Resistance of lymphocytic choriomeningitis virus to alpha/beta interferon and to gamma interferon

The susceptibility to alpha/beta interferon (IFN-α/β) or to gamma interferon (IFN-γ) of various lymphocytic choriomeningitis virus (LCMV) strains was evaluated in C57BL/6 mice and in various cell lines. Anti-IFN-γ treatment in vivo revealed that the LCMV strains Armstrong, Aggressive, and WE were most susceptible to IFN-γ whereas Traub, CI 13-Armstrong, and Docile were resistant. The same pattern of susceptibility to recombinant IFN-γ was observed in vitro. In vivo treatment with anti-IFN-α/β showed a sizeable increase in replication of Aggressive, Armstrong, and WE; effects were less pronounced for Docile, CI 13-Armstrong, or Traub. Correspondingly, WE, Armstrong, and Aggressive were all relatively sensitive to purified IFN- α/β in vitro, and CI 13-Armstrong, Docile, and Traub were more resistant. Overall, there was a good correlation between the capacity of LCMV strains to establish a persistent infection in adult immunocompetent mice and their relative resistance to IFN-γ and IFN-α/β.