However, we cannot exclude that the lack of JamB expression also favors a

better control of metastasis by the immune system since our results show that metastasis of B16F10 expressing ovalbumin are totally cured by cytolytic T cells directed against ovalbumin without the need of priming. Ongoing experiments AZD5363 in vitro aim to define whether JamB and/or JamC are involved in cytolytic T cell recruitment and activation at metastatic sites. This will help to decipher if preventing metastasis with anti-JamC treatment will be counter-balanced by adverse effects on the immune system. 1 M. Aurrand-Lions et al., J Immunol 174 (10), (2005). 2 C. Lamagna et al., Cancer research 65 (13), (2005). 3 C. Zimmerli et al., J Immunol 182 (8), (2009). 4 C. Fuse et al., J MI-503 solubility dmso Biological Chemistry 282 (11), (2007). O48 Epstein Barr Virus Infection in Hodgkin’s Lymphoma: A Mechanism Facilitating Induced Regulatory T Cells Recruitment Violaine Francois1, Olivier Morales1, Céline Miroux1, Stéphane Depil1, Anne-Valérie Decouvelaere2,

Pauline Lionne-Huyghe3, Hervé Groux4, Claude Auriault4, Yvan De Launoit1, Véronique Nutlin-3 nmr Pancre1, Nadira Delhem 1 1 CNRS, UMR 8161, Institut de Biologie de Lille, Lille, France, 2 Service d’Anatomo-Pathologie, Pôle Biologie Pathologie, Eurasanté, Lille, France, 3 Service des Maladies du sang, CHRU, Lille, France, 4 UMR 6097, IPMC, Nice, France Purpose: CD4+ helper and

regulatory T cells play important but opposing roles in regulating host immune responses against Hodgkin’s Lymphoma (HL). MTMR9 In 20–40% of patients with HL, Epstein Barr Virus (EBV) is present in the neoplastic cells, however very little is known about regulatory mechanisms induced in presence of EBV. Here, we described associations of regulatory T cells (Treg) with EBV-positive and EBV-negative Hodgkin’s lymphoma. Methods: In a retrospective, population-based study, patients with Hodgkin’s lymphoma were reclassified according to the WHO classification, and EBV status was assessed by in-situ hybridisation of EBV-encoded small RNAs. Using quantitative real time PCR, we first analyzed gene expression of chemokines, immunosuppressive cytokines and regulatory T cells markers on RNA isolated from nodes of 20 EBV-positive HL patients and from 20 EBV-negative HL patients. We also investigated presence of regulatory T cell markers in PBMCs and sequential tonsil biopsies of HL patients. Results: We described in nodes of EBV-positive HL patients, a significant increase of gene expression for the major immunosuppressive cytokine: IL-10 which was correlated with an increased gene expression of several markers of regulatory T cells (CD4+CD25+, Fox P3,CTLA4, GITR). This increase was confirmed by immunohistochemical on frozen nodes biopsies and by flow cytometry on PBMCs of HL patients.