title: Immune response in nasopharynx, lung, and blood elicited by experimental nasal pneumococcal vaccines containing live or heat-killed lactobacilli as mucosal adjuvants.
abstract: This work analyzes the humoral and cellular immune responses induced by live (LcV) and heat-killed (LcM) Lactobacillus casei associated with the pneumococcal antigen (P-Ag) at the nasopharynx level, considering nasal-associated lymphoid tissue (NALT) as the primary inductive site of the mucosal immune system, and lung and blood as effector sites. Levels of P-Ag IgA and IgG antibodies, main types of B and T cells, and cytokines in mucosal and systemic compartments were evaluated. The results showed that both LcM+P-Ag and LcV+P-Ag vaccines effectively induced IgA and IgG anti-P-Ag Abs in the upper and lower respiratory tract and plasma. These results correlated with increased IgA+ cells in NALT and lung that was induced by the experimental vaccines. Moreover, numbers of IgG+ cells increased in the blood. Profiles of inflammatory and regulatory cytokines were evaluated and their possible implications for the defense against pneumococci was assessed. Considering the overall results, the potential mechanisms of immune stimulation induced by LcM and LcV used as adjuvants are discussed. LcV and LcM showed similar effects on the immune system. Strain viability is not crucial for the stimulation of the antigen-specific immune response, and LcM is a convenient and effective mucosal adjuvant.
authors: a Facultad de Agronomía y Zootecnia, Florentino Ameghino S/N, El Manantial, Universidad Nacional de Tucumán, Tucumán, Argentina.
authors: Elisa O
authors: EO
authors: Vintiñi
authors: Marcela
authors: M
authors: Medina
mesh_terms: D000818:Animals; D001769:Blood; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D005260:Female; D007111:Immunity, Cellular; D056724:Immunity, Humoral; D007780:Lacticaseibacillus casei / Q000276:immunology*; D008168:Lung / Q000276:immunology* / Q000378:metabolism; D008297:Male; D051379:Mice; D009092:Mucous Membrane / Q000276:immunology; D009305:Nasopharynx / Q000276:immunology* / Q000378:metabolism; D009666:Nose / Q000276:immunology*; D022242:Pneumococcal Vaccines / Q000276:immunology*; D014613:Vaccines, Attenuated
chemical_list: D016207:Cytokines; D022242:Pneumococcal Vaccines; D014613:Vaccines, Attenuated