CD4+CD25(high) Treg cells in peripheral blood during remission and exacerbation of allergic asthma in children

Serum CDC42 reflects the exacerbation risk and severity, Th1/2 cell imbalance and inflammation in asthmatic children

Aim: To explore the clinical implication of serum CDC42 in asthmatic children. Materials & methods: Serum CDC42 from 80 asthmatic children experiencing exacerbation, 80 asthmatic children in remission and 40 healthy controls was detected by ELISA. Results: CDC42 was highest in asthmatic children experiencing exacerbation followed by asthmatic children in remission and healthy controls (p < 0.001). Among asthmatic children experiencing exacerbation, CDC42 positively correlated with exacerbation severity (p = 0.011), Th2 (p = 0.017), TNF-α (p < 0.001), IL-6 (p = 0.009) and IL-8 (p = 0.008) and negatively correlated with Th1/Th2 ratio (p = 0.028). In asthmatic children in remission, CDC42 correlated with lower Th1/Th2 ratio (p = 0.028) and higher TNF-α (p = 0.026). In healthy controls, CDC42 showed no correlation with Th1/2 or inflammatory cytokines. Conclusion: Circulating CDC42 reflects exacerbation risk, Th1/2 imbalance and inflammation in asthmatic children.

Allergic Rhinitis and House Dust Mite Sensitization Determine Persistence of Asthma in Children

OBJECTIVE

To specify clinical and immunological parameters of the mechanisms, which may lead to development of persistent asthma, or regression of the disease symptoms.

METHODS

Eighty children with childhood asthma, diagnosed in the past by using the modified Asthma Predicted Index (mAPI), were divided into two groups: remission group and persistent group. There were 3 study visits (baseline, at 6 mo, and at 12 mo). Clinical remission of asthma was defined as the absence of asthma symptoms for at least 12 mo without treatment. The patients could switch from one group to another during the 12 mo of follow-up. Clinical, inflammatory, and immunoregulatory predictors of asthma remission/persistence were analyzed.

RESULTS

The presence of mAPI criteria as well as house dust mite (HDM) allergy and allergic rhinitis at 7-10 y, were associated with a reduced prevalence of asthma remission. The increased eosinophil blood count in mAPI criteria was associated with a lower expression of CD25 positive cells. HDM allergy was associated with a higher fractional exhaled nitric oxide (FeNO) level (p = 0.0061) and higher expression of CD25CD71 (p = 0.0232). Allergic rhinitis was associated with a higher expression of PPAR (p = 0.0493) and CD25CD71 (p = 0.0198), and lower expression of glycoprotein A repetitions predominant (GARP).

CONCLUSIONS

Persistence of childhood asthma was largely determined by the presence of allergic rhinitis and sensitization to HDM. Additionally, API criteria but not immunoregulation processes, were related to asthma persistence.

Physical activity in asthma control and its immune modulatory effect in asthmatic preschoolers

BACKGROUND

The impact of physical activity on immune response is a hot topic in exercise immunology, but studies involving asthmatic children are scarce. Our aims were to examine whether there were any differences in the level of physical activity and daily TV attendance, to assess its role on asthma control and immune responses to various immune stimulants.

METHODS

Weekly physical activity and daily television attendance were obtained from questionnaires at inclusion of the PreDicta study. PBMC cultures were stimulated with phytohemagglutinin (PHA), R848, poly I:C, and zymosan. A panel of cytokines was measured and quantified in cell culture supernatants using luminometric multiplex immunofluorescence beads-based assay.

