Nasal administration of Lactococcus lactis improves local and systemic immune responses against Streptococcus pneumoniae

Abstract

Lactococcus lactis NZ9000 is a non-pathogenic non-invasive bacterium extensively used for the delivery of antigens and cytokines at the mucosal level. However, there are no reports concerning the per se immunomodulatory capacity of this strain. The aim of the present study was to investigate the intrinsic immunostimulating properties of the nasal administration of L. lactis NZ9000 in a pneumococcal infection model. Mice were preventively treated with L. lactis Key words adjuvant, Lactococcus lactis, nasal administration, pneumococcal infection.Bacterial respiratory diseases remain a major cause of morbidity and mortality in both developed and developing communities. In Argentina, Streptococcus pneumoniae is one of the most important respiratory pathogens (1). This bacterium can migrate to mucosal areas that are normally sterile and lead to a variety of mucosal infections such as otitis media or pneumonia. In addition, pneumococci can induce invasive cases of septicemia and meningitis. The high morbidity associated with this microorganism remains a leading cause of mortality in the young and the elderly (2). The deaths caused by S. pneumoniae are concentrated in developing countries, where the rates are

Lactococcus lactisas an adjuvant and delivery vehicle of antigens against pneumococcal respiratory infections

“…Nasal administration of L. lactis was also able to induce the activation of the systemic innate immune response, which was revealed by the increase in the microbicidal function of blood neuthophils and peritoneal cavity phagocytes. 49 The capacity of LAB to induce the production of cytokines is well documented, 59,60 these mediator molecules being probably responsible for the above effect on blood and peritoneal cavity. Moreover, recent findings demonstrated in vitro that L. lactis NZ 9000 cells are able to upregulate the expression of MHC-II and CD86 co-stimulatory molecules in bone marrow derived dendritic cells.…”

“…61 Finally, in the bone marrow cells of mice the nasal administration of L. lactis showed: (a) a decrease in the percentage of the post-mitotic pool (metamyelocytes, band cells and neutrophils), probably related to the release of mature neutrophils and the production of granulocytes in response to inflammatory signals; 62 (b) an increase in bone marrow CD19 + cells, possibly related to the increase in serum anti-pneumococcal IgG; (c) a decrease in CD4 + cells, probably caused by the mobilization of cells towards the site of infection. 49 Then, preventive nasal administration of L. lactis at the appropriate dose was able to induce a local and systemic specific immune response.…”

“…48 However, the immunological intrinsic properties of this lactococcus were not evaluated. Furthermore, the effect of nasal L. lactis administration on the local and the systemic immune response using a pneumococcal infection model 49 was evaluated. Nasal administration of L. lactis cells increased the clearance rate of S. pneumoniae from lung and prevented the dissemination of pneumococci into blood.…”

A Foreign Protein Incorporated on the Tip of T3 Pili in Lactococcus lactis Elicits Systemic and Mucosal Immunity

“…LAB are also attractive vaccine vectors because they have been found to have natural adjuvant activity (23,41). In addition, L. lactis is a natural Toll-like receptor agonist (10,18,25,39) that can stimulate the production of various interleukins, which can increase the antigen-specific immune response.…”

Viruses and bacteria in Th2‐biased allergic airway disease

“…Some investigations have shown that the oral administration of probiotics and prebiotics may benefit allergic rhinitis patients (95)(96)(97). Moreover, the local nasal administration of Lactococcus lactis NZ9000 can affect the local and systemic immune responses against Streptococcus pneumonia (98). Probiotics seem a promising therapeutic approach for allergic airway diseases, but there are still many controversial issues in this field.…”