The role of T lymphocytes in asthma.
There is now overwhelming evidence to support a major role for T cells in asthma, in particular the involvement of T helper type 2 (Th2) cells in atopic allergic asthma as well as nonatopic and occupational asthma. There may also be a minor contribution from T cytotoxic type 2 CD8+T cells. Several Th2 cytokines have potential to modulate airway inflammation, in particular interleukin-13 which induces airway hyperresponsiveness independently of IgE and eosinophilia in animal models. The identification of transcription factors controlling Th1, Th2 and T-regulatory cell (T(Reg)) development further support the Th2 hypothesis since GATA3 is overexpressed and T-bet underexpressed in the asthmatic airway and Foxp3 is induced in asthma by corticosteroid treatment. Specific T-cell-directed immunotherapy may allow induction/modulation of T-cell responses, and elucidation of the mechanisms of T(Regs) may allow further optimization of immunotherapy. Recent advances in the understanding of dendritic cell function in directing T-cell responses may uncover further therapeutic targets. Efficacy of cyclosporin and anti-CD4 treatment in chronic severe asthma argues for continued T-cell involvement, but whether remodeling contributes to pathology inaccessible to antiinflammatory treatment or T-cell immunotherapy remains an important question.
Kay
A Barry
AB
National Heart and Lung Institute,& Leukocyte Biology Section, Imperial College, London, UK. a.b.kay@imperial.ac.uk
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D001249:Asthma / Q000276:immunology* / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D002465:Cell Movement; D016207:Cytokines / Q000276:immunology / Q000378:metabolism; D006801:Humans; D008213:Lymphocyte Activation; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism
D016207:Cytokines