Human Polymorphonuclear Cells Support Zika Virus to Cross Endothelial Monolayer and Access Bloodstream.

The rapid spread of new outbreaks of human infection caused by Zika virus (ZIKV) has raised many global concerns since 2016. Despite the increasing knowledge of this virus, data on the pathogenesis of ZIKV are still missing. In particular, it is still unknown how the virus crosses the endothelial monolayer and gets access to the bloodstream. In the present work, we used human umbilical vein endothelial cells (HUVECs) as a model to study ZIKV infection in vitro. We demonstrated that HUVECs are an optimal reservoir for viral replication, as they were able to sustain ZIKV infection up to two weeks, without showing a cytopathic effect. In order to evaluate the integrity of endothelial monolayer, immunofluorescence was performed on mock-infected or ZIKV-infected cells ± peripheral blood mononuclear cells (PBMCs) or polymorphonuclear cells (PMN), 48 h p.i., by using an anti-VE-Cadherin antibody, a major adherence protein that maintains the integrity of intercellular junctions. In addition to infection, we noted that the presence of some components of the immune system, such as PMNs, played an important role in altering the endothelial monolayer in cell junctions, suggesting that presence at the site of infection probably promotes the spread of ZIKV in vivo in the bloodstream.

Comparative Performance of a New SARS-CoV-2 Rapid Detection System.

The extraordinary global demand for reagents and diagnostic instruments needed for timely detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has rapidly affected their availability. In order to meet diagnostic needs, it has been necessary to develop new diagnostic procedures. To date, molecular diagnostic tools have represented the gold standard for diagnosis of SARS-CoV-2 infection, and thus an alternative and real-time PCR system was required. To this aim, a molecular rapid test which works with direct real-time RT-PCR may be a relevant aid. In the present work, the accuracy, sensitivity, and specificity of the bKIT Virus Finder COVID-19 rapid molecular test by Hyris Ltd. was evaluated. Moreover, the influence of a different swab storage medium composition was examined relative to that of a routinely used comparator assay. The Hyris Ltd. assay showed an overall agreement of 100% with the comparator based on a panel consisting of 74 retrospective positive nasopharyngeal swabs (NPSs), collected either in universal transport medium (UTM) or using ESwab. No false-positive result was achieved on samples that previously tested negative. Cross-reactivity screening on microorganisms that commonly colonize the human upper respiratory tract was not detected, excluding the risk of false-positive results. Simultaneously, drugs frequently administered to cure respiratory diseases did not interfere with the analytical performance of the assay. Our results showed that the Hyris Ltd. bKIT Virus Finder COVID-19 is a reliable assay for rapid qualitative detection of SARS-CoV-2, providing the advantage of less complex and unambiguous interpretation of results. Indeed, skilled technicians are not required, and thus the Hyris system is suitable as a rapid and easy system for SARS-CoV-2 diagnosis. IMPORTANCE In order to overcome the increased demand for diagnostic tools for the timely detection of SARS-CoV-2 infection, we tested the bKIT Virus Finder COVID-19 molecular rapid test by Hyris Ltd. The new system was confirmed as a reliable assay for rapid SARS-CoV-2 detection, since sensitivity and specificity parameters were fully satisfied. Moreover, the bKIT Virus Finder COVID-19 provides the advantage of easy results interpretation, since skilled technicians are not required, and thus the Hyris system is a valuable SARS-CoV-2 rapid diagnosis system.

Antibody response to SARS-CoV-2 in infected patients with different clinical outcome.

Data regarding antibody responses to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in patients infected with COVID-19 are not yet available. In this study, we aimed to evaluate serum antibody responses in patients regardless of the outcome. We measured the circulating immunoglobulin G (IgG) antibody levels in 60 subjects with a certified history of SARS-CoV-2 infection by using immunoenzymatic, chemiluminescent, and Neutralization assays. Half patients had a severe infection, the other half were pauci-symptomatic. We analyzed their antibody response to see the trend of the humoral response. Our results showed a significant difference in circulating IgG level among the two groups. The neutralizing antibody response against SARS-CoV-2 was significantly higher among those who had severe disease. Furthermore, ten subjects from each group were screened twice, and a declining antibody trend was observed in pauci-symptomatic individuals. These findings provide evidence that humoral immunity against SARS-CoV-2 in pauci-symptomatic people is weak and may not be long-lasting. This may have implications for immunity strategy and prevention, since it is still not clear whether a time-dependent decrease of both circulating and neutralizing antibodies to nonprotective levels could occur in a longer time span and whether potential vaccines are able to induce a herd immunity and a durable response.

