In ovarian cancer, the immune system fails to eradicate established tumors partly due to the induction of immune tolerance within tumor microenvironment. In this study, we investigated the contribution of plasmacytoid dendritic cells (pDC) in the establishment of immune tolerance in a cohort of 44 ovarian cancer patients. In the tumor and malignant ascites, CD4+CD123+BDCA2+ pDC were the most abundant dendritic cell subset; however, they were profoundly depleted in peripheral blood. The presence of pDC in primary ovarian cancer, but not ascites, was an independent prognostic factor associated with early relapse. Following chemotherapy, we observed a partial restoration of blood pDC levels in patients in complete remission. These findings show preferential recruitment of pDC into tumors where they express a partially mature phenotype that may reflect an in situ activation. Importantly, compared with pDC found in ascites or blood, tumor-associated pDC (TApDC) produced less IFN-?, TNF-?, IL-6, macrophage inflammatory protein-1?, and RANTES in response to toll-like receptor stimulation, and alterations in pDC functions were mainly mediated through tumor-derived TNF-? and TGF-?. Unlike ascites-derived pDC, TApDC induced IL-10 production from allogeneic naive CD4+ T lymphocytes, suggesting the existence of a paracrine immunosuppressive loop. Taken together, our findings indicate that both local and systemic dysfunction of pDC play a critical role in the progression of ovarian cancer via induction of immune tolerance. Cancer Res; 71(16); 5423–34. ©2011 AACR. cancerres.aacrjournals.org
... Read On
You can link to this article on your web site using following code:
We're looking for comments that are interesting, substantial or highly amusing. If your comments are excessively self-promotional (use your real name, no keywords please), obnoxious, or even worse, boring, you will be banned from commenting. Your comment must be related to the post. Please do not comment on how great or wonderful the post is. All comments are moderated and, if approved, will display in less than 24 hours.
comments powered by Disqus. blog comments powered by
Tags For This Article
cancer res, cd4 t lymphocytes, cells, cohort, Dendritic, immune tolerance, independent prognostic factor, inflammatory protein, ovarian, ovarian cancer patients, pDC, plasmacytoid dendritic cells, Quantitative, TApDC, tolerance, tumor microenvironment