The immune response is heavily driven by the chemical and molecular milieu at the site of injury and/or infection. Immune cell function is dictated by a plethora of signaling molecules, including cytokines, chemokines, and growth factors, secreted by immune cells, local cells, pathogens, and tumor cells. These molecules regulate immune cell migration, infiltration, phenotype, activation, and potency. The physical properties of the local environment also affect the immune response. For example, increased vascular permeability is critical for facilitating the movement of immune cells from the circulation into the tissue, while extracellular matrix degradation is immunosuppressive.1
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1. D.F. Quail and J.A. Joyce. “Microenvironmental regulation of tumor progression and metastasis,” Nat Med
19(11): 1423-1437, 2013.