Bacteria challenge in smoke-exposed mice exacerbates inflammation and skews the inflammatory profile.

Rationale: The pathogenesis of chronic obstructive pulmonary disease is associated with acute episodes of bacterial exacerbations. The most commonly isolated bacteria during episodes of exacerbation is nontypeable Haemophilus influenzae (NTHI).Objectives: In this study, we investigated the in vivo consequences of cigarette smoke exposure on the inflammatory response to an NTHI challenge.Methods: C57BL/6 and BALB/c mice were exposed to cigarette smoke for 8 weeks and subsequently challenged intranasally with NTHI.Measurements and Main Results: We observed increased pulmonary inflammation and lung damage in cigarette smoke–exposed NTHI-challenged mice as compared with control NTHI-challenged mice. Furthermore, although NTHI challenge in control mice was marked by increases in tumor necrosis factor-α, IL-6, MIP-2, and KC/GROα, NTHI challenge in cigarette smoke–exposed mice led to a prominent up-regulation of a different subset of inflammatory mediators, most notably MCP-1, -3, and -5, IP-10, and MIP-1γ. This...