title: Signals through CD40 play a critical role in the pathophysiology of Schistosoma mansoni egg antigen--induced allergic rhinitis in mice.
abstract: BACKGROUND
  Interaction between CD40 and CD40L is thought to regulate immune responses in several allergic diseases. However, little is known about its in vivo role in the pathophysiology of allergic rhinitis. We sought to determine whether the lack of signals through CD40 affects the pathophysiology of allergic rhinitis using a murine model.
  
  
  METHODS
  Wild type (WT) and CD40-deficient BALB/c (CD40-/-) mice were sensitized intranasally to Schistosoma mansoni egg antigen (SEA). After repeated sensitization, histamine responsiveness, serum antibody titer including immunoglobulin E (IgE), nasal eosinophilia, and cytokine production by nasal mononuclear cells were determined in each group.
  
  
  RESULTS
  Intranasal sensitization with SEA in WT mice elicited a strong Th2 response including SEA-specific IgE production, nasal eosinophilia, and interleukin (IL)-4, and IL-5 production by nasal mononuclear cells after antigen challenge. Production of SEA-specific IgE and IgG1 was abolished in SEA-sensitized CD40-/- mice. These mice showed impaired nasal eosinophilia and displayed markedly reduced histamine-induced nasal hyperresponsiveness as compared with WT mice. Furthermore, reduced production of IL-4 and IL-5 by nasal mononuclear cells was seen in CD40-/- mice.
  
  
  CONCLUSIONS
  These results show that signals through CD40 play a critical role in not only IgE production but also pathophysiology of allergic rhinitis such as nasal hyperresponsiveness and nasal eosinophilia.
authors: Department of Microbiology, The Ohio State University, Columbus, Ohio 43210, USA.
authors: Hisashi
authors: H
authors: Hattori
authors: Mitsuhiro
authors: M
authors: Okano
authors: Shin
authors: S
authors: Kariya
authors: Kazunori
authors: K
authors: Nishizaki
authors: Abhay R
authors: AR
authors: Satoskar