TTV and other anelloviruses: The astonishingly wide spread of a viral infection

Spezia, Pietro Giorgio; Focosi, Daniele; Baj, Andreina; Novazzi, Federica; Ferrante, Francesca Drago; Carletti, Fabrizio; Minosse, Claudia; Matusali, Giulia; Maggi, Fabrizio

doi:10.1016/j.amolm.2023.100006

Cited by 10 publications

(7 citation statements)

References 42 publications

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“…Their genomic structure is similar to each other, but they differ in terms of genome length. The TTV genome is 3.5 to 3.9 Kb in length, whereas the TTMDV genome is up to 2.3 Kb, and the TTMV genome is 2.7 to 2.9 Kb [ 1 , 47 ]. TTV has diverse tissue tropism, and the virus genome has the ability to replicate simultaneously in several different tissues and organs, such as the liver, spleen, pancreas, bone marrow, muscle, lung, kidney, peripheral blood mononuclear cells (PBMC), etc [ 21 , 48 ].…”

Section: Overview Of Anelloviruses Characteristicsmentioning

confidence: 99%

“…More clearly, it can be said that TTV indicates the state of the host’s immune system. However, considering that there is little information about the other two viruses, TTMV and TTMDV, in immunosuppressed patients, stronger conclusions can be made by measuring the viral load of these two viruses in the immunosuppressed state and examining them [ 1 , 115 – 117 ]. Disorders of immunosuppression can provide opportunities for increased TTV replication, and for this reason, the amount of this virus is used to monitor the immune status of transplant patients [ 96 , 118 ].…”

Section: Immune System Diseasesmentioning

confidence: 99%

“…Torque teno virus (TTV) belongs to alphatorquevirus, torque teno mini virus (TTMV) belongs to betatorquevirus and torque teno midi virus (TTMDV) belongs to gammatorquevirus. The genome of these viruses is circular single-stranded, negative-sense DNA ranging from ∼2.0 to 3.9 kilobases (kb); the capsid of these viruses has icosahedron symmetry, and their total particle diameter is about 18 to 30 nm, and their nucleocapsid does not have a lipid envelope [ 1 – 6 ]. Human anelloviruses (AVs) are among the most common human viruses and are considered part of the human virome.…”

Section: Introductionmentioning

confidence: 99%

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The mysterious anelloviruses: investigating its role in human diseases

Sabbaghian,

Gheitasi,

Shekarchi

et al. 2024

BMC Microbiol

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Anelloviruses (AVs) that infect the human population are members of the Anelloviridae family. They are widely distributed in human populations worldwide. Torque teno virus (TTV) was the first virus of this family to be identified and is estimated to be found in the serum of 80–90% of the human population. Sometime after the identification of TTV, Torque teno mini virus (TTMV) and Torque teno midi virus (TTMDV) were also identified and classified in this family. Since identifying these viruses, have been detected in various types of biological fluids of the human body, including blood and urine, as well as vital organs such as the liver and kidney. They can be transmitted from person to person through blood transfusions, fecal-oral contact, and possibly sexual intercourse. Recent studies on these newly introduced viruses show that although they are not directly related to human disease, they may be indirectly involved in initiating or exacerbating some human population-related diseases and viral infections. Among these diseases, we can mention various types of cancers, immune system diseases, viral infections, hepatitis, and AIDS. Also, they likely use the microRNAs (miRNAs) they encode to fulfill this cooperative role. Also, in recent years, the role of proliferation and their viral load, especially TTV, has been highlighted to indicate the immune system status of immunocompromised people or people who undergo organ transplants. Here, we review the possible role of these viruses in diseases that target humans and highlight them as important viruses that require further study. This review can provide new insights to researchers.

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Section: Overview Of Anelloviruses Characteristicsmentioning

confidence: 99%

Section: Immune System Diseasesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The mysterious anelloviruses: investigating its role in human diseases

Sabbaghian,

Gheitasi,

Shekarchi

et al. 2024

BMC Microbiol

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“…Torque teno virus (TTV) has recently gained attention as a functional marker of the immune system. TTV is considered ubiquitous in the healthy population and has not been linked to the etiology of clinical disease [ 1 , 2 , 3 , 4 ]. TTV load increases with immunosuppression and therefore is a potential marker of immune status, wherein a decline in immune function coincides with a rise in TTV load [ 1 , 5 , 6 ].…”

Section: Introductionmentioning

confidence: 99%

High-Density Lipoprotein Particles and Torque Teno Virus in Stable Outpatient Kidney Transplant Recipients

Jonker,

Doorenbos,

Kremer

et al. 2024

Viruses

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Torque teno virus (TTV) is emerging as a potential marker for monitoring immune status. In transplant recipients who are immunosuppressed, higher TTV DNA loads are observed than in healthy individuals. TTV load measurement may aid in optimizing immunosuppressive medication dosing in solid organ transplant recipients. Additionally, there is a growing interest in the role of HDL particles in immune function; therefore, assessment of both HDL concentrations and TTV load may be of interest in transplant recipients. The objective of this study was to analyze TTV loads and HDL parameters in serum samples collected at least one year post-transplantation from 656 stable outpatient kidney transplant recipients (KTRs), enrolled in the TransplantLines Food and Nutrition Cohort (Groningen, the Netherlands). Plasma HDL particles and subfractions were measured using nuclear magnetic resonance spectroscopy. Serum TTV load was measured using a quantitative real-time polymerase chain reaction. Associations between HDL parameters and TTV load were examined using univariable and multivariable linear regression. The median age was 54.6 [IQR: 44.6 to 63.1] years, 43.3% were female, the mean eGFR was 52.5 (±20.6) mL/min/1.73 m2 and the median allograft vintage was 5.4 [IQR: 2.0 to 12.0] years. A total of 539 participants (82.2%) had a detectable TTV load with a mean TTV load of 3.04 (±1.53) log10 copies/mL, the mean total HDL particle concentration was 19.7 (±3.4) μmol/L, and the mean HDL size was 9.1 (±0.5) nm. The univariable linear regression revealed a negative association between total HDL particle concentration and TTV load (st.β = −0.17, 95% CI st.β: −0.26 to −0.09, p < 0.001). An effect modification of smoking behavior influencing the association between HDL particle concentration and TTV load was observed (Pinteraction = 0.024). After adjustment for age, sex, alcohol intake, hemoglobin, eGFR, donor age, allograft vintage and the use of calcineurin inhibitors, the negative association between HDL particle concentration and TTV load remained statistically significant in the non-smoking population (st.β = −0.14, 95% CI st.β: −0.23 to −0.04, p = 0.006). Furthermore, an association between small HDL particle concentration and TTV load was found (st.β = −0.12, 95% CI st.β: −0.22 to −0.02, p = 0.017). Higher HDL particle concentrations were associated with a lower TTV load in kidney transplant recipients, potentially indicative of a higher immune function. Interventional studies are needed to provide causal evidence on the effects of HDL on the immune system.

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“…In this respect, the quantification of the Torque Teno virus (TTV) has been introduced as an immunometer to assess the individual immunocompetence. 1,2 Almost all healthy individuals and SOT recipients are infected with 1 to 22 species of these nonpathogen Anelloviruses . TTV plasma load is detected by means of real-time polymerase chain reaction, and since 2021, a commercial assay with Conformité Européenne certification is available for clinical use.…”

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confidence: 99%