Figure 3.

Lactate in the tumor microenvironment. The tumor microenvironment (TME) is characterized by various cell types, including stromal and immune cells. Tumor cells secrete large amounts of lactate into TME, leading to acidosis, and modulate the metabolism of innate and adaptive immune cells, inhibiting the activation and proliferation of CD8⁺ T cells and NK cells. Lactate positively affects the immunosuppressive functions of Treg cells. Furthermore, lactate favors the polarization of alternatively activated (M2-like) phenotype macrophages, exerting an anti-inflammatory role, and participates in tumor growth and invasion.