Ubiquitin and Not Only Unfolded Domains Drives Toscana Virus Non-Structural NSs Protein Degradation.

The non-structural protein NSs of the Phenuiviridae family members appears to have a role in the host immunity escape. The stability of Toscana virus (TOSV) NSs protein was tested by a cycloheximide (CHX) chase approach on cells transfected with NSs deleted versions fused to a reporter gene. The presence of intrinsically disordered regions (IDRs) both at the C- and N-terminus appeared to affect the protein stability. Indeed, the NSsΔC and NSsΔN proteins were more stable than the wild-type NSs counterpart. Since TOSV NSs exerts its inhibitory function by triggering RIG-I for proteasomal degradation, the interaction of the ubiquitin system and TOSV NSs was further examined. Chase experiments with CHX and the proteasome inhibitor MG-132 demonstrated the involvement of the ubiquitin-proteasome system in controlling NSs protein amount expressed in the cells. The analysis of TOSV NSs by mass spectrometry allowed the direct identification of K104, K109, K154, K180, K244, K294, and K298 residues targeted for ubiquitination. Analysis of NSs K-mutants confirmed the presence and the important role of lysine residues located in the central and the C-terminal parts of the protein in controlling the NSs cellular level. Therefore, we directly demonstrated a new cellular pathway involved in controlling TOSV NSs fate and activity, and this opens the way to new investigations among more pathogenic viruses of the Phenuiviridae family.

Seroprevalence to Measles Virus after Vaccination or Natural Infection in an Adult Population, in Italy.

An increase in measles cases worldwide, with outbreaks, has been registered in the last few years, despite the availability of a safe and highly efficacious vaccine. In addition to an inadequate vaccination coverage, even in high-income European countries studies proved that some vaccinated people were also found seronegative years after vaccination, thus increasing the number of people susceptible to measles infection. In this study, we evaluated the immunization status and the seroprevalence of measles antibodies among 1092 healthy adults, either vaccinated or naturally infected, in order to investigate the persistence of anti-measles IgG. Among subjects who received two doses of measles vaccine, the neutralizing antibody titer tended to decline over time. In addition, data collected from a neutralization assay performed on 110 healthy vaccinated subjects suggested an inverse correlation between neutralizing antibody titers and the time elapsed between the two vaccinations, with a significant decline in the neutralizing titer when the interval between the two doses was ≥11 years. On the basis of these results, monitoring the serological status of the population 10-12 years after vaccination could be important both to limit the number of people who are potentially susceptible to measles, despite the high efficacy of MMR vaccine, and to recommend a booster vaccine for the seronegatives.

Toscana virus non-structural protein NSs acts as E3 ubiquitin ligase promoting RIG-I degradation.

It is known that the non-structural protein (NSs) of Toscana virus (TOSV), an emergent sandfly-borne virus causing meningitis or more severe central nervous system injuries in humans, exerts its function triggering RIG-I for degradation in a proteasome-dependent manner, thus breaking off the IFN-ß production. The non-structural protein of different members of Bunyavirales has recently appeared as a fundamental protagonist in immunity evasion through ubiquitination-mediated protein degradation targets. We showed that TOSV NSs has an E3 ubiquitin ligase activity, mapping at the carboxy-terminal domain and also involving the amino-terminal of the protein. Indeed, neither the amino- (NSsΔN) nor the carboxy- (NSsΔC) terminal-deleted mutants of TOSV NSs were able to cause ubiquitin-mediated proteasome degradation of RIG-I. Moreover, the addition of the C-terminus of TOSV NSs to the homologous protein of the Sandfly Fever Naples Virus, belonging to the same genus and unable to inhibit IFN-ß activity, conferred new properties to this protein, favoring RIG-I ubiquitination and its degradation. NSs lost its antagonistic activity to IFN when one of the terminal residues was missing. Therefore, we showed that NSs could behave as an atypical RING between RING (RBR) E3 ubiquitin ligases. This is the first report which identified the E3 ubiquitin ligase activity in a viral protein among negative strand RNA viruses.

A novel polymorphism in BRCA2 exon 8 and breast cancer risk in South India.

