Effect of EMAPII on dendritic cells

Abstract

Scope and Method of Study:

EMAPII, a multi functional cytokine has been considered for anti-tumor therapy owing to its anti angiogenic properties. However, the effects of EMAPII on immune system cells like dendritic cells have not been studied. In this study, we analyzed the effects of EMAPII on dendritic cells that play a very important role in mounting anti tumor immunity. Various in vitro, in vivo and ex vivo studies were conducted to analyze the effect of EMAPII on dendritic cells.

Findings and Conclusions:

Endothelial Monocyte Activating Polypeptide (EMAPII) is chemotactic for dendritic cells. EMAPII reduces the release of T cell chemoattractants by dendritic cells and decreases the expression of cytokines such as IL12,IL3,IL7 that are important for activating T cells. It also down regulates the expression of CD40 ligand on dendritic cells that would render the associating T cells tolerogenic. Under normal conditions, EMAPII is released by apoptotic cells and plays an important role in inducing tolerance to self antigens. This property of EMAPII provides it with a potential to treat auto immune disorders. However, the ability of EMAPII to induce tolerance could be exploited by tumor cells. Induction of tolerance to self antigens would render tumor cells unsusceptible to immune clearance. From our data we conclude that EMAPII favors tumor survival and is not a suitable candidate for anti tumor therapy.