RESULTS

Asthmatic preschoolers showed significantly more TV attendance than their healthy peers (58.6% vs. 41.5% 1-3 h daily and only 25.7% vs. 47.2% ≤1 h daily) and poor asthma control was associated with less frequent physical activity (PA) (75% no or occasional activity in uncontrolled vs. 20% in controlled asthma; 25% ≥3 times weekly vs. 62%). Asthmatics with increased PA exhibited elevated cytokine levels in response to polyclonal stimulants, suggesting a readiness of circulating immune cells for type 1, 2, and 17 cytokine release compared to subjects with low PA and high TV attendance. This may also represent a proinflammatory state in high PA asthmatic children. Low physical activity and high TV attendance were associated with a decrease in proinflammatory cytokines. Proinflammatory cytokines were correlating with each other in in vitro immune responses of asthmatic children, but not healthy controls, this correlation was more pronounced in children with sedentary behavior.

CONCLUSION

Asthmatic children show more sedentary behavior than healthy subjects, while poor asthma control is associated with a substantial decrease in physical activity. Our results suggest that asthmatic children may profit from regular exercise, as elevated cytokine levels in stimulated conditions indicate an immune system prepared for responding strongly in case of different types of infections. However, it has to be considered that a hyperinflammatory state in high PA may not be beneficial in asthmatic children.

MALT1 in asthma children: A potential biomarker for monitoring exacerbation risk and Th1/Th2 imbalance-mediated inflammation

BACKGROUND

Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) participates in the immune-related allergic response and inflammation flare, while its clinical role in asthma children is still unknown. Herein, this study aimed to investigate MALT1 expression, and its correlation with exacerbation risk, T helper (Th)1, Th2 cells (and their secreted cytokines), as well as inflammatory cytokines in asthma children.

METHODS

Sixty children with asthma exacerbation and 60 children with remission asthma were enrolled in this study; then their blood MALT1, Th1, Th2 cells, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interferon-gamma (IFN-γ), and interleukin-4 (IL-4) were detected. Besides, blood MALT1 in another 20 health controls was also determined.

RESULTS

Mucosa-associated lymphoid tissue lymphoma translocation protein 1 was highest in children with asthma exacerbation, followed by children with remission asthma, and lowest in health controls (p < 0.001). MALT1 could distinguish children with asthma exacerbation from children with remission asthma (area under the curve (AUC): 0.757, 95% CI: 0.670-0.843). In children with asthma exacerbation, MALT1 was negatively linked with IFN-γ (p = 0.002) and Th1 cells (p = 0.050), but positively related to Th2 cells (p = 0.027) and exhibited a positive correlation trend (without statistical significance) with IL-4 (p = 0.066); meanwhile, MALT1 was positively correlated with exacerbation severity (p = 0.010) and TNF-α (p = 0.003), but not linked with IL-6 (p = 0.096). In children with remission asthma, MALT1 only was negatively associated with Th1 cells (p = 0.023), but positively linked with TNF-α (p = 0.023).

CONCLUSION

Mucosa-associated lymphoid tissue lymphoma translocation protein 1 serves as a potential biomarker for monitoring exacerbation risk and Th1/Th2 imbalance-mediated inflammation of asthma children.

Immunoregulatory Effects of Subcutaneous Immunotherapy on Lymphocyte Subgroups and Cytokines in Children with Asthma

Objective

Asthma is a syndrome that incorporates many immune phenotypes. The immunologic effects of subcutaneous immunotherapy (SCIT) exerts on allergic asthma remain still largely unknown. Here, we investigated the effects of SCIT on cytokine production and peripheral blood levels of lymphocyte subtypes in children with mite-induced moderate and severe allergic asthma.

Methods

The study included 60 kids with mite-induced allergic asthma from 5 to 10 years old. All subjects had received antiasthmatic pharmacologic for 3 months at baseline. Half of the children were treated with SCIT combined with pharmacologic treatment named the SCIT group and the other half only with pharmacologic therapy named the no-SCIT group. Total asthma symptom score (TASS) and total medication score (TMS) were recorded. Flow cytometry was used to identify lymphocyte subtypes: type 2 innate lymphocytes (ILC2s), type 1 (Th1) and type 2 (Th2) helper T cells, T helper 17 (Th17) cells, and regulatory T (Treg) cells. ELISA, flow cytometry, and cytometric bead array were used to assess cytokines IL-13, IFN-γ, IL-4, IL-17, and TGF-β, at baseline and 3 and 6 months after study treatment in both groups of patients.

