TTV agent pathogne? ou marqueur de pollution anthropique? Pisa - PowerPoint PPT Presentation

Speaker's name : Fabrizio Maggi, Department of Translational Research, University of Pisa Virology Division, Pisa University Hospital TTV agent pathogène? ou marqueur de pollution anthropique? Pisa Virology Division Paris, December 17, 2018

V i ro m e  the full compendium of viruses from a particular habitat, including not only pathogenic viruses but also viruses essentially devoid of pathogenic potential ~10% ~30% ~60% Wylie et al. Transl Res 2012; Virgin, Cell 2014; Zou et al. Microbiome 2016; Freer et al. Curr Med Chem 2018 Pisa Virology Division

Anelloviruses: the most prevalent component of blood virome Pisa Virology Division De Vlaminck et al. Cell 2013

T TV: the prototype of anelloviruses Torquetenovirus Anellovirus (TTV) Spandole et al. Arch Virol 2015 Pisa Virology Division

H u m a n T T V s t o r y Studies on clinical significance TTV clone TTV in human discovery Virome (Nishizawa et al.1997) (Li et al. 2012) Lack of 1997 2007 2013 1998, 1999 2001 2005 2012 interest TTV image Anelloviridae TTV in TTV genome by EM Family transplantation characterization (Iitoh et al. 2001) (ICTV) (De Vlaminck et al. 2 013) (Okamoto et al. 1998; Mushahwar et al. 1999) Pisa Virology Division

T T V p r o p e r t i e s  GENOME: small circular ssDNA (2.2 to 3.7 kb) (the genetically simplest of all known replication-competent viruses hitherto detected in humans) JT41F LC011 CT30F KC186 ViPi04 CT43F JT05F PMV Kt-08F Kt-10F JT14F JT19F KAV tth6 JT03F TCHN-D1 TCHN-D2 CT25F  GENETIC VARIABILITY: extremely high JT34F CT23F CT39F CT44F TA278 JT33F GH1 L01 TX011 CHN2 tth5 tth13 JA20 JA10 T3PB SENV-G L02 (at least 29 human TTV species, each consisting of numerous types) SENV-C US32 JA2B JA1 SENV-H US35 SENV-B tth16 TCHN-G1 P/1C1 TUPB TUS01 HEL32/6a SENV-A TCHN-E SAa38 TCHN-C1 TJN02 SENV-F SANBAN SENV-D TJN01 IR1031 tth4 L03 SENV-E SAa-01 0.1 SAa-10 SAa-39 SA-j30 TYM9 SAf-09 TCHN-A TCHN-F  PREVALENCE: very high in the general population (~90%), acquired very early in life through many routes of transmission  PERSISTENCE: chronic and productive infections (> 80% of infected people)  UBIQUITY: detected in all the tissues and organs, T lymphocytes probably the main site of virus replication Miyata et al. 1999; Takahashi et al. 2000; Okamoto et al. 2001; Bendinelli et al. 2001; Pisa Virology Division Jones et al. 2005; Bendinelli and Maggi, 2005; Ninomiya et al. 2007; 2008; Maggi et al. 2006; 2010

Dynamics of chronic TTV viremia, relative to other viruses Mean virion half- New virions entering Virus Reference life in plasma (hrs.) plasma per day Whalley et al. 2001 HBV : 28.8 > 1.7 x 10 13 > 1.3 x 10 12 Neumann et al. 1998 HCV : 2.7 > 2.0 x 10 10 TTV : 4.3 Maggi et al. 2010 > 9.8 x 10 9 Ramratnam et al. 1999 HIV : < 1 Pisa Virology Division

T T V d i a g n o s i s “Universal” real -time UTR PCR Genogroup-specific PCRs 1. In house TaqMan rtPCR 2. Commercial R-gene TTV assay Genogroups 4 and 5 3. Droplet digital PCR UTR: UTR Genogroups 1, 2 and 3 TT V ORF1: Pisa Virology Division Maggi et al. J Clin Microbiol 2005; Maggi et al. in preparation

TTV pathogeneicity: an extraordinary difficult issue to untangle Reasons:  extremely high prevalence of active TTV infections among apparently healthy individuals  TTV presence in many different tissues  existence of numerous TTV species  frequent occurrence of co-infections by two or more species of TTV  wide range of TTV loads in different individuals Maggi and Bendinelli, Rev Med Virol 2010 Pisa Virology Division

I n v e s t i g a t i o n s o n t h e p a t h o g e n i c p o t e n t i a l o f T T V Etiological agent of disease or cofactor of other diseases ? Blood diseases Kidney diseases (2000-01) Hepatitis (2002) (1997) Periodontal diseases (2004) Respiratory diseases (2001-05) SLE (2005) Cancer Autoimmune diseases (2005) (2006-10) In spite of all efforts, to date 20 years after its discovery, no conclusive evidence has been reached Bendinelli et al. 2001; Maggi and Bendinelli, 2010 Pisa Virology Division

