CD4⁺CD25 ^high FOXP3⁺ Regulatory T Cells Correlate with FEV₁ in North Indian Children with Cystic Fibrosis

Abstract

Cystic fibrosis (CF) lung disease is characterized by dysregulated inflammatory response in the airways. CD4⁺CD25⁺ regulatory T cells play a crucial role in maintaining the immune homeostasis. However their role in the disease pathogenesis of CF remains unexplored. Aim: To determine the percentage of circulating CD4⁺CD25^high, FoxP3⁺ T cell expression in children with CF and controls. Furthermore to evaluate the relationship between CD4⁺CD25^high, FOXP3 T cell % and the clinical status of the disease (lung function). Methods: CD4⁺CD25⁺, intracellular FoxP3 expression in peripheral blood were estimated using flowcytometry in 20 children with CF and 10 healthy controls. Spirometry was carried out according to the standard guidelines. Results: We observed a significant difference in CD4⁺CD25⁺T cell% in children with CF (5.2 ± 1.2) versus controls (6.8 ± 1.4, p < 0.05), CD4⁺CD25^highTcell% in CF (1.72 ± 0.36) versus controls (2.59 + 0.42, p < 0.003). Similarly a significant difference was observed in FoxP3 T cell% CF: (60.7 ± 6.19) versus controls (76.8 ± 5.16), p < 0.001. A significant positive correlation between FoxP3 T cell% and FEV₁ in children with CF(r = 0.822, p < 0.01) was observed.CD4⁺CD25^high T cell% correlated positively with FEV₁ (r = 0.742, p < 0.01). Conclusion: Our findings report the first evidence of a decreased expression of circulating CD4⁺CD25^high FoxP3⁺ T cells in children with CF. Furthermore circulating CD4+ CD25^high, FOXP3⁺ T cell percentage correlated with FEV₁.

• Cystic fibrosis
• FEV₁
• regulatory T cells

Acknowledgments

The Senior Research Associateship, CSIR Scientist Pool Scheme (No. B-11562) is duly acknowledged. N. Anil was involved in conceptualizing the research proposal, performed all experimental procedures, analyzed the data and wrote the manuscript. M. Singh was responsible for patient recruitment, obtaining informed consent and data analysis.