Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Human and Animal Cell Bank, Iranian Biological Resource Center (IBRC), ACECR, Tehran, Iran.
Infect Genet Evol. 2020 Nov;85:104426. doi: 10.1016/j.meegid.2020.104426. Epub 2020 Jun 16.
Human T-lymphotropic virus type-1 (HTLV-1) is a retrovirus that causes the neurological disorder HTLV-1 associated myelopathy/ tropical spastic paraparesis (HAM/TSP) and/or adult T-cell leukemia/lymphoma (ATLL). Iran is one of the endemic regions of the HTLV-1 in the Middle East. To infer the origin of the virus in Iran and to follow the movements of human population and routes of virus spread to this country, phylogenetic and phylodynamic analyses were performed. To this purpose, the long terminal repeat (LTR) region of HTLV-1 was used. New LTR sequences were obtained from 100 blood samples which infected with HTLV-1. Moreover, all Iranian LTR sequences which have been reported so far, were obtained from GenBank database. Sequences were aligned and maximum-likelihood and Bayesian tree topologies were explored. After identification of Iranian specific cluster, molecular-clock and coalescent models were used to estimate time to the most recent common ancestor (tMRCA). Bayesian Skyline Plots (BSP), representing population dynamics HTLV-1 strains back to the MRCA, were estimated using BEAST software. Phylogenetic analysis demonstrated that the Iranian, Kuwaiti, German, Israelite and southern Indian isolates are located within the widespread "transcontinental" subgroup A clade of HTLV-1 Cosmopolitan subtype a. Molecular clock analysis of the Iranian cluster dated back their respective tMRCA to be 1290 AC with a 95% HPD confidence intervals (918, 1517). BSPs indicated a rapid exponential growth rate in the effective number of infections prior the 15th century. Our results support the hypothesis of a multiple introductions of HTLV-1 into Iran with the majority of introductions occurring in prior the 15th century, at the same time the Mongol invasion of Iran. Our results further suggest that HTLV-1 introduction into Iran was facilitated by the commercial/migratory linkage as known as the ancient Silk Road which linked China to Antioch (now in Turkey).
人类 T 淋巴细胞白血病病毒 1 型（HTLV-1）是一种逆转录病毒，可引起神经疾病 HTLV-1 相关性脊髓病/热带痉挛性截瘫（HAM/TSP）和/或成人 T 细胞白血病/淋巴瘤（ATLL）。伊朗是中东地区 HTLV-1 的流行地区之一。为了推断病毒在伊朗的起源，并追踪人类种群的迁徙和病毒传播到该国的途径，进行了系统发育和系统动力学分析。为此，使用了 HTLV-1 的长末端重复（LTR）区域。从 100 份感染 HTLV-1 的血液样本中获得了新的 LTR 序列。此外，从 GenBank 数据库中获得了迄今为止所有已报道的伊朗 LTR 序列。对序列进行了比对，并探索了最大似然和贝叶斯树拓扑结构。在鉴定出伊朗特有的聚类后，使用分子钟和合并模型来估计最近共同祖先（tMRCA）的时间。使用 BEAST 软件，通过贝叶斯天空图（BSP）来估计代表回到 MRCA 的 HTLV-1 株系的种群动态。系统发育分析表明，伊朗、科威特、德国、以色列和印度南部的分离株位于广泛的“跨大陆”HTLV-1 世界性 A 亚群的 A 分支内。对伊朗聚类的分子钟分析将其各自的 tMRCA 回溯到公元前 1290 年，95%的 HPD 置信区间（918，1517）。BSP 表明，在 15 世纪之前，感染的有效数量呈快速指数增长。我们的结果支持 HTLV-1 多次传入伊朗的假说，其中大多数传入发生在 15 世纪之前，当时蒙古入侵了伊朗。我们的结果进一步表明，丝绸之路将中国与安提阿（现位于土耳其）连接起来，商业/迁徙联系促进了 HTLV-1 传入伊朗。
