Comparison of antitumoral and protumoral macrophage migration by targeting differentially regulated chemokine receptors

Macrophages can display various functional traits in the tumor microenvironment, depending on the tumor type and the stage of tumor progression. The polarized scheme of macrophage activation describes antitumoral (activation by INF-g) and protumoral (activation by IL-4) phenotypes. Tumor associated macrophages are attracted to the tumor by the combined effects of various factors, including chemokines. We investigated chemokine receptors CCR1, CCR2 and CCR5 in the directed migration of polarized macrophages, including a macrophage cell line, bone marrow derived macrophages and tumour associated macrophages of an experimental melanoma lung metastasis. Inhibiting chemokine receptors in lung colonization reduced the infiltration of both protumoral and antitumoral macrophages