EFFECT OF AN IMMUNOBIOTIC NASAL PRIMING ON MUCOSA-ASSOCIATED LYMPHOID TISSUE IN MALNOURISHED MICE

IVIR MAXIMILIANO; GUTIERREZ FLORENCIA; BASILE BRENDA; JULIO VILLENA; SUSANA SALVA; ALVAREZ, SUSANA

Congreso; LXVII Reunión Científica Anual de la Sociedad Argentina de Inmunología; 2019

Immunobiotic lactic acid bacteria became an interesting and non-invasive alternative for therecovery of the respiratory immune response in malnourished host. Malnutrition inducesatrophy of mucosa-associated-lymphoid-tissue. Little is known about the effect of malnutritionon the nasopharynx-associated-lymphoid-tissue (NALT). The effect of nasally administeredLactobacillus rhamnosus CRL1505 on NALT and its relationship with distant lymphoid tissueswas evaluated. Weaned mice were malnourished with a protein-free diet (PFD) for 21d.Malnourished mice received balanced conventional diet (BCD) during 7d (BCD group) or BCDwith nasal supplementation with L. rhamnosus CRL1505 (108cells/mouse/day) during the last 2days of treatment (BCD+Lr group). Malnourished control mice (MC) received PFD while thewell-nourished control group (WC) consumed BCD. After the treatments, mice were challengewith LPS (10 mg/kg weight) by intranasal route. Flow cytometry studies were carried out onthymus, spleen, lung-BALT and NALT, to study the impact on B and T cells. Protein-malnutritionsignificantly reduced the number of total cells, B and T cells in all the studied organs. BCDtreatment was not able to normalize these cell populations. However, the BCD+Lr group showednormal numbers of spleen, lung and NALT B cells. In addition, only this group reducedquantitative alterations of CD4+ T cells in the spleen, thymus and lung induced by malnutrition.After challenge, the BCD+Lr group showed the number of mature B cells and CD8+ cells similarto de WC. These results highlight the importance of NALT as a target for the probioticsadministration to improve respiratory immunity in immunocompromised malnourished hosts.