Children with Chronic Immune Thrombocytopenia Exhibit High Expression of Human Endogenous Retroviruses TRIM28 and SETDB1.

Chronic immune thrombocytopenia (CITP) is an autoimmune disease whose underlying biologic mechanisms remain elusive. Human endogenous retroviruses (HERVs) derive from ancestral infections and constitute about 8% of our genome. A wealth of clinical and experimental studies highlights their pivotal pathogenetic role in autoimmune diseases. Epigenetic mechanisms, such as those modulated by TRIM28 and SETDB1, are involved in HERV activation and regulation of immune response. We assessed, through a polymerase chain reaction real-time Taqman amplification assay, the transcription levels of pol genes of HERV-H, HERV-K, and HERV-W; env genes of Syncytin (SYN)1, SYN2, and HERV-W; as well as TRIM28 and SETDB1 in whole blood from 34 children with CITP and age-matched healthy controls (HC). The transcriptional levels of all HERV sequences, with the exception of HERV-W-env, were significantly enhanced in children with CITP as compared to HC. Patients on eltrombopag treatment exhibited lower expression of SYN1, SYN2, and HERV-W-env as compared to untreated patients. The mRNA concentrations of TRIM28 and SETDB1 were significantly higher and were positively correlated with those of HERVs in CITP patients. The over-expressions of HERVs and TRIM28/SETDB1 and their positive correlations in patients with CITP are suggestive clues of their contribution to the pathogenesis of the disease and support innovative interventions to inhibit HERV and TRIM28/SETDB1 expressions in patients unresponsive to standard therapies.

Pregnancy Is Associated with Impaired Transcription of Human Endogenous Retroviruses and of TRIM28 and SETDB1, Particularly in Mothers Affected by Multiple Sclerosis.

Accumulating evidence highlights the pathogenetic role of human endogenous retroviruses (HERVs) in eliciting and maintaining multiple sclerosis (MS). Epigenetic mechanisms, such as those regulated by TRIM 28 and SETDB1, are implicated in HERV activation and in neuroinflammatory disorders, including MS. Pregnancy markedly improves the course of MS, but no study explored the expressions of HERVs and of TRIM28 and SETDB1 during gestation. Using a polymerase chain reaction real-time Taqman amplification assay, we assessed and compared the transcriptional levels of pol genes of HERV-H, HERV-K, HERV-W; of env genes of Syncytin (SYN)1, SYN2, and multiple sclerosis associated retrovirus (MSRV); and of TRIM28 and SETDB1 in peripheral blood and placenta from 20 mothers affected by MS; from 27 healthy mothers, in cord blood from their neonates; and in blood from healthy women of child-bearing age. The HERV mRNA levels were significantly lower in pregnant than in nonpregnant women. Expressions of all HERVs were downregulated in the chorion and in the decidua basalis of MS mothers compared to healthy mothers. The former also showed lower mRNA levels of HERV-K-pol and of SYN1, SYN2, and MSRV in peripheral blood. Significantly lower expressions of TRIM28 and SETDB1 also emerged in pregnant vs. nonpregnant women and in blood, chorion, and decidua of mothers with MS vs. healthy mothers. In contrast, HERV and TRIM28/SETDB1 expressions were comparable between their neonates. These results show that gestation is characterized by impaired expressions of HERVs and TRIM28/SETDB1, particularly in mothers with MS. Given the beneficial effects of pregnancy on MS and the wealth of data suggesting the putative contribution of HERVs and epigenetic processes in the pathogenesis of the disease, our findings may further support innovative therapeutic interventions to block HERV activation and to control aberrant epigenetic pathways in MS-affected patients.

Expressions of Type I and III Interferons, Endogenous Retroviruses, TRIM28, and SETDB1 in Children with Respiratory Syncytial Virus Bronchiolitis.

