Benjamin Arp

Functional Analysis of HLA-DR3: A Mutational Approach

Class II mutant B lymphoblastoid cell lines (B-LCL) affected in presentation of soluble antigen to HLArestricted antigen-specific T cells can be used to characterize the molecular interactions involved in antigen presentation. We have isolated class II mutants in the DR3 haplotype, a haplotype of particular interest because of its association with several autoimmune diseases (1). Here, we describe the use of antigen loss mutants to localize restriction elements to the DRβ1, DRβ3, and non-DR dimers of the DR3 haplotype, and the use of mutants expressing altered DR3 molecules to identify regions of DR3 molecules involved in antigen presentation and in α/β chain association.