Effect of HLA phenotype and gender on expression of various forms of class I HLA in plasma.
To understand the complexity of plasma HLA antigens, the distribution of different molecular weight forms of class I HLA in plasma was investigated in 44 HLA-phenotyped and unrelated individuals. Plasma class I HLA were immunoprecipitated by using the W6/32 anti-HLA monoclonal antibody, separated by SDS-polyacrylamide gel electrophoresis and characterized by immunoblotting with the HC-10 monoclonal antibody. Four different forms of HLA heavy chains (HLA-HC) with relative molecular masses of 44, 39, 36, and 34 kd were detected. Plasma samples from all individuals contained 44 and 36 kd HLA-HC, but varied as to the presence of 39 and 34 kd HLA-HC. Eighteen percent of the individuals did not have any detectable class I HLA with 39-kd heavy chains in their plasma and 61% did not have plasma class I HLA with 34-kd heavy chains. Thus, four different distribution patterns were identified for plasma class I HLA among all individuals included in our study. The distribution patterns in four different individuals were evaluated quarterly and remained unchanged during 1 year follow-up. A significant association of absence of 39-kd plasma class I HLA-HC with female gender (p less than 0.05) and HLA-B7 phenotype (p less than 0.00015) was also found. Further pedigree analyses of four families of HLA-B7-positive and 39-kd HLA-HC-negative probands indicated that genetic factor(s) other than those associated with HLA-B7 allele and female gender is involved in regulating the expression of the plasma class I HLA with 39-kd heavy chains.
Haga
J A
JA
Department of Pathology and Laboratory Medicine, University of Florida College of Medicine, Gainesville 32610-0275.
Riley
W J
WJ
Kao
K J
KJ
D000293:Adolescent; D000328:Adult; D000911:Antibodies, Monoclonal; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D005786:Gene Expression Regulation; D006680:HLA Antigens / Q000097:blood* / Q000235:genetics; D015395:Histocompatibility Antigens Class I / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D010375:Pedigree; D010641:Phenotype; D012737:Sex Factors
D000911:Antibodies, Monoclonal; D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I