Krautz G M, Peterson J D, Godsel L M, Krettli A U, Engman D M
Departamento de Bioquimica e Immunologia, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais e Centro de Pesquisas Rene Rachou Fiocruz, Belo Horizonte, Brazil.
Am J Trop Med Hyg. 1998 Feb;58(2):137-43. doi: 10.4269/ajtmh.1998.58.137.
Heat-shock proteins of the 70-kD (hsp70) family are targets of humoral and cellular immune responses following bacterial or parasitic infections, including Chagas' disease. In the present study, we measured antibodies in human sera reactive with hsp70s from the cytoplasm (cy-hsp70), mitochondrion (mt-hsp70), and endoplasmic reticulum (grp78) of Trypanosoma cruzi. Of the three hsp70s tested, only grp78 detected T. cruzi infection in more than 90% of nontreated (NT) patients, with cy-hsp70 and mt-hsp70 detecting only 78% and 25% of NT patients, respectively. Reactivity of leishmanial sera was 77% with cy-hsp70, 13% with grp78, and 5% with mt-hsp70. Therefore, considering sensitivity and specificity, the best candidate for T. cruzi serodiagnosis is grp78. Combination of grp78 with a T. cruzi 24-kD flagellar calcium binding protein (FCaBP) increased the diagnostic sensitivity from 90% to 97% but increased leishmanial reactivity from 3% to 8%. To determine whether hsp70s are useful for discriminating between cured and noncured patients treated with trypanocidal drugs, we tested sera from treated noncured (TNC) patients and cured patients who have positive conventional serology, termed treated dissociated (TD). The cy-hsp70 and grp78 reacted with 74% and 68% of TNC patient sera, respectively, but these antigens did not discriminate TNC from TD patients (52% and 45% positive, respectively). The mt-hsp70 was detected by sera from few TNC patients (18%) and no TD patients. Although individual hsp70s were not useful for determining the effect of trypanocidal drugs on T. cruzi infection in individual patients, the majority of TNC patient sera (70-80%) reacted with two or three of the hsp70s. In contrast, no TD sera reacted with all three hsp70s, and 40% did not react with any of the hsp70s, indicating that the number of hsp70s detected decreases following successful treatment. Considered together, these results show that grp78 has potential as a diagnostic antigen and that absence of reactivity to all three hsp70s may be indicative of effective treatment.
70-kD热休克蛋白（hsp70）家族是细菌或寄生虫感染（包括恰加斯病）后体液免疫和细胞免疫反应的靶点。在本研究中，我们检测了人类血清中与克氏锥虫细胞质（cy-hsp70）、线粒体（mt-hsp70）和内质网（grp78）中的hsp70发生反应的抗体。在所检测的三种hsp70中，只有grp78在超过90%的未治疗（NT）患者中检测到克氏锥虫感染，而cy-hsp70和mt-hsp70分别仅在78%和25%的NT患者中检测到感染。利什曼病血清与cy-hsp70的反应性为77%，与grp78的反应性为13%，与mt-hsp70的反应性为5%。因此，考虑到敏感性和特异性，克氏锥虫血清学诊断的最佳候选者是grp78。grp78与克氏锥虫24-kD鞭毛钙结合蛋白（FCaBP）联合使用可将诊断敏感性从90%提高到97%，但利什曼病反应性从3%提高到8%。为了确定hsp70是否有助于区分接受杀锥虫药物治疗的未治愈和已治愈患者，我们检测了来自治疗后未治愈（TNC）患者和传统血清学呈阳性的已治愈患者（称为治疗后解离患者，TD）的血清。cy-hsp70和grp78分别与74%和68%的TNC患者血清发生反应，但这些抗原无法区分TNC患者和TD患者（分别为52%和45%呈阳性）。很少有TNC患者（18%）的血清检测到mt-hsp70，而TD患者血清均未检测到。尽管单个hsp70无助于确定杀锥虫药物对个体患者克氏锥虫感染的影响，但大多数TNC患者血清（70 - 80%）与两种或三种hsp70发生反应。相比之下，没有TD血清与所有三种hsp70发生反应，40%的TD血清与任何一种hsp70均无反应，这表明成功治疗后检测到的hsp70数量减少。综合考虑，这些结果表明grp78有作为诊断抗原的潜力，对所有三种hsp70均无反应可能表明治疗有效。
