CCL2 and infection: To study the influence of B1R/B2R on the inflammatory response at the primary site of infection, we measured cytokine (tumor necrosis factor (TNF) α, interleukin (IL)-1β, and IL-6) and chemokine (CXCL1, CXCL2, and CCL2) levels in whole lung homogenates (Fig. 2).