Interferons (IFNs) and IFN-stimulated genes (ISGs) play essential roles for the control of viral infections. Their expression in infants with respiratory syncytial virus (RSV) bronchiolitis is poorly defined. Human endogenous retroviruses (HERVs) represent 8% of our genome and modulate inflammatory and immune reactions. TRIM28 and SETDB1 participate in the epigenetic regulation of genes involved in the immune response, including IFNs and HERVs. No study has explored the expression of HERVs, TRIM28, and SETDB1 during RSV bronchiolitis. We assessed, through a PCR real-time Taqman amplification assay, the transcription levels of six IFN-I ISGs, four IFNλs, the pol genes of HERV-H, -K, and -W families, the env genes of Syncytin (SYN)1 and SYN2, and of TRIM28/SETDB1 in whole blood from 37 children hospitalized for severe RSV bronchiolitis and in healthy children (HC). The expression of most IFN-I ISGs was significantly higher in RSV+ patients than in age-matched HC, but it was inhibited by steroid therapy. The mRNA concentrations of IFN-λs were comparable between patients and age-matched HC. This lack of RSV-driven IFN-III activation may result in the defective protection of the airway mucosal surface leading to severe bronchiolitis. The expression of IFN-III showed a positive correlation with age in HC, that could account for the high susceptibility of young children to viral respiratory tract infections. The transcription levels of every HERV gene were significantly lower in RSV+ patients than in HC, while the expressions of TRIM28/SETDB1 were overlapping. Given the negative impact of HERVs and the positive effects of TRIM28/SETDB1 on innate and adaptive immune responses, the downregulation of the former and the normal expression of the latter may contribute to preserving immune functions against infection.

Vitamin D status in internationally adopted children: the northwest Italy experience.

BACKGROUND: The majority of internationally adopted children, before adoption, might have experienced malnutrition, exposure to infectious diseases, environmental deprivation, and neglect; they could also develop medical problems such as vitamin D deficiency. Scantly data are available about vitamin D status in internationally adopted children and, to our knowledge, no report exists on Italian adoptees. METHODS: We carried out a prospective multicenter study, involving three Pediatric Centers in Piedmont, Italy, to collect information about 25-hydroxyvitamin D (25[OH]D) profile in adoptees, shortly after their arrival in Italy. RESULTS: In 142/158 internationally adopted children 25(OH)D was measured: 75 males and 67 females, with a mean age of 4.22±2.2 years. Fifty-three (37.3%) of them came from Asia, 48 (33.8%) from Africa, 24 (16.9%) from Eastern Europe, and 17 (12%) from Latin America. The median level of 25(OH)D in serum was 21.5 ng/mL (IQR range 14.3-29.7 ng/mL): 26 (18.2%) of the examined children had an insufficiency of 25-OHD, whereas 36 (25.2%) had a deficiency. Adoptees with longer time of institution stay had a significant risk to develop 25(OH)D deficiency. The Asian origin proved to be a risk factor to develop 25(OH)D deficiency, whereas the age >1 year was significantly associated with 25(OH)D insufficiency. CONCLUSIONS: Our survey showed that vitamin D deficiency and insufficiency, in internationally adoptees, are frequent and relevant health problems.

MW Polyomavirus in diarrheal Italian infants.

BACKGROUND: MXPyV, like MWPyV, was identified in stool samples from children suffering diarrhea in Mexico. In this study, we used a home-made real time PCR to investigate the presence of this novel viruses in stool specimen collected from under-five-year-old children with gastroenteritis. METHODS: A total of 192 fecal specimens previously screened for RV, ADV, NoV, HPeV and SaV, were tested for MWPyV with Taqman real time PCR. RESULTS: The most detected virus was NoV GII (33.8%), followed by RV (21.3%), SaV (10.9%), HPeV (8%), NoV GI (6.7%) and Adv (1%). Real time PCR detected MWPyV in 1/192 (0.5%) patients. CONCLUSIONS: We detected MWPyV in 0.5% of fecal specimens collected from pediatric patients suffering gastroenteritis which is smaller than the previously reported in literature (4.4% in Australia and 12% Mexico).

Intrapartum use of zidovudine in a large cohort of pregnant women living with HIV in Italy.

