Institute for Integrative Systems Biology (I2SysBio), Universitat de València-CSIC, Valencia, Spain.
FISABIO-Salud Pública, Generalitat Valenciana, Valencia, Spain.
Microbiol Spectr. 2023 Jun 15;11(3):e0492822. doi: 10.1128/spectrum.04928-22. Epub 2023 May 18.
Anelloviruses represent the major and most diverse component of the healthy human virome, referred to as the anellome. In this study, we determined the anellome of 50 blood donors, forming two sex- and age-matched groups. Anelloviruses were detected in 86% of the donors. The number of detected anelloviruses increased with age and was approximately twice as high in men as in women. A total of 349 complete or nearly complete genomes were classified as belonging to torque teno virus (TTV), torque teno mini virus (TTMV), and torque teno midi virus (TTMDV) anellovirus genera (197, 88, and 64 sequences, respectively). Most donors had intergenus (69.8%) or intragenus (72.1%) coinfections. Despite the limited number of sequences, intradonor recombination analysis showed 6 intragenus recombination events in ORF1. As thousands of anellovirus sequences have been described recently, we finally analyzed the global diversity of human anelloviruses. Species richness and diversity were close to saturation in each anellovirus genus. Recombination was found to be the main factor promoting diversity, although its effect was significantly lower in TTV than in TTMV and TTMDV. Overall, our results suggest that differences in diversity between genera may be caused by variations in the relative contribution of recombination. Anelloviruses are the most common human infectious viruses and are considered essentially harmless. Compared to other human viruses, they are characterized by enormous diversity, and recombination is suggested to play an important role in their diversification and evolution. Here, by analyzing the composition of the plasma anellome of 50 blood donors, we find that recombination is also a determinant of viral evolution at the intradonor level. On a larger scale, analysis of anellovirus sequences currently available in databases shows that their diversity is close to saturation and differs among the three human anellovirus genera and that recombination is the main factor explaining this intergenus variability. Global characterization of anellovirus diversity could provide clues about possible associations between certain virus variants and pathologies, as well as facilitate the implementation of unbiased PCR-based detection protocols, which may be relevant for using anelloviruses as endogenous markers of immune status.
圆环病毒是健康人类病毒组的主要且最多样化的组成部分,被称为圆环组。在这项研究中,我们确定了 50 名献血者的圆环组,形成了两个性别和年龄匹配的组。在 86%的供体中检测到了圆环病毒。检测到的圆环病毒数量随年龄增长而增加,男性约为女性的两倍。总共分类了 349 个完整或几乎完整的基因组,属于 torque teno 病毒(TTV)、torque teno mini 病毒(TTMV)和 torque teno midi 病毒(TTMDV)圆环病毒属(分别为 197、88 和 64 个序列)。大多数供体存在属间(69.8%)或属内(72.1%)的合并感染。尽管序列数量有限,但在 ORF1 中进行的供体内重组分析显示有 6 个属内重组事件。由于最近描述了数千个圆环病毒序列,我们最终分析了人类圆环病毒的全球多样性。在每个圆环病毒属中,物种丰富度和多样性都接近饱和。发现重组是促进多样性的主要因素,尽管它在 TTV 中的作用明显低于 TTMV 和 TTMDV。总体而言,我们的结果表明,属间多样性的差异可能是由重组相对贡献的变化引起的。圆环病毒是最常见的人类感染性病毒,被认为基本上是无害的。与其他人类病毒相比,它们具有巨大的多样性,并且重组被认为在其多样化和进化中发挥着重要作用。在这里,通过分析 50 名献血者血浆圆环组的组成,我们发现重组也是供体内病毒进化的决定因素。在更大的范围内,对当前数据库中可用的圆环病毒序列进行分析表明,它们的多样性接近饱和,并且在三个人类圆环病毒属之间存在差异,重组是解释这种属间变异性的主要因素。对圆环病毒多样性的全球特征描述可以提供有关某些病毒变体与病理学之间可能存在关联的线索,并有助于实施基于 PCR 的无偏检测协议,这对于将圆环病毒用作免疫状态的内源性标志物可能是相关的。