Cytotoxic activity of normal killers and the lymphocytic proliferative response to specific viral antigens in influenza in mice

Inoculation of CBA mice with pathogenic influenza A/PR8/34 (H1N1) virus and non-pathogenic A/Krasnodar/101/59 (H2N2) virus demonstrated that the pathogenic strain enhanced the synthesis of serum interferon and activated the function of normal killers, but had a relatively low capacity of causing in vitro proliferative response of spleen lymphocytes of intact and in vivo primed animals. In contrast, the nonpathogenic virus had less marked interferon-inducing capacity and that of activating normal killers, but induced a very high proliferative response of lymphocytes in culture.