Cell type specific effects of TREM-2 on S. pneumoniae and TLR2 mediated cytokine production.

(A–B) WT and Trem-2−/− BMDM (n = 4 per genotype) were treated with 2×107 CFU/ml S. pneumoniae or 100 ng/ml LPS for 6 h and TNF-α (A) or KC (B) levels were measured in the supernatant. (C–D) WT and Trem-2−/− AM (n = 4 per genotype/time point) were treated with 2×107 CFU/ml S. pneumoniae (C) or 10 µg/ml S. pneumoniae LTA (D) for the indicated times and KC and TNF-α levels were measured in the supernatant. (E–F) WT and Trem-2−/− AM (n = 4 per genotype/MOI) were treated with the indicated doses of S. pneumoniae and TNF-α (E) and KC (F) levels were determined in the supernatant. Statistical comparisons are done versus WT cells (A–B) at a given timepoint (C–D), or at a particular MOI of S. pneumoniae (E–F), and indicated as: * p<0.05, ** p<0.005, *** p<0.001, **** p = <0.0001. All data represent mean ± SEM and are representative of two independent experiments.