HLA-DQA1 ALLELE AND SUBALLELE TYPING USING NONCODING SEQUENCE POLYMORPHISMS - APPLICATION TO 4AOHW CELL PANEL TYPING

HLA-DQA1 typing of the 4AOHW cell panel is presented using a novel str ategy that exploits both intron and exon polymorphisms. Intron sequenc es adjacent to the variable HLA-DQA1 second exon exhibit stable polymo rphisms that are specific for locus alleles and certain suballelic DR/ DQ haplotypes. A PCR-RFLP method has been developed that is based on a mplification of a: 780-bp segment extending from intron I through exon 2 to intron 2. Stable sequence polymorphisms provide restriction enzy me sites and confer mobility variations detected on polyacrylamide min igel electrophoresis. Direct band comparison of amplified products and restriction fragments with known standards facilitates pattern compar ison, obviating the requirement for accurate molecular weight determin ation. This method, using only two enzymes, identifies a total of 11 a llelic and suballelic groups, including all eight DQA1 alleles encoded at the second exon.