The presence of IgA on the surface of rat thoractic duct lymphocytes which contain internal IgA.

The presence of lymphocytes with internal IgA among cells from rat thoracic duct lymph wdy. The number of cells detected was greater in animals kept in a convential animal house compared with those maintained under specific pathogen-free conditions. Thoracic duct lymph from B rats and adult thymectomized rats also contained cell with internal IgA. The surface Ig of the IgA-containing cells was studied using a double-labeling technique with (126I) anti-Ig to detect surface Ig, and fluorescein-conjugated anti-IgA in large amounts, but very little IgM and no surface IgG2. The surface IgA was not acquired passively.