| dc.description |
Soluble protein antigens do not stimulate helper or effector T lymphocytes unless they have first been processed and exposed to the T lymphocytes by appropriate antigen-presenting cells. This antigen presentation was found to be controlled by products of genes in the major histocompatibility complex (MHC), designated Hâ 2 in the mouse. Efficient antigen presentation to T lymphocytes is obtained only when both presenting and responding cells share alleles within the I region of the MHC<sup>1</sup>. Furthermore, immune response (Ir) genes in the MHC influence the choice of antigenic determinants recognized on the immunogenic molecule<sup>2</sup>. To investigate the molecular mechanisms underlying Ir gene expression, we have inserted membrane components isolated from cells of one Ir genotype into recipient cells of a different Ir genotype, using membrane vesicles composed of donor plasma membranes and envelope glycoproteins from Sendai virus<sup>3</sup>. We now report that this â membrane-engineeringâ enables genetically inappropriate antigen-presenting cells to communicate to T lymphocytes antigenic determinants of beef or sheep insulins, antigens under control of Ir genes in mice<sup>4</sup>. This demonstrates that structural products of MHC genes, expressed and active at the plasma membrane, function in the Ir phenotype of the response to insulin. |
