The role of transfected HLA-DQ genes in the mixed lymphocyte reaction-like condition.

DR gene products are commonly thought to be involved in the induction of the mixed lymphocyte reaction (MLR). However, very little is known about the role of HLA-DQ antigens in the MLR. To address this question, we introduced DQ alpha and beta chain genes into mouse L cells, a human T-cell line, and a human premonocytoid cell line using a liposome-mediated transfer technique. The DQ alpha and DQ beta genomic clones were isolated from a DR2 DQw1 and a DR3 DQw2 phage library, respectively. The pSV2-Neo gene was introduced as a selection marker with both DQ alpha and DQ beta. The resultant transfected cells were able to bind several HLA class II monoclonal antibodies. In addition, these cells were found to be efficient in stimulating peripheral blood lymphocyte proliferation under MLR-like conditions, implying a role for HLA-DQ molecules in HLA-D typing differences.