title: Stimulation of respiratory immunity by oral administration of Lactococcus lactis.
abstract: This work demonstrates that non-recombinant Lactococcus lactis NZ, administered by the oral route at the proper dose, is able to improve resistance against pneumococcal infection. Lactococcus lactis NZ oral administration was able to improve pathogen lung clearance, increased survival of infected mice, and reduced lung injuries. This effect was related to an upregulation of the respiratory innate and specific immune responses. Administration of L. lactis NZ improved production of bronchoalveolar lavage (BAL) fluid TNF-alpha, enhanced recruitment of neutrophils into the alveolar spaces, and induced a higher activation of BAL phagocytes compared with the control group. Lactococcus lactis NZ administered orally stimulated the IgA cycle, increased IgA+ cells in intestine and bronchus, and improved production of BAL IL-4 and IL-10 during infection. Moreover, mice treated with L. lactis NZ showed higher levels of BAL anti-pneumococcal IgA and IgG. Taking into consideration that orally administered L. lactis NZ stimulates both the innate and the specific immune responses in the respiratory tract and that bacterial and viral antigens have been efficiently produced in this strain, L. lactis NZ is an excellent candidate for the development of an effective pneumococcal oral vaccine.
authors.affiliation: Laboratorio de Bioquímica y Clínica Experimental, Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, Tucumán 4000, Argentina.
authors.forename: Julio
authors.initials: J
authors.lastname: Villena
authors.forename: Marcela
authors.initials: M
authors.lastname: Medina
authors.forename: Elisa
authors.initials: E
authors.lastname: Vintiñi
authors.forename: Susana
authors.initials: S
authors.lastname: Alvarez
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D006801:Humans; D007109:Immunity; D016753:Interleukin-10 / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D013294:Lactococcus lactis / Q000276:immunology*; D008168:Lung / Q000276:immunology* / Q000382:microbiology; D008171:Lung Diseases / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control; D008297:Male; D051379:Mice; D011008:Pneumococcal Infections / Q000276:immunology* / Q000382:microbiology / Q000517:prevention & control; D013296:Streptococcus pneumoniae / Q000502:physiology
chemical_list: D000907:Antibodies, Bacterial; D016753:Interleukin-10; D015847:Interleukin-4