Th17 cells recognize a broader spectrum of bacterial antigens than antibodies. (A) Experimental design. Whole-cell lysate (WCL), cytosol (Cyto), and membrane (Mem) fractions, as well as outer membrane vesicles (OMVs) were isolated from NT127, Eagan, and 86-028NP. Hi, H. influenzae. (B) Reactivity of pooled immune sera from NT127-infected mice to different bacterial fractions was analyzed by ELISA. (C) Lung lymphocytes from NT127-infected mice were stimulated with different bacterial fractions, and IL-17 production by CD4 T cells was measured by ICS.