Figure 3. Mast cells regulate the infiltration and function of Treg cells in tumor microenvironment.

(A) Mast cells regulate the infiltration of Treg cells. 5×10⁶ BMMCs with or without anti-SCF or c-kit antibodies, were injected into tumor-bearing mice by i.v. injection. Bone marrow cells were used as control. Seven days later, the tumor-infiltrating lymphocytes were used to analyze CD3⁺Foxp3⁺ Treg cells by flow cytometry. The left shown was the representative of FACS profiles. The right shown was the combined reproducible data (n = 6), *, P<0.05, compared to BM cell control. (B) Mast cells regulate the suppressive function of Treg cells. BMMCs with or without antibodies, were injected into tumor-bearing mice (n = 6). Seven days later, tumor-infiltrating Treg cells were isolated as described in Materials and Methods and the suppression assay was performed as described in Materials and Methods .