Related Experiment Video
Updated: May 3, 2026
Isolation and Th17 Differentiation of Naïve CD4 T Lymphocytes
Published on: September 27, 2013
IL-17F sequence variant (His161Arg) is associated with protection against asthma and antagonizes wild-type IL-17F
Mio Kawaguchi1, Daisuke Takahashi, Nobuyuki Hizawa
1First Department of Internal Medicine, Showa University School of Medicine, Tokyo, Japan.
Background:
IL-17F is a recently discovered cytokine that plays a role in tissue inflammation by inducing release of proinflammatory and neutrophil-mobilizing cytokines. Upregulated IL17F gene expression has been observed at sites of allergen challenge in the airways of patients with asthma, suggesting that IL-17F is involved in the pathophysiology of asthma.
Objective:
To investigate the role of IL-17F in asthma pathogenesis, we conducted genetic analyses of association of asthma with the common variants of IL17F, using 867 unrelated Japanese subjects.
Methods:
Five polymorphisms were studied, including the coding-region sequence variant single nucleotide polymorphism rs763780 (7488T/C), which causes a His-to-Arg substitution at amino acid 161 (H161R). Functional consequences of the H161R substitution were examined by using recombinant wild-type and mutant IL-17F proteins.
Results:
Homozygosity of the H161R variant was inversely associated with asthma; the odds ratio (95% CI) for asthma was 0.06 (0.01-0.43) for the H161R homozygote compared with the wild-type homozygote (P = .0039). This result remains significant (P = .0079) after adjustment for the presence of atopy using the Mantel-Haenszel chi2 test. In addition, in vitro functional experiments demonstrated that the H161R variant of IL-17F lacks the ability to activate the mitogen-activated protein kinase pathway, cytokine production, and chemokine production in bronchial epithelial cells, unlike wild-type IL-17F. Furthermore, the H161R variant blocked induction of IL-8 expression by wild-type IL-17F.
Conclusion:
The current findings indicate that the IL-17F H161R variant influences the risk of asthma and is a natural IL-17F antagonist, suggesting a potential role for IL-17F in the etiology of asthma.
Related Concept Videos
01:20Asthma: Pathogenesis and Management
Asthma is classified as allergic and non-allergic. Allergens such as dust mites, pollen, and pet dander trigger allergic asthma, while factors like cold air, intense emotions, or exercise can induce non-allergic asthma.
01:19Antiasthma Drugs: Leukotriene Modifiers
Leukotriene modifiers work through two distinct mechanisms:
01:25Antiasthma Drugs: Mast Cell Stabilizers and Anti-IgE Drugs
Mast cell stabilizers, such as cromolyn (also known as sodium cromoglycate) and nedocromil (Tilade), are effective drugs in asthma management. These stabilizers hinder histamine release by skillfully obstructing the activation of mast cells and other cellular entities. Notably, they navigate this task without...
01:24T Cell Types and Functions
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
01:26Asthma-II: Pathophysiology and Classification
Additionally, environmental and genetic factors play crucial roles in determining an individual's susceptibility to asthma and the severity of their condition.
Critical processes in asthma pathophysiology include:
01:28Asthma I: Introduction