ABSTRACT
Objective To investigate the frequency of CD4~+CD25~+FoxP3~+regulatory T cells (Treg)and the expression of the functional protein,FoxP3,in patients with active tuberculosis and the relationship between Treg and the pathogenesis of tuberculosis.Methods Forty-five patients with active tuberculosis(including 25 cases of pulmonary tuberculosis and 20 tuberculous lymphadenitis), 20 healthy controls,20 recovered tuberculosis patients and 6 patients with reactive hyperplasia in cer- vical lymph node were enrolled.The frequency of CD4~+ CD25~+ FoxP3~+ Treg in the peripheral blood was measured by flow cytometry.FoxP3 mRNA expression was determined by real-time reverse transcriptase-polymerase chain reaction(RT-PCR)and the expression of FoxP3 protein in lymphoid tissues was measured by immunohistochemistry.Results The frequency of natural Treg in the peripheral blood from the patients with active tuberculosis was 2.91%?0.23%,which was signifi- cantly higher than that of healthy control group(1.22%?0.18%)and recovered tuberculosis patients(1.50%?0.17%,P