BACKGROUND: Intravenous administration of zidovudine (ZDV) during labour is a key step for vertical HIV transmission (VT) prevention, but there is no evidence of benefit when maternal HIV-RNA at delivery is <50 copies/mL. The aim of this study is evaluating the appropriateness of intrapartum ZDV use in Italy. METHODS: Observational study including mother-infant pairs with perinatal HIV exposure during 2002-2019, enrolled in the Italian Register for HIV Infection in Children. Univariable and multivariable logistic regression were used to evaluate factors associated with VT. RESULTS: A total of 3,861 infants, born from 3,791 pregnancies were included. The frequency of ZDV use was 79.9%, 92.1%, 93.7% and 92.8% when HIV-RNA was not available, ≥400 copies, between 50 and 399 copies, and <50 copies/mL. Thirty-three out of 3861 (0.85%) infants were subsequently diagnosed with HIV, 25/3861 (0.6%) of them born to mothers receiving intrapartum ZDV, and 31 (93.9%) to mothers with HIV-RNA ≥50 copies/mL or not available. In women with HIV-RNA < 50 copies/mL, ART discontinuation during pregnancy was the strongest risk factor for VT (odds ratio, OR, 23.1, 95%CI 2.4-219.3), while a higher gestational age (OR 0.6, 95%CI 0.4-0.8) and PEP administration to the newborn (aOR 0.004, 95%CI <0.0001-0.4) were protective factors. Intrapartum ZDV administration did not influence the final outcome in this group. CONCLUSIONS: In ART era, more transmission events may occur in utero, limiting value of intrapartum ZDV, particularly for women with suppressed HIV-RNA load. More attention to the HIV-RNA testing of mothers before delivery may avoid unnecessary ZDV use.

Enhanced Expression of Human Endogenous Retroviruses, TRIM28 and SETDB1 in Autism Spectrum Disorder.

Human endogenous retroviruses (HERVs) are relics of ancestral infections and represent 8% of the human genome. They are no longer infectious, but their activation has been associated with several disorders, including neuropsychiatric conditions. Enhanced expression of HERV-K and HERV-H envelope genes has been found in the blood of autism spectrum disorder (ASD) patients, but no information is available on syncytin 1 (SYN1), SYN2, and multiple sclerosis-associated retrovirus (MSRV), which are thought to be implicated in brain development and immune responses. HERV activation is regulated by TRIM28 and SETDB1, which are part of the epigenetic mechanisms that organize the chromatin architecture in response to external stimuli and are involved in neural cell differentiation and brain inflammation. We assessed, through a PCR realtime Taqman amplification assay, the transcription levels of pol genes of HERV-H, -K, and -W families, of env genes of SYN1, SYN2, and MSRV, as well as of TRIM28 and SETDB1 in the blood of 33 ASD children (28 males, median 3.8 years, 25-75% interquartile range 3.0-6.0 y) and healthy controls (HC). Significantly higher expressions of TRIM28 and SETDB1, as well as of all the HERV genes tested, except for HERV-W-pol, were found in ASD, as compared with HC. Positive correlations were observed between the mRNA levels of TRIM28 or SETDB1 and every HERV gene in ASD patients, but not in HC. Overexpression of TRIM28/SETDB1 and several HERVs in children with ASD and the positive correlations between their transcriptional levels suggest that these may be main players in pathogenetic mechanisms leading to ASD.

Enhanced expression of endogenous retroviruses and of TRIM28 and SETDB1 in children with food allergy.

BACKGROUND: Human endogenous retroviruses (HERVs) represent 8% of our genome. They originate from ancestral infections and although no longer contagious they can regulate transcription of adjacent cellular genes, produce viral RNAs sensed as non-self by pattern recognition receptors, and encode viral proteins, such as Syncytin (SYN) 1 and 2, that exhibit potent immunomodulatory properties. Based on this, HERVs have been studied and proposed as relevant cofactors in several chronic inflammatory and immune-mediated diseases. HERV transcription is regulated by host TRIM28 and SET domain bifurcated histone lysine methyltransferase 1 (SETDB1), which in turn exert crucial regulatory functions on the host immune system. No studies explored the expression of HERVs, TRIM28, and SETDB1 in allergic patients. METHODS: We assessed, through a polymerase chain reaction real time Taqman amplification assay, the transcription levels of pol genes of HERV-H, HERV-K, HERV-W, and of env genes of SYN1 and SYN2, as well as of TRIM28 and SETDB1 in whole blood from 32 children with IgE-mediated food allergy, 19 with food protein-induced enterocolitis syndrome (FPIES), and in healthy control children. RESULTS: The expression levels of pol genes of HERV-H, -K, and -W were significantly enhanced in patients with IgE-mediated FA or FPIES as compared to control subjects, while the mRNA concentrations of SYN1 and SYN2 were comparable in each group of children. Both TRIM28 and SETDB1 mRNA levels were significantly higher in allergic patients. CONCLUSIONS: Given the influence of HERVs and of TRIM28 and SETDB1 on innate and adaptive immune responses, their transcriptional activation in children with food allergies suggest that they might play important roles in the development of these diseases.

