Memory immune responses and protection of chickens against a nephropathogenic infectious bronchitis virus strain by combining live heterologous and inactivated homologous vaccines.

In this study, we evaluated antibody and cell-mediated immune (CMI) responses in the mucosal and systemic compartments and protection against challenge with a nephropathogenic Brazilian (BR-I) strain of infectious bronchitis virus (IBV) in chickens submitted to a vaccination regime comprising a priming dose of heterologous live attenuated Massachusetts vaccine followed by a booster dose of an experimental homologous inactivated vaccine two weeks later. This immunization protocol elicited significant increases in serum and lachrymal levels of anti-IBV IgG antibodies and upregulated the expression of CMI response genes, such as those encoding CD8? chain and Granzyme homolog A in tracheal and kidney tissues at 3, 7, and 11 days post-infection in the vaccinated chickens. Additionally, vaccinated and challenged chickens showed reduced viral loads and microscopic lesion counts in tracheal and kidney tissues, and their antibody and CMI responses were negatively correlated with viral loads in the trachea and kidney. In conclusion, the combination of live attenuated vaccine containing the Massachusetts strain with a booster dose of an inactivated vaccine, containing a BR-I IBV strain, confers effective protection against infection with nephropathogenic homologous IBV strain because of the induction of consistent memory immune responses mediated by IgG antibodies and TCD8 cells in the mucosal and systemic compartments of chickens submitted to this vaccination regime.

Bibliographic Details

Main Authors:	SANTOS, R. M. dos, FERNANDO, F. S., MONTASSIER, M. de F. S., SILVA, K. R., LOEPS, P. D., PAVANI, C., BORZI, M. M., OKINO, C. H., MONTASSIER, H. J.
Other Authors:	Romeu Moreira dos Santos, UNESP; Filipe Santos Fernando, UNESP; Maria de Fátima Silva Montassier, UNESP; Ketherson Rodrigues Silva, UNESP; Priscila Diniz Lopes, UNESP; Caren Pavani, UNESP; Mariana Monezi Borzi, UNESP; CINTIA HIROMI OKINO, CPPSE; Helio José Montassier, UNESP.
Format:	Artigo de periódico biblioteca
Language:	English eng
Published:	2019-09-04
Subjects:	Cell mediated immunity, Oil adjuvant, Avian coronavirus, Humoral immunity, Mucosal immunity,
Online Access:	http://www.alice.cnptia.embrapa.br/alice/handle/doc/1111878
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