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

Using a GEE model we found an interaction between virus presence, susceptibility to colonization, increased colonization density, and increased FH levels. This is the first time that For each experiment, the average recovered colony-forming units (CFUs) from the control condition (adherence of D39 untreated bacteria to noninflamed cells) was used to calculate fold change of all remaining conditions. The symbol þ represents statistical significance compared with control condition using unpaired t-test ( þ Pr0.05 and þ þ Pr0.005). The symbol * represents statistical significance compared with untreated bacteria of same epithelial condition using unpaired Student's t-test (*Pr0.05 and **Pr0.005). (a, b) . For the inhibition of FH assay the positive control (without anti-PspC and with FH) is represented by black filled histogram. (c) Epithelial adherence of D39 was evaluated following treatment of bacteria with purified anti-PspC IgG containing low levels of FH (3.5 mg ml À 1 residual from purification of serum samples, gray dots) or with anti-PspC IgG before addition of high levels of FH (10 mg ml À 1 , open dots) and compared with untreated bacteria. (d) Adherence of D39DPspC untreated (black squares) or treated with purified anti-PspC IgG (gray dots) was evaluated. (e) D39 epithelial internalization was measured in untreated bacteria (black squares) and bacteria treated with the purified anti-PspC IgG (gray dots) or the total IgG purified from the same serum samples as control for antibody specificity (open squares). The symbol þ represents statistical significance compared with control condition using unpaired t-test ( þ Pr0.05 and þ þ Pr0.01). The symbol ** represents statistical significance compared with untreated bacteria on inflamed epithelial condition (black squares) using unpaired t-test (*Pr0.05 and **Pr0.005).