tetano
Editor, Senior Moderator
Infect Immun. 2016 Nov 28. pii: IAI.00530-16. [Epub ahead of print]
[h=1]Protection against Streptococcus pneumoniae invasive pathogenesis by a protein based vaccine is achieved by suppression of nasopharyngeal bacterial density during Influenza A virus co-infection.[/h] Khan MN[SUP]1[/SUP], Xu Q[SUP]2[/SUP], Pichichero ME[SUP]2[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] An increase in Streptococcus pneumoniae (Spn) nasopharyngeal (NP) colonization density during a viral co-infection initiates pathogenesis. To mimic natural Spn pathogenesis, we commensally colonized the NP of adult C57BL/6 mice with Spn serotypes (STs) 6A or 8, and then co-infected with mouse-adapted H1N1 influenza A virus (PR/8/34). Spn established effective commensal colonization and Influenza co-infection caused Spn NP density to increase, resulting in bacteremia and mortality. We then studied histidine triad protein D (PhtD), a Spn adhesin vaccine candidate, for its ability to prevent invasive Spn disease in adult and infant mice. In adult mice, the efficacy of PhtD vaccination was compared with that of PCV13. Vaccination with PCV13 led to a greater reduction of Spn NP density (>2.5 log) compared to PhtD vaccination (∼1 log reduction). However, there was no significant difference observed with regard to the prevention of Spn bacteremia and no difference in mortality. Depletion of CD4[SUP]+[/SUP] T cells in PhtD vaccinated adult mice but not PCV13-vaccinated mice caused a loss of vaccine induced protection. In infant mice, passive transfer of antisera or CD4[SUP]+[/SUP] T cells from PhtD vaccinated adult mice led to a non-significant reduction in NP colonization density. Whereas, passive transfer of antisera and CD4[SUP]+[/SUP] T cells was needed to cause a significant reduction in NP colonization density. For the first time these data show a similar outcome with regard to prevention of invasive Spn pathogenesis with a protein vaccine as occurs with a glycoconjugate vaccine despite a less robust reduction in NP bacterial density.
Copyright ? 2016, American Society for Microbiology. All Rights Reserved.
PMID: 27895132 DOI: 10.1128/IAI.00530-16
[PubMed - as supplied by publisher]
[h=1]Protection against Streptococcus pneumoniae invasive pathogenesis by a protein based vaccine is achieved by suppression of nasopharyngeal bacterial density during Influenza A virus co-infection.[/h] Khan MN[SUP]1[/SUP], Xu Q[SUP]2[/SUP], Pichichero ME[SUP]2[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] An increase in Streptococcus pneumoniae (Spn) nasopharyngeal (NP) colonization density during a viral co-infection initiates pathogenesis. To mimic natural Spn pathogenesis, we commensally colonized the NP of adult C57BL/6 mice with Spn serotypes (STs) 6A or 8, and then co-infected with mouse-adapted H1N1 influenza A virus (PR/8/34). Spn established effective commensal colonization and Influenza co-infection caused Spn NP density to increase, resulting in bacteremia and mortality. We then studied histidine triad protein D (PhtD), a Spn adhesin vaccine candidate, for its ability to prevent invasive Spn disease in adult and infant mice. In adult mice, the efficacy of PhtD vaccination was compared with that of PCV13. Vaccination with PCV13 led to a greater reduction of Spn NP density (>2.5 log) compared to PhtD vaccination (∼1 log reduction). However, there was no significant difference observed with regard to the prevention of Spn bacteremia and no difference in mortality. Depletion of CD4[SUP]+[/SUP] T cells in PhtD vaccinated adult mice but not PCV13-vaccinated mice caused a loss of vaccine induced protection. In infant mice, passive transfer of antisera or CD4[SUP]+[/SUP] T cells from PhtD vaccinated adult mice led to a non-significant reduction in NP colonization density. Whereas, passive transfer of antisera and CD4[SUP]+[/SUP] T cells was needed to cause a significant reduction in NP colonization density. For the first time these data show a similar outcome with regard to prevention of invasive Spn pathogenesis with a protein vaccine as occurs with a glycoconjugate vaccine despite a less robust reduction in NP bacterial density.
Copyright ? 2016, American Society for Microbiology. All Rights Reserved.
PMID: 27895132 DOI: 10.1128/IAI.00530-16
[PubMed - as supplied by publisher]