cord-factors and Cardiovirus-Infections

Preventive intraperitoneal trehalose dimycolate (TDM) treatment of mice, inoculated with encephalomyocarditis (EMC) virus by the same route, caused restriction of virus growth in the peritoneum, which was correlated to IFN production in peritoneal fluids prior to infection. Peritoneal macrophages from TDM-treated mice (TDM-PM) spontaneously secreted IFN-alpha/beta in large amounts. By their supernatants, TDM-PM could transfer an antiviral state against EMC virus to permissive resident peritoneal macrophages from control mice. IFN-alpha/beta produced by TDM-PM was found to be involved in this transfer activity. TDM-PM also exerted a strong antiviral effect on EMC virus-infected L-929 cells, which increased with time and the macrophage-target cell ratio. This activity also occurred by an IFN-alpha/beta-dependent mechanism. These data point to the role of IFN-alpha/beta production prior to EMC virus infection in the antiviral activities of TDM-PM and, more generally, in the outcome of viral infection.

Topics: Animals; Antiviral Agents; Ascitic Fluid; Cardiovirus Infections; Cell Line; Cells, Cultured; Cord Factors; Disease Models, Animal; Encephalomyocarditis virus; Female; Interferon-alpha; Interferon-beta; Macrophages, Peritoneal; Mice

Preventive treatment of mice with trehalose 6,6' dimycolate (TDM), an immunomodulator of bacterial origin, enhances their resistance to encephalomyocarditis (EMC) virus infection. The protective effect of TDM is totally abolished by the injection of silica particles in mice, demonstrating the role of macrophages in the antiviral action of TDM. In vitro, peritoneal macrophages from mice treated with TDM (TDM-PM) exhibit an intrinsic antiviral activity against EMC virus, while resident peritoneal macrophages (RES-PM) are permissive to this virus. Greater amounts of interferon are detected in supernatants of cultures of TDM-PM than of RES-PM. Neutralization of interferon (IFN) by addition in vitro of anti-IFN alpha/beta serum markedly reduces the antiviral activity of TDM-PM. These results indicate that interferon alpha/beta is involved in the intrinsic anti-EMC virus activity of peritoneal macrophages from mice treated with TDM.

Topics: Animals; Brain; Cardiovirus Infections; Cells, Cultured; Cord Factors; Encephalomyocarditis virus; Female; Interferon-alpha; Interferon-beta; Interferons; Macrophages, Peritoneal; Mice; Silicon Dioxide