Cell-mediated immune response to influenza virus infections in mice.

The local and systemic cell-mediated immune (CMI) responses to influenza virus infection in mice were examined by leukocyte migration inhibition and lymphocyte-mediated cytotoxicity tests. Mice were inoculated intranasally with 5 50% lethal doses of the A/WSN (H0N1) strain of influenza virus. Cells from the lymph nodes draining the upper and lower respiratory tract were used to measure the local response, and the spleen was the source of cells used for systemic determinations. The local response by pulmonary lymph node cells was greater and appeared earlier than was observed systemically in the spleen. The specificity of the CMI response was investigated by using a heterologous virus strain, A/Jap (H2N2), and recombinants A/Jap-NWS (H2N1) and A/NWS-Jap (H0N1), obtained from a cross between A/Jap (H2N2) and a virus, A/NWS (H0N1), with surface antigenic specificity similar to that of the inoculated virus. From the results of both tests used as correlates of CMI, it appeared that the response was specific against the hemagglutinin component of the inoculated virus. No reactivity was observed against the heterologous virus A/Jap (H2N2) nor against the recombinant A/Jap-NWS (H2N1) bearing the same neuradminidase as that of the inoculated virus.