Malchiodi E L, Chiaramonte M G, Taranto N J, Zwirner N W, Margni R A
Instituto de Estudios de la Inmunidad Humoral (IDEHU-CONICET), Cátedra de Inmunología, FFyB-UBA, Buenos Aires.
Clin Exp Immunol. 1994 Sep;97(3):417-23. doi: 10.1111/j.1365-2249.1994.tb06104.x.
Results of our studies on the reactivity of chagasic and leishmaniasic sera with the purified T. cruzi-specific antigen 163B6, as assessed by ELISA, and with complex antigenic mixtures from T. cruzi and Leishmania mexicana, by immunoblotting, are presented here. Our objective was to identify the antigens responsible for the exhibited cross-reactivity between trypanosomiasis and leishmaniasis, and to find a specific reactivity pattern corresponding to each parasitosis. In spite of the high cross-reactivity observed with the immunoblotting, the use of 7.5% A-B gels made it possible to identify a characteristic pattern for each parasitosis, that could be distinguished by the naked eye. The characteristic pattern corresponding to chagasic patients was ascribed to reactivity with T. cruzi bands of mol. wts 131, 125, 116, 111, 51-45 and 43 kD, that were not recognized by leishmaniasic sera. Trypanosoma cruzi antigens of mol. wts 85, 81, 70, 65-60, 37 and 32 kD were considered as crossing antigens, since they were recognized by leishmaniasis sera. With L. mexicana, most of the chagasic patients presented reaction with antigen of mol. wts 124, 107, 92, 59 and 32 kD, while bands of mol. wts 155, 140, 73, 56 and 48 kD were recognized only by leishmaniasic sera. In this study we found 12 out of 45 sera of patients with leishmaniasis, from a region endemic for both parasitoses, which exhibited a pattern of bands very similar to those corresponding to chagasic individuals, strongly suggesting a mixed infection. This hypothesis was verified by using a purified specific antigen of T. cruzi, Ag163B6, which would be the major cysteine proteinase of this specie (cruzipain). By ELISA, these 12 sera showed a positive reaction with this purified antigen, as those of chagasic patients, thus leading to the confirmation of the presence of a mixed infection.
本文展示了我们通过酶联免疫吸附测定（ELISA）研究恰加斯病和利什曼病血清与纯化的克氏锥虫特异性抗原163B6的反应性，以及通过免疫印迹法研究其与克氏锥虫和墨西哥利什曼原虫复合抗原混合物的反应性的结果。我们的目标是确定导致锥虫病和利什曼病之间出现交叉反应的抗原，并找到对应于每种寄生虫病的特异性反应模式。尽管在免疫印迹中观察到高度交叉反应，但使用7.5%的A - B凝胶能够识别出每种寄生虫病的特征模式，肉眼即可区分。恰加斯病患者的特征模式归因于与分子量为131、125、116、111、51 - 45和43 kD的克氏锥虫条带的反应性，利什曼病血清无法识别这些条带。分子量为85、81、70、65 - 60、37和32 kD的克氏锥虫抗原被视为交叉抗原，因为它们能被利什曼病血清识别。对于墨西哥利什曼原虫，大多数恰加斯病患者与分子量为124、107、92、59和32 kD的抗原发生反应，而分子量为155、140、73、56和48 kD的条带仅被利什曼病血清识别。在本研究中，我们发现来自两种寄生虫病流行地区的45名利什曼病患者血清中有12份呈现出与恰加斯病个体非常相似的条带模式，强烈提示存在混合感染。通过使用纯化的克氏锥虫特异性抗原Ag163B6（该抗原是该物种的主要半胱氨酸蛋白酶，即克氏锥虫蛋白酶）验证了这一假设。通过ELISA，这12份血清与该纯化抗原呈现阳性反应，与恰加斯病患者的血清反应相同，从而证实了混合感染的存在。
