Recognition of HLA-DR1/DRB1*0101 molecules presenting HLA-A2 derived peptides by a human recombinant antibody, Fab-5 A1.
MHC molecules present peptides in their binding groove to T-cell receptors inducing proliferation or cytotoxicity of alloreactive T cells. A previously generated human monoclonal antibody (mAb) UL-5 A1, recognizing a conformational epitope formed by HLA DR1/DRB1*0101 molecules and HLA-A2 derived peptides, demonstrates T-cell-like recognition of the peptide/MHC complex (PMC). To study the genes of the antigen binding region, the nucleotide sequences of the rearranged genes in the variable regions of UL-5 A1 were determined and the V-gene usage (VH3, V lambda 2) was identified by comparison with published germlines. The genes encoding heavy (Fd) and light (L) chains of UL-5 A1 were linked and expressed in a bacterial system. Specificity of the recombinant Fab-5 A1 was determined with HLA-typed LCLs by flow cytometric analysis. As demonstrated in competitive inhibition assays, UL-5 A1 and Fab-5 A1 recognize the same PMC epitope on HLA-A2+, -DR1/DRB1*0101+ typed LCLs. Additionally, mAb UL-5 A1 and Fab-5 A1 both recognize HLA-A2-, -DR1/DRB1*0101+ LCLs exogenously loaded with HLA-A2 peptides (105-117, 103-117). UL-5 A1-like antibodies against peptide/MHC complexes could prove valuable tools for research on T-cell recognition and MHC function.
Löffler
D
D
Department of Transfusion Medicine, University Ulm, Germany.
Welschof
M
M
Goldmann
S F
SF
Wölpl
A
A
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000276:immunology; D017951:Antigen Presentation / Q000276:immunology*; D001483:Base Sequence; D001667:Binding, Competitive; D002461:Cell Line, Transformed; D018076:DNA, Complementary; D005434:Flow Cytometry; D015789:HLA-A2 Antigen / Q000276:immunology*; D006684:HLA-DR Antigens / Q000276:immunology*; D015798:HLA-DR1 Antigen / Q000276:immunology*; D059811:HLA-DRB1 Chains; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology; D017421:Sequence Analysis
D000911:Antibodies, Monoclonal; D018076:DNA, Complementary; D015789:HLA-A2 Antigen; D006684:HLA-DR Antigens; D015798:HLA-DR1 Antigen; D059811:HLA-DRB1 Chains; D007140:Immunoglobulin Fab Fragments; D010455:Peptides; D011994:Recombinant Proteins