[Immune response of mice to experimental influenza]

The immune response of BALB/c mice to a pathogenic and nonpathogenic strains of influenza type A virus was studied. In this system of experimental influenza infection the pathogenic influenza A/PR8/34 (HON1) virus was found to induce sensitization of T-lymphocytes and production of clones cytotoxic for syngeneic target cells. Nonpathogenic influenza A/Krasnodar/101/59 (H2N2) virus had a less marked capacity to induce sensitization of lymphocytes and production of clones cytotoxic for syngeneic target cells. But the nonpathogenic virus strain had a sufficiently high mitogenic activity and stimulated proliferation of lymphocytes sensitized by a heterogenous influenza virus strain.