Respiratory syncytial virus G and/or SH protein alters Th1 cytokines, natural killer cells, and neutrophils responding to pulmonary infection in BALB/c mice

BALB/c mice sensitized to vaccinia virus expressed G protein of respiratory syncytial virus (RSV) develop a Th2-type cytokine response and pulmonary e osinophilia when challenged with live RSV. In this study, BALB/c mice were immunized or challenged with am RSV mutant lacking the G and SH proteins or with DNA vaccines coding for RSV G or F protein. F or G protein DNA vaccin es were capable of sensitizing for pulmonary eosinophilia. The absence of t he G and/or SH protein in the infecting virus resulted in a consistent incr ease both in pulmonary natural killer cells and in gamma interferon and tum or necrosis factor expression, as well as, with primary infection, a variab le increase in neutrophils and CD11b(+) cells. The development of pulmonary eosinophilia in formalin-inactivated RSV-vaccinated mice required the pres ence of the G and/or SH protein in the challenge virus. These data show tha t G and/or SH protein has a marked impact on the inflammatory and innate im mune response to RSV infection.