Viral Antigen Expression Research Articles

High MHC-II expression in Epstein\u2013Barr virus-associated gastric cancers suggests that tumor cells serve an important role in antigen presentation

EBV-associated gastric adenocarcinomas (EBVaGCs) often exhibit better clinical outcomes than EBV negative gastric cancers (GCs), which could be related to their consistent expression of foreign viral antigens. Antigen-presenting cells (APCs) present peptide antigens in the context of the class-II major histocompatibility complex (MHC-II). During inflammatory conditions, epithelial cells express MHC-II and function as accessory APCs. Utilizing RNA-seq data from nearly 400 GC patients, we determined the impact of EBV-status on expression of MHC-II components, genes involved in their regulation, and T-cell co-stimulation. Virtually all MHC-II genes were significantly upregulated in EBVaGCs compared to normal tissues, or other GC subtypes. Genes involved in antigen presentation were also significantly upregulated in EBVaGCs, as were the key MHC-II transcriptional regulators CIITA and RFX5. This was unexpected as the EBV encoded BZLF1 protein can repress CIITA transcription and is expressed in many EBVaGCs. Furthermore, MHC-II upregulation was strongly correlated with elevated intratumoral levels of interferon-gamma. In addition, expression of co-stimulatory molecules involved in T-cell activation and survival was also significantly increased in EBVaGCs. Thus, gastric adenocarcinoma cells may functionally contribute to the highly immunogenic tumor microenvironment observed in EBVaGCs via a previously unappreciated role in interferon-induced antigen presentation.

Features of IgG-antibodies production to individual Cytomegalovirus proteins in various eye diseases (age-related macular degeneration and central serous chorioretinopathy)

Age-related macular degeneration (AMD) and central serous chorioretinopathy (CSC) are diseases targeting the posterior segment of the eye that often lead to lowered visual functions. Pathogenesis of such disorders largely remains unclear. Among the risk factors of developing chronic inflammation, various microorganisms are considered, particularly Cytomegalovirus (CMV ). The study was aimed at analyzing the humoral response to individual viral proteins during chronic and reactivated CMV infection in AMD and CSC patients. Materials and methods. 104 CMV-seropositive patients were enrolled in the study including 75 AMD and 29 CSC subjects. IgM- and IgG-antibodies specific to CMV late viral antigens as well as IgG antibodies against the main non-structural immediate early (IE) antigen were evaluated by ELISA. IgG antibodies to individual CMV phosphoproteins such as the main non-structural immediate early protein (IE), the DNA-binding phosphoprotein pp52, and the tegument phosphoproteins (pp150, pp65, and pp28) were assessed by using Line-Immunoassay: recombinant antigens containing immunodominant protein fragments derived from viral antigens (p52, p150, p65, p28) were used. Positive (bands 2+) and strongly positive (bands 3+) data were only used for analysis. Results. It was shown that in both groups patients with chronic CMV infection had comparable rate of detected antibodies specific to individual antigens. The level of seropositivity to CMV р150 and р65 was significantly higher than that to CMV р52 and р28 (p 0.05). Patients with AMD compared to patients with CSС had significantly higher moderate positive response (2+) to all the antigens examined. Upon reactivation of chronic CMV infection in AMD patients, the level of seropositivity to all antigens was increased, the number of cases with an intensely positive response to individual antigens was elevated, but patients with moderate positive response still prevailed. However, reactivation of chronic CMV infection was observed only in 6 CSС patients, allowing to perform no comparative analysis between these two groups. Conclusion. The main difference between CMV-chronically infected patients with AMD and CSC was not found at the level of seropositivity to individual CMV recombinant antigens, but rather in magnitude of antibody production so that AMD patients in comparison to CSC patients displayed moderate antibody production (bands 2+). A marked difference was related to the level of antibodies against CMV p150: AMD patients showed moderate antibody response (bands 2+), whereas CSC subjects dominated with strong positive response (bands 3+) (p 0.05). It seems that moderate antibody production to recombinant CMV antigens examined in AMD patients occurs due to a weak expression of such viral antigens during chronic infection, resulting in long-term maintenance of antigenic stimulation leading to prolonged inflammation.

