Airway eosinophils: allergic inflammation recruited professional antigen-presenting cells.
The capacity of airway eosinophils, potentially pertinent to allergic diseases of the upper and lower airways, to function as professional APCs, those specifically able to elicit responses from unprimed, Ag-naive CD4(+) T cells has been uncertain. We investigated whether airway eosinophils are capable of initiating naive T cell responses in vivo. Eosinophils, isolated free of other APCs from the spleens of IL-5 transgenic mice, following culture with GM-CSF expressed MHC class II and the costimulatory proteins, CD40, CD80, and CD86. Eosinophils, incubated with OVA Ag in vitro, were instilled intratracheally into wild-type recipient mice that adoptively received i.v. infusions of OVA Ag-specific CD4(+) T cells from OVA TCR transgenic mice. OVA-exposed eosinophils elicited activation (CD69 expression), proliferation (BrdU incorporation), and IL-4, but not IFN-gamma, cytokine production by OVA-specific CD4(+) T cells in paratracheal lymph nodes (LN). Exposure of eosinophils to lysosomotropic NH(4)Cl, which inhibits Ag processing, blocked each of these eosinophil-mediated activation responses of CD4(+) T cells. By three-color fluorescence microscopy, OVA Ag-loaded eosinophil APCs were physically interacting with naive OVA-specific CD4(+) T cells in paratracheal LN after eosinophil airway instillation. Thus, recruited luminal airway eosinophils are distinct allergic "inflammatory" professional APCs able to activate primary CD4(+) T cell responses in regional LNs.
Wang
Hai-Bin
HB
Division of Allergy and Inflammation, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA.
Ghiran
Ionita
I
Matthaei
Klaus
K
Weller
Peter F
PF
D019264:Adoptive Transfer; D000485:Allergens / Q000276:immunology*; D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology; D000938:Antigen-Presenting Cells / Q000276:immunology*; D015703:Antigens, CD / Q000276:immunology; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D016207:Cytokines / Q000096:biosynthesis; D004195:Disease Models, Animal; D004804:Eosinophils / Q000187:drug effects / Q000276:immunology* / Q000637:transplantation; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis / Q000187:drug effects / Q000276:immunology; D006967:Hypersensitivity / Q000276:immunology*; D007249:Inflammation / Q000276:immunology; D007262:Infusions, Intravenous; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008822:Mice, Transgenic; D010047:Ovalbumin / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology; D015854:Up-Regulation / Q000187:drug effects / Q000276:immunology
D000485:Allergens; D015703:Antigens, CD; D016207:Cytokines; D000949:Histocompatibility Antigens Class II; D000643:Ammonium Chloride; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D010047:Ovalbumin