Antitumoral activity of Enterococcus faecalis CECT7121 on a T- cell lymphoma.

MOLINA MATÍAS; DI SCIULLO PAULA; CASTRO MARISA; SPARO MÓNICA; MONGINI CLAUDIA; MANGHI MARCELA

Rio de Janeiro. Brasil

Congreso; 13th International Congress of Immunology; 2007

Currently it results of interest to evaluate microorganisms with anti-tumoral activity. In previous works we demonstrated in BALB/c mice that Enterococcus faecalis CECT7121 (Ef CECT7121) induces the production of IL-6, IL-12p40 and TNFa by peritoneal macrophages. LBC is an aggressive T-cell lymphoma that kills the host in 17 days when is inoculated intraperitoneally (ip) at 1x106. The aim of this work was to study the anti-tumor effects of Ef CECT7121 on LBC cells. Syngeneic BALB/c mice (n11) previosly injeted ip with 2.5x108 UFC of Ef CECT7121 a day before, were inoculated ip with 106 LBC cells per mouse. The percentage of survivors (% SV) was recorded. At day 30, 70% of mice pretreated with Ef CECT7121 survived while no survival mice were recorded in control group. In vitro, LBC cell proliferation measured by 3H thymidine uptake was inhibited (15-25%) by Ef CECT7121 when co-cultivated during 24 h in a dose dependent manner, without any effect on normal splenocytes. This data correlated with apoptosis results determined by Acridine Orange and Ethidium Bromide staining and DNA nucleosomal fragmentation. Our results show that Ef CECT7121 has an antiproliferative activity both in vitro and in vivo on LBC T-cell lymphoma. This effect is dose-dependent and suggests that inhibition of cellular viability may be attributed to the fact that Ef CECT7121 may bind to the membrana receptor sites of the susceptible cells.