Clinical efficacy of atrial fibrillation ablation depending on histological changes in the myocardium

There is a group of patients with so-called idiopathic atrial fibrillation (AF) without the causes of arrhythmia established by a standard examination. Aim. To study the effect of histological changes in the myocardium in patients with idiopathic AF on the effectiveness of ablation. Material and methods. The study included 101 patients with idiopathic AF All patients underwent ablation, during which a myocardial biopsy was performed. Depending on the results of intervention, 3 groups were formed: 1 — no AF within 12 months, 2 — recurrent arrhythmia within first 3 months of follow-up, 3 — recurrent arrhythmia after first 3 months of follow-up. To assess inflammatory changes and the severity of fibrosis, histological and immunohistochemical tests of myocardial biopsies were performed. Results . Histological criteria for lymphocytic myocarditis in group 1 observed in 47,5% of patients, in groups 2 and 3 in 27,3% and 25%, respectively. Infiltration of less than 7 cells per 1 mm 2 by CD3+ lymphocytes prevailed in group 3. The activity of inflammation in the studied groups did not significantly differ. The minimum severity of fibrosis was significantly less frequently recorded in group 1 than in group 2 and 3. Nonexpression of viral antigens in the first group was significantly less common than in the second and third groups. Moreover, the combination of expression of enterovirus VP1 and human herpesvirus 6 antigens was significantly more often recorded in the first group. Positive correlation was found between the expression of viral antigens and markers of endo- and myocardial fibrosis. Conclusion. The primary risk factor for recurrent arrhythmia was the initial stage of fibrosis, while inflammatory changes and viral infection were not risk factors. The presence of viral antigens in the myocardium had an indirect effect on the clinical outcome.

Abstract 3630: Comprehensive integrated HBV DNA profiling in HCC patients with GGH by HBV-targeted NGS and PacBio sequencing analysis

Abstract Despite current antiviral therapy success in reducing viral load in patients with chronic hepatitis B virus (HBV), persistent viral surface antigen (HBsAg) remains a risk factor of HCC. Recent evidence has shown that integrated HBV can serve as a source for continued viral antigen expression, despite the lack of detectable replication. Given the oncogenicity of pre-S mutant proteins and its expression in type II ground glass hepatocytes (GGH) even in the absence of viral replication, we assessed the likelihood of GGH as a pre-malignant state as compared to other adjacent-to-tumor non-GGH “normal” tissue by investigating the integrity of integrated HBV DNA. We developed a sensitive HBV-targeted NGS and downstream bioinformatics pipeline, ChimericSeq, to identify HBV-host junctions. A pilot study of 10 HBV-HCC patients, each with six micro-dissected FFPE tissue sections (2 tumor, 2 GGH, 2 HBsAg-negative), was subjected to HBV-targeted NGS and ChimericSeq analysis. We identified integrated HBV DNA in 90% of HCC as well as its matched GGH, and identified PreS2 deletions, for instance, deletion at nt. 43-52. Surprisingly, the recurrent insertional driver mutations of TERT, CCNE1, and ABCC13 integration were detected in 9 of 10 (90%) of this GGH/HCC patient cohort. Next we performed PacBio amplicon sequencing of integrated HBV DNA including Pre-S sequences to comprehensively profile the integrity of the integrated HBV DNA, such as insertional mutations or deletion, and mutations across the different frozen tissue sections (tumor, GGH, HBsAg-negative). Our data suggest that HBV integration of cancer driver genes occurs early during course of infection and integrated DNA evolved over time during carcinogenesis. Overall, a sensitive workflow to comprehensively profile integrated HBV DNA in HCC patients enables further investigation of the role of HBV integration during tumorigenesis. Citation Format: Yu-Lan Kao, Yih-Ping Su, Hung-Wen Tsai, Ih-Jen Su, Selena Lin, Wei Song, Ying-Hsiu Su. Comprehensive integrated HBV DNA profiling in HCC patients with GGH by HBV-targeted NGS and PacBio sequencing analysis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3630.

