Halstead S B, Larsen K, Kliks S, Peiris J S, Cardosa J, Porterfield J S
Am J Trop Med Hyg. 1983 Jan;32(1):157-63. doi: 10.4269/ajtmh.1983.32.157.
Tissue culture-adapted dengue 2 virus (DEN 2), strain 16681, exhibits antibody-dependent enhancement of infection (ADE) in P388D1 cells, a mouse macrophage-like cell line. ADE is dependent upon maintaining DEN 2 multiplicity of infection at between 0.1 and 0.001, and can be simply measured in multi-well plastic plates. The assay uses either trypsinized or non-trypsinized P388D1 cells at 5 x 10(5) cells per ml, an appropriate dilution of DEN 2 virus, and a source of antibody, and is most conveniently performed without further washing of stationary cultures, which are incubated in 5% CO2. Trypsinization of P388D1 cells prior to the addition of virus-serum mixtures reduced infection in control cultures thus increasing ADE. When cells were washed after incubation of virus-serum mixtures for 1 hour, a paradoxical increase of infection in cultures exposed to virus plus normal serum was noted, which reduced the sensitivity of the ADE assay. Using human cord blood sera, ADE titers measured in human monocytes and P388D1 cells were closely similar. This convenient and economical assay will facilitate large scale biological and epidemiological studies of dengue virus enhancing antibodies.
经组织培养适应的登革2型病毒（DEN 2），毒株16681，在P388D1细胞（一种小鼠巨噬细胞样细胞系）中表现出抗体依赖性感染增强（ADE）。ADE取决于将DEN 2感染复数维持在0.1至0.001之间，并且可以在多孔塑料板中简单地进行测量。该测定使用每毫升5×10⁵个细胞的胰蛋白酶消化或未消化的P388D1细胞、适当稀释的DEN 2病毒以及抗体来源，并且最方便的是在不进一步洗涤固定培养物的情况下进行，固定培养物在5%二氧化碳中孵育。在添加病毒 - 血清混合物之前对P388D1细胞进行胰蛋白酶消化会降低对照培养物中的感染，从而增加ADE。当病毒 - 血清混合物孵育1小时后对细胞进行洗涤时，发现暴露于病毒加正常血清的培养物中感染出现反常增加，这降低了ADE测定的灵敏度。使用人脐血血清，在人单核细胞和P388D1细胞中测得的ADE滴度非常相似。这种方便且经济的测定将有助于对登革病毒增强抗体进行大规模生物学和流行病学研究。
