Bal M S, Beuria M K, Mandal N N, Das M K
Immunology Division, Regional Medical Research Centre (ICMR), Chandrasekharapur, Bhubaneswar - 751023, Orissa, India.
Parasite Immunol. 2003 Feb;25(2):107-11. doi: 10.1046/j.1365-3024.2003.00604.x.
The IgG response to a filarial surface antigen (DssdI) was evaluated in circulating antigen (Og4C3 test) positive and negative individuals from the Wuchereria bancrofti endemic region of Orissa, India. Circulating filarial antigen (CFA) positive individuals exhibited depressed antibody levels to DssdI and individuals with high antibody levels were invariably CFA negative. Low IgG levels to DssdI are associated with CFA positivity irrespective of microfilaraemia and clinical status. Thus asymptomatic microfilaraemic individuals with antigen positivity exhibited low IgG levels similar to symptomatic (chronic filariasis with elephantiasis, hydrocele) or asymptomatic amicrofilaraemic individuals with antigenemia. Western blot analysis revealed a band of approximately 210 kDa reactive with CFA-negative, but not with CFA-positive sera. DssdI was subjected to mild periodate oxidation to investigate the role of carbohydrate epitopes. The treatment considerably reduced the antigenic recognition of DssdI, stressing the immunodominance of carbohydrate residues of DssdI in infection-free individuals. In contrast, individuals with active infection failed to produce such antibodies to filarial surface carbohydrates.
在印度奥里萨邦班氏吴策线虫流行地区，对循环抗原（Og4C3检测）呈阳性和阴性的个体，评估其对丝虫表面抗原（DssdI）的IgG反应。循环丝虫抗原（CFA）阳性个体对DssdI的抗体水平较低，而抗体水平高的个体CFA总是呈阴性。无论是否存在微丝蚴血症和临床状态，对DssdI的低IgG水平都与CFA阳性有关。因此，抗原阳性的无症状微丝蚴血症个体表现出与有症状（伴有象皮肿、鞘膜积液的慢性丝虫病）或无症状无微丝蚴血症且有抗原血症的个体相似的低IgG水平。蛋白质免疫印迹分析显示，有一条约210 kDa的条带与CFA阴性血清反应，但不与CFA阳性血清反应。对DssdI进行轻度高碘酸盐氧化，以研究碳水化合物表位的作用。该处理显著降低了对DssdI的抗原识别，强调了DssdI碳水化合物残基在未感染个体中的免疫优势。相比之下，有活动性感染的个体未能产生针对丝虫表面碳水化合物的此类抗体。
