The Effect of Pneumococcal Polysaccharide Vaccine in a Mouse Model of Allergic Rhinitis

Objectives This study aimed to determine if pneumococcal polysaccharide vaccine (PPV) could suppress allergic inflammation in an allergic rhinitis mouse model and to explore whether differences exist regarding the effect of PPV according to timing of administration. Study Design In vivo study using an animal model. Setting Catholic Research Institutes of Medical Science. Subjects and Methods BALB/c mice were divided into control, Der f , Pre‐S, and Post‐S groups. The allergen was Dermatophagoides farinae ( Der f ). Pneumococcal polysaccharide vaccine was administered before (Pre‐S) or after (Post‐S) sensitization. Allergic symptoms and eosinophils in nasal mucosa, interferon‐γ, interleukin (IL)–13, and IL‐10 in nasal lavage fluid and serum Der f –specific IgE were measured. T‐bet, GATA‐3, and Foxp3 mRNA in spleen were determined by real‐time polymerase chain reaction. Flow cytometry of CD4 + CD25 + Foxp3 + T cells in spleen was analyzed. Results In the Pre‐S group, symptom score, serum Der f –specific IgE, eosinophils, IL‐13, and GATA‐3 mRNA were decreased ( P <. 05), and IL‐10, Foxp3 mRNA, and CD4 + CD25 + Foxp3 + T cells were increased compared with those in Der f group ( P <. 05). In the Post‐S group, symptom score, serum Der f –specific IgE, and GATA‐3 mRNA were decreased ( P < . 05), and Foxp3 mRNA and CD4 + CD25 + Foxp3 + T cells were increased compared with those in the Der f group ( P <. 05). Conclusion These results suggest that PPV administered before or after sensitization suppresses Th2 response and enhanced induction of regulatory T cells in an allergic rhinitis model. In addition, there was no significant difference between the degrees of effects in these 2 conditions. In the future, we can consider PPV to be a preventative agent for allergic rhinitis.