IMMUNITY TO RETROVIRAL INFECTION - THE FRIEND-VIRUS MODEL

Friend virus infection of adult immunocompetent mice is a well establi shed model for studying genetic resistance to infection by an immunosu ppressive retrovirus, This paper reviews both the genetics of immune r esistance and the types of immune responses required for recovery from infection, Specific major histocompatibility complex (MHC) class I an d II alleles are necessary for recovery, as is a non-MHC gene, Rfv-3, which controls virus-specific antibody responses, In concordance with these genetic requirements are immunological requirements for cytotoxi c T lymphocyte, T helper, and antibody responses, each of which provid es essential nonoverlapping functions, The complexity of responses nec essary for recovery from Friend virus infection has implications for b oth immunotherapies and vaccines, For example, it is shown that succes sful passive antibody therapy is dependent on MHC type because of the requirement for T cell responses, For vaccines, successful immunizatio n requires priming of both T cell and B cell responses, In vivo deplet ion experiments demonstrate different requirements for CD8(+) T cells depending on the vaccine used, The implications of these studies for h uman retroviral diseases are discussed.