Human monoclonal antibody with T-cell-like specificity recognizes MHC class I self-peptide presented by HLA-DR1 on activated cells.
Alloreactive T cells recognize peptides presented in the binding groove of major histocompatibility complex molecules (MHCs), whereas B cells mainly recognize the MHCs independent of bound peptides. Here, we demonstrate that the human B-cell repertoire comprises B cells which can be stimulated during pregnancy to produce antibodies reacting with MHCs in a way similar to T cells. The human monoclonal antibody UL-5A1 recognizes DR1(DRA/DRB1*0101) molecules on lymphoblastoid cell lines only if they co-express HLA-A2 or if they have been loaded with HLA-A2-derived peptides. The effect of the HLA-A2 peptide 105-117 on UL-5A1 reactivity was specific, time and dose-dependent. Reactivity increased when naturally processed peptides were removed from DR1 molecules before the HLA-A2 peptide 105-117 was loaded. UL-5A1 reacted specifically with cells that had been activated. The results imply a role of activation of cells in peptide processing and/or loading.
Wölpl
A
A
Department of Transfusion Medicine, University of Ulm, Red Cross Blood Bank Ulm, Germany.
Halder
T
T
Kalbacher
H
H
Neumeyer
H
H
Siemoneit
K
K
Goldmann
S F
SF
Eiermann
T H
TH
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity / Q000276:immunology*; D017951:Antigen Presentation / Q000276:immunology*; D002461:Cell Line, Transformed; D003165:Complement System Proteins / Q000276:immunology; D018984:Epitopes, T-Lymphocyte; D005260:Female; D015789:HLA-A2 Antigen / Q000276:immunology; D006684:HLA-DR Antigens / Q000276:immunology; D015798:HLA-DR1 Antigen / Q000276:immunology*; D059811:HLA-DRB1 Chains; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008213:Lymphocyte Activation; D008297:Male; D008969:Molecular Sequence Data; D010455:Peptides; D011233:Precipitin Tests; D011247:Pregnancy; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D018984:Epitopes, T-Lymphocyte; D015789:HLA-A2 Antigen; D006684:HLA-DR Antigens; D015798:HLA-DR1 Antigen; D059811:HLA-DRB1 Chains; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D010455:Peptides; D003165:Complement System Proteins