Evidence for discoordinate regulation of the HLA-DPB1 gene.
Characterization of cell lines derived from patients with type II bare lymphocyte syndrome, a pathological state in which the constitutive and inducible expression of HLA class II antigens is lacking, has permitted the identification of several trans-acting factors involved in the coordinated regulation of HLA class II genes. Although an increasing body of evidence has pointed to the existence of a discoordinate regulation of HLA class II loci, the mechanisms underlying such regulation are essentially unknown. In the present study, 45.EM2, a mutant lymphoblastoid cell line with a new pattern of HLA discoordinate expression is characterized. 45.EM2 expresses HLA-DR and -DQ but fails to express HLA-DP. The absence of HLA-DP expression in 45.EM2 is the result of a transcriptional defect, leading to a lack of DPB1 mRNA. By contrast, DPA1 transcription in this LCL is not impaired. The characteristics of 45.EM2 described here suggest the existence of a specific trans-acting factor involved in the control of DPB1 gene expression.
Coiras
M T
MT
Departmento de Microbiología II, Universidad Complutense, Madrid, Spain.
Alvarez-Barrientos
A M
AM
Díaz
G
G
Arroyo
J
J
Sánchez-Pérez
M
M
D002461:Cell Line, Transformed; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D006682:HLA-DP Antigens / Q000235:genetics*; D059867:HLA-DP alpha-Chains; D059868:HLA-DP beta-Chains; D006801:Humans; D008156:Luciferases / Q000235:genetics; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis; D016511:Severe Combined Immunodeficiency / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics; D014162:Transfection
D006682:HLA-DP Antigens; D059867:HLA-DP alpha-Chains; D059868:HLA-DP beta-Chains; C071172:HLA-DPA1 antigen; C071170:HLA-DPB1 antigen; D012333:RNA, Messenger; D014157:Transcription Factors; D008156:Luciferases