B cells inhibits the antitumor immunity against an established murine fibrosarcoma

MAGLIOCO, ANDREA; MACHUCA, DAMIÁN; BADANO, MARÍA NOEL; NANNINI, PAULA; CAMERANO, GABRIELA VERÓNICA; COSTA, HECTOR; MEISS, ROBERTO; RUGGIERO, RAÚL; GIORDANO, MIRTA; DRAN, GRACIELA

Oncology Letters

Spandidos publications UK LTD

Lugar: Londres; Año: 2017 vol. 13 p. 3225 - 3232

Despite B cell classic role in favouring immune response, an inhibitory role for B lymphocytes in tumor immunity has been recently turned into focus. In the mouse fibrosarcoma MCC, the loss of immunogenicity and the establishment of tolerance are paralleled by systemic immune suppression and the appearance of IL-10- producing B cells in the tumor- draining lymph nodes. The aim of this paper was to study the role of B cells in the immune evasion and tolerance exhibited by MCC by means of depleting these cells in tumor bearing mice. We found that B cell depletion, once the tumor is established resulted in lower tumor growth and delayed onset of tolerance. Additionally, B cell absence exacerbated T cell dependent- tumor rejection, reduced the regulatory T cell population and increased cytotoxic CD8+ T cells both in the lymph node and tumor tissue. More, T cell dependent- tumor rejection was increased in B cell- absence. Contrarily to these signs of immune activation, B cell depletion performed before tumor implantation resulted in enhanced tumor progression[C1] suggesting the inhibition of the immune antitumor response. In vitro analysis showed a direct effect of B cells upon T cell proliferation partially mediated by IL-10 secretion. These results suggest that B cells contribute to the immunological tolerance of MCC tumor and that B cell depletion would unmask a pre- existing antitumor response. The present findings draw attention to the convenience of modulating B cells in the development of future and more effective immunotherapies against cancer.