Parker S J, Smith F M, Johnson A M
Department of Microbiology and Infectious Diseases, Flinders Medical Centre, Bedford Park, South Australia.
J Parasitol. 1991 Jun;77(3):402-9.
Recombinant proteins of the RH strain of Toxoplasma gondii were produced by expression in Escherichia coli as glutathione S-transferase (GST) fusion proteins. Enzyme-linked immunosorbent assays were established using 2 of these fusion proteins termed H4/GST and H11/GST. The assays were able to detect antibodies in the sera of mice orally infected with either the cyst or oocyst stage of a pork isolate of T. gondii. In addition, the sera from mice infected with 1 of 4 different T. gondii isolates were investigated for their binding to these fusion proteins. Antibodies in the sera of all mice bound to H11/GST, but not all sera recognized H4/GST. Delayed-type hypersensitivity (DTH) responses to the fusion proteins were found when the mice were sensitized intradermally with H4/GST and H11/GST and challenged with the homologous fusion protein. However, no DTH response was recorded when mice were challenged with homologous fusion proteins after infection with T. gondii, or after immunization with a sonicate of the RH strain of the parasite. In addition, cellular responses were not stimulated against either of the fusion proteins in in vitro assays. These 2 fusion proteins were recognized by anti-T. gondii antibodies in experimental murine infections, and they are therefore potential candidates as antigens in assays for the diagnosis of human toxoplasmosis.
通过在大肠杆菌中表达作为谷胱甘肽S-转移酶（GST）融合蛋白，制备了刚地弓形虫RH株的重组蛋白。使用其中两种称为H4/GST和H11/GST的融合蛋白建立了酶联免疫吸附测定法。这些测定法能够检测口服感染刚地弓形虫猪肉分离株的包囊或卵囊阶段的小鼠血清中的抗体。此外，还研究了感染4种不同刚地弓形虫分离株之一的小鼠血清与这些融合蛋白的结合情况。所有小鼠血清中的抗体都与H11/GST结合，但并非所有血清都能识别H4/GST。当用H4/GST和H11/GST对小鼠进行皮内致敏并用同源融合蛋白进行攻击时，发现对融合蛋白有迟发型超敏反应（DTH）。然而，当小鼠感染刚地弓形虫后或用该寄生虫RH株的超声裂解物免疫后用同源融合蛋白进行攻击时，未记录到DTH反应。此外，在体外试验中，针对这两种融合蛋白均未刺激细胞反应。在实验性小鼠感染中，这两种融合蛋白都能被抗刚地弓形虫抗体识别，因此它们是人类弓形虫病诊断测定中作为抗原的潜在候选物。
