In previous studies, we have shown that MS lesions are characterized by enhanced expression of transcription factors associated with stress responses, ie, IRF-1, NF-kappaB, and CREB-1, which modulate expression of both classes of major histocompatibility complex (MHC) molecules.
We show that phagocytic macrophages in active demyelinating MS lesions displayed a moderate to strong immunostaining of the MHC-specific transcription factors RFX and CIITA, as well as the general transcription factors NF-kappaB, IRF1, STAT1, USF, and CREB, which was congruent with a strongly enhanced expression of HLA-DR, HLA-DQ, HLA-DP, and HLA class I.