Potential use of immunobiotic lactic acid bacteria for the recovery of innate immune response in a cyclophosphamide-immunosuppression mice model

SALVA SUSANA; VILLENA JULIO; PACHECO VICTORIA; ALVAREZ SUSANA

Buenos Aires

Congreso; 1º Congreso Franco-Argentino de Inmunología; 2010

Sociedad Argentina de Inmunología

Cyclophosphamide (Cy) is a drug commonly used in the treatment of cancer because of its high toxicity on tumor cells. However, Cy frequently affects normal cells in different organs and tissues. One of the most important toxic effects of Cph is the induction of myelosuppression, leading to a state of immunosuppression with increased susceptibility to infections by virus, fungi or bacteria. Previously, we demonstrated that the preventive treatment with immunobiotic lactic acid bacteria (LAB) improves the recovery of myeloid cells population in Cy-treated mice. The aim of this work was to determine the ability of immunobiotic LAB, to improve the innate immune response against the opportunistic pathogen Candida albicans (Ca) in Cy-treated mice. Different groups of Swiss-albino mice were fed Lactobacillus casei CRL431 (Lc431, 109 cells/d/mouse) or L. rhamnosus CRL1506 (Lr06, 108 cells/d/mouse) for 2 or 5 consecutive days respectively. After each treatment, these mice and untreated controls (CG) received an intraperitoneal injection of Cy (150 mg/Kg). We analyzed the resistance to systemic challenge with Ca, by assessing the survival of infected mice and enumeration of the pathogen in blood, liver and spleen. In addition we studied the innate immune response against Ca, through the analysis of phagocytic cell counts in blood, and their recruitment to peritoneal cavity (pc), using both conventional haematological methods and flow cytometry. The preventive administration of Lc431 and Lr06 induced: a) an increase in the survival of Cy-treated mice infected with Ca (CG=40%; Lc431=70%; Lr06=60%); b) a decrease of Ca counts in infected tissues and its early elimination of the liver and spleen; c) an improvement of leukocytes recruitment into the infected organs (pc leukocytes CG=1,7±0,7; Lc431=6,0±0,5; Lr06=6,3±0,1 106 cells/L); and d) an increase of Gr-1+ cells in blood and peritoneal fluid (pc Gr1+ cells CG=2,1±0,6; Lc431=37,35±3,0; Lr06=35,0±2,4 105 cells/L). Therefore, the influence of preventive administration of LAB on innate immunity would be responsible, at least in part, of the increased resistance to infection by Ca.