Studies on Rabbit Lymphocytes in Vitro

Abstract

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,

Studies on Rabbit Lymphocytes in Vitro

“…The maximum per cent blast transformation induced by antisera of different specificities tested in this and in previous studies is given in Table IV. The high percentages induced with anti-IgG, anti-IgM, and anti-IgA sera were interpreted to indicate that all lymphocytes contained determinants of IgG and IgM; and approximately ~ of these lymphocytes contained determinants of IgA as well (5). This interpretation is inconsistant with observations that plasma cells contain only one immunoglobulin group at a time.…”

“…(Received for publication 15 January 1968) Antisera to rabbit leukocytes (1) or to rabbit immunoglobulins (2)(3)(4)(5) may stimulate cultures of rabbit peripheral lymphocytes. Such antisera stimulate lymphocytes in vitro to synthesize RNA, DNA, and protein, to transform into immature "blast" cells, and to undergo division (2).…”

The Requirement of More Than One Antigenic Determinant for Immunogenicity

“…Others are bound to or incorporated into the surface of cells, and we should like to think that antigen-sensitive cells precommitted to the synthesis of antibody molecules of one specificity carry samples of such molecules at their surface. Experimental evidence is available (22)(23)(24)(25) for the existence of immunoglobulin-like receptors on a majority of the lymphocytes. It is unlikely that a cell would synthesize receptor molecules of two different specificities recognizing two unrelated antigenic determinants that we have brought together in a hapten-carrier complex.…”

Studies on Rabbit Lymphocytes in Vitro

“…Immunofluorescence studies of plasma cells indicate that a given plasma cell contains only one immunoglobulin group at a time (9)(10)(11). In contrast, studies on the induction of lymphocyte transformation in vitro with sheep antisera specific for IgG, IgA, and IgM indicate that each lymphocyte contains the determinants of IgG and IgM at the same time; with approximately one-third of the lymphocytes containing all three major immunoglobulin groups (IgG, IgA, and IgM) at a time (12).…”