The suppression of insulin-specific immune responses by the administration of insulin-derivatized syngeneic cells and soluble lysates from these cells.

The results of this study demonstrated that the i.v. administration of insulin, in the form of a conjugate with either syngeneic spleen cells (SC) or peritoneal exudate cells (PEC), markedly reduced the capacity of recipient mice to develop insulin-specific immune responses, as manifested by diminished in vivo IgE antibody production and by depressed in vitro, lymph node cell proliferation responses, respectively. Furthermore, it was shown that i.v. injection of insulin-PEC conjugates induced the activation of suppressor cells that had the capacity to downregulate insulin-specific IgG plaque-forming cell (PFC) responses. Finally, it was also determined that freezing and thawing of the insulin-PEC conjugates resulted in the release of a soluble tolerogenic molecule and/or membrane preparation that could also markedly depress insulin-specific IgG antibody production.