Effect of Lactobacillus rhamnosus CRL1505 on the Il-17A/GM-CSF axis in the intestinal mucosa and neutrophil homeostasis of bone marrow in a model of immunosuppression by cyclophosphamide

ANDRÉS DANIEL GRAMAJO LOPEZ; LUCILA SAAVEDRA; ELVIRA MARÍA HEBERT; JULIO VILLENA; SUSANA ALVAREZ; SUSANA SALVA

Mar del Plata

Congreso; LXIII Reunión Anual de la Sociedad Argentina de Investigación Clínica, LXVI Reunión Anual de la Sociedad Argentina de Inmunología, Reunión Anual de la Sociedad Argentina de Fisiología; 2018

SAI-SAIC

Gut microbiota is able to control immunity in distant tissues through regulation of granulopoiesis at primary immune sites as bone marrow (BM). The dietary supplementation with probiotic Lactobacillus rhamnosus CRL1505 (Lr05) improves steady-state and emergency granulopoiesis in immunosupressed hosts. While the Lr05 viability is an important factor to achieve optimal effects, it is possible to stimulate immunity using non-viable Lr05. The aim of this work was to study the effect of oral administration of viable or non-viable Lr05 (Lr05V or Lr05NV, respectively) on the IL-17A/GM-CSF axis in the intestinal mucosa and neutrophil homeostasis of bone marrow, in a model of immunosuppression by cyclophosphamide (Cy). Adult Swiss-mice were orally treated with Lr05V or Lr05NV during five consecutive days. On day 6, lactobacilli-treated and untreated control mice received one intraperitoneally dose of Cy (150 mg/kg). The Cy did not change the IL17A-producing innate lymphoid cells frequency of the small intestinal lamina propria (IL-17A+RORγt+CD4+NKp46+). However, both Lr05V and Lr05NV are able to increase these cells on lamina propria after the administration of the Cy. These results were correlated with an increase in the serum IL-17A levels (p