Unconventional strategies for the suppression of allergic asthma.
Allergic asthma results from an intrapulmonary allergen-driven Th2 response and is characterized by intermittent airway obstruction, airway hyperreactivity, and airway inflammation. An inverse association between allergic asthma and microbial infections has been observed. And this observation constitutes the base of the hygiene hypothesis. Here we discuss the hygiene hypothesis with emphasis on regulatory cells. We review the evidence for the emergence of regulatory cells, such as CD4(+)CD25(+) T cells during infection or during induction of tolerance by mucosal antigen administration. The review focuses also on the emergence of activated CD8(+) T cells and macrophages, induced by infections or microbial products, which also can result in the suppression of asthma. The underlying mechanisms by which regulatory immune cells suppress asthma may represent novel unconventional strategies controlling asthma.
Mucida
Daniel de Sousa
DS
Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo-05508-900, SP, Brazil.
de Castro Keller
Alexandre
A
Fernvik
Eva Christina
EC
Russo
Momtchilo
M
D000818:Animals; D001249:Asthma / Q000188:drug therapy* / Q000209:etiology; D016827:CD8 Antigens / Q000276:immunology; D006801:Humans; D006967:Hypersensitivity / Q000150:complications*; D007108:Immune Tolerance / Q000276:immunology / Q000502:physiology; D018928:Immunity, Mucosal / Q000502:physiology; D008264:Macrophages / Q000276:immunology / Q000502:physiology; D013601:T-Lymphocytes / Q000276:immunology / Q000502:physiology
D016827:CD8 Antigens