Results

Both groups can significantly improve clinical symptoms in children with asthma. SCIT can significantly reduce asthma medication after 6 months of treatment. SCIT induced a significantly higher and progressive reduction in ILC2 percentage and IL-13 levels after 3 and 6 months of treatment compared with baseline and compared with no-SCIT patients. Significant differences were detected in the Th1/Th2 cell ratio and IFN-γ/IL-4 cytokine ratio between groups after 6 months of treatment. Similarly, the Th17/Treg ratio and IL-17/TGF-β ratio in the SCIT group were much lower than those in the no-SCIT group after 3-6 months of treatment.

Conclusion

SCIT is a promising option to reduce the percentage of ILC2 and regulate Th1/Th2 and Th17/Treg immune balance in the peripheral blood of children with asthma.

Regulatory T cells regulate the distribution of natural killer T cells through CD39 signal transduction in asthma

Natural killer T cells (NKT cells) and regulatory T cells (Treg cells) are two important immune regulatory cells which both play critical roles in asthma. Our previous experiments revealed that activation of Treg cells suppressed NKT cells in asthma. However, the possible regulatory effects and the mechanisms linking Treg cells and NKT cells remain poorly understood. The current study was designed to further investigate the regulatory effect and its possible mechanisms of Treg cells on NKT cells function, especially the distribution of NKT cells. Regulatory T cell (Treg), responder T cell (Teff) and Natural killer T cell (NKT) were isolated and purified. After Lentivirus carrying CD39 (Le-CD39) was transfected into Treg cells, the immune phenotype of Treg cells was changed and the suppressive effect of Treg cells on Teff cells with an activation of Treg cells was enhanced, marking with a high expression level of interleukin 10 (IL-10) and transforming growth factor β (TGF-β). Up-regulation of CD39 expression led to lower ATP level in cell culture supernatant. To further explore its function in asthma, we introduced an ovalbumin (OVA)-induced mice model of asthma. And the data showed that up-regulation of CD39 remarkably alleviated OVA-induced hallmarks of the asthma and increased NKT cells in the spleen and peripheral blood; however, decreased NKT cells in the lung. Furthermore, up-regulation of CD39 decreased the levels of interleukin 4 (IL-4) and interferon γ (IFN-γ) in the lung of OVA-treated mice. Our results strongly suggest that Treg cells could be activated by CD39 signal transduction and then affected the distribution of NKT cells in the OVA-induced mice model of asthma.

Th17/Treg dysregulation in allergic asthmatic children is associated with elevated notch expression

BACKGROUND

Notch signaling pathway is critically involved in the differentiation of T helper (Th) cells, key players in the pathogenesis of allergic diseases.

OBJECTIVE

The study is to explore whether Th17/Treg dysregulation in children with allergic asthma (AA) is associated with alteration of Notch expression.

METHODS

Thirty-five patients with AA and thirty-five healthy control children were selected. Flow cytometry was used to detect Th17 and Treg cells. Quantitative real-time polymerase chain reaction (QRT-PCR) was used to measure the expression of Notch1 mRNA. The correlations among Notch1 mRNA expression, the percentage of Th17 cells, and Th17/Treg ratio were calculated.

RESULTS

Th17 and Treg cells were significantly increased and decreased, respectively, in children with AA than in healthy control (p < 0.001). mRNA level of Notch1 was elevated in children with AA comparing to healthy controls (p < 0.001). The mRNA expression of Notch1 was positively correlated with the percentage of Th17 cells (r = 0.775, p < 0.001) and Th17/Treg ratio (r = 0.698, p < 0.001).