Self-Amplifying RNA Viruses as RNA Vaccines

Single-stranded RNA viruses such as alphaviruses, flaviviruses, measles viruses and rhabdoviruses are characterized by their capacity of highly efficient self-amplification of RNA in host cells, which make them attractive vehicles for vaccine development. Particularly, alphaviruses and flaviviruses can be administered as recombinant particles, layered DNA/RNA plasmid vectors carrying the RNA replicon and even RNA replicon molecules. Self-amplifying RNA viral vectors have been used for high level expression of viral and tumor antigens, which in immunization studies have elicited strong cellular and humoral immune responses in animal models. Vaccination has provided protection against challenges with lethal doses of viral pathogens and tumor cells. Moreover, clinical trials have demonstrated safe application of RNA viral vectors and even promising results in rhabdovirus-based phase III trials on an Ebola virus vaccine. Preclinical and clinical applications of self-amplifying RNA viral vectors have proven efficient for vaccine development and due to the presence of RNA replicons, amplification of RNA in host cells will generate superior immune responses with significantly reduced amounts of RNA delivered. The need for novel and efficient vaccines has become even more evident due to the global COVID-19 pandemic, which has further highlighted the urgency in challenging emerging diseases.

Evaluation of an in vitro virus culture system of anti-virus study of the Chinese herb

Influenza A virus was selected for anti-virus study with a garlic extract and a Chinese herb, Anoectochilus formosanus Hay. The virus was inoculated into the human promonocyte cell line, HL-CZ, which had been estabished in this laboratory. The infected cells have shown viral antigens detected by immunofluorescence staining with both monoclonal antibodies against virus nucleoprotein (NP) and hemagglutinin (HA) after 1-3 days of virus inoculation. This in vitro virus culture system was used as a tentative model for evaluating anti-virus activity of Chinese herbs. The relative minimum concentration of cytotoxicity (MCC) of the herb preparation to the HL-CZ cells was observed and determined during 7 days of cultivation. The MCCs tested for garlic and A. formosanus Hay extracts were 1:10 dilution (from the original package of garlic essence) (10% w/v) and 4.0 mg/ml, respectively. In several experiments, the average number of cells infected with the influenza A virus was 59.7%; those of the cells simultaneously treated with sub-MCC of garlic A. formosanus Hay and amantadine solutions were 19.4%, 33.6%, and 30.6%, respectively. These results suggest that the expression of influenza viral antigens in cells was partially inhibited by the component in these herb extracts. In addition, the replication of viral RNA was measured by polymerase chain reaction (PCR) after the HA1 region of viral hemagglutinin gene was converted into cDNA with reverse transcription. It was shown that viral HA gene could be detected 12 hours post-inoculation even in the presence of Chinese herbs. This method could be applied to detect the replication of viral RNA when the virus-infected cells were treated with the extracts of Chinese herbs.

Broad-Spectrum Host-Based Antivirals Targeting the Interferon and Lipogenesis Pathways as Potential Treatment Options for the Pandemic Coronavirus Disease 2019 (COVID-19).

