CD4 and autoimmune disease: Moreover, after specific restimulation, PV1 blockade selectively blocked IFN-γ production by CD4+ lymphocytes Taken together, our data suggest that mPEG PV1-Fab’ acts mainly on IFN-γ-producing CD4+ T cells and emphasize that this specific CD28 blockade strategy is a potential specific and alternative tool for the treatment of autoimmune disorders in the eye.