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Updated: May 22, 2026

Real-Time, Semi-Automated Fluorescent Measurement of the Airway Surface Liquid pH of Primary Human Airway Epithelial Cells
Published on: June 13, 2019
Lymphocyte CFTR promotes epithelial bicarbonate secretion for bacterial killing
Xiao Xiao Tang1, Kin Lam Fok, Hao Chen
1Epithelial Cell Biology Research Center, School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, NT, HKSAR, Hong Kong, China.
Lymphocytes expressing cystic fibrosis transmembrane conductance regulator (CFTR) enhance lung epithelial bicarbonate secretion and bacterial defense. This CFTR-dependent interaction is crucial for innate immunity against respiratory infections.
Area of Science:
- Immunology
- Cell Biology
- Respiratory Medicine
Background:
- The role of cystic fibrosis transmembrane conductance regulator (CFTR) in lymphocytes is not well understood.
- CFTR is known for its role in ion transport, particularly in epithelial tissues.
Purpose of the Study:
- To investigate the physiological role of CFTR expressed in lymphocytes.
- To explore the interaction between lymphocytes and lung epithelial cells in the context of host defense.
Main Methods:
- Co-culture of lymphocytes with the Calu-3 lung epithelial cell line.
- Utilizing lymphocytes from CFTR knockout mice to assess CFTR dependency.
- Investigating the role of E-cadherin in lymphocyte-epithelial cell interactions.
- Analyzing carbonic anhydrase (CA-2, CA-4) expression and bacterial killing capacity.
Main Results:
- Lymphocyte co-culture with Calu-3 cells enhanced epithelial bicarbonate (HCO3-) secretion and bacterial killing.
- This enhancement was abolished with CFTR knockout lymphocytes and reduced by interfering with E-cadherin.
- Impaired E-cadherin and CA-4 expression was observed in CFTR knockout mice following bacterial lipopolysaccharide (LPS) challenge.
Conclusions:
- Lymphocyte-epithelial cell interactions stimulate an innate host defense mechanism against bacterial infection.
- This mechanism involves CFTR-dependent epithelial bicarbonate production/secretion.
- CFTR expression in lymphocytes is critical for this immune response.
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