Characterization of Cmv- and Lcv-Specific T Cell Responses and Their Sensitivity to Immunosuppression in Cynomolgus Macaques (P6367)

Abstract Herpesviruses such as cytomegalovirus (CMV) and Epstein Barr virus (EBV) often cause disease under conditions of immunosuppression, such as transplant or AIDS. Loss of control of herpesvirus infections occurs at least in part due to loss or dysfunction of virus-specific T cells. An increasing array of immunosuppressive therapeutics are being developed that target different subsets of T cells or their functions. To better understand effects of therapeutics on antiviral T cells, we have used ELISPOT and ICS to measure T cell responses against CMV and lymphcryptovirus (LCV; analogous to EBV) in cynomolgus macaques. Our work has shown that nearly all monkeys respond against both viruses, although the numbers of T cells specific for CMV are larger than those against LCV. We have also characterized the variability in the magnitude of the T responses to both viruses over time. In addition, we have examined the effects of immunosuppressive agents on the numbers and function of antiviral T cells. Our work reveals remarkable stability of herpesvirus-specific T cells, even under conditions where drugs abolish T cell stimulation for a period of several weeks.