@article{MontalbandelBarrioPenskiSchlahsaetal.2016,
  author    = {Montalb{\´a}n del Barrio, Itsaso and Penski, Cornelia and Schlahsa, Laura and Stein, Roland G. and Diessner, Joachim and W{\"o}ckel, Achim and Dietl, Johannes and Lutz, Manfred B. and Mittelbronn, Michel and Wischhusen, J{\"o}rg and H{\"a}usler, Sebastian F. M.},
  title     = {Adenosine-generating ovarian cancer cells attract myeloid cells which differentiate into adenosine-generating tumor associated macrophages - a self-amplifying, CD39- and CD73-dependent mechanism for tumor immune escape},
  series = {Journal for ImmunoTherapy of Cancer},
  volume    = {4},
  journal   = {Journal for ImmunoTherapy of Cancer},
  number    = {49},
  doi       = {10.1186/s40425-016-0154-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-146624},
  year      = {2016},
  abstract  = {Background Ovarian cancer (OvCA) tissues show abundant expression of the ectonucleotidases CD39 and CD73 which generate immunomodulatory adenosine, thereby inhibiting cytotoxic lymphocytes. Little, however, is known about the effect of adenosine on myeloid cells. Considering that tumor associated macrophages (TAM) and myeloid-derived suppressor cells (MDSC) constitute up to 20 \% of OvCA tissue, we investigated the effect of adenosine on myeloid cells and explored a possible contribution of myeloid cells to adenosine generation in vitro and ex vivo. Methods Monocytes were used as human blood-derived myeloid cells. After co-incubation with SK-OV-3 or OAW-42 OvCA cells, monocyte migration was determined in transwell assays. For conversion into M2-polarized "TAM-like" macrophages, monocytes were co-incubated with OAW-42 cells. Ex vivo TAMs were obtained from OvCA ascites. Macrophage phenotypes were investigated by intracellular staining for IL-10 and IL-12. CD39 and CD73 expression were assessed by FACS analysis both on in vitro-induced TAM-like macrophages and on ascites-derived ex situ-TAMs. Myeloid cells in solid tumor tissue were analyzed by immunohistochemistry. Generation of biologically active adenosine by TAM-like macrophages was measured in luciferase-based reporter assays. Functional effects of adenosine were investigated in proliferation-experiments with CD4+ T cells and specific inhibitors. Results When CD39 or CD73 activity on OvCA cells were blocked, the migration of monocytes towards OvCA cells was significantly decreased. In vivo, myeloid cells in solid ovarian cancer tissue were found to express CD39 whereas CD73 was mainly detected on stromal fibroblasts. Ex situ-TAMs and in vitro differentiated TAM-like cells, however, upregulated the expression of CD39 and CD73 compared to monocytes or M1 macrophages. Expression of ectonucleotidases also translated into increased levels of biologically active adenosine. Accordingly, co-incubation with these TAMs suppressed CD4+ T cell proliferation which could be rescued via blockade of CD39 or CD73. Conclusion Adenosine generated by OvCA cells likely contributes to the recruitment of TAMs which further amplify adenosine-dependent immunosuppression via additional ectonucleotidase activity. In solid ovarian cancer tissue, TAMs express CD39 while CD73 is found on stromal fibroblasts. Accordingly, small molecule inhibitors of CD39 or CD73 could improve immune responses in ovarian cancer.},
  language  = {en}
}
@article{HarterBernatzScholzetal.2015,
  author    = {Harter, Patrick N. and Bernatz, Simon and Scholz, Alexander and Zeiner, Pia S. and Zinke, Jenny and Kiyose, Makoto and Blasel, Stella and Beschorner, Rudi and Senft, Christian and Bender, Benjamin and Ronellenfitsch, Michael W. and Wikman, Harriet and Glatzel, Markus and Meinhardt, Matthias and Juratli, Tareq A. and Steinbach, Joachim P. and Plate, Karl H. and Wischhusen, J{\"o}rg and Weide, Benjamin and Mittelbronn, Michel},
  title     = {Distribution and prognostic relevance of tumor-infiltrating lymphocytes (TILs) and PD-1/PD-L1 immune checkpoints in human brain metastases},
  series = {Oncotarget},
  volume    = {6},
  journal   = {Oncotarget},
  number    = {38},
  doi       = {10.18632/oncotarget.5696},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-137107},
  pages     = {40836 -- 40849},
  year      = {2015},
  abstract  = {The activation of immune cells by targeting checkpoint inhibitors showed promising results with increased patient survival in distinct primary cancers. Since only limited data exist for human brain metastases, we aimed at characterizing tumor infiltrating lymphocytes (TILs) and expression of immune checkpoints in the respective tumors. Two brain metastases cohorts, a mixed entity cohort (n = 252) and a breast carcinoma validation cohort (n = 96) were analyzed for CD3+, CD8+, FOXP3+, PD-1+ lymphocytes and PD-L1+ tumor cells by immunohistochemistry. Analyses for association with clinico-epidemiological and neuroradiological parameters such as patient survival or tumor size were performed. TILs infiltrated brain metastases in three different patterns (stromal, peritumoral, diffuse). While carcinomas often show a strong stromal infiltration, TILs in melanomas often diffusely infiltrate the tumors. Highest levels of CD3+ and CD8+ lymphocytes were seen in renal cell carcinomas (RCC) and strongest PD-1 levels on RCCs and melanomas. High amounts of TILs, high ratios of PD-1+/CD8+ cells and high levels of PD-L1 were negatively correlated with brain metastases size, indicating that in smaller brain metastases CD8+ immune response might get blocked. PD-L1 expression strongly correlated with TILs and FOXP3 expression. No significant association of patient survival with TILs was observed, while high levels of PD-L1 showed a strong trend towards better survival in melanoma brain metastases (Log-Rank p = 0.0537). In summary, melanomas and RCCs seem to be the most immunogenic entities. Differences in immunotherapeutic response between tumor entities regarding brain metastases might be attributable to this finding and need further investigation in larger patient cohorts.},
  language  = {en}
}