Makino Y, Tadano M, Arakaki S, Fukunaga T
Department of Virology, Faculty of Medicine, University of the Ryukyus, Okinawa, Japan.
Am J Trop Med Hyg. 1991 Nov;45(5):636-43. doi: 10.4269/ajtmh.1991.45.636.
Truncated dengue-4 E protein was produced as a fusion protein in insect cells using a baculovirus expression vector to examine its usefulness as a diagnostic antigen. A peroxidase-anti-peroxidase (PAP) staining method was used to examine the immunoreactivity of the antigenic determinants in recombinant virus-infected Sf-9 cells with human sera obtained from dengue (DEN) and Japanese encephalitis (JE) endemic areas (41 sera from DEN patients and 39 sera from JE patients or individuals with high JE-antibody titers). The expressed E protein, in which one-third of the carboxy-terminal end was deleted, reacted with sera from DEN patients, but it failed to react or responded only faintly with sera from JE patients. The antibody titers obtained by the staining method correlated with those obtained by enzyme-linked immunosorbent assay (ELISA) (r = 0.64, P less than 0.01). Calculation of the ratio (R) of the titer obtained by the PAP staining method to the ELISA titer can clearly differentiate DEN antibody from JE antibody (high R values in DEN sera and low R values in JE sera). The recombinant protein would be especially useful for diagnostic purposes in regions where DEN and JE viruses co-circulate.
使用杆状病毒表达载体在昆虫细胞中产生截短的登革热4型E蛋白，作为融合蛋白，以检测其作为诊断抗原的效用。采用过氧化物酶-抗过氧化物酶（PAP）染色法，用从登革热（DEN）和日本脑炎（JE）流行地区获得的人血清检测重组病毒感染的Sf-9细胞中抗原决定簇的免疫反应性（41份来自登革热患者的血清和39份来自日本脑炎患者或日本脑炎抗体效价高的个体的血清）。表达的E蛋白缺失了三分之一的羧基末端，与登革热患者的血清发生反应，但与日本脑炎患者的血清不发生反应或仅发生微弱反应。通过染色法获得的抗体效价与通过酶联免疫吸附测定（ELISA）获得的抗体效价相关（r = 0.64，P < 0.01）。计算PAP染色法获得的效价与ELISA效价的比值（R），可以清楚地区分登革热抗体和日本脑炎抗体（登革热血清中的R值高，日本脑炎血清中的R值低）。该重组蛋白在登革热病毒和日本脑炎病毒共同流行的地区用于诊断目的将特别有用。
