The production of hybridomas from the gut associated lymphoid tissue of tumour bearing rats. I. Mesenteric nodes as a source of IgG producing cells.

Rat X rat hybridomas secreting antibodies with tumour specificity have been prepared using cells from the mesenteric nodes of rats bearing syngeneic sarcomata in their Peyer's patches. The antibodies obtained, which embraced all of the major immunoglobulin classes, varied in cellular reactivity from the individually tumour specific to cross-reactive with both normal and tumour cells. Several IgA producing hybridomas were prepared using this protocol but IgG secretors were obtained more frequently and they accounted for about half of the specific hybridomas. Specific IgG producers were found to predominate also when hybridomas were prepared from the mesenteric nodes of a rat immunized by injection of horseradish peroxidase into the Peyer's patches. Comparison of these data with our earlier results using spleen cells taken from rats that were either hyperimmunized with, or were bearing the same tumours in the leg, show that mesenteric nodes draining a tumour growing in the Peyer's patches are a much better source specific IgG producing B cells.