Article

CD4+ T-cell expansion predicts neutralizing antibody responses to monovalent, inactivated 2009 pandemic influenza A(H1N1) virus subtype H1N1 vaccine

Department of Pediatrics, Division of Infectious Diseases, University of Rochester Medical Center, 601 Elmwood Ave, Box 690, Rochester, NY 14642, Phone: 585-275-5944, Fax: 585-273-1104.
The Journal of Infectious Diseases (Impact Factor: 5.78). 11/2012; 207(2). DOI: 10.1093/infdis/jis684
Source: PubMed

ABSTRACT Background. The ability of influenza vaccines to elicit CD4 T cells and the relationship between induction of CD4 T cells and vaccine-induced neutralizing antibody responses has been controversial. The emergence of the swine-origin H1N1 influenza pandemic (pH1N1) in 2009 provided a unique opportunity to examine responses to an influenza vaccine composed of both novel and previously encountered antigens and to probe the relationship between B and T-cell responses to vaccination.Methods. We tracked CD4 T-cell and antibody responses of human subjects vaccinated with monovalent subunit pH1N1 vaccine. The specificity and magnitude of the CD4 T-cell response was evaluated using cytokine EliSpot assays in conjugation with peptide pools representing distinct influenza proteins.Results. Our studies revealed that vaccination induced readily detectable CD4 T cells specific for conserved portions of hemagglutinin (HA) and the internal viral proteins. Interestingly, expansion of HA-specific CD4 T cells was most tightly correlated with the antibody response.Conclusions. These results indicate that CD4 T-cell expansion may be a limiting factor in development of neutralizing antibody responses to pandemic influenza vaccines and suggest that approaches to facilitate CD4 T-cell recruitment may increase the neutralizing antibody produced in response to vaccines against novel influenza strains.

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