Characterization of arterial antigens using arterial antigen-reactive T cell clones from spontaneously hypertensive rats.

We have previously demonstrated that arterial antigens derived from the aorta of spontaneously hypertensive rats (SHRs) stimulate arterial antigen-reactive T cell clones established from the spleens of SHR to proliferate and release cytokines. To identify immunogenic protein components associated with the arterial wall, arterial antigen-reactive T cell clones were tested against arterial antigens separated by SDS-PAGE and transferred to nitrocellulose. The greatest T cell reactivity was obtained with protein bands of molecular weight 66 kDa, 50 kDa, and 45 kDa. T cell clones reactive against the 50 and 45 kDa antigens from gels failed to respond to proteins of other molecular weight (M(r)) separated under reducing or nonreducing conditions, suggesting that these molecules are not subunits of larger proteins and may represent monomeric antigens polymerized into the arterial wall. These data suggest that certain epitopes of arterial wall antigens are immunogenic. T cells activated with these immunogenic epitopes could initiate or perpetuate vasculitis in the arteries of hypertensive rats.