Fig 6. Schematic diagram shows the basal immunophenotyping of axillary Th cells of non-IBC vs. IBC patients, and the immunoregulatory role of tumor Sdc-1 for CD4⁺ Th cell polarization of non-IBC patients.

(A) IBC patients are characterized by lower frequencies of circulating Th₁ and Th₂ subsets drained from axillary tributaries as compared to non-IBC patients. Relative to other Th subsets, T_reg (CD4⁺Foxp3⁺) subset represents the lowest frequency among Th cells of non-IBC patients. (B) Upregulation of IL-23 and DLL4 expression mediated by Sdc-1 silencing in IBC cells may drive Th₁₇ polarization under indirect and direct co-culture conditions. In addition, Sdc-1 silencing enhances T_reg cell polarization under both indirect and direct co-culture conditions, whereas induces only Th₁ polarization under indirect co-culture conditions.