Critical role of IL-5 in antigen-induced pulmonary eosinophilia, but not in lymphocyte activation.
Infiltration of antigen-specific CD4+ T cells and production of interleukin (IL)-5 in inflammatory regions play a central role in antigen-induced pulmonary eosinophilia. Genetically IL-5-deficient mice lack antigen-induced airway eosinophilia, but little is known about the role of IL-5 in accumulation and activation of CD4+ T cells in the lung and in airway hyperresponsiveness (AHR). ASCARIS SUUM extract (Asc) has been used to induce airway eosinophilia and analyze airway inflammation in IL-5 receptor alpha-chain-deficient (IL-5RKO) mice. We examined the role of IL-5 in CD4+ T cell activation, cytokine production, and AHR upon Asc sensitization. Pulmonary CD4+ T cells in Asc-immunized mice were activated and produced IL-5 upon local exposure to Asc in both wild-type (WT) and IL-5RKO mice. IL-2, IL-4, IL-5, IL-10 and eotaxin were detected in bronchoalveolar lavage fluid of both WT and IL-5RKO mice following exposure to Asc. Airway eosinophilia and AHR were seen only in WT mice, but not in IL-5RKO mice. We conclude that IL-5 appears to be required for the accumulation of eosinophils and AHR in the inflammatory lung. However, IL-5 does not play a critical role in the accumulation of activated CD4+ T cells in the inflammatory lung.
Matsumoto
Nobuhiro
N
Third Department of Internal Medicine, Miyazaki Medical College, Japan.
Katoh
Shigeki
S
Mukae
Hiroshi
H
Matsuo
Takeshi
T
Takatsu
Kiyoshi
K
Matsukura
Shigeru
S
D000403:Airway Resistance; D000818:Animals; D000947:Antigens, Helminth / Q000008:administration & dosage; D017165:Ascaris suum / Q000276:immunology; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018925:Chemokines / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D004802:Eosinophilia / Q000209:etiology / Q000276:immunology*; D015848:Interleukin-5 / Q000378:metabolism*; D008171:Lung Diseases / Q000209:etiology / Q000276:immunology*; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018123:Receptors, Interleukin / Q000172:deficiency / Q000235:genetics
D000947:Antigens, Helminth; D018925:Chemokines; D016207:Cytokines; D015848:Interleukin-5; D018123:Receptors, Interleukin