寄生虫IgE依赖组胺释放因子抗体抑制致敏肥大细胞释放组胺作用的研究

Inhibition of histamine release from sensitized mast cells by antibodies specific for parasite-origina-ted IgE-dependent histamine-releasing factors

目的观察抗寄生虫IgE依赖组胺释放因子(HRF)抗体对重组大鼠IgE依赖组胺释放因子(rRHRF)诱导致敏肥大细胞释放组胺功能的影响。方法用纯化的日本血吸虫和华支睾吸虫IgE依赖组胺释放因子重组蛋白rSjHRF和rCsHRF分别免疫大鼠,分离免疫血清并通过亲和层析纯化出总IgG。将rRHRF(终浓度为75μg/mL)分别与2种纯化抗体(浓度梯度为3/5,2/5,1/5,0)37℃预先反应30min后,再加入卵清蛋白变应原致敏的大鼠肺肥大细胞,利用荧光分光光度法测定rRHRF诱导肥大细胞组胺释放量。实验中采用未致敏大鼠血清纯化所得总IgG作为对照。结果得到了纯化的抗rSjHRF IgG和抗rC-sHRFIgG,抗rCsHRF IgG和抗rSjHRF IgG可明显抑制大鼠内源性IgE依赖HRF诱导致敏肥大细胞释放组胺的功能,但抗体抑制作用的强弱与抗体浓度之间的剂量依赖关系还需进一步实验验证。结论抗寄生虫IgE依赖组胺释放因子抗体具有抑制大鼠IgE依赖组胺释放因子诱导致敏肥大细胞释放组胺的作用,可能是参与寄生虫感染抑制宿主Ⅰ型超敏反应发生的免疫学机制之一,为预防和控制Ⅰ型超敏反应提供了新的思路。

Objective To investigate the effects of antibodies specific for parasite-originated IgE-dependent histamine-releasing factors （HRFs） on histamine release from sensitized mast cells induced by recombinant rat IgE-dependent histamine-releasing factor （rRI-IRF）. Methods Wistar rats were respectively immunized with purified recombinant IgE-dependent HRFs from Schistosoma japonicum or Clonorchis sinensis （rSjHRF or rCsHRF）, and then the immunized sera were isolated and the total IgG were purified by affinity chromatography, rRHRF with a final concentration of 75 μg/mL were incubated with purified anti-rCsHRF IgG and anti-rSjHRF IgG （with a serial concentration rates of 3/5, 2/ 5, 1/5, 0） at 37℃ for 30 min, then aliquots of the mast cells obtained from the lungs of OVA-immtmized rats were added and the histamine release induced by rRHRF was measured by the spectrofluorometric procedure. Purified total IgG from normal rat was used as control. Results Purified anti-rCsHRF IgG and anti-rSjHRF IgG were obtained and these purified IgG inhibited histamine release from the sensitized rat mast cells induced by rRHRF, while the dose-dependent relationship needs more efforts. Conclusion Antibodies specific for parasite-originated IgE-dependent HRFs could inhibit histamine release from the sensitized rat mast cells induced by rat IgE-dependent HRF, which may be one of the immunological mechanisms in the protecting effect of parasitic infection against allergic diseases and propose a new idea for the prevention and control of allergic diseases. a