Primed lymphocyte testing specificity of alloreactive lymphocyte clones for HLA-B locus determinants

We have generated two alloreactive T-lymphocyte clones that recognize the products of the HLA-B locus. The primed lymphocyte testing (PLT) reactivity of clone HJ21 was monospecific for the HLA-B antigen Bw49, a subtype specificity of HLA-Bw21. The PLT specificity of clone RD3 was strongly associated with HLA-Bw21. Several monoclonal antibodies against class I HLA molecules inhibited the PLT responses of these clones whereas class II monoclonal antibodies had no effect. These observations provide experimental evidence that class I products of the HLA-B locus may directly be involved in lymphocyte alloactivation.