Abstract:Objective:To investigate whether human alveolar type Ⅱ epithelial cells express IL-22R and whether it generates human β-defensin-2 (HBD-2) under the stimulation with IL-22. Methods: First,flow cytometry(FCM) detected the expression of IL-22R on alveolar type Ⅱ epithelial cells;second,cells were stimulated with recombinant human IL-22(rhIL-22) for 0,2,4,8,16,24 hours,separately,and then RT-PCR tested the expression of HBD-2;third,the cells were stimulated with different concentration (0,4,20,100,500 ng/ml) of IL-22 for optimal dose. Results: The membranes of alveolar type Ⅱ epithelial cells highly expressed IL-22R and the positive rate is (99.90 ± 0.13)%;24 hours is an effective time for HBD-2 expression with IL-22 treatment,and the optimal concentration is 100 ng/ml. Conclusion: The alveolar type Ⅱ epithelial cells highly express IL-22R,and the interaction of IL-22 and IL-22R induces the HBD-2 gene expression in alveolar epithelium in a time- and concentration-dependent manner.