Fig. 5

Chitin reduces immunosuppressive myeloid subpopulations and increases anti-PD-1-stimulated lymphocytic subpopulations in 4T1 and 66cl4 primary tumors. A-L Primary tumors were isolated from the untreated, anti-PD-1-, chitin- and chitin + anti-PD-treated 4T1- and 66cl4-based model at 5 w p.i. and processed into a single cell suspension for flow cytometric immunophenotyping (n = 5 for all groups). A,B Number of myeloid subpopulations (including PMN-MDSCs, M-MDSCs, TANs, TAMs and DCs) per gram of primary tumor in the untreated and treated 4T1- (A) and 66cl4-based model (B). C,D Number of M1 and M2 TAM subtypes per gram of primary tumor (C) and calculated M1/M2 TAM ratio (D) in the 4T1-based model. E,F Number of M1 and M2 TAM subtypes per gram of primary tumor (E) and calculated M1/M2 TAM ratio (F) in the 66cl4-based model. G,H Number of lymphocytic subpopulations (including CD4⁺ and CD8α⁺ T-cells, B-cells, NK cells and NK-T cells) per gram of primary tumor in the untreated and treated 4T1- (G) and 66cl4-based model (H). I,J Percentage of granzyme B⁺, Ki67⁺, IFN-γ⁺ and PD-1⁺ cells within the primary tumor CD8α⁺ T-cell population in the untreated and treated 4T1- (I) and 66cl4-based model (J). K,L Percentage of FoxP3⁺ cells within the primary tumor CD4⁺ T-cell population in the untreated and treated 4T1- (K) and 66cl4-based model (L). M,N Levels for MIP-2, MCP-1, IFN-γ and TNF-α in primary tumor lysates from the untreated and treated 4T1- (M) and 66cl4-based model (N) at 5 w p.i. (n = 5 for all groups in the 4T1-based model; n = 11 for all groups in the 66cl4-based model). Data are presented as the means ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001