Conditioned media (CM) from CMT167 cells induces higher levels of PD-L1 in bone marrow derived macrophages than CM from LLC cells. (A) Bone marrow derived macrophages were treated with CM from CMT167 cells or LLC cells. Data represent the mean of 3 experiments using 3 separate isolations of CM. (B) A representative overlay of PD-L1 expression is shown from untreated BMDMs (blue), BMDMs treated with LLC CM (green), and BMDMs treated with CMT167 CM (red). Similar results were obtained in 3 independent experiments using 3 separate isolations of CM. (C) IL7 and IL15 mRNA expression was determined by RNA-seq from CMT167 cells and LLC cells, both in vitro and in vivo. (D) Effects of IL7 and IL15 neutralization on upregulation of PD-L1 on BMDMs induced by CMT167 CM. Data represent the mean and SEM from 3 independent experiments. Statistically significant differences are indicated as determined by one-way ANOVA; * = P < 0.05, ** = P < 0.01, *** = P < 0.001.