Folgueira Cristina, Martínez-Bonet Marta, Requena Jose M
Centro de Biología Molecular Severo Ochoa (CSIC-UAM), Universidad Autónoma de Madrid, Madrid, Spain.
BMC Res Notes. 2010 Jan 21;3:13. doi: 10.1186/1756-0500-3-13.
RNA-binding proteins of the PUF family share a conserved domain consisting of tandemly repeated 36-40 amino acid motifs (typically eight) known as Puf repeats. Proteins containing tandem repeats are often dominant targets of humoral responses during infectious diseases. Thus, we considered of interest to analyze whether Leishmania PUF proteins result antigenic during visceral leishmaniasis (VL).
Here, employing whole-genome databases, we report the composition, and structural features, of the PUF family in Leishmania infantum. Additionally, the 10 genes of the L. infantum PUF family were cloned and used to express the Leishmania PUFs in bacteria as recombinant proteins. Finally, the antigenicity of these PUF proteins was evaluated by determining levels of specific antibodies in sera from experimentally infected hamsters. The Leishmania PUFs were all recognized by the sera, even though with different degree of reactivity and/or frequency of recognition. The reactivity of hamster sera against recombinant LiPUF1 and LiPUF2 was particularly prominent, and these proteins were subsequently assayed against sera from human patients. High antibody responses against rLiPUF1 and rLiPUF2 were found in sera from VL patients, but these proteins resulted also recognized by sera from Chagas' disease patients.
Our results suggest that Leishmania PUFs are targets of the humoral response during L. infantum infection and may represent candidates for serodiagnosis and/or vaccine reagents; however, it should be kept in mind the cross-reactivity of LiPUFs with antibodies induced against other trypanosomatids such as Trypanosoma cruzi.
PUF家族的RNA结合蛋白共享一个保守结构域，该结构域由串联重复的36 - 40个氨基酸基序（通常为八个）组成，称为Puf重复序列。含有串联重复序列的蛋白质通常是传染病期间体液免疫反应的主要靶点。因此，我们认为分析利什曼原虫PUF蛋白在内脏利什曼病（VL）期间是否具有抗原性很有意义。
在此，利用全基因组数据库，我们报告了婴儿利什曼原虫PUF家族的组成和结构特征。此外，克隆了婴儿利什曼原虫PUF家族的10个基因，并用于在细菌中表达利什曼原虫PUF作为重组蛋白。最后，通过测定实验感染仓鼠血清中的特异性抗体水平来评估这些PUF蛋白的抗原性。利什曼原虫PUF均被血清识别，尽管反应程度和/或识别频率不同。仓鼠血清对重组LiPUF1和LiPUF2的反应性尤为突出，随后针对人类患者血清对这些蛋白质进行了检测。在VL患者的血清中发现了针对rLiPUF1和rLiPUF2的高抗体反应，但恰加斯病患者的血清也能识别这些蛋白质。
我们的结果表明，利什曼原虫PUF是婴儿利什曼原虫感染期间体液免疫反应的靶点，可能代表血清诊断和/或疫苗试剂的候选物；然而，应牢记LiPUF与针对其他锥虫（如克氏锥虫）诱导产生的抗体的交叉反应性。
