Strategies to alleviate original antigenic sin responses to influenza viruses

• Authors: Jin Hyang Kim, Emory University; William G. Davis, Centers for Disease Control and Prevention; Suryaprakash Sambhara, Centers for Disease Control and Prevention; Joshy Jacob, Emory University
• Journal Title: Proceedings of the National Academy of Sciences
• Volume: Volume 109, Number 34
• Publisher: National Academy of Sciences | 2012-08-21, Pages 13751-13756
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1073/pnas.0912458109
• Subjects: Health Sciences, Immunology; Biology, Microbiology
• Keywords: cross-reactivity; antigen presentation; memory T-cell activation

Abstract

Original antigenic sin is a phenomenon wherein sequential exposure to closely related influenza virus variants reduces antibody (Ab) response to novel antigenic determinants in the second strain and, consequently, impairs the development of immune memory. This could pose a risk to the development of immune memory in persons previously infected with or vaccinated against influenza. Here, we explored strategies to overcome original antigenic sin responses in mice sequentially exposed to two closely related hemagglutinin 1 neuraminidase 1 (H1N1) influenza strains A/PR/8/34 and A/FM/1/47. We found that dendritic cell–activating adjuvants [Bordetella pertussis toxin (PT) or CpG ODN or a squalene-based oil-in-water nanoemulsion (NE)], upon administration during the second viral exposure, completely protected mice from a lethal challenge and enhanced neutralizing-Ab titers against the second virus. Interestingly, PT and NE adjuvants when administered during the first immunization even prevented original antigenic sin in subsequent immunization without any adjuvants. As an alternative to using adjuvants, we also found that repeated immunization with the second viral strain relieved the effects of original antigenic sin. Taken together, our studies provide at least three ways of overcoming original antigenic sin.