The peripheral lymphocytes of the rabbit may be stimulated in vitro to transform into immature blast cells by sheep antisera to rabbit immunoglobulin G (IgG) and to rabbit IgG subunits (L chain, H chain, Fab piece, Fc piece), suggesting that the peripheral lymphocyte contains IgG molecules (1). Studies on lymphocytes from newborn rabbits using rabbit anti-allotype sera (2) and preincubation of lymphocytes prior to stimulation with anti-allotype (3) sera indicate that the IgG molecules present in lymphocytes are produced by these cells and are not obtained from the environment.Recent studies by Van F u r t h e t al. (4) demonstrate that cultures of the peripheral lymphocytes of humans are capable of producing immunoglobulins of the three major classes; i.e., IgG, IgA, and IgM. The studies to be described in the present report were designed to determine if antisera specific for rabbit IgA and IgM would be capable of inducing blast transformation and DNA synthesis in peripheral lymphocyte cultures. The results indicate that anti-IgM is as effective as anti-IgG in stimulating lymphoblast transformation and that anti-IgA is also stimulating, although not as effective as the other antisera.
Materials and MethodsProduction of Antisera.--Anti-lgA: Rabbit immunoglobulin A was obtained from the colostrum of newly delivered does by chemical precipitation of whey and Sephadex G-200 fractionation (5). The preparation was tested by immunoelectrophoresis against sheep and goat polyvalent antisera to rabbit whole serum and only IgA was detectable. Each of two sheep was injected intramuscularly in the left shoulder and flank with 3 mg of IgA protein in 0.5 ml of saline emulsified with an equal volume of complete Freund's adjuvant (control 478918,