The nonpolymorphic MHC class II isotype, HLA-DQA2, is expressed on the surface of B lymphoblastoid cells
- Details
- Publication Year 1997-03-01,Volume 158,Issue #5,Page 2116-2125
- Journal Title
- JOURNAL OF IMMUNOLOGY
- Publication Type
- Journal Article
- Abstract
- The more centromeric of the two human MHC class II DQA genes, DQA2, has not previously been shown to express a protein product, However, its high degree of sequence similarity to DQA1, the fact that it is highly evolutionarily conserved, and the recent demonstration of its transcription in some cell lines suggest that a DQA2 alpha-chain may be expressed, Polyclonal antipeptide antisera were generated and shown to be specific for DQA2 in Western blotting of Triton X-114 preparations of B lymphoblastoid cell lines, DQA2 expression is variable, although always at least threefold less than that of DQA1, and is found in all haplotypes examined, Immunoprecipitations of biotin-labeled cell surface proteins reveal that DQA2 appears at the cell surface, In keeping with others' findings, no evidence for an expressed DQB2 beta-chain was found, prompting investigation of the means by which DQA2 gains access to the cell surface, Antisera specific for allotypic and isotypic MHC class II P-chains were used in sequential immunoprecipitation experiments to search for a beta-chain partner for DQA2, and a transfectant system was established in an attempt to promote pairing of DQA2 with a selected DQB1 (*0501) chain, In neither case was DQA2 found to dimerize with an MHC class II beta-chain, Despite this, DQA2 is capable of forming a complex with invariant chain.
- Publisher
- AMER ASSOC IMMUNOLOGISTS
- Keywords
- MAJOR HISTOCOMPATIBILITY COMPLEX; DX-ALPHA GENE; DEPENDENT DIABETES-MELLITUS; HLA-DR MOLECULES; INVARIANT CHAIN; TRANSGENIC MICE; A-BETA; HEAVY-CHAINS; T-CELL; ALLELIC POLYMORPHISM
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Creation Date: 1997-03-01 12:00:00