Protective Heterologous Antiviral Immunity and Enhanced Immunopathogenesis Mediated by Memory T Cell Populations

摘要: A basic principle of immunology is that prior immunity results in complete protection against a homologous agent. In this study, we show memory T cells specific to unrelated viruses may alter the host's primary immune response second virus. Studies with panel heterologous viruses, including lymphocytic choriomeningitis (LCMV), Pichinde (PV), vaccinia (VV), and murine cytomegalo (MCMV) showed one these many cases enhanced clearance virus early infection. Such protective was common, but it depended on sequence not necessarily reciprocal. Cell transfer studies both CD4 CD8 cell populations from LCMV-immune mice were required naive hosts challenged PV or VV. case versus VV, there an recruitment phenotype interferon (IFN) γ–secreting CD4+ CD8+ into peritoneal cavity increased IFN-γ levels initial site replication. receptor knockout confirmed role for mediating effect by when VV PV. some sequences populations, although clearing challenge more rapidly, elicited IFN-γ–dependent immunopathogenesis form acute fatty necrosis. These indicate how host responds infectious agent function its history previous infections their influence pool.