In India the incidence of breast cancer is on the rise and it is rapidly becoming the number one cancer in females, pushing cervical cancer to the second spot. The contribution of BRCA2 to the development of the sporadic form of breast cancer remains undefined. To assess the role of SNPs in exon 8 of the BRCA2 gene in breast cancer development in India, a population-based study was here carried out on 107 breast cancer patients and 96 controls by PCR-RFLP and DNA sequencing. T-C transitions at positions 29 bp and 44 bp in relation to the total sequence of exon 8 were identified. Characterization of BRCA genes is relevant in a prevention setting as well as for the clinical management of hereditary breast cancer patients. The presently identified novel mutation in exon8 of the BRCA2 gene might have clinical significance.

DNA damage induction and repair inhibition among building construction workers in South India.

Construction industry workers are exposed to many known carcinogens in their complex occupational environment. Since there are no past studies on genotoxicity among this group in the Indian subcontinent, workers engaged in different construction sites at Coimbatore, Tamil Nadu, India, were assessed here. We enrolled 96 workers and 68 control subjects with similar mean age, smoking, tobacco chewing prevalence and alcohol consumption, for analysis of DNA damage in blood leucocytes by micronucleus (MN) and comet assays. DNA repair inhibition was also analyzed by assessing the XPD gene. Construction workers showed a significant increase in MN and comet tail length compared to controls with adjustment for smoking habits, tobacco chewing, alcohol consumption and years of exposure (P<0.05). The results indicated that chronic occupational exposure to cement during construction work could lead to increased levels of DNA damage and repair inhibition.

Genotoxic effects of textile printing dye exposed workers in India detected by micronucleus assay.

The textile printing industry in South India employs a great number of workers that may possibly be exposed to toxic compounds. In the present study, subjects from textile printing units were investigated for the presence of genetic damage in their peripheral blood lymphocytes using micronucleus assay. Proliferation was also investigated using a nuclear division index. It was found that the micronucleus frequency was considerably greater in exposed subjects than in non exposed control subjects, but division was not increased in a statistically significant way. For the time being, this investigation should be considered as a preliminary study in which the influence of potential confounders could be adequately assessed. However, our results are non-ambiguous, indicating a potential health risk in these workers.

Evaluation of DNA damage induction and repair inhibition in welders exposed to hexavalent chromium.

The soluble hexavalent chromium Cr (VI) used in industrial welding is an environmental contaminant widely recognized to act as a carcinogen, mutagen and teratogen towards humans and animals. The carcinogenic potential of metals is a major issue in defining human health risk from exposure. In the present investigation, 93 welders and 60 control subjects with similar mean ages, smoking prevalences and alcohol consumption were enrolled for DNA damage analysis in blood leucocytes by Micronucleus assay (MN) and the Comet assay. DNA repair inhibition was also analyzed by assessing XPD gene polymorphism. Welders showed a significant increase in micronucleated cells compared to controls with respect to their smoking habits and alcohol consumption, age and years of exposure (P<0.05). Results indicated that the welders had a larger mean comet tail length than that of the controls (P<0.05). The current study suggested that chronic occupational exposure to Cr (VI) during welding could lead to increased levels of DNA damage and repair inhibition.

XRCC1399 and hOGG1326 polymorphisms and frequencies of micronuclei, comet and chromosomal aberrations among tobacco chewers: a South Indian population study.

DNA repair plays a critical role in protecting the genome of the cell from the insults of cancer-causing agents such as those found in tobacco. Reduced DNA repair capacity may constitute a significant risk factor for cancers. Recently, a number of polymorphisms in several DNA repair genes have been discovered, these polymorphisms may affect DNA repair capacity and thus modulate cancer susceptibility in exposed populations. In the present study, we explored the relationship between polymorphisms in the DNA repair gene XRCC1399 and hOGG1326 genotypes using polymerase chain reaction-restriction fragment length polymorphism (PCR/RFLP) and risk of cancer development. 156 smokeless tobacco users and 70 controls without significant exposure to mutagens were recruited. Questionnaires were completed to obtain detailed occupational, smoking, and medical histories. A standard micronucleus assay, comet assay and chromosomal aberration assays were used as a marker of genetic damage. There were significant differences in the micronucleus (MN), Comet scores and chromosomal aberrations (CA) between smokeless tobacco users and control subjects by Student's t-test (P< 0.05). These findings provide evidence for the view that polymorphisms in DNA repair genes may modify individual susceptibility to tobacco related cancers and justify additional studies to investigate their potential role in development of cancer.