Tumoral immune suppression by macrophages expressing fibroblast activation protein-α and heme oxygenase-1.

ABSTRACT: The depletion of tumor stromal cells that are marked by their expression of the membrane protein fibroblast activation protein-α (FAP) overcomes immune suppression and allows an anticancer cell immune response to control tumor growth. In subcutaneous tumors established with immunogenic Lewis lung carcinoma cells expressing ovalbumin (LL2/OVA), the FAP(+) population is comprised of CD45(+) and CD45(-) cells. In the present study, we further characterize the tumoral FAP(+)/CD45(+) population as a minor subpopulation of F4/80(hi)/CCR2(+)/CD206(+) M2 macrophages. Using bone marrow chimeric mice in which the primate diphtheria toxin receptor is restricted either to the FAP(+)/CD45(+) or to the FAP(+)/CD45(-) subset, we demonstrate by conditionally depleting each subset that both independently c

SUBMITTER: Arnold JN 

PROVIDER: S-EPMC4007628 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature