CCL2 and infection: In murine models of pulmonary infections by Gram-negative bacteria such as Klebsiella pneumoniae, by Gram-positive bacteria such as Mycobacterium tuberculosis, or by H1N1 influenza virus, infected mice generate neuroinflammation without direct infection in the brain, with elevated levels of IL-1β, TNFα, keratinocyte chemoattractant (KC), IL-12, IL-17, IP-10/CXCL10, DAMP S100A8, monocyte chemoattractant protein-1 (MCP1), IFN-γ, iNOS, and 2,3-dioxygenase (IDO).