A single amino acid substitution in the human histocompatibility leukocyte antigen DR3 beta chain selectively alters antigen presentation |
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| Authors: | E Mellins B Arp B Ochs H Erlich D Pious |
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| Affiliation: | Department of Pediatrics, University of Washington, Seattle 98195. |
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| Abstract: | Activation of T lymphocytes by immunogenic peptides bound to HLA molecules is a central event in the generation of an immune response. To determine the sites on HLA molecules involved in this process, we isolated mutant EBV-transformed B cell clones that express altered HLA-DR3 molecules. One mutant has lost the ability to stimulate a T cell clone specific for a mycobacterial protein, but retains the ability to stimulate other antigen-specific T cells. The DNA sequence of the complete DR alpha and beta coding regions revealed a single nucleotide change resulting in a glutamic acid to lysine substitution at amino acid 9 in the first hypervariable region of the DR beta chain. These results are discussed in relation to a recently proposed model of class II molecule structure. |
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