CCL2 and infection: Compared to ΔClbA and the control group, production of inflammatory cytokines IL-1a, IL-1b, IL-6, IL-12, and G-CSF, and chemokines KC (IL-8), MCP-1 (CCL2), MIP-1a (CCL3), and MIP-1b (CCL4), was significantly increased upon K. pneumoniae 1084S infections in the brain (Figure 5).