Antigen expression in different parenchymal cell types of rat kidney and heart.

Rat glomerular epithelial, and mesangial and tubular cells were isolated by steel meshes of different pore sizes and enzymatic treatment. Rat heart endothelial cells were isolated by enzymatic disaggregation. Endothelial, glomerular mesangial, glomerular epithelial and tubular cells were cultured in Minimum essential medium until they reached confluency (5 to 9 days). These different rat parenchymal cell types were characterized by morphology and antibody stainings. Endothelial cells were characterized by factor VIII positivity and mesangial cells were desmin positive. Both glomerular epithelial and tubular cells expressed the brush border and Tamm-Horsfall antigens, but in vivo injected trypan blue accumulated selectively to proximal tubular cells. Class I expression was high (84 to 95% of about 10(5) cells grown in Lab-Tek culture chambers were reactive with anti-class I antibody) in unstimulated endothelial, glomerular epithelial and tubular cells and was even higher (100%) after incubation with gamma-interferon for three days. Mesangial cells expressed class I considerably less in normal state (34%), but gamma-interferon induction upregulated it to 95%. Both the surface and intracytoplasmic expression of class I antigens were upregulated with three-day gamma-interferon treatment. Class II expression was low in all unstimulated cells (5 to 10%). The three-day gamma-interferon treatment upregulated both surface as well as cytoplasmic expression of class II antigens in all cell types.