CCL2 and infection: Finally, when Gardner et al. (13) compared infections of C57BL/6 mice with either LR or a 1960s Asian isolate closely related to the AF15561 strain, they found notably less inflammatory infiltrate in the feet of Asian strain-infected mice, as well as lower peak footpad swelling and significantly lower levels of monocyte chemoattractant protein 1 (MCP-1), gamma interferon (IFN-γ), and alpha/beta interferon (IFN-α/β).