Interaction between des-Tyr1-gamma-endorphin and HLA class I molecules: serological detection of an HLA-A2 subtype.

Preincubation of lymphocytes with des-Tyr1-gamma-endorphin (DT gamma E) inhibits the reaction between some HLA alloantisera and their corresponding antigens. One HLA-A2-specific antiserum was found which could detect a subtype of the HLA-A2 antigen on DT gamma E-treated lymphocytes from some donors. Comparison with the HLA-A2 subtypes as defined by a combination of cytotoxic T lymphocyte typing and biochemistry showed a complete correlation with the previously described HLA-A2.3 subtype.