Immune induction of Ia antigens in activated T cells and in kidney epithelial cells in mice.

A rat monoclonal antibody against mouse Ia antigens was used to investigate the induction of Ia expression by activated T cells and renal epithelial cells during immune responses. The induction of low levels of surface Ia on activated helper and cytotoxic/suppressor T-cell phenotypes was directly demonstrated by differential fluorescence staining. Renal epithelial cells were observed to become strongly Ia-positive after primary immunization with alum-precipitated protein antigen, or after secondary challenge with the soluble antigen used for priming.