FIG. 6.

HLA-DP surface expression on transferents and their presentation of WI-1 to T cells. (A) Flow cytometric analysis of HLA-DP expression on DP-null mutants and on the HLA-DP transferents described in Fig. 5A. Expression of HLA-DP is restored by the gene transfer, as demonstrated by MAb B7/21 staining of representative transferent 3C1. Transferent EM-13/17-3B expressed an amount of DP (not shown) similar to that on 3C1 despite its failure to present antigen (see below). (B) The HLA-DP mutants and transferents were tested for presentation of WI-1 to clone K20B. The HLA-DP transferent with the βw4 gene (3C1 in Fig. 5A) presented WI-1 to K20B, whereas the transferent with the DPw4α chain (EM-13/17-3B) did not present antigen. nWI-1, native WI-1.