IL22 and susceptibility to pneumonia measurement: Because IL-23 is, with IL-1b, a key developmental/survival cytokine for both ILCs and adaptive γδ T lymphocytes [27,28,29,38,39,41] and has been shown to be essential for the induction of IL-22 in Klebsiella pneumoniae and Streptococcus.pneumoniae lung infection models [9,38], we hypothesized that over-expression of IL-23, through an adenovirus-mediated strategy would rescue mice against a lethal dose of PAO1.