PURPOSE: Role of gamma delta T cells at the pulmonary level in children with CF remains unexplored. We studied the invitro intracellular cytokine expression in children with CF and normal controls to correlate the cytokine expression by alpha beta gamma delta T-cells with the clinical status.
METHODS: Induced sputum from fifteen children with CF age (2-11 years) and 10 age matched controls was studied. The in vitro intracellular cytokine expression was studied upon stimulation with PHA using flowcytometery. Ten thousand T lymphocyte cells were gated based on CD3 expression. Anti TCR alpha beta, FITC labelled and Anti TCR gamma delta, IFN- gamma, PE labelled monoclonal antibodies were used. Shwachman scoring was done in these patients once on enrollment and subsequently after three months following therapy.
RESULTS: We observed a significantly higher percentage expression of CD3+ IFN-gamma by gamma delta T cells (36.8 + 4.1) in children with CF p<0.001 as compared to alpha beta T cells (26.8+ 4.1). We also observed a significant difference in the IFN-gamma by gamma delta T cells in children with CF (36.8 + 4.9) as compared to controls (7.1 + 2.3) p<0.001. Gamma delta T cells were better producers of IL-8 in children with CF (19.8 + 4.1) Vs alpha beta T cells (14.0 + 3.2) p<0.05.On follow up we observed a significant decrease in IL-8 levels in children with CF and an increase in IFN-gamma levels. We also found a significant positive correlation between gamma delta IFN-gamma and Shwachman score on follow up. r=0.864 p<0.001.
CONCLUSION: Conclusion:- We have demonstrated the role of gamma delta T cells in immune imbalance in CF lungs through cytokine dysregulation. An improvement in the Shwachman score of these children correlated with the increase in IFN-gamma levels.
CLINICAL IMPLICATIONS: Cytokine dysregulation by gamma delta T cells can be an important target for possible immune regulation in lungs of children with cystic fibrosis.
DISCLOSURE: Meenu Singh, None.