PROIMI   05436
PLANTA PILOTO DE PROCESOS INDUSTRIALES MICROBIOLOGICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Immunomodulatory activity of Lactobacillus rhamnosus CRL1505 on macrophages and dendritic cells in immunocompromised mice
Autor/es:
SALVA SUSANA; ALVAREZ SUSANA; BARBIERI NATALIA; VILLENA JULIO; HERRERA MATIAS
Lugar:
San Miguel de tucuman
Reunión:
Simposio; V International Symposium on Lactic Acid Bacteria: Benefitting from Lactic Acid Bacteria - Progress in Health and Food; 2016
Institución organizadora:
Reference Centre for Lactobacilli (CERELA-CONICET)
Resumen:
Immunomodulation has been shown to be one of the major functions of probiotic bacteria. We demonstrated that priming of the respiratory mucosa of immunocompromised malnourished (M) mice with Lactobacillus rhamnosus CRL1505 (Lr) significantly improved the number and activity of phagocytic cells and the number of B cells in spleen and lungs. Moreover, administration of live lactobacilli directly to the respiratory mucosa resulted in a diminished susceptibility to Streptococcus pneumoniae (Sp) infection and an improved innate and humoral immune response against the respiratory pathogen. Antigen-presenting cells (APCs) play a major role in sensing potential dangers to initiate an adequate and efficient adaptive immune response. Dendritic cells (DCs), macrophages (Ma) and to a certain extent monocytes (Mo) are typical examples of APCs. We studied the effects of nasally administered Lr05 on the number and activity of lung and spleen APCs during the dietary recovery of malnourished mice and in the setting of Sp infection. Weaned mice were malnourished with a protein-free diet for 21 days. M mice received balanced conventional diet (BD) for 7 days or BD for 7 days with nasal Lr supplementation (BD+Lr) during the last 2d. At the end of the treatments, all groups were infected with Sp. Flow cytometry studies were carried out in lung and spleen to study Mo, Ma and DCs. Wellnourished (N) and M mice were used as control groups. On the one hand, malnutrition induced a decrease of the number and functionality of lung and spleen APCs. The BD+Lr treatment, unlike BD group, was able to increase the number of lung Mo (CD11c-CD11b+F4/80+ cells) and Ma (CD11c+CD11b-/lowAF+F4/80+ cells) reaching values similar to N mice. Lung myeloid DCs were identified as CD11c+CD11b+AF-F4/80- (CD11blow and CD11b+ subsets) and plasmacytoid DCs as CD11c+CD11b-/lowAF-F4/80-B220+. The mice treated with Lr were also able to increase the number of this population with a more remarkable effect on CD11b+ DC subpopulation. Even more, only DB+Lr group showed an upregulation of MHC II expression of Ma and DCs in lung and spleen. On the other hand, the challenge with Sp increased the lung Mo, Ma and DC numbers in all experimental groups. However, the lung Mo of BD+Lr mice were higher than these cells of BD mice and similar to the N group. Although both repletion treatments showed similar values of lung Ma after the infection, the Ma activation state in BD+Lr mice was higher than those of BD group. The number of spleen APCs also increased after the challenge with the respiratory pathogen. The BD+Lr mice were able to increase the splenic Ma number and normalized the DCs number compared with the N group, as well as their activation state following Sp infection. In conclusion, L. rhamnosus CRL1505 can improve the number of Ma and DCs as well as regulate their activation, providing further evidence that this Lactobacillus has the ability to influence and steer immune response.