ABSENCE OF TNFR1 ENHANCES INFILTRATION OF CD4 + /CD8 + T-LYMPHOCYTES IN THE TUMOR MICROENVIRONMENT REDUCING SUBCUTANEOUS MELANOMA GROWTH.

YAMILA RODRIGUEZ; CECILIA DELLA VEDOVA; SERGIO E ALVAREZ; LUDMILA CAMPOS; DIEGO CROCI; MELINA CASTRO; DARÍO RAMIREZ

Mar del Plata

Congreso; LXI REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIÓN CLÍNICA (SAIC); 2016

A tumor is not simply a mass of genetically modified andidentical cells. eoplastic cells are in close interaction ith endothelial,stromal and immune cells by both cellcell contact andsoluble factors in the tumor microenvironment. The participationof natural iller cells, C and C T lymphocytes TLand proinflammatory macrophages are determinant in cancerregression. Hoever, tumor cells have mechanisms to evadethe immune response and modulate the microenvironment alloingthe establishment of cell phenotypes that promote tumorgroth, invasion and metastasis. Thus, the tumor microenvironmenthas a crucial role in cancer progression. Indeed, in a modelofsubcutaneous implantation of F murine melanoma cells,e have previously shon a diminished tumor groth in tumornecrosis alpha receptor TF mice compared to ildtype T mice. Here, e aimed to establish the role of immunecells and cytoines in this differential response. The number oflie tumor associated macrophages TAs F/ Cand lymphocytic infiltrate C C LT as evaluated by flocytometry in tumor samples collected days after inoculationof F cells. n addition, e estimated CCL and L levelsby C and ELSA respectively. Although expression of CCLchemoine involved in macrophage recruitment as significantlyhigher in tumor tissue from TF mice, no differences in thenumber or TAs ere observed. Furthermore, reduced levelsof L in TF mice ere accompanied by a significantlyhigher lymphocytic infiltrate C and C. Altogether, thesedata indicates that absence of TF in CL/ mice enhancesantitumor immune responses leading to diminished tumor groth.