alternative promoters, Pmed1/2 and Pprox, in the 5' end of the FcgammaRIIIA gene. In this study, we focused on the Pmed1 promoter and demonstrated this 93-bp region to be highly specific in governing restriction to NK/T cell lines. This property of Pmed1 is context independent and can extend to a disparate promoter. Deletion analysis defined a contribution of two separate elements located to the 5' 21-bp (-942/-922) and 3' 72-bp (-921/-850) regions of Pmed1 in conferring NK/T cell specificity. The 5' part of Pmed1 contains binding sites for Sp1 and NK element-recognizing factors and substitution mapping studies revealed a critical requirement of the Sp1-I site. The importance of Sp1 protein to regulate maximal Pmed1 promoter activity was further established by EMSAs and cotransfection experiments in Sp1-null Drosophila SL2 cells. Our data suggest that Sp1 can contribute, in part, to NK/T cell restriction and further indicate that the FcgammaRIIIA Pmed1 sequence might be useful to direct the NK/T cell-specific expression of heterologous genes.
Heusohn
Frank
F
Department of Clinical Immunology, Hannover Medical School, Hannover, Germany.
Wirries
Gundula
G
Schmidt
Reinhold E
RE
Gessner
J Engelbert
JE
D020413:3' Untranslated Regions / Q000276:immunology; D020121:5' Untranslated Regions / Q000276:immunology; D001483:Base Sequence; D001666:Binding Sites, Antibody / Q000235:genetics; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D018984:Epitopes, T-Lymphocyte / Q000235:genetics / Q000276:immunology; D020868:Gene Silencing / Q000276:immunology; D006801:Humans; D019169:Jurkat Cells; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010957:Plasmids / Q000235:genetics / Q000276:immunology; D011401:Promoter Regions, Genetic / Q000235:genetics / Q000276:immunology*; D011485:Protein Binding / Q000235:genetics / Q000276:immunology; D017452:Receptors, IgG / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D020218:Response Elements / Q000276:immunology; D016329:Sp1 Transcription Factor / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D016385:TATA Box / Q000276:immunology; D014162:Transfection
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D018984:Epitopes, T-Lymphocyte; D017452:Receptors, IgG; D016329:Sp1 Transcription Factor