MEMORY TCR REPERTOIRES ANALYZED LONG-TERM REFLECT THOSE SELECTED DURING THE PRIMARY RESPONSE

Normal T cell repertoire selection and evolution in antigen-specific r esponses is poorly understood. We have recently described an MHC class I-restricted response characterized by an overwhelming expansion of C D8 cells expressing a V(beta)10 TCR, thus allowing the identification of antigen-selected cells directly ex vivo. Our present strategy to fo llow the overall TCR repertoire selection was to monitor the expressio n of a particular TCR alpha chain (V(alpha)8) on antigen-selected V be ta(10)(+) cells by four-color flow cytometry. We demonstrate that whil e there is substantial variation among the responder mice in V(alpha)8 usage, the repertoires of individual animals remain relatively stable over long periods of time (>1 year), with or without repeated antigen ic challenge. Thus if any evolution of this response occurs upon re-ex posure to antigen, it would appear not to skew the TCR repertoire esta blished during the primary response.