title: Functional characterization of a chicken major histocompatibility complex class II B gene promoter.
abstract: A 0.7 kilobase (kb) DNA fragment from the 5' flanking region of a chicken major histocompatibility complex (MHC) class II B gene was cloned into chloramphenicol acetyltransferase (CAT) reporter vectors and was transfected into a chicken macrophage cell line that expresses a low level of MHC class II antigens. Positive orientation-dependent promoter activity of the chicken DNA was evident in a reporter construct containing an SV40 enhancer. Deletion analysis of this 0.7 kb DNA fragment revealed a short fragment in the 3' end that was crucial for the promoter function and negative regulatory elements (NRE) located further upstream. The conserved MHC class II X and Y boxes did not have a significant effect on promoter activity. Sequence analysis of the 0.7 kb class II B gene upstream region suggests possible involvement of interferon (IFN), E twenty-six specific (ETS)-related proteins, and other factors in regulating this promoter. A chicken T-cell line culture supernatant increased surface expression of MHC class II antigens, as well as class II promoter activity, in this macrophage cell line. This first functional characterization of a chicken MHC class II B gene promoter will aid in understanding the regulatory mechanisms that control the expression of these genes.
authors.affiliation: The Departments of Animal Science and of Microbiology, Immunology, and Preventive Medicine, 201 Kildee Hall, Iowa State University, Ames, IA 50011, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.forename: H S
authors.initials: HS
authors.lastname: Lillehoj
authors.forename: C H
authors.initials: CH
authors.lastname: Hsu
authors.forename: S L
authors.initials: SL
authors.lastname: Carpenter
authors.forename: S J
authors.initials: SJ
authors.lastname: Lamont
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002645:Chickens / Q000235:genetics* / Q000276:immunology; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004247:DNA; D005802:Genes, MHC Class II; D008264:Macrophages / Q000276:immunology; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D017384:Sequence Deletion
chemical_list: D017077:Culture Media, Conditioned; D004247:DNA; D015500:Chloramphenicol O-Acetyltransferase