AUTHOR=Lu Kun-Hui , Tounsi Amel , Shridhar Naveen , Küblbeck Günter , Klevenz Alexandra , Prokosch Sandra , Bald Tobias , Tüting Thomas , Arnold Bernd 

TITLE=Dickkopf-3 Contributes to the Regulation of Anti-Tumor Immune Responses by Mesenchymal Stem Cells

JOURNAL=Frontiers in Immunology

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2015.00645

DOI=10.3389/fimmu.2015.00645

ISSN=1664-3224

ABSTRACT=<p>Mesenchymal stem cells (MSCs) are known to limit immune responses <italic>in vivo</italic> by multiple soluble factors. Dickkopf-3 (DKK3), a secreted glycoprotein, has recently been identified as a novel immune modulator. Since DKK3 has been reported to be produced by MSCs, we investigated whether DKK3 contributes to the immune suppression of anti-tumor responses by MSCs. Whereas wild-type MSCs inhibited immune responses against two different transplantation tumors, DKK3-deficient MSCs did not affect the rejection process. Increased CD8<sup>+</sup> T cell and reduced M2-type macrophages infiltration was observed in tumors inoculated together with DKK3-deficient MSCs. Thus, DKK3 could alter the composition of the tumor stroma, thereby supporting the MSCs-mediated suppression of immune responses against these tumor transplants.</p>