Autoantibodies in vitiligo patients recognize multiple domains of the melanin-concentrating hormone receptor.
Previously, we reported the identification of autoantibodies against the melanin-concentrating hormone receptor 1 in patients with vitiligo. In this study, the B cell epitopes on melanin-concentrating hormone receptor 1 that are recognized by these autoantibodies have been identified. Deletion derivatives of melanin-concentrating hormone receptor 1 complementary DNA were constructed and then translated in vitro with the concomitant incorporation of [35S]-methionine into the protein products. The [35S]-labeled melanin-concentrating hormone receptor 1 derivatives were subsequently used in radio-binding assays to investigate the reactivity of sera from nine vitiligo patients that were known to contain antibodies to the receptor. Analysis of the results obtained in the radio-binding assays suggested the existence of multiple antibody binding sites on melanin-concentrating hormone receptor 1, including regions between amino acids 1 to 138 and 139 to 298. Several patients exhibited autoantibodies to more than one melanin-concentrating hormone receptor 1 epitope indicating a heterogeneous humoral response to the receptor. Computer prediction of the potential B cell epitopes on melanin-concentrating hormone receptor 1 revealed that the epitope domains identified overlapped, at least in part, with regions predicted to be highly antigenic.
Gottumukkala
Raju V S R K
RV
Division of Clinical Sciences (North), University of Sheffield, Sheffield, UK.
Waterman
Elizabeth A
EA
Herd
Laura M
LM
Gawkrodger
David J
DJ
Watson
Philip F
PF
Weetman
Anthony P
AP
Kemp
E Helen
EH
D000328:Adult; D000368:Aged; D000918:Antibody Specificity; D001323:Autoantibodies / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology; D018076:DNA, Complementary; D018985:Epitopes, B-Lymphocyte / Q000276:immunology; D005260:Female; D017353:Gene Deletion; D006801:Humans; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D011979:Receptors, Pituitary Hormone / Q000235:genetics / Q000276:immunology*; D014820:Vitiligo / Q000276:immunology*
D001323:Autoantibodies; D001324:Autoantigens; D018076:DNA, Complementary; D018985:Epitopes, B-Lymphocyte; D011979:Receptors, Pituitary Hormone; C092274:melanin-concentrating hormone receptor