title: B and T lymphocyte attenuator inhibits antigen-induced eosinophil recruitment into the airways.
abstract: BACKGROUND
  Signaling through CD28 family co-receptors regulates activation of CD4(+) T cells positively and negatively. It has been shown that stimulatory co-receptors such as CD28 and ICOS play critical roles in the induction of allergic airway inflammation. However, the role of B and T lymphocyte attenuator (BTLA), an inhibitory co-receptor expressed preferentially in Th1 cells, in the regulation of allergic airway inflammation remains to be determined.
  
  
  METHODS
  We examined antigen-induced eosinophil recruitment and cytokine production in the airways in antigen-sensitized BTLA-deficient (BTLA-/-) mice. We also examined antigen-induced cytokine production and cell proliferation of splenic T cells in antigen-sensitized BTLA-/- mice.
  
  
  RESULTS
  Antigen-induced eosinophil recruitment and IL-5 production in the airways was enhanced in antigen-sensitized BTLA-/- mice. On the other hand, antigen-induced Th1 and Th2 cytokine production as well as T cell proliferation of splenocytes was normal in BTLA-/-mice.
  
  
  CONCLUSIONS
  BTLA inhibits antigen-induced eosinophil recruitment into the airways by preventing IL-5 production from Th2 cells.
authors.affiliation: Department of Allergy and Clinical Immunology, Graduate School of Medicine, Chiba University, Chiba City, Chiba, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Tamachi
authors.forename: Norihiko
authors.initials: N
authors.lastname: Watanabe
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Oya
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Kagami
authors.forename: Koich
authors.initials: K
authors.lastname: Hirose
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Saito
authors.forename: Itsuo
authors.initials: I
authors.lastname: Iwamoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakajima
mesh_terms: D000280:Administration, Inhalation; D000818:Animals; D000941:Antigens / Q000008:administration & dosage / Q000633:toxicity; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D002634:Chemotaxis, Leukocyte; D004802:Eosinophilia / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D004804:Eosinophils / Q000502:physiology*; D005260:Female; D007114:Immunization; D007371:Interferon-gamma / Q000032:analysis; D015847:Interleukin-4 / Q000032:analysis; D015848:Interleukin-5 / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D010047:Ovalbumin / Q000008:administration & dosage / Q000633:toxicity; D011971:Receptors, Immunologic / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D012130:Respiratory Hypersensitivity / Q000209:etiology / Q000473:pathology*; D013154:Spleen / Q000166:cytology; D018418:Th2 Cells / Q000378:metabolism*
chemical_list: D000941:Antigens; C488868:BTLA protein, mouse; D015848:Interleukin-5; D011971:Receptors, Immunologic; D015847:Interleukin-4; D007371:Interferon-gamma; D010047:Ovalbumin