Two-Step schedule of anti-tumor immunotherapy: anti-inflammatory treatment and dendritic cell-based vaccination

PAULA CHIARELLA; JUAN BRUZZO; GABRIELA C. FERNANDEZ; VERMEULEN MONICA; MARISA VULCANO; MARTIN A. ISTURIZ; OSCAR D. BUSTUOABAD; RAUL A. RUGGIERO

National Hellenic Research Foundation. Athens-Greece.

Congreso; Recent Advances in Cancer Immunotherapy with an emphasis on vaccines.; 2008

Although animals can be prophylactically immunized against the growth of some tumor implants, most of the attempts to use immunotherapy to cause the regression of animal and human tumors once they have become established have been unsuccessful, even when strongly immunogenic murine tumors were used as target. The aim of this work was to understand the nature of this refractoriness in order to elaborate an efficient immunotherapeutic schedule. By employing a strong immunogenic murine fibrosarcoma (MC-C), we have demonstrated that MC-C tumor bearing mice can generate a T-cell mediated antitumor immune response which disappears when MC-C grows over 500 mm3. This tumor-associated immunosupression was coincidental with the emergence of a systemic inflammatory condition characterized by: a) a high number of circulating and splenic granulocytes, most of them displaying activation and high expression of Gr1+ Mac1+ markers (n=6, p