T T V a n d r e s p i r a t o r y d i s e a s e s Children with acute Asthmatic children respiratory diseases (ARD) FEF 25 – 75 / FVC 160 140 p < 0.001 120 100 p < 0.05 100 80 Lung function index r = - 0.334; p = 0.010 60 % TTV positive 80 40 20 60 120 FEV 1 /FVC 40 110 100 20 r = - 0.312; p = 0.016 90 0 80 BP Milder ARD * 170 FEF 25 – 75% Nasal swabs ( No.: 54 BP, 46 milder ARD ) 120 Plasma ( No.: 62 BP, 89 milder ARD ) 70 r = - 0.321; p = 0.013 20 2 3 4 5 6 7 8 9 Nasal TTV load * Including laryngitis, bronchitis, and bronchiolitis (log 10 DNA copies/ml) Maggi et al. J Virol 2003; Pifferi et al. J Infect Dis 2005 Pisa Virology Division

TTV and human diseases  A component of the normal human microflora, essentially devoid of pathogenic potential  An ‘‘orphan’’ virus waiting to be linked to disease(s):  only occasional infections aggressive to become the cause of significant clinical disease?  TTV cofactor in some human diseases having a multifactorial origin?  TTV species diverse in their ability to induce pathogeneicity? Maggi and Bendinelli, Rev Med Virol 2010 Pisa Virology Division

TTV as a potential bio-marker • Prevalence • Fast and cheap quantification by rtPCR • Ubiquity • Insensitivity to antiviral drugs TTV has proved useful in 2 main fields as marker:  to detect anthropic pollution  to follow up kinetics of functional immune competence Pisa Virology Division

TTV as a marker of anthropic pollution  Because of its extremely high resistance  TTV is frequently found in: • wastewater (38 – 100%) • drinking water (5-12%) • river water  surface samples (15%) collected in hospital settings  air samples (16%) collected in hospital settings  May be particularly useful for evaluating the efficiency of treatment or cleaning procedures in microbe removal (i.e. in wastewater or in blood products) Charest et al. J Water Health 2015; Vecchia et al. Food Environ Virol 2013; Diniz- Mendes et al. J Appl Microbiol 2008; Verani et al. Water Sci Technol 2006; Carducci et al. J Hosp Infect 2011 Pisa Virology Division

TTV as a marker for evaluating the nanofiltration efficacy Pisa Virology Division

Levels of TTV viremia 10 log copies/ml Level range 3 log copies/ml Healthy Mean: 2.3 log donors 1 log copies/ml 1 log copies/ml Pisa Virology Division Maggi et al. in preparation

Factors that may impact on the size of TTV viremia Virus – related No./spectrum/turnover of cells replicating TTV(s) H* No. of virions produced per cell and daily H Rate of virions release/clearance into/from the circulation H Proportion of immunocomplexed virions H No. of different TTVs harbored EA Synergy or interference between the TTVs carried EA Acute intercurrent superinfection by a different TTV EA Fac tors Immunological Depressed immune responses P Changes in the functional integrity and relative proportion of cells H participating in such responses Counts of circulating lymphocytes EA Immune activation by superimposed exogenous immunogens EA Other host – related factors Concomitant infections by other pathogens H Host – related Presence of concomitant noninfectious pathologies (tumours, etc.) EA Immunosuppressive therapies P Local accumulation of proliferating lymphoid cells H Regeneration rate of susceptible cells H TTV viremia Age P * P: proved; EA: at least some direct evidence available; H: hypothetical Pisa Virology Division Maggi and Bendinelli, 2010

TTV viremia and age N. total subjects: 370 p < 0.001 Pisa Virology Division Haloschan et al . 2014; Giacconi et al. Exp Gerontol 2018

TTV and mortality in elderly subjects  379 elderly subjects who were followed up for 3 yrs (age range 60 – 105 yrs )  The proportion of pts died after 3 yrs of follow-up: • 22% for pts with TTV copies ≥ 4.0  TTV load is a strong parameter for predicting • 5% for pts with TTV copies < 4.0 the mortality (Cox regression analysis) TTV < 10 2 * Independent Dependent variable "Death" variable β p Age - 0.095 0.004 10 2 = TTV < 10 4 Triglycerides 0.001 0.789 HDL -0.003 0.848 Cu/Zn ratio -0.749 0.058 TTV ≥ 10 4 Gender 0.409 0.466 *copies / ug DNA TTV load 1.386 0.009 Giacconi et al . Exp Gerontol 2018 Pisa Virology Division

Biomarker assays useful in predicting post-transplant complications Cotton, J Infect Dis 2018 Pisa Virology Division

TTV viremia in kidney/liver tranplant patients 8 Transplant patients Liver (n. 280) (Log 10 copies / ml) (n. 144) 7 TTV DNA 6 Healthy donors p < 0.001 5 * (n. 30) Kidney (n. 146) 4 3 0 10 20 30 40 50 60 70 80 90 120 150 180 360 0 10 20 30 40 50 60 70 80 90 120 150 180 360 D ay s p o s t - t ra n s p l a n t Pisa Virology Division Maggi et al. submitted

TTV viremia predicts CMV reactivation (Log copies/ml 95% CI) Mean TTV DNA* 5 Total n. 69 n. 136 * measured between 0 and 4 10 days post-transplant n. 205; p = 0.001 3 - + (Log copies/ml 95% CI) M e a n T T V D N A* n. 39 5 n. 30 Liver Kidney n. 27 n. 109 4 n. 139; p = 0.038 n. 66; p = 0.033 3 + - + - C M V d e t e c t i on a c r o s s 4 m o n t h s p o s t - t x Pisa Virology Division Maggi et al. Sci Rep 2018