Identification of heterologous Torque Teno Viruses in humans and swine

Abstract

Torque Teno Viruses (TTVs) are ubiquitous viruses which are highly prevalent in several mammalian species. Human TTV’s are epidemiologically associated with several human disease conditions such as respiratory illnesses, auto-immune disorders and hepatitis. Recently it was found that swine TTV’s (TTSuVs) can act as primary pathogens. The common occurrence of TTVs as environmental contaminants and the increasing interest in the use of swine organs for xenotransplantation lend importance to the question of whether TTV’s can cross-infect across species. In this study, we examined human and swine sera by swine or human TTV-specific PCRs, to determine whether swine TTVs (TTSuV) DNA can be detected in humans and vice versa. Surprisingly, both human and TTSuV DNA were present in a majority of the samples tested. Transfection of human PBMC’s with TTSuV1 genomic DNA resulted in productive viral infection which was sustained for the three serial passages tested. Lymphoproliferative responses in infected human PBMCs were diminished when compared to the controls. Furthermore, mild to moderate antibody responses against the TTSuV1 ORF2 protein was detected in 16 of the 40 human sera by ELISA. Therefore, these study findings provide initial and fundamental evidence for possible cross-species transmission of TTVs.

A new full-length virus genome sequencing method reveals that antiviral RNAi changes geminivirus populations in field-grown cassava

“…CIDER-Seq can also be applied to other important viruses with similar genome sizes and topology, including e.g. Porcine circoviruses, Chicken anemia virus, and the recently discovered, ubiquitous, human-infecting Torque teno virus (Ssemadaali et al 2016). The circular dsDNA Human papillomavirus is another important target for future CIDER-Seq experiments.…”

Possible risks posed by single‐stranded DNA viruses of pigs associated with xenotransplantation

“…Interestingly, TTV DNA is found in pigs and TTSuV DNA is found in humans . Preliminary evidence indicates TTSuV1 replication in human peripheral blood monocytes (PBMCs) and the presence of antibodies against TTSuV1 ORF2 (a nonstructural protein) in human serum samples suggests a zoonotic potential . Of note, TTSuV1‐infected human PBMCs are shown to be impaired in their mitogenic response .…”

“…Preliminary evidence indicates TTSuV1 replication in human peripheral blood monocytes (PBMCs) and the presence of antibodies against TTSuV1 ORF2 (a nonstructural protein) in human serum samples suggests a zoonotic potential . Of note, TTSuV1‐infected human PBMCs are shown to be impaired in their mitogenic response . In addition to humans, TTSuV1 DNA and antibodies against TTSuV1 ORF2 antibodies are found in many mammalian hosts such as horses, cattle, sheep, and dogs, indicative of promiscuity in the host range of TTSuV1 .…”

“…The potential of this virus to infect human‐origin cell lines needs to be further explored, as this may offer clues to its zoonotic potential. Although the pathogenicity of neither TTV nor TTSuVs has been clearly established, the potential of TTSuV to cross the species barrier and suppress the mitogenic response of human PBMCs raises a concern in xenotransplantation …”

Caracterização genômica e evolutiva de vírus zoonóticos nas Américas

“…conceitualmente denomina-se zoonose reversa. Este é o caso do vírus Torque Teno de suínos da família Anelloviridae (6).…”