卡介菌多糖核酸对慢性荨麻疹患者外周血淋巴细胞分泌干扰素γ和白介素4的影响

Influence of polysaccharide nucleic acid fraction of bacillus Calmette-Guerin on the secretion of interferon-γ and interleukin-4 by peripheral blood lymphocytes from patients with chronic urticaria

目的探讨卡介菌多糖核酸治疗慢性荨麻疹的可能机制。方法用不同浓度卡介菌多糖核酸处理慢性荨麻疹患者外周血淋巴细胞，并设立健康对照组。用免疫细胞化学法和酶联免疫吸附试验（ELISA）检测卡介菌多糖核酸作用96h后淋巴细胞分泌干扰素（IFN）-γ和白介素（IL）-4的水平。结果慢性荨麻疹患者外周血淋巴细胞IFN-1的表达量明显低于健康对照组（P〈0．05），经不同浓度卡介菌多糖核酸作用96h后，慢性荨麻疹患者外周血淋巴细胞分泌IFN-1明显增多，且随着卡介菌多糖核酸浓度的增加而逐渐接近健康对照组。慢性荨麻疹患者外周血淋巴细胞IL-4的表达量明显高于健康对照组（P〈0．05），经不同浓度卡介菌多糖核酸作用96h后，慢性荨麻疹患者外周血淋巴细胞分泌IL-4明显减少，且随着卡介菌多糖核酸浓度的增加而逐渐接近健康对照组。结论卡介菌多糖核酸体外可促进慢性荨麻疹患者外周血淋巴细胞分泌IFN-γ，抑制淋巴细胞分泌IL-4，起到调节免疫的作用。

Objective To investigate the possible mechanism involved in the therapeutic potential of polysaccharide nucleic acid fraction of bacillus Calmette-Guerin （BCG-PSN） for chronic urticaria. Methods Peripheral blood lymphocytes were obtained from 30 patients with chronic urticaria, and subjected to culture in vitro with the presence of various concentrations of BCG-PSN for 96 hours. Then, immunocytochemistry and enzyme-linked immunosorbent assay （ELISA） were performed to quantify the expression levels of interferon-＇y （IFN-~） and interleukin-4 （IL-4） on, and in the culture supematant of, these cells. The peripheral blood ]ymphocytes from 30 health check-up examinees served as the control. Results The untreated lymphocytes from patients with chronic urticaria showed significantly lower IFN-＇y expression （P 〈 0.05）, but significantly higher IL-4 expression （P 〈 0.05） compared with those from the controls. The 96-hour treatment with BCG-PSN induced an obvious increase in the level of IFN-＂/, but a marked decrease in that of IL-4, in the culture supernatant of patient- derived lymphocytes, and with the increase in BCG-PSN concentration, the levels of both IFN-γ and IL-4 secreted by patient-derived lymphocytes gradually approximated to those by the control lymphocytes. Conclusion BCG- PSN may exert an immunomodulatory effect via upregulating the secretion of IFN-γ but downregulating that of IL-4 by peripheral blood lymphocytes from patients with chronic urticaria.