Alteration of the T-cell receptor repertoire in A. CA mice expressing anEa d transgene

In an effort to generate an A.CA mouse expressing E^d, the Ea^d gene has been introduced into A. CA mice which lack the major histocompatibility complex (MHC) class II E molecule. Flow cytometric analysis shows cell surface expression of the E chain on lymphocytes and macrophages in the transgenic mice. Analysis of T-cell receptor (Tcr) genes deleted in some E-expressing mouse strains demonstrates that T cells expressingTcrb-VS are partially deleted in these transgenic mice while those expressingTcrb-V8 andTcrb-11 are not. In addition, the expressed E^d chain can promote Mycoplasma arthriditis mitogen (MAM)-induced T-cell proliferation. The expression of the Ea chain, presumably as an Aß^fE^d heterodimer, can alter the peripheral T-cell repertoire and T-cell reactivity to a microbial superantigen.