Off-label use of combined antiretroviral therapy, analysis of data collected by the Italian Register for HIV-1 infection in paediatrics in a large cohort of children.

BACKGROUND: Early start of highly active antiretroviral therapy (HAART) in perinatally HIV-1 infected children is the optimal strategy to prevent immunological and clinical deterioration. To date, according to EMA, only 35% of antiretroviral drugs are licenced in children < 2 years of age and 60% in those aged 2-12 years, due to the lack of adequate paediatric clinical studies on pharmacokinetics, pharmacodynamics and drug safety in children. METHODS: An observational retrospective study investigating the rate and the outcomes of off-label prescription of HAART was conducted on 225 perinatally HIV-1 infected children enrolled in the Italian Register for HIV Infection in Children and followed-up from 2001 to 2018. RESULTS: 22.2% (50/225) of included children were receiving an off-label HAART regimen at last check. Only 26% (13/50) of off-label children had an undetectable viral load (VL) before the commencing of the regimen and the 52.0% (26/50) had a CD4 + T lymphocyte percentage > 25%. At last check, during the off label regimen, the 80% (40/50) of patients had an undetectable VL, and 90% (45/50) of them displayed CD4 + T lymphocyte percentage > 25%. The most widely used off-label drugs were: dolutegravir/abacavir/lamivudine (16%; 8/50), emtricitbine/tenofovir disoproxil (22%; 11/50), lopinavir/ritonavir (20%; 10/50) and elvitegravir/cobicistat/emtricitabine/ tenofovir alafenamide (10%; 10/50). At logistic regression analysis, detectable VL before starting the current HAART regimen was a risk factor for receiving an off-label therapy (OR: 2.41; 95% CI 1.13-5.19; p = 0.024). Moreover, children < 2 years of age were at increased risk for receiving off-label HAART with respect to older children (OR: 3.24; 95% CI 1063-7.3; p = 0.001). Even if our safety data regarding off-label regimens where poor, no adverse event was reported. CONCLUSION: The prescription of an off-label HAART regimen in perinatally HIV-1 infected children was common, in particular in children with detectable VL despite previous HAART and in younger children, especially those receiving their first regimen. Our data suggest similar proportions of virological and immunological successes at last check among children receiving off-label or on-label HAART. Larger studies are needed to better clarify efficacy and safety of off-label HAART regimens in children, in order to allow the enlargement of on-label prescription in children.

HERV-K and W expression in peripheral mononuclear cells of children with Henoch-Schönlein purpura and relation with TLR activation.

BACKGROUND: HERVs expression seems impaired in several diseases, ranging from autoimmune to neoplastic disorders. However, various stimuli may re-activate HERVs transcription. Henoch-Schönlein purpura is the most common cause of vasculitis in children. The role of microbial antigens in the pathogenesis of HSP remains elusive. Toll-like receptors (TLRs) are the first line of defense for the host to initiate an immune and inflammatory response. We aimed to investigate HERV, K and W expression in peripheral mononuclear cells of children with HSP and relation with TLRs activation. METHODS: The study enrolled 63 children affected by HSP. We used RT-PCR to detect GAPDH in the peripheral blood mononuclear cells samples to normalize the data. Subsequently, the viral pol gene HERVs and TLRs transcripts in the same samples were assessed. RESULTS: HERV K and W was expressed in all samples analyzed but the level of expression was much lower in the HSP that in HC P=0.0006 and P=0.0004 for HERV-K and -W respectively. TLR2 was hyper-expressed in 39 vs. 63 (62%) of the HSP, TLR3 in 23 vs. 63 (42%), TLR4 in 42 vs. 63 (66%) and TLR9 in 32 vs. 63 (52%). The different expression was statistically significant only for TLR4 (P=0.0276) no for TLR2,3 and 9 (P=0.1251; 0.3964 and 0.1882 respectively). Spearman's test demonstrated no correlation between the low expression of HERV-K and HERV-W and high expression of TLRs. CONCLUSIONS: The results of the present study demonstrated that mRNA expression of HERV-K and -W and TLRs did not directly correlated.