The ongoing Coronavirus Disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) signals an urgent need for an expansion in treatment options. In this study, we investigated the anti-SARS-CoV-2 activities of 22 antiviral agents with known broad-spectrum antiviral activities against coronaviruses and/or other viruses. They were first evaluated in our primary screening in VeroE6 cells and then the most potent anti-SARS-CoV-2 antiviral agents were further evaluated using viral antigen expression, viral load reduction, and plaque reduction assays. In addition to remdesivir, lopinavir, and chloroquine, our primary screening additionally identified types I and II recombinant interferons, 25-hydroxycholesterol, and AM580 as the most potent anti-SARS-CoV-2 agents among the 22 antiviral agents. Betaferon (interferon-β1b) exhibited the most potent anti-SARS-CoV-2 activity in viral antigen expression, viral load reduction, and plaque reduction assays among the recombinant interferons. The lipogenesis modulators 25-hydroxycholesterol and AM580 exhibited EC50 at low micromolar levels and selectivity indices of >10.0. Combinational use of these host-based antiviral agents with virus-based antivirals to target different processes of the SARS-CoV-2 replication cycle should be evaluated in animal models and/or clinical trials.

Surgical Mask Partition Reduces the Risk of Noncontact Transmission in a Golden Syrian Hamster Model for Coronavirus Disease 2019 (COVID-19).

BackgroundCoronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is believed to be mostly transmitted by medium-to-large sized respiratory droplets although airborne transmission is theoretically possible in healthcare settings involving aerosol-generating procedures. Exposure to respiratory droplets can theoretically be reduced by surgical mask usage. However, there is a lack of experimental evidence supporting surgical mask usage for prevention of COVID-19.MethodsWe used a well-established golden Syrian hamster SARS-CoV-2 model. We placed SARS-CoV-2-challenged index hamsters and naïve hamsters into closed system units each comprising two different cages separated by a polyvinyl chloride air porous partition with unidirectional airflow within the isolator. The effect of a surgical mask partition placed in between the cages was investigated. Besides clinical scoring, hamster specimens were tested for viral load, histopathology, and viral nucleocapsid antigen expression.ResultsNon-contact transmission was found in 66.7% (10/15) of exposed naïve hamsters. Surgical mask partition for challenged index or naïve hamsters significantly reduced transmission to 25% (6/24, P=0.018). Surgical mask partition for challenged index hamsters significantly reduced transmission to only 16.7% (2/12, P=0.019) of exposed naïve hamsters. Unlike the severe COVID-19 manifestations of challenged hamsters, infected naïve hamsters had lower clinical scores, milder histopathological changes, and lower viral nucleocapsid antigen expression in respiratory tract tissues.ConclusionsSARS-CoV-2 could be transmitted by respiratory droplets or airborne droplet nuclei in the hamster model. Such transmission could be reduced by surgical mask usage, especially when masks were worn by infected individuals.

Noninvasive chimeric DNA profiling identifies tumor-originated HBV integrants contributing to viral antigen expression in liver cancer.

Host genome integration of HBV sequence is considered to be significant in HBV antigen expression and the development of hepatocellular carcinoma (HCC). We developed a probe-based capture strategy to enrich integrated HBV DNA for deep-sequencing analysis of integration sites in paired patient samples derived from tumor, liver tissue adjacent to tumor, saliva and plasma, as a platform for exploring the correlation, significance and utility of detecting integrations in these sample types. Most significantly, alpha fetoprotein levels significantly correlated to the amounts of integrations detected in tumor. Viral-host chimeric DNA fragments were successfully detected at high sequencing coverage in plasma rather than saliva samples from HCC patients, and each fragment of this type was only seen once in plasma from chronic hepatitis B patients. Almost all plasma chimeric fragments were derived from integrations in tumor rather than in adjacent liver tissues. Over 50% of them may produce viral-host chimeric transcripts according to deep RNA sequencing in paired tissue samples. Particularly, in patients with low HBV DNA level (< 250 UI/ml), the seemingly normal HBsAg titers may be explained by larger amounts of integrations detected. Meanwhile, we developed a strategy to predict integrants by pairing breakpoints for each integration event. Among four resolved viral patterns, the majority of Pattern I events (81.2%) retained the complete opening reading frame for HBV surface proteins. We achieve the efficient enrichment of plasma cell-free chimeric DNA from integration site, and demonstrate that chimeric DNA profiling in plasma is a promising noninvasive approach to monitor HBV integration in liver cancer development and to determine the ability of integrated sequences to express viral proteins that can be targeted, e.g. by immunotherapies.

