Fig. 1.

L-MDSC expand in response to LM and suppress CAR-T. LM were established by splenic injections of either MC38 or MC38CEA tumor cells, and livers were harvested 2 weeks of tumor growth. Flow cytometry was used to evaluate the expansion of L-MDSC in response to LM. a Sequential gating of L-MDSC as live, CD11b+, and Gr-1+ liver leukocytes from normal or tumor-bearing livers. Cells were enriched by immunomagnetic beading for CD45+ NPC prior to staining. b Dot plot confirming high level of Gr-1 and CD11b co-expression among liver leukocytes. c L-MDSC were co-cultured with CFSE-labeled anti-CEA CAR-T stimulated by irradiated MC38CEA cells, and pooled results from three independent experiments are graphed. The percentages of cells having undergone division (CFSE-low) were normalized to the unstimulated group. Bar graphs represent mean ± SEM; dot plots and histograms are representative of ≥3 mice per group and have been confirmed with at least two separate experiments (*p ≤ 0.05, **p ≤ 0.01)