Purpose: Non cystic fibrosis (Non-CF) bronchiectasis in childhood is an important cause of chronic suppurative lung disease in the developing countries. It is well known that T lymphocytes play a key role in the disease pathogenesis of non CF bronchiectasis. Gamma delta T cells are implicated in disease pathogenesis of several chronic disorders including asthma and tuberculosis. However their role immune dysregulation in Non-CF bronchiectasis airways remains unexplored.
The aim of the study was to compare the cytokine (IFN-gamma, IL-2, IL-8, IL-4 and IL-6) production by gamma delta T and alpha beta T cells upon stimulation with PMA-Io, in induced sputum of children with Non-CF bronchiectasis, (n=20; age 7–12 years) and ten healthy controls. The cytokines were estimated by flowcytometry (BD, FACScaliburTM) using CellQuest software. Furthermore association between cytokine expression and lung function was also estimated.
We observed a high expression of gamma delta IFN-gamma in non CF bronchiectasis as compared to controls (34.6+0.84) Vs (10.1+0.26) p<0.01. Gamma delta IL-8 in children with non CF bronchiectasis (19.8+0.68) was significantly higher as compared to gamma delta IL-8 in controls (9.4+0.42), p<0.05. Similarly, a higher expression of gamma delta IL-2 in non CF bronchiectasis (24.6+0.78) Vs controls (12.1+0.48), p<0.05 was observed. No significant difference in IL-4, IL-6 expression between the two groups was observed. A significant negative correlation between gamma delta IL-8 & FEV1 (p<0.05) was observed.
Gamma delta T cells contribute to the immune dysregulation in the airways of children with non CF bronchiectasis, through production of proinflammatory cytokines.
Immune dysregulation by gamma delta T cells in the airways of children with non CF bronchiectasis could serve as a target for future therapeutic interventions.
Nidhi Anil, No Financial Disclosure Information; No Product/Research Disclosure Information