Regulatory B cells present in lymph nodes draining a murine tumor

MAGLIOCO ANDREA; MACHUCA DAMIAN; CAMERANO GABRIELA; COSTA HÉCTOR; RUGGIERO RAÚL; DRAN GRACIELA

MEDICINA (BUENOS AIRES)

MEDICINA (BUENOS AIRES)

Lugar: Buenos Aires; Año: 2014 p. 185 - 188

0025-7680

In cancer, B cells have been classically associated with antibody secretion, antigen presentation and T cell activation. However, a possible role for B lymphocytes in impairing antitumor response and collaborating with tumor growth has been brought into focus by the recently described capacity of B cells to negatively affect immune responses in autoimmune diseases. The highly immunogenic mouse tumor MCC loses its immunogenicity and induces systemic immunosuppression and tolerance as it grows. In this model we have previously demonstrated that MCC growth is paralleled by a marked and progressive increase in B cell number and proportion in the tumor draining lymph nodes (TDLN), along with a less prominent increase in T regulatory cells. The aim of this work was to study B cell characteristics and function in the lymph nodes draining MCC tumor and to analyze whether these cells may be playing a role in suppressing antitumor response and favoring tumor progression. Results indicate that B cell from TDLN expressed increased CD86 and MHCII co-stimulatory molecules denoting activated phenotype, as well as intracellular IL-10, FASL and Granzyme B, molecules with regulatory immunosuppressive properties. Additionally, B cells showed high inhibitory activity upon T cell proliferation ex vivo, and a mild capacity to secrete antibodies. We conclude that even when evidence of B cell-mediated activation of the immune response is present, B cells from TDLN exhibit regulatory phenotype and inhibitory activity, probably contributing to the state of immunological tolerance characteristic of the advanced tumor state.