Avian pathogenic Escherichia coli is a current problem in the poultry industry, causing mortality and economic losses. This paper evaluates the dynamics in immune response after the use of spray vaccination against E. coli and, thereby, seeks to understand how the vaccine can provide protection. During the early stages of response to vaccination the presence of antigen-presenting cells is predominant, but these diminish within the first 7 days after vaccination. The immune correlate of protection of vaccination using the E. coli vaccine Poulvac E. coli (aroA-deficient mutant strain) probably does not depend on the production of circulating antibodies (as assessed through the presence of B lymphocytes) and is linked to the presence of CD4 TCRVβ1 . These cells act on mucosa tissue stimulating the production of immunoglobulin A. Vaccination stimulated a high state of immunocompetence, as assessed by measurement of several cellular subsets. This state of “immune alertness,” however, may be associated with reduced weight gain. The high presence of naive and memory CD8 cells in the vaccinated group at 14 and 21 days postvaccination may indicate greater ability in the future to prevent tissue invasion by E. coli, based on the possibility that these cells will proliferate rapidly to a new stimulus. The simultaneous use of vaccine with the antibiotic ceftiofur sodium interferes with the immune response obtained through vaccination. In combination, the data obtained in this study indicate that the immune response produced by a spray vaccine against E. coli is mainly a cellular response, especially relevant to the sites in contact with the pathogen. It is suggested that there is a strong cell migration to the mucous membranes, where macrophages act first and then lymphocytes take part to protect the host. It is believed that recruited lymphocytes will act in the production of secreted IgA, which probably plays a greater role in the defense when compared with circulating immunoglobulins. The assessment of cellular dynamics by flow cytometry made it possible to elucidate the operation mechanism of the live E. coli vaccine.
Nota de Investigación—Efecto de la vacuna contra E. coli en aerosol en la inmunidad de aves comerciales.
La Escherichia coli patógena para las aves es un problema actual en la industria avícola, que es causa de mortalidad y pérdidas económicas. En este trabajo se evaluó la dinámica en la respuesta inmune después de la utilización de la vacunación en aerosol contra E. coli y de este modo, el objetivo de este trabajo es entender cómo esta vacuna puede proporcionar protección. Durante las primeras etapas de la respuesta a la vacunación, la presencia de células presentadoras de antígeno es predominante, pero esto disminuye dentro de los primeros siete días después de la vacunación. La correlación inmune de la protección por la vacunación utilizando la vacuna de E. coli Poulvac E. coli (cepa mutante deficiente del gene aroA) probablemente no depende de la producción de anticuerpos circulantes (como se evaluó a través de la presencia de linfocitos B) y está vinculada a la presencia de CD4 TCRVβ1 . Estas células actúan sobre la mucosa estimulando la producción de inmunoglobulina A. La vacunación estimula un alto estado de inmunocompetencia, según lo evaluado por la medición de varios subconjuntos celulares. Sin embargo, este estado de “alerta inmune”, puede estar asociado c