Minicircle DNA vector expressing interferon-lambda-3 inhibits hepatitis B virus replication and expression in hepatocyte-derived cell line

BackgroundInterferon-alpha (IFNα) is a first-line treatment option for chronic hepatitis B virus (HBV) infection, but the severe systemic side-effects limited its clinical application. Interferon-lambda (IFNλ) with comparable antiviral activity and less toxic side-effects is thought to be a good alternative interferon to IFNα. Additionally, the gene vector mediated sustainably expression of therapeutic product in the target cells/tissue may overcome the shortcomings resulted from the short half-life of IFNs.ResultsWe constructed a liver-specific IFNλ3-expressing minicircle (MC) vector under the control of a hepatocyte-specific ApoE promoter (MC.IFNλ3) and investigated its anti-HBV activity in a HBV-expressing hepatocyte-derived cell model (HepG2.2.15). As expected, the MC.IFNλ3 vector capable of expressing IFNλ3 in the recipient hepatocytes has demonstrated robust anti-HBV activity, in terms of suppressing viral antigen expression and viral DNA replication, via activation the interferon-stimulated gene (ISG) expression in HepG2.2.15 cells.ConclusionsGiven the MC vector can be easily delivered into liver, the liver-targeted IFN gene-transfer (MC.IFNλ3), instead of systemic administrating IFN repeatedly, provides a promising concept for the treatment of chronic HBV infection.

Distinctive EBV infection characteristics in children from a developing country

BackgroundIn developing countries, Epstein–Barr virus (EBV) infection is mostly asymptomatic in early childhood. EBV persistence may lead to different malignancies, such as B cell derived lymphomas. In Argentina, most children are seropositive at three years and an increased association between EBV and lymphoma was proved in children under 10 years old by our group. ObjectiveOur aim was to characterize EBV infection at the site of entry and reactivation of viral infection —the tonsils— in order to better understand the mechanism of viral persistence in pediatric patients. MethodsA cohort of 54 patients was described. We assessed specific antibodies profiles in sera; viral proteins presence by IHC on FFPE samples and EBV type from fresh tissue. ResultsEBV type 1 was prevalent, mostly in the youngest patients. Asymptomatic primary infected patients presented higher viral loads and Latency 0/I or II patterns, whereas the Latency III pattern was observed mostly in healthy carriers. There were no differences between groups in the expression of viral lytic antigens. This study discloses new features in patients undergoing primary infection from a developing population. Low viral inoculum and restricted viral antigen expression may be responsible for the lack of symptoms in children from our country.

Restriction of exogenous DNA expression by SAMHD1

SAMHD1 (Sterile Alpha Motif and Histidine-aspartate Domain containing protein 1) has been documented as a host factor that restricts HIV-1 and some DNA viruses. In this work, we attempted to explore possible effects of SAMHD1 on exogenous DNA and show that SAMHD1 exerts a general inhibition on the expression of exogenous DNA in vitro and in mice. This inhibition is achieved through repressing transcription of exogenous DNA. Intriguingly, unlike SAMHD1’s restriction of HIV-1, such restriction does not require the dNTPase or RNase activities, or T592 phosphorylation of SAMHD1. Mechanistically, SAMHD1 enhances the expression of interferon regulatory factor-1 (IRF1), while IRF1 upregulation was demonstrated to inhibit exogenous DNA expression in a similar fashion as SAMHD1. IFNλ1, whose induction has been associated with IRF1 activation, is dispensable for SAMHD1/IRF1-mediated restriction of exogenous DNA, and neither type I nor II interferons appear to be involved. We also demonstrate that SAMHD1/IRF1-mediated restriction can effectively inhibit hepatitis B virus (HBV) antigen expression and progeny virus production in mouse models. In conclusion, these data support restriction of exogenous DNA as a novel function of SAMHD1.

