Rapid Publications Interferon-Mediated Induction of la Antigen Expression on Isolated Murine Whole Islets and Dispersed Islet Cells

Islets from male B10.BR mice (H-2) were isolated by the collagenase technique, handpicked with a Pasteur pipette, and incubated (either intact or after dispersion with Dispase) for 0, 3, 5, 7,10, or 14 days in tissue culture medium supplemented with either lymphokine supernatants or recombinant murine interferon-7. Islets and single cells were examined for IA molecules by use of indirect immunofluorescence. la-positive islet cells were identified on the surface of islets incubated with 5-10% lymphokine for >4 days or with 10,100, or 1000 ng/ml interferon for >6 days. Islets incubated in unsupplemented medium were la negative. Incubation with 5% lymphokine induced la expression on 10-40% dispersed islet cells cultured for >9 days. Dual immunofluorescent staining for la and insulin revealed that la-positive cells included both pand non-p-cells. DIABETES 1986; 35:1174-77.