Characterization and in vivo distribution of influenza-virus-specific T-lymphocytes in the murine respiratory tract.

Cloned populations of antigen-specific, murine T-lymphocytes, maintained in long-term continuous culture, have been reported to exhibit functional activity upon adoptive transfer. Few data are currently available on the in vivo distribution of these homogeneous, functional cell populations. Such information is important to understanding the mechanisms by which T-lymphocytes exert their effector activity. We examined 2 cloned populations of influenza virus-specific T-lymphocytes. One clone was a Lyt-2+, L3T4-, class I MHC-restricted, cytolytic T-lymphocyte subset. The other clone was a Lyt-2-, L3T4+, Class II MHC-restricted clone of the helper/amplifier T-cell subset. Both clones promote recovery from lethal pulmonary influenza infection upon adoptive transfer. Using cell populations labeled with [3H]thymidine, we examined the distribution of these cells in tissue sections from various organs. These cloned cell populations were preferentially retained in the lungs of uninfected and influenza-virus-infected animals. This retention is independent of the cell's viral antigenic specificity, but may be dependent on the phenotype of the clone. Once retained in the lungs, these cells migrated across the bronchial lamina propria and entered the epithelium and pulmonary lumen. The significance of these observations for in vivo T-lymphocyte functions is discussed.