Ulrik Stervbo-Kristensen, Dominika Pohlmann, Udo Baron, Cecilia Bozzetti, Karsten Jürchott, Julia Nora Mälzer, Mikalai Nienen, Sven Olek, Toralf Roch, Axel Ronald Schulz, Sarah Warth, Avidan Neumann, Andreas Thiel, Andreas Grützkau, Nina Babel
- Immunosenescence is a hallmark of the aging immune system and is considered the main cause of a reduced vaccine efficacy in the elderly. Although \(\gamma \delta\) T cells can become activated by recombinant influenza hemagglutinin, their age-related immunocompetence during a virus-induced immune response has so far not been investigated. In this study we evaluate the kinetics of \(\gamma \delta\) T cells after vaccination with the trivalent 2011/2012 northern hemisphere seasonal influenza vaccine. We applied multi-parametric flow cytometry to a cohort of 21 young (19–30 years) and 23 elderly (53–67 years) healthy individuals. Activated and proliferating \(\gamma \delta\) T cells, as identified by CD38 and Ki67 expression, were quantified on the days 0, 3, 7, 10, 14, 17, and 21. We observed a significantly lower number of activated and proliferating \(\gamma \delta\) T cells at baseline and following vaccination in elderly as compared to young individuals. The kinetics changes of activated \(\gamma \delta\) T cells were much stronger in the young, while corresponding changes in the elderly occurred slower. In addition, we observed an association between day 21 HAI titers of influenza A and the frequencies of \(Ki67^{+}\) \(\gamma \delta\) T cells at day 7 in the young. In conclusion, aging induces alterations of the \(\gamma \delta\) T cell response that might have negative implications for vaccination efficacy.