Figure 5.

The expression of toll-like receptors (TLRs) (I), cytokines (II), and chemokines (III) after 72 h of repeated particulate matter (PM) stimulation. The protein levels of toll-like receptors (TLRs), cytokines, and chemokines were determined by enzyme-linked immunosorbent assay. (A) The heat-treated PM₁₀ $\left({\text{PM}}_{\text{10}}^{-}\right)$ group. (B) The non-heat-treated PM₁₀ $\left({\text{PM}}_{\text{10}}^{+}\right)$ group. (C) Heat-treated PM_2.5 $\left({\text{PM}}_{\text{2.5}}^{-}\right)$ group. (D) The non-heat-treated PM_2.5 $\left({\text{PM}}_{\text{2.5}}^{+}\right)$ group. Data are presented as means ± SEs. Different letters indicate significant (p < 0.05) differences of mean value among the four experimental groups. The experiment was performed using six BALB/c mice per group.