STUDY OF THE EXPRESSION OF CD39 ON CD4 CONVENTIONAL T CELLS FROM TUMOR-BEARING MICE AND BREAST CANCER PATIENTS.

BOSSIO, SABRINA N.; RAMELLO, MARIA CECILIA; CANALE, FERNANDO P.; NUÑEZ, NICOLAS; PIAGGIO, ELIANE; GRUPPI ADRIANA; ACOSTA RODRIGUEZ E V; MONTES, CAROLINA L.

Mar del Plata

Congreso; LXIV Reunión científica anual de la Sociedad Argentina de Inmunología, en conjunto con la reunión anual de SAIC y SAFE.; 2016

Sociedad Argentina de Inmunología, en conjunto con la reunión anual de SAIC y SAFE.

(944) STUDY OF THE EXPRESSION OF CD39 ON CD4CONVENTIONAL T CELLS FROM TUMOR-BEARINGMICE AND BREAST CANCER PATIENTSSabrina Noemi Bossio1, María Cecilia Ramello1, FernandoPablo Canale1, Nicolás Gabriel Núñez2, Eliane Piaggio2,3,Adriana Gruppi1, Eva Virginia Acosta Rodríguez1, CarolinaLucía Montes1.1Centro de Investigaciones en Bioquímica Clínica e Inmunología(CIBICI-CONICET), Departamento de BioquímicaClínica, Facultad de Ciencias Químicas, Universidad Nacionalde Córdoba, Haya de la Torre y Medina Allende, CiudadUniversitaria, Córdoba, Argentina. 2Institut Curie, PSL ResearchUniversity, INSERM U932, F-75005, Paris, France.3Centre d?Investigation Clinique Biothérapie CICBT 1428,Institut Curie, Paris, F-75005 France.CD39 is an ecto-enzyme capable of hydrolyzing extracellularATP to AMP, which can be further hydrolyzed into adenosineby CD73. CD39 is expressed by different cell populations suchas B cells and Foxp3+ regulatory CD4+ T cells (Tregs), amongothers. We aimed to study the expression of CD39 on conventionalFoxp3- CD4+ T cells (Tconv) from tumor-bearing mice andpatients with breast cancer. C57BL/6 mice were injected withMCA cancer cells. Tumors, spleens and draining lymph nodes(dLN) were extracted on day 17. We observed higher frequencyof CD39-expressing Tconv in tumor respect to spleen (p≤0.001)and dLN (p≤0.001). In addition, CD39 expression was higher intumor-infiltrating Tconv respect to Tconv from spleen and dLN andcomparable to the expression on Tregs. We detected in tumorsthat 57,7±5,9% and 59,5±3,0% of CD39+ Tconv express CD73 andPD-1 respectively, while they do not express TIGIT. PD-1 expressionin CD39+ Tconv was significantly higher in tumors comparedto spleens and dLN (p≤0.001 in both). We observed that around60% of tumor-infiltraiting CD39+ Tconv exhibited effector memoryphenotype. Analysis of CD39 expression on T cells from tumorand metastasic (Met) or non-metastasic (NonMet) LN from cancerpatients, revealed that in tumor 13,7±5,7% of Tconv expressedCD39. The frequency of CD39-expressing Tconv was higher inMetLN respect to Non-MetLN and absent in peripheral blood.CD39+ Tconv in tumors and MetLN exhibited higher frequencyof PD-1+, TIGIT+ and BTLA+ cells than CD39- Tconv (p≤0.05).The higher expression of inhibitory receptors is associated withfunctional impairment, in fact, within CD39+ Tconv we detecteddecreased frequency of TNF and IFNγ-producing cells comparedto CD39- Tconv, in both, tumors and MetLN (p≤0.05). Togetherthese results suggest that tumor microenvironment drives theacquisition of immunoregulatory molecules on conventional CD4+T cells which may impact in tumor progression.