Epstein barr virus encodes miRNAs to assist host immune escape.

Epstein-barr virus (EBV) is a definite tumorigenic virus, which can form life-long latency in the host, which is difficult to be recognized and completely eliminated by the immune system. It is closely related to the occurrence and development of nasopharyngeal cancer, gastric cancer and various types of lymphoma. At present, a total of 44 Epstein-barr virus-encoded microRNAs (EBV miRNAs) have been found. In response to the immune system of the body, EBV miRNAs can inhibit the expression and presentation of viral antigens, inhibit immune activation and immunotoxicity, assisting host cells to escape from immunity, and providing conditions for further immortalized tumorigenesis of the host cells.

HTLV-1 contains a high CG dinucleotide content and is susceptible to the host antiviral protein ZAP

BackgroundHuman T cell leukaemia virus type 1 (HTLV-1) is a retrovirus associated with human diseases such as adult T-cell leukaemia/lymphoma and HTLV-1 associated myelopathy/tropical spastic paraparesis. In contrast to another human retrovirus, human immunodeficiency virus type 1 (HIV-1), HTLV-1 persists in the host not via vigorous virus production but mainly via proliferation and/or long-term survival in the form of silent proviruses in infected host cells. As a result, HTLV-1-infected cells rarely produce virus particles in vivo even without anti-retroviral treatment. That should be an advantage for the virus to escape from the host immune surveillance by minimizing the expression of viral antigens in host cells. However, why HIV-1 and HTLV-1 behave so differently during natural infection is not fully understood.ResultsWe performed cap analysis of gene expression (CAGE) using total RNAs and nascent, chromatin-associated, RNAs in the nucleus and found that HTLV-1 RNAs were processed post-transcriptionally in infected cells. RNA processing was evident for the sense viral transcripts but not the anti-sense ones. We also found a higher proportion of CG di-nucleotides in proviral sequences of HTLV-1-infected cells, when compared to the HIV-1 genomic sequence. It has been reported recently that CG dinucleotide content of viral sequence is associated with susceptibility to the antiviral ZC3HAV1 (ZAP), suggesting the involvement of this protein in the regulation of HTLV-1 transcripts. To analyse the effect of ZAP on HTLV-1 transcripts, we over-expressed it in HTLV-1-infected cells. We found there was a dose-dependent reduction in virus production with ZAP expression. We further knocked down endogenous ZAP with two independent targeting siRNAs and observed a significant increase in virus production in the culture supernatant. Other delta-type retroviruses such as simian T-cell leukaemia virus and bovine leukaemia virus, also contain high CG-dinucleotide contents in their viral genomes, suggesting that ZAP-mediated suppression of viral transcripts might be a common feature of delta-type retroviruses, which cause minimal viremia in their natural hosts.ConclusionsThe post-transcriptional regulatory mechanism involving ZAP might allow HTLV-1 to maintain a delicate balance required for prolonged survival in infected individuals.

PD-1 Blockade and TLR7 Activation Lack Therapeutic Benefit in Chronic Simian Immunodeficiency Virus-Infected Macaques on Antiretroviral Therapy.

Antiretroviral therapy (ART) limits human immunodeficiency virus 1 (HIV-1) replication but does not eliminate the long-lived reservoir established shortly after viral acquisition. A successful HIV cure intervention necessitates either elimination or generation of long-term immune control of the persistent viral reservoir. Immune modulating strategies in conjunction with ART hold promise for achieving cure by inducing viral antigen expression and augmenting infected cell killing. Programmed death-1 (PD-1) blockade is a potential means to both activate and eliminate the latent reservoir by restoring exhausted T cell function. We assessed the therapeutic efficacy of PD-1 blockