Association of soluble HLA-G plasma levels with HLA-G alleles.
Soluble HLA-G (sHLA-G) molecules are found in the peripheral blood of healthy females and males, in cord blood and in amniotic fluids and discussed to be a mediator in maternal-fetal tolerance. In this study we investigated whether there are allele-specific differences in expression of sHLA-G molecules. For this, the sHLA-G plasma concentrations of 94 healthy unrelated individuals were measured by ELISA and correlated to their HLA-G genotypes, as determined by sequence analysis of exon 2 and 3 of the HLA-G gene. Mean sHLA-G levels in individuals with the most common HLA-G alleles G*01011 (27.0+/-2.1 SEM ng/ml, n=66), G*01012 (28.4+/-3.2 SEM ng/ml, n=34) were very similar. In contrast, individuals carrying the HLA-G*01013 (8.1+/-1.7 SEM ng/ml, n=17) or the "null" allele HLA-G*0105N (8.2+/-3.2 SEM ng/ml, n=7) presented significantly (P(c)=0.001 and P(c)<0.01, resp.) reduced sHLA-G levels. Furthermore, individuals with the HLA-G*01041 allele had significantly (P(c)=0.004) increased sHLA-G levels (42.5+/-4.6 SEM ng/ml, n=14). These results demonstrate that the generation of sHLA-G molecules is associated to certain HLA-G alleles and imply that sHLA-G levels are under genetic control. As low and high sHLA-G plasma levels did not segregate with HLA haplotypes including the HLA-G*01013 or *01041 allele, additional mechanisms may be involved in the regulation of the individual sHLA-G levels. Nevertheless, the existence of "low" and "high secretor" HLA-G alleles further suggests different levels of functionality in immune regulation.
Rebmann
V
V
Institute of Immunology, University Hospital of Essen, Essen, Germany.
van der Ven
K
K
Pässler
M
M
Pfeiffer
K
K
Krebs
D
D
Grosse-Wilde
H
H
D000483:Alleles; D005260:Female; D006680:HLA Antigens / Q000097:blood* / Q000235:genetics*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000097:blood* / Q000235:genetics*; D006801:Humans; D008297:Male; D010375:Pedigree; D011897:Random Allocation; D012995:Solubility
D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I