CONCLUSION

Children with AA showed dysregulation of Th17/Treg cells in peripheral blood. Such change is accompanied with overexpression of Notch1, indicating Th17/Treg dysregulation in children with AA is associated with elevated Notch expression.

Allergen-Specific CD4(+) T Cells in Human Asthma

In allergic asthma, aeroallergen exposure of sensitized individuals mobilizes robust innate and adaptive airway immune responses, stimulating eosinophilic airway inflammation and the activation and infiltration of allergen-specific CD4(+) T cells into the airways. Allergen-specific CD4(+) T cells are thought to be central players in the asthmatic response as they specifically recognize the allergen and initiate and orchestrate the asthmatic inflammatory response. In this article, we briefly review the role of allergen-specific CD4(+) T cells in the pathogenesis of human allergic airway inflammation in allergic individuals, discuss the use of allergen-major histocompatibility complex class II tetramers to characterize allergen-specific CD4(+) T cells, and highlight current gaps in knowledge and directions for future research pertaining to the role of allergen-specific CD4(+) T cells in human asthma.

CD4(+), CD25(+), FOXP3 (+) T Regulatory Cell Levels in Obese, Asthmatic, Asthmatic Obese, and Healthy Children

The aim of this prospective case control study is to determine CD4(+), CD25(+), and FoxP3(+) T regulatory cells (Tregs) and T helper cells (Ths) in obese, asthmatic, asthmatic obese, and healthy children. Obese (n = 40), asthmatic (n = 40), asthmatic obese (n = 40), and healthy children (n = 40) were included in this study. Blood samples collected from children were marked with CD4, CD25, ve Foxp3 in order to detect Tregs and Ths by flow cytometric method. Statistical analyses were performed. p ≤ 0.05 was chosen as meaningful threshold. Tregs exhibiting anti-inflammatory nature were significantly lower in obese (0.16 %; p ≤ 0.001), asthmatic (0.25 %; p ≤ 0.01), and asthmatic obese (0.29 %; p ≤ 0.05) groups than control group (0.38 %). Ths were counted higher in asthma group than control (p ≤ 0.01) and obese (p ≤ 0.001) groups. T cell immunity plays important roles in chronic inflammatory diseases such as obesity and asthma pathogeneses. Decreased numbers of Tregs found in obese, asthmatic, and asthmatic obese children might represent a challenge of these cells.

Immune response to Streptococcus pneumoniae in asthma patients: comparison between stable situation and exacerbation

In Argentina, more than 3 million people suffer from asthma, with numbers rising. When asthma patients acquire viral infections which, in turn, trigger the asthmatic response, they may develop subsequent bacterial infections, mainly by Streptococcus (S.) pneumoniae. This encapsulated Gram(+) bacterium has been considered historically a T cell-independent antigen. Nevertheless, several papers describe the role of T cells in the immune response to S. pneumoniae. We evaluated the response to S. pneumoniae and compared it to the response to Mycobacterium (M.) tuberculosis, a different type of bacterium that requires a T helper type 1 (Th1) response, in cells from atopic asthmatic children, to compare parameters for the same individual under exacerbation and in a stable situation whenever possible. We studied asthma patients and a control group of age-matched children, evaluating cell populations, activation markers and cytokine production by flow cytometry, and cytokine concentration in serum and cell culture supernatants by enzyme-linked immunosorbent assay (ELISA). No differences were observed in γδ T cells for the same patient in either situation, and a tendency to lower percentages of CD4(+) CD25(hi) T cells was observed under stability. A significantly lower production of tumour necrosis factor (TNF)-α and a significantly higher production of interleukin (IL)-5 was observed in asthma patients compared to healthy individuals, but no differences could be observed for IL-4, IL-13 or IL-10. A greater early activation response against M. tuberculosis, compared to S. pneumoniae, was observed in the asthmatic patients' cells. This may contribute to explaining why these patients frequently acquire infections caused by the latter bacterium and not the former.