Live attenuated influenza virus (LAIV) induces different mucosal T cell function in nonsmokers and smokers.

Smokers are more susceptible to respiratory infections, including influenza. To explore the effect of smoking on influenza-induced responses within the nasal mucosa, we have developed a protocol using inoculation with live attenuated influenza virus (LAIV) vaccine followed by sampling of the nasal mucosa. Mucosal cell populations were harvested through superficial biopsy of the nasal inferior turbinate pre and post LAIV inoculation and analyzed using flow cytometry. The majority of nasal biopsy CD45+ immune cells at baseline were CD3+ T lymphocytes. Following LAIV, these lymphocytes increased in nonsmokers but not in smokers. A subset of individuals was negative for helper T cell marker CD4 and cytotoxic T cell marker CD8 but positive for the γδ T cell receptor (TCR). Increases in γδ TCR+ cells were greater in nonsmokers, than in smokers. Thus, LAIV-induced changes in CD3 T as well as γδ T lymphocyte percentages are suppressed in smokers compared to nonsmokers.