Transformation of human colostrum lymphocytes with Epstein-Barr virus and the production of IgA in culture.

Human colostrum lymphocytes obtained on day 2-5 after delivery were found to be as susceptible to transformation with Epstein-Barr virus (EBV) as peripheral lymphocytes. An enzymelinked immunosorbent assay showed that the proportion of transformed cells producing IgA, IgG, and IgM varied from colostrum specimen to specimen. 1 microgram/ml of IgA could be produced by freshly transformed cell mixture. But the capacity to produce IgA was lost or decreased by one order of magnitude during and after cloning of producing cells; the highest production with cloned cell cultures was about 0.2 micrograms/ml. Immunofluorescence staining of IgA-positive cells showed instability of the capacity of transformed cells to produce IgA.