Variation of Regulatory T Lymphocytes in the Peripheral Blood of Children with Allergic Rhinitis

CD8+ Tregs ameliorate inflammatory reactions in a murine model of allergic rhinitis

BACKGROUND

CD8⁺CD25⁺fork-head box transcription factor (Foxp3)⁺ regulatory T cells (CD8⁺ Tregs) play a role in immune tolerance. However, the role of these cells in allergic rhinitis (AR) has not been elucidated. The study aimed to evaluate influences of CD8⁺ Tregs on inflammatory conditions in a murine model of AR.

METHODS

A murine model of AR was established. CD8⁺ Tregs were isolated from mice nasal mucosa and cultured in vitro. We examined interleukin (IL)-10 and transforming growth factor (TGF)-β in cell cultures. Then, we administered CD8⁺ Tregs into mice nasal mucosal cultures, and examined eosinophil cation protein (ECP), IL-4, IL-5 and IL-13 in these cultures. Finally, we adoptively transferred CD8⁺ Tregs into mice models, and evaluated percentages of CD8⁺ Tregs, numbers of sneezing and nasal rubbing, and counts of eosinophils and contents of ECP, IL-4, IL-5, IL-13, IL-10 and TGF-β in nasal lavage fluid (NLF) in mice.

RESULTS

The percentage of CD8⁺ Tregs from AR mice was reduced. IL-10 and TGF-β were increased in cell cultures from AR mice. ECP, IL-4, IL-5 and IL-13 were decreased after the AR mice CD8⁺ Tregs administration in mucosal cultures. However, their contents were not changed after normal CD8⁺ Tregs treatment. Additionally, the adoptive transfer of AR CD8⁺ Tregs enhanced the percentage of CD8⁺ Tregs and levels of IL-10 and TGF-β in NLF, reduced numbers of sneezing and nasal rubbing, and counts of eosinophils and concentrations of ECP, IL-4, IL-5 and IL-13 in NLF. However, normal CD8⁺ Tregs could not change above parameters.

CONCLUSION

These findings show that CD8⁺ Tregs may inhibit inflammatory responses in the AR condition.

Vitamin D Status in Egyptian Children With Allergic Rhinitis

Objective: This study aimed to assess the serum levels of vitamin D in an Egyptian cohort of children with allergic rhinitis (AR) and to evaluate any correlation of vitamin D status with the disease severity. Patient and methods: One hundred twenty children with AR and 100 healthy children were included in our study. We studied the serum levels of vitamin D 25(OH)D and 1,25(OH)2D in all participants. The associations between vitamin D levels and clinical characteristics of AR were examined. Results: In AR group, the serum levels of calcium, (25(OH)D and 1,25(OH)2D levels were significantly lower (p < .0001, p < .001, and p < .0001, respectively) in AR children than in controls. Furthermore, the mean 25-OHD3 levels in patients with moderate/severe AR were significantly lower than those with mild AR (p < .001). We found significant negative correlations between mean 25(OH)D levels and total nasal symptom score (r = -.62, p = .002) and total immunoglobulin E levels (r = -.27, p = .013) in AR group. Conclusions: Vitamin D deficiency is a frequent finding among Egyptian children with AR when compared to the healthy group. A significant inverse association was observed between vitamin D levels and AR disease severity.

Characterization of Regulatory T Cells in Preterm and Term Infants

Our study aimed to study regulatory T cells (Tregs) and their expression of CD45RA, HLA-DR, and CD39 in preterm and full-term infants. In an observational study, we used a three-color flow cytometry for determination of Tregs and their expression of CD45RA, HLA-DR, and CD39 in preterm and full-term infants. The percentages of CD4⁺CD25^+highFoxp3⁺, CD39⁺ Tregs, HLA-DR⁺ Tregs and the expression of Foxp3⁺ in CD4⁺CD25^+highFoxp3 Tregs cells were significantly lower in neonates when compared to healthy adult controls. The levels of naïve resting Tregs (CD45RA⁺Tregs) were significantly higher in neonates than controls. The percentages of CD4⁺CD25^+highFoxp3⁺Tregs, total CD4⁺CD25⁺ and CD4⁺CD25^+high were significantly higher in preterm infants when compared to the full-term group. Moreover, CD45RA⁺Tregs were significantly higher in preterm than in term infants. We found significant inverse correlations between the gestational age and the levels of both Tregs (r = - 0.395, p = 0.017) and CD45RA⁺Tregs (r = - 0.422, p = 0.010). Relative to full-term, the frequencies, and phenotypes of Tregs were affected by prematurity. A larger longitudinal study with a sufficient number of newborns is needed to investigate the Treg pool of term and preterm infants thoroughly and to explore the association between the Treg pool and clinical variables.