Intranasal immunization with phosphorylcholine suppresses allergic rhinitis in mice

Objectives/Hypothesis Intranasal immunization with phosphorylcholine (PC) is known to reduce immunoglobulin (Ig)E production. However, its effects on the occurrence of allergic rhinitis (AR) are unknown. This study was performed to evaluate the effects of PC‐keyhole limpet hemocyanin (PC‐KLH) and to examine the effects on the occurrence of AR in a murine model of AR. Study Design In vivo study using an animal model. Methods Forty‐five female BALB/c mice were divided into three groups; those pretreated with intranasal administration of PC‐KLH followed by intraperitoneal sensitization and nasal challenge with ovalbumin (OVA) (group A), those untreated with PC‐KLH followed by sensitization and nasal challenge with OVA (group B), and those untreated with PC‐KLH or OVA as controls (group C). Nasal symptoms, allergic inflammation in the nasal mucosa, OVA specific IgE production, and cytokine profile were compared among those three groups. Dendritic cells (DCs) were isolated from splenic cells and PC‐KLH–stimulated interleukin (IL)‐12p40 production was measured. Results The mice pretreated with PC‐KLH showed lower allergic nasal symptoms and inflammation compared to untreated mice. The levels of total IgE and OVA‐specific IgE in serum, and IL‐4 production by nasal and splenic CD4 + T cells were significantly reduced by PC‐KLH pretreatment. Furthermore, IL‐12p40 production by DCs was induced by PC‐KLH in a dose‐dependent manner. Conclusions Intranasal administration of PC‐KLH suppressed allergic inflammation in nasal mucosa and antigen‐specific IgE production by downregulating Th2‐type immune response. Intranasal immunization with PC might be useful to prevent AR and upper airway bacterial infection. Level of Evidence NA. Laryngoscope , 128:E234–E240, 2018