BriefDefinitive Report HERPESVIRUS SAIMIRI STRAIN II IMMORTALIZES A RESTRICTED MARMOSET T8 LYMPHOCYTE SUBPOPULATION IN VITRO

Some viruses preferentially infect restricted subpopulations of lymphocytes . The pathogenesis of the diseases induced by these lymphotropic viruses is determined at least in part by this selectivity of infection . Herpesvirus saimiri, a lymphotropic herpesvirus that causes no apparent disease in its natural host Saimiri sciureus (squirrel monkey), induces a fulminant lymphoproliferative syndrome in a variety of other New World primate species (1) . Animals die after experimental H. saimiri infection, with manifestations that may include leukemia, parenchymal lymphocytic infiltration, and occasionally solid tumor masses . Lymphoblastoid cell lines derived from these tumors have been shown to express a number of T cell-associated membrane structures (2) . While extensive characterization of this virally induced disease has been carried out, little work has been done to elucidate the nature of the interactions between H. saimiri and the T lymphocyte . We have recently shown (3) that PBL of Callithrixjacchus (common marmoset) can be reproducibly immortalized in vitro by H. saimiri . This has facilitated the examination of interactions between this lymphotropic virus and its target cells . In the present study we have shown that lymphoid lines derived from common marmoset PBL by in vitro immortalization with H. saimiri strain 11 have NK cell function and phenotypic markers of both T cells (T 12, T8) and NK cells (NKH 1) . In fact, the H. saimiri strain 11 immortalized cell represents a remarkably restricted subset of the PBL population of the common marmoset .