Recognition of alloantigens and induction of experimental allergic encephalomyelitis by a murine encephalitogenic T cell clone.

In this communication we report a SJL/J (H-2s, Mlsc)-derived encephalitogenic T cell clone 4b.14a which has dual specificities for myelin basic protein/I-As and allogeneic H-2Ik gene products. Monoclonal antibodies specific for public class II major histocompatibility complex (MHC) determinants (Ia.17, I-Ak, r and Ia.7) and anti-L3T4 antibody inhibited the response of the clone 4b.14a to alloantigens, but a monoclonal antibody specific for a private determinant on I-Ak (Ia.2) did not inhibit the response. Although this clone proliferated in response to allogeneic spleen cells expressing H-2Ik determinants regardless of disparate Mlsa, b, c, d alleles, CBA/N cells (H-2k, Mlsnull) failed to stimulate the clone 4b.14a. These results suggest that recognition of allogeneic class II MHC molecules by this clone requires recognition with non-MHC gene products such as Mls. In addition, the clone 4b.14a stimulated by alloantigens could mediate clinical signs of experimental allergic encephalomyelitis in syngeneic recipients. However, interleukin 2 of rat spleen cell origin alone failed to activate the clone cells to make them encephalitogenic, though it could make them proliferate. The significance of these findings for T cell recognition and activation is discussed.