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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Virus and Prion Research » Research » Publications at this Location » Publication #312039

Title: Lymphocyte responses in the lungs of vaccinated pigs following homologous and heterologous influenza A virus challenge.

item Hughes, Holly
item Bond, Zahra
item GAUGER, PHILLIP - Iowa State University
item Baker, Amy
item Brockmeier, Susan
item Loving, Crystal

Submitted to: Autumn Immunology Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/14/2014
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Vaccine associated enhanced respiratory disease (VAERD) has been described in pigs vaccinated with whole-inactivated influenza virus (WIV) following infection with heterologous influenza A virus (IAV). WIV vaccination elicits production of non-neutralizing antibody that is cross-reactive to the challenge IAV strain suggesting immune complexes or antibody dependent cell-mediated cytotoxicity could contribute to VAERD pathology. Moreover, pathological findings in VAERD lungs include significant lymphocytic infiltration and increased levels of proinflammatory cytokines. A characterization of lymphocytes in lungs following IAV challenge has not been completed and such information will contribute to understanding the mechanism of VAERD versus cross-protection. WIV vaccinated pigs had a transient increase in IAV-specific IFNgamma secreting cells (SC) in peripheral blood and numbers were heightened after challenge. Post-challenge IAV-specific IFNgamma SC in the lungs were increased in pigs with VAERD compared to non-vaccinated, challenged controls. CD8 T cells and NK cells were significantly higher in the lungs of pigs protected from homologous challenge, suggesting these cells may play a role in protection. Interestingly, pigs with VAERD had a significant increase of CD4/CD8 double-positive T cells that was not observed in pigs without VAERD. These data further describe the lymphocytic pathology seen in VAERD and suggest double-positive memory T cells may contribute to disease pathology.