Real-World Analysis of Survival and Clinical Events in a Cohort of Italian Perinatally HIV-1 Infected Children From 2001 to 2018.

Background: Combined antiretroviral therapy (cART) has been associated with a steep decrease in mortality and morbidity in HIV-1 infected children. New antiretroviral molecules and drug classes have been developed and the management of HIV-infected children has improved, but recent data on survival are limited. Methods: An observational retrospective study investigating changes in mortality and morbidity was conducted on 1,091 perinatally HIV-1 infected children enrolled in the Italian Register for HIV Infection in Children and followed-up from 2001 to 2018. Results: Three hundred and fifty-four (32%) AIDS events and 26 (2%) deaths occurred overtime. Mortality rates decreased from 0.4/100 person-years in 2001-2006 to 0.27/100 person-years in 2007-2012 and 0.07/100 person-years in 2013-2018. Notably, 92% of the dead children were born in Italy, but only 50% were followed-up since birth or within three months of age. Seventy three percent of children had started cART at age ≥6 months; 23% were treated for <30 days before death. B and C clinical events progressively decreased (P < 0.0001). Opportunistic infections significantly decreased over time, but still were the most common events in all the periods (6.76/100 person-years in 2013-2018). In the last period, severe bacterial infections were the most common ones. Cancer rates were 0.07/100; 0.17/100; 0.07/100 person-years in the three periods, respectively. Conclusions: Progressive reductions both in mortality and in rates of class B and C clinical events and OIs have been observed during the cART era. However, deaths were still registered; more than half of dead children were enrolled after birth and had belatedly started cART.

COVID-19 in Children: Expressions of Type I/II/III Interferons, TRIM28, SETDB1, and Endogenous Retroviruses in Mild and Severe Cases.

Children with the new coronavirus disease 2019 (COVID-19) have milder symptoms and a better prognosis than adult patients. Several investigations assessed type I, II, and III interferon (IFN) signatures in SARS-CoV-2 infected adults, however no data are available for pediatric patients. TRIM28 and SETDB1 regulate the transcription of multiple genes involved in the immune response as well as of human endogenous retroviruses (HERVs). Exogenous viral infections can trigger the activation of HERVs, which in turn can induce inflammatory and immune reactions. Despite the potential cross-talks between SARS-CoV-2 infection and TRIM28, SETDB1, and HERVs, information on their expressions in COVID-19 patients is lacking. We assessed, through a PCR real time Taqman amplification assay, the transcription levels of six IFN-I stimulated genes, IFN-II and three of its sensitive genes, three IFN-lIIs, as well as of TRIM28, SETDB1, pol genes of HERV-H, -K, and -W families, and of env genes of Syncytin (SYN)1, SYN2, and multiple sclerosis-associated retrovirus (MRSV) in peripheral blood from COVID-19 children and in control uninfected subjects. Higher expression levels of IFN-I and IFN-II inducible genes were observed in 36 COVID-19 children with mild or moderate disease as compared to uninfected controls, whereas their concentrations decreased in 17 children with severe disease and in 11 with multisystem inflammatory syndrome (MIS-C). Similar findings were found for the expression of TRIM-28, SETDB1, and every HERV gene. Positive correlations emerged between the transcriptional levels of type I and II IFNs, TRIM28, SETDB1, and HERVs in COVID-19 patients. IFN-III expressions were comparable in each group of subjects. This preserved induction of IFN-λs could contribute to the better control of the infection in children as compared to adults, in whom IFN-III deficiency has been reported. The upregulation of IFN-I, IFN-II, TRIM28, SETDB1, and HERVs in children with mild symptoms, their declines in severe cases or with MIS-C, and the positive correlations of their transcription in SARS-CoV-2-infected children suggest that they may play important roles in conditioning the evolution of the infection.

Impaired transcription of human endogenous retroviruses in the sperm with exception of syncytin 1: short communication.

BACKGROUND: Human endogenous retroviruses (HERVs), remnants of ancestral infections, represent 8% of the human genome. HERVs are co-opted for important physiological functions during embryogenesis; however, little is known about their expression in human gametes. We evaluated the transcriptional levels of several retroviral sequences in human spermatozoa. METHODS AND RESULTS: We assessed, through a Real-Time PCR assay, the transcription levels of the pol genes of HERV-H, -K and -W families and of env genes of syncytin (Syn)1 and Syn2 in the spermatozoa from 8 normospermic subjects. The entity and distribution of their expressions were compared to values found in white blood cells (WBCs) from 16 healthy volunteers. The level of HERV transcripts was significantly lower in spermatozoa than in WBCs for HERV-H-pol, HERV-K-pol, HERV-W-pol, and Syn2.In contrast, the level of expression of Syn1 in the sperm was similar to that found in WBCs and it was significantly higher than the mRNA concentrations of other HERV genes in spermatozoa. CONCLUSIONS: Our findings show, for the first time, the presence of several retroviral mRNAs in the sperm, although in low amounts. The higher concentration of Syn1 suggests that it could play a key role in the fusion process between gametes during fertilization and, perhaps, be involved in embryo development. Further studies could clarify whether aberrant HERV expressions, in particular of Syn1, negatively affect fertilization and embryo growth and whether sperm manipulation procedures, such as cryopreservation, may potentially influence HERV transcription in the human male gamete.

Epidemiology, Clinical Features and Prognostic Factors of Pediatric SARS-CoV-2 Infection: Results From an Italian Multicenter Study.

Background: Many aspects of SARS-CoV-2 infection in children and adolescents remain unclear and optimal treatment is debated. The objective of our study was to investigate epidemiological, clinical and therapeutic characteristics of pediatric SARS-CoV-2 infection, focusing on risk factors for complicated and critical disease. Methods: The present multicenter Italian study was promoted by the Italian Society of Pediatric Infectious Diseases, involving both pediatric hospitals and general pediatricians/family doctors. All subjects under 18 years of age with documented SARS-CoV-2 infection and referred to the coordinating center were enrolled from March 2020. Results: As of 15 September 2020, 759 children were enrolled (median age 7.2 years, IQR 1.4; 12.4). Among the 688 symptomatic children, fever was the most common symptom (81.9%). Barely 47% of children were hospitalized for COVID-19. Age was inversely related to hospital admission (p < 0.01) and linearly to length of stay (p = 0.014). One hundred forty-nine children (19.6%) developed complications. Comorbidities were risk factors for complications (p < 0.001). Viral coinfections, underlying clinical conditions, age 5-9 years and lymphopenia were statistically related to ICU admission (p < 0.05). Conclusions: Complications of COVID-19 in children are related to comorbidities and increase with age. Viral co-infections are additional risk factors for disease progression and multisystem inflammatory syndrome temporarily related to COVID-19 (MIS-C) for ICU admission.

Overexpression of endogenous retroviruses in children with celiac disease.

Human endogenous retroviruses (HERVs) represent 8% of our genome. Although no longer infectious, they can regulate transcription of adjacent cellular genes, produce retroviral RNAs, and encode viral proteins that can modulate both innate and adaptive immune responses. Based on this, HERVs have been studied and proposed as contributing factors in various autoimmune disorders. Celiac disease (CD) is considered an autoimmune disease, but HERV expression has not been studied in celiac patients. The aim of this study is to assess the transcription levels of pol genes of HERV-H, -K, and -W and of their TRIM28 repressor in WBCs from celiac children and age-matched control subjects. A PCR real-time TaqMan amplification assay was used to evaluate HERV and TRIM28 transcripts with normalization of the results to glyceraldehyde-3-phosphate dehydrogenase. The RNA levels of pol genes of the three HERV families were significantly higher in WBCs from 38 celiac patients than from 51 control subjects. TRIM28 transcription was comparable between the two study populations.Conclusion: Present results show, for the first time, that pol genes of HERV-H, -K, and -W are overexpressed in patients with CD. Given their proinflammatory and autoimmune properties, this suggests that HERVs may contribute to the development of CD in susceptible individuals. What is Known: • Based on this, HERVs have been studied and proposed as contributing factors in various autoimmune disorders. What is New: • Present results show, for the first time, that pol genes of HERV-H, -K, and -W are overexpressed in patients with CD.

Human Endogenous Retroviruses Are Preferentially Expressed in Mononuclear Cells From Cord Blood Than From Maternal Blood and in the Fetal Part of Placenta.

Background: Placenta shows high transcription levels of human endogenous retroviruses (HERVs) that are overexpressed during embryonic and fetal development. Methods: In order to gather further information on the degree of HERV activation in maternal and fetal tissues we assessed the transcription levels of pol genes of HERV-H, -K, and -W in PBMCs of newborns and their mothers as well as in chorion (fetal part) and decidua basalis (maternal part) of the placenta using a real time PCR assay. Results: Transcripts of pol genes of the three HERV families were significantly higher in mononuclear cells from cord blood than from maternal blood and in the fetal part than in the maternal part of the placenta. Conclusions: The HERV over-expressions in cells and tissues of the offspring are further clues that they play pivotal physiologic roles during early life events and suggest that HERV-driven abnormalities of pregnancy and fetal development may derive mostly from the conceptus, not from the mother.

Chronic HCV Infection Is Associated with Overexpression of Human Endogenous Retroviruses that Persists after Drug-Induced Viral Clearance.

Chronic hepatitis C virus (HCV) infection is associated with several hepatic and extrahepatic complications, including cancers and autoimmune disorders, whose frequency is reduced but not abolished after drug-induced viral clearance. The causes of these complications and of their persistence are ill-defined. Human endogenous retroviruses (HERVs) are remnants of ancestral infections and constitute 8% of the human genome. Most HERV elements are inactive, but some are transcribed. HERV overexpression is associated with many cancers and autoimmune diseases with a putative pathogenetic role. Several viral infections trigger HERV activation, but there are no studies on HCV-infected subjects. We assessed, through a PCR real-time amplification assay, the transcription levels of the pol genes of HERV-H, -K, and -W, and of their repressor TRIM28 in white blood cells (WBCs) of vertically infected children, both before and after therapy with direct-acting antivirals (DAAs). The results documented significantly higher expressions of HERV-H-pol and HERV-K-pol, not of HERV-W-pol, in HCV-infected subjects as compared to age-matched controls. HERV RNA levels remained unchanged after DAA-driven viral clearance. No significant variations in transcription levels of TRIM28 were observed in infected subjects. Our findings demonstrate HERV-H-pol and HERV-K-pol overexpression in subjects with chronic HCV infection, without variations after a positive response to DAAs; this might justify their predisposition to cancers and autoimmune disorders that persist after a DAA-induced resolution of viremia.

Enhanced expression of human endogenous retroviruses in new-onset type 1 diabetes: Potential pathogenetic and therapeutic implications.

Human endogenous retroviruses (HERVs) have been studied and proposed as relevant cofactors in several autoimmune diseases, including type 1 diabetes (T1D), though with controversial results and no study at disease onset. In order to gather further information on the potential role of HERVs in the development of T1D we assessed the transcription levels of pol genes of HERV-H, HERV-K, and HERV-W in peripheral leucocytes from 37 children and adolescents with new-onset T1D and 50 age-matched control subjects. A PCR real time Taqman amplification assay was used to evaluate HERV transcripts with normalisation of the results to glyceraldehyde-3-phosphate dehydrogenase. The expression levels of HERV-H-pol gene and HERV-W-pol gene were significantly higher in diabetic patients than in control subjects. Conversely, no significant difference emerged in the expression levels of HERV-K-pol gene between diabetic patients and controls. The activation of HERV-H and HERV-W in new-onset T1D suggests their importance in the pathogenesis of the disease and supports targeted therapeutic attempts to hinder their activation.