TLR5 and gut micro-organisms involved in influenza vaccine response, research suggests

Coloured scanning electron micrograph (SEM) of the influenza virus on cell surface — Coloured scanning electron micrograph (SEM) of influenza viruses (green), a cause of human influenza, on the surface of a culture cell (orange)

The mechanisms by which influenza vaccination elicits a host immune response are not fully understood, and a significant proportion of vaccinated individuals – particularly the young and elderly – remain susceptible to infection.

Bali Pulendran, from the Emory Vaccine Center, Atlanta, Georgia, and colleagues recently identified a correlation between toll-like receptor 5 (TLR5) expression shortly after vaccination and the subsequent magnitude of the antibody response.

Writing in Immunity
^[1] (online, September 2014), Pulendran’s group now demonstrates that TLR5 is required for the antibody response to vaccination and that it acts via the intestinal microbiota.

Interestingly, TLR5-mediated sensing of the microbiota impacted antibody responses to the trivalent inactivated influenza vaccine and to the inactivated polio vaccine but not to adjuvanted vaccines or the live-attenuated yellow fever vaccine.