Artículos de revistas
Oral immunization with recombinant Lactococcus lactis confers protection against respiratory pneumococcal infection
Fecha
2008-10-25Registro en:
Villena, Julio Cesar; Medina, Marcela Susana; Raya, Raul Ricardo; Alvarez, Gladis Susana; Oral immunization with recombinant Lactococcus lactis confers protection against respiratory pneumococcal infection; National Research Council Canada-NRC Research Press; Canadian Journal Of Microbiology; 54; 10; 25-10-2008; 845-853
0008-4166
1480-3275
CONICET Digital
CONICET
Autor
Villena, Julio Cesar
Medina, Marcela Susana
Raya, Raul Ricardo
Alvarez, Gladis Susana
Resumen
In the present work, we evaluated if oral immunization with the pneumococcal protective protein A (PppA), expressed in the cell wall of Lactococcus lactis (L. lactis PppA+), was able to confer protective immunity against Streptococcus pneumoniae. Mice were immunized orally with L. lactis PppA+ for 5 consecutive days. Vaccination was performed one (nonboosted group) or 2 times with a 2 week interval between each immunization (boosted group). Oral priming with L. lactis PppA+ induced the production of anti-PppA IgM, IgG, and IgA antibodies in serum and in bronchoalveolar (BAL) and intestinal (IF) lavage fluids. Boosting with L. lactis PppA+ increased the levels of mucosal and systemic immunoglobulins. Moreover, the avidity and the opsonophagocytic activity of anti-PppA antibodies were significantly improved in the boosted group. The presence of both IgG1 and IgG2a anti-PppA antibodies in serum and BAL and the production of both interferon γ and interleukin-4 by spleen cells from immunized mice indicated that L. lactis PppA+ stimulated a mixture of Th1 and Th2 responses. The ability of L. lactis PppA+ to confer cross-protective immunity was evaluated using challenge assays with serotypes 3, 6B, 14, and 23F. Lung bacterial cell counts and hemocultures showed that immunization with L. lactis PppA+ improved resistance against all the serotypes assessed, including serotype 3, which was highly virulent in our experimental animal model. To our knowledge, this is the first demonstration of protection against respiratory pneumococcal infection induced by oral administration of a recombinant lactococcal vaccine.