ALPHAVIRUS-SPECIFIC CYTOTOXIC T-LYMPHOCYTES RECOGNIZE A CROSS-REACTIVE EPITOPE FROM THE CAPSID PROTEIN AND CAN ELIMINATE VIRUS FROM PERSISTENTLY INFECTED MACROPHAGES

Persistent alphavirus infections in synovial and neural tissues are be lieved to be associated with chronic arthritis and encephalitis, respe ctively, and represent likely targets for CD8(+) alpha beta cytotoxic T lymphocytes (CTL). Here we show that the capsid protein is a dominan t target for alphavirus-specific CTL in BALB/c mice and that capsid-sp ecific CTL from these mice recognize an H-2K(d) restricted epitope, QY SGGRFTI. This epitope lies in the highly conserved region of the capsi d protein, and QYSGGRFTI-specific CTL were cross reactive across a ran ge of Old World alphaviruses. In vivo the acute primary viraemia of th ese highly cytopathic viruses was unaffected by QYSGGRFTI-specific CTL . Hen-ever, in vitro these CTL were able to completely clear virus fro m macrophages persistently and productively infected with the arthroge nic alpha-virus Ross River virus.