Inflammatory responses are key to controlling infectious challenge however they must be tightly regulated in order to avoid damaging the functional tissue within which they are being expressed. The IL-12 family of cytokines is recognized to play an important role in regulating the antigen-specific lymphocyte response during inflammation but these cytokines can also regulate the function of innate lymphocytes and myeloid cells at the site of initial challenge. In this session I will discuss the role of several IL-12 family members in generating and modulating the early inflammatory response to bacterial challenge in the lung.