The production of hybridomas from the gut associated lymphoid tissue of tumour bearing rats. II. Peripheral intestinal lymph as a source of IgA producing cells.

Peripheral intestinal lymph afferent to the mesenteric nodes has been collected from rats bearing syngeneic sarcomata in their Peyer's patches and the B cells used to produce rat X rat hybridomas. Analysis of the hybridoma supernatants by radioimmunoassay for the presence of immunoglobulins, showed that hybridomas secreting IgA predominated. Eleven out of the 15 hybridomas selected for antibody binding to cells of the immunising tumour secreted IgA antibodies, and six of these were tumour specific. Efferent mesenteric lymph (i.e. normal thoracic duct lymph), on the other hand, was found to be a poor source of B cells for hybridoma production and no specific IgA secreting hybridomas were obtained. The high yield of IgA secreting hybridomas obtained shows that peripheral intestinal lymph is a better source of IgA committed B cells than are the mesenteric nodes or thoracic duct lymph. We conclude that the IgA producing cells in the latter tissues are too far along the differentiation pathway to plasma cells to undergo successful somatic cell fusion.