Modulation of nasopharyngeal innate defenses by viral coinfection predisposes individuals to experimental pneumococcal carriage

Glennie, S; Gritzfeld, J F; Pennington, S H; Garner-Jones, M; Coombes, N; Hopkins, M J; Vadesilho, C F; Miyaji, E N; Wang, D; Wright, A D; Collins, A M; Gordon, S B; Ferreira, D M

We investigated whether nasal wash fluid containing FH would influence bacterial adherence. FH binding to pneumococcus resulted in greater in vitro epithelial adherence, an effect that was partially reduced by purified human anti-PspC antibodies. To explore the reasons behind this partial reduction, we mapped PspC epitopes and revealed that adults lack anti-PspC antibodies that recognize the FH binding site. Our results suggest that blocking the PspC-FH interaction with a mucosal vaccine could potentially reduce colonization density and the viral-associated pneumococcal disease burden.