Vitamin D reduces the differentiation and expansion of Th17 cells in young asthmatic children
Introduction
Asthma is a heterogeneous disease, usually characterized by chronic airway inflammation (GINA 2014, http://www.ginasthma.org/). Asthma phenotypes can be classified as mild, moderate, or severe according to the magnitude of the inflammation (Hamid and Tulic, 2009). Asthma was considered mainly as a T helper 2 (Th2) mediated disease, characterized by production of interleukin (IL)-4, IL-5, and IL-13 together with eosinophilic infiltration of the bronchial mucosa. However, a CD4+ Th 17 mediated response has also been observed in patients that exhibit chronic inflammation (Pène et al., 2008, Al-Ramli et al., 2009, McKinley et al., 2008). The pro-inflammatory role of Th17 cells and Th17-associated cytokines, IL-17A and IL-17F, is widely recognized (Cosmi et al. 2011). The cytokine milieu has a decisive effect on the balance between developing immunosuppressive regulatory T cells or proinflammatory Th17 cells. Dysregulation of the cytokine balance can therefore contribute to autoimmunity and chronic inflammation (Hamzaoui et al., 2011, Silverpil and Linden, 2012). In children with asthma, Th17 cells were increased in peripheral blood and induced sputum (Maalmi et al., 2014, Hamzaoui et al., 2011). Increased levels of IL-17 A/F were observed in asthmatic airways, and first candidate gene studies suggested single nucleotide polymorphisms (SNPs) in IL17A and IL17F to be associated with asthma (Hamzaoui et al., 2011, Chen et al., 2010). Th17 and regulatory T (Treg) cells are reciprocally deregulated in asthmatics. The finding of overexpression of RORC (Th17) and low expression of FOXP3 (Treg) in asthma suggests that these proteins have a significant role in this process (Hamzaoui et al. 2011).
A number of studies have demonstrated that Vitamin D (Vit D) could modulate the activity of dendritic cells (DCs). It was found that Vit D inhibited the differentiation and maturation of DCs reducing the expression of major histocompatibility complex (MHC) class II molecules and preventing the secretion of proinflammatory cytokines (Arnson et al., 2007, Fujio et al., 2010).
In this study, we found that 25(OH)D3 inhibited the differentiation of Th17 from naive CD4+ T cells both in young asthmatic patients and in healthy controls. We also found that 25(OH)D3 inhibited the expression of Th17 cell effector molecules such as RORC, IL-17, IL-23R, and CCR6. Finally, we showed that DCs were involved in the 25(OH)D3-mediated suppression of the Th17 cell response.
Section snippets
Patients
Ten children with well-defined asthma were recruited from the Department of Paediatric Respiratory Diseases, Abderrahman Mami Hospital (Ariana, Tunisia), using the criteria set by the Global Initiative for Asthma guidelines (Van Weel et al. 2008). Detailed definitions of the inclusion and exclusion criteria for the enrolment of asthmatic subjects were reported previously (Hamzaoui et al., 2010a, Hamzaoui et al., 2010b, Hamzaoui et al., 2011, Hamzaoui et al., 2013). The protocols for the study
Serum vitamin D levels
Ten patients with asthma and ten healthy controls are examined in this work. Data of asthmatic patients and control subjects are depicted in Table 1. The severity of asthma in this group of patients was presented according to GINA guidelines. The severity of asthma was depicted as mild in our patients group. No difference was observed in the body weight between asthmatic children [30.7 kg; range: 24–37] and the healthy control group [31.5 kg; range: 22–40]. Deficient values of vitamin D were
Discussion
This study showed that Vit D decreases the expression of Th17 mediated cytokines through DC modulation in young asthmatic patients. Several studies have reported associations of low vitamin D status with poor pulmonary function and increased incidence of respiratory infections, asthma, and chronic obstructive pulmonary disease (Brehm et al., 2010). Low levels of vitamin D have been associated with asthma severity and loss of control, together with recurrent exacerbations (Berraies et al. 2014).
Conflict of interests
The authors declare that they have no conflict of interests.
Authors’ contributions
AH and KH designed the experiments; AH, AB, JA and BH selected the patients; WK and KH did the experiments; KH, WK, and AB analyzed the data; KH, AH and AB wrote the manuscript. All authors read and approve the final manuscript.
References (41)
- et al.
TH17-associated cytokines (IL-17A and IL-17F) in severe asthma
J. Allergy Clin. Immunol.
(2009) - et al.
Vitamin D suppresses Th17 cytokine production by inducing C/EBP homologous protein (CHOP) expression
J. Biol. Chem.
(2010) - et al.
Vitamin D serum levels and markers of asthma control in Italian children
J. Pediatr.
(2011) - et al.
The family of IL-10-secreting CD4+ T cells
Adv. Immunol.
(2010) - et al.
The instructive role of dendritic cells on T cell responses: lineages, plasticity and kinetics
Curr. Opin. Immunol.
(2001) - et al.
Analysis of relative gene expression data using real-time quantitative PCR and the 2(-Delta Delta C(T)) method
Methods
(2001) - et al.
IL-17 is increased in asthmatic airways and induces human bronchial fibroblasts to produce cytokines
J. Allergy Clin. Immunol.
(2001) - et al.
Antigen-specific T cell sensitization is impaired in IL-17-deficient mice, causing suppression of allergic cellular and humoral responses
Immunity
(2002) - et al.
Decreased serum vitamin D levels in children with asthma are associated with increased corticosteroid use
J. Allergy Clin. Immunol.
(2010) - et al.
The roles of CCR6 in migration of Th17 cells and regulation of effector T-cell balance in the gut
Mucosal Immunol.
(2009)
Phenotypic and functional features of human Th17 cells
J. Exp. Med.
Vitamin D and autoimmunity: new aetiological and therapeutic considerations
Ann. Rheum. Dis.
Link between vitamin D and airway remodelling
J. Asthma Allergy
Serum vitamin D levels and severe asthma exacerbations in the Childhood Asthma Management Program study
J. Allergy Clin. Immunol.
The polymorphism of IL-17G-152A was associated with childhood asthma and bacterial colonization of the hypopharynx in bronchiolitis
J. Clin. Immunol.
Th17 cells: new players in asthma pathogenesis
Allergy
Modulators of the nuclear receptor retinoic acid receptor-related orphan receptor-γ (RORγ or RORc)
J. Med. Chem.
Immunobiology of critical pediatric asthma
Clin. Rev. Allergy Immunol.
Global Strategy for Asthma Management and Prevention, Global Initiative for Asthma (GINA)
Immunobiology of asthma
Annu. Rev. Pharmacol.
Cited by (55)
Vitamin D and adaptive immunity in health and disease
2023, Feldman and Pike's Vitamin D: Volume Two: Disease and TherapeuticsVitamin D modulates the transcription factors of T cell subsets to anti-inflammatory and regulatory profiles in preeclampsia
2021, International ImmunopharmacologyHigh salt diet may promote progression of breast tumor through eliciting immune response
2020, International Immunopharmacology