Deficiency of MCP-1/CCL2 and CCR2 affects NTHI-induced regulation of other CC chemokines. qRT-PCR shows that NTHI-induced up-regulation of MCP-2/CCL8 is markedly enhanced in SLFs of MCP-1-/- mice compared to the wild type mouse (A). It is noted that the regulation of MCP-3/CCL7 is not affected. CCR2 deficiency enhances NTHI-induced up-regulation of MCP-1/CCL2, but not MCP-2/CCL8 (B). Primary SLFs derived from the wild type, MCP-1-deficient and CCR2-deficient mice were exposed to the NTHI lysate for 3 h. Results were expressed relative to the fold change of mRNA levels, taking the value of the non-treated group as 1. MCP-1/CCL2 deficiency up-regulates CCR2 expression in the splenocytes, but CCR1 expression is not affected (C). mRNA levels of CCR1 and CCR2 were relatively shown, taking the CCR2 level of the wild type splenocytes as 1. *: p < 0.05. The experiments were performed in triplicate and repeated three times. Values are given as the mean ± standard deviation.