Analysis of the in vitro immune response to insulin. I. Primary induction of insulin-specific T helper cells and characterization of the genetic control of the helper cell response to bovine and porcine insulin.

The in vitro induction and assay of bovine or porcine insulin specific T helper cells is described. Using a modified Marbrook-Diener culture system, helper cells were generated either by incubating purified T cells with insulin and macrophages or with supernatant obtained from insulin-incubated macrophages (GRF). The macrophage-T cell interaction required for helper cell induction was genetically restricted and the genes responsible were mapped to the left of the I-B subregion of the H-2 complex. The Ir gene control of the helper cell response to insulin was examined. It was found that the H-2d T cells became helper cells if incubated with bovine or porcine insulin and the appropriate macrophages. H-2b T cells only became helper cells if incubated with bovine but not with porcine insulin and macrophages. The Ir genes controlling that response were also mapped to the left of I-B. Studies to determine the cellular sites of Ir gene expression revealed that Ir genes function at the level of macrophages, although other sites have not been excluded.