Pulmonary epithelial T cells induced by viral infection express T cell receptors α/β

Abstract

Cells were recovered from the lungs of mice by bronchoalveolar lavage before and after infection with respiratory syncytial (RS) virus. Uninfected mice yielded mostly macrophages, but after RS virus infection lymphocytes also appeared. Recovered cells were stained for CD4, CD8 and either CD3, T cell receptor (TcR) α/β or TcR γ/δ and analyzed by 3-color flow cytometry. Both the CD4⁺CD8⁻ and CD4⁻CD8⁺ subpopulations stained uniformly for CD3 and TcR α/β, while none stained for TcR γ/δ. Of the CD4⁻CD8⁻ cells, about 5% stained for CD3 and TcR α/β during the first week after infection, although this figure increased during the second week. A small and variable fraction of this subset stained for TcR γ/δ. These results oppose the view that lymphocytes expressing TcR γ/δ predominate in initial epithelial immune responses to viral infections.