Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, MD, USA.
Cell Host Microbe. 2023 Jan 11;31(1):58-68.e5. doi: 10.1016/j.chom.2022.11.002. Epub 2022 Dec 1.
Redondoviruses are circular Rep-encoding single-stranded DNA (CRESS) viruses of high prevalence in healthy humans. Redondovirus abundance is increased in oro-respiratory samples from individuals with periodontitis, acute illness, and severe COVID-19. We investigated potential host cells supporting redondovirus replication in oro-respiratory samples and uncovered the oral amoeba Entamoeba gingivalis as a likely host. Redondoviruses are closely related to viruses of Entamoeba and contain reduced GC nucleotide content, consistent with Entamoeba hosts. Redondovirus and E. gingivalis co-occur in metagenomic data from oral disease and healthy human cohorts. When grown in xenic cultures with feeder bacteria, E. gingivalis was robustly positive for redondovirus RNA and DNA. A DNA proximity-ligation assay (Hi-C) on xenic culture cells showed enriched cross-linking of redondovirus and Entamoeba DNA, supporting E. gingivalis as the redondovirus host. While bacteria are established hosts for bacteriophages within the human virome, this work shows that eukaryotic commensals also contribute an abundant human-associated virus.
圆形病毒是一种在健康人群中普遍存在的圆形 Rep 编码单链 DNA（CRESS）病毒。在牙周炎、急性疾病和严重 COVID-19 患者的口咽样本中，圆形病毒的丰度增加。我们研究了支持口咽样本中圆形病毒复制的潜在宿主细胞，并发现口腔变形虫 Entamoeba gingivalis 可能是其宿主。圆形病毒与 Entamoeba 病毒密切相关，并且含有减少的 GC 核苷酸含量，与 Entamoeba 宿主一致。圆形病毒和 E. gingivalis 在口腔疾病和健康人群的宏基因组数据中共同存在。当在与饲养细菌的异养培养物中生长时，E. gingivalis 对圆形病毒 RNA 和 DNA 的检测呈强阳性。对异养培养细胞的 DNA 邻近连接分析（Hi-C）显示，圆形病毒和 Entamoeba DNA 的交联得到了富集，支持 E. gingivalis 是圆形病毒的宿主。虽然细菌是人类病毒组中噬菌体的既定宿主，但这项工作表明，真核共生菌也为丰富的人类相关病毒做出了贡献。
