Regulation by complementary idiotypes. Ig protects the clone producing it

1984: all idiotypes are equal, but some are more equal than others

Our analysis of idiotypic dominance suggests that 3 elements play an important role. The first is the genetic material that encodes the dominant idiotype. As dominant idiotypes appear to reflect germ-line-encoded sequences, one can not express a particular idiotype unless that sequence is present in the germ line. The germ-line-encoded sequences, in turn, would, I predict, be specific for commonly encountered or former environmental pathogens. The second element is the environmental antigens themselves. These antigens will induce the production of idiotype, and will prime idiotype-bearing B cells, such that idiotypic dominance emerges. In the absence of such influences, the pattern of idiotypic expression appears to differ. The third influence is regulatory. My own studies have shown that idiotype found in normal serum plays an important role in the maturation and/or function of one such cell, an idiotype-specific helper T cell. It is my working hypothesis that such cells play several roles in idiotypic dominance, but that this is the least of their important roles. Rather, such cells, being specific for idiotopes associated with antibodies specific for environmentally encountered pathogens, would be important in the priming and rapid reactivation of B cells bearing such idiotopes. As such, they speak to the basic role of the immune system, the protection of the organism from infection.

Human auto-antiidiotypes regulating T cell-mediated reactivity to tetanus toxoid

While investigating the effect on B cells of repetitive in vivo immunization with tetanus toxoid (TT), we observed the subsequent development of specific anergy for T cell delayed hypersensitivity (DTH) to TT. This appeared approximately 35 d after a series of five booster immunizations. Concurrently, in vitro T cell blastogenic responses were preserved. Serum obtained when the skin tests were nonreactive demonstrated a profound inhibitory activity on T cell reactivity. This activity was shown to be anti-antibody activity that was both anti-F(ab)'2 and, specifically, anti-TT F(ab)'2. It blocked binding of TT to a pool of allogeneic antibodies and also inhibited allogeneic antigen-specific T cell blastogenesis. Thus, we could identify activity in the serum of hyperimmunized individuals that appeared auto-anti-idiotypic (anti-id) and represented a single or family of major crossreacting idiotypes (id) for TT. The expression of the auto-anti-id correlated with the loss of T cell reactivity in vivo and in vitro. Subsequent examinations revealed persistent, specific cutaneous anergy beyond six months, which was then associated with a failure of T cells to react with antigen in vitro. Mixing experiments with cells from these later times and cryopreserved autologous cells obtained prior to hyperimmunization revealed there had been the development of antigen-specific T suppressor cells. Thus, in vivo DTH tolerance following hyperimmunization was associated with an inhibitory serum activity that appeared to be anti-id. Persistence of tolerance (greater than 6 mo) occurred with the development of T suppressor cells.