Differential induction of HLA-A and -B reporters by CIITA.

HeLa cells (A) and YHHH cells (B) were transfected in parallel with HLA-A, HLA-B, and DRA CAT reporter vectors with (+) or without (−) 1 μg of CIITA expression vector. Induced activity of the HLA-B reporter for each cell type was defined as 100 U. (C) YHHH cells were transfected with HLA-A or HLA-B reporter vectors on their own (−) or with 0.5 μg of expression vectors for RelA (A), CIITA (CII), or both (++). Activity of the HLA-B reporter in the presence of both RelA and CIITA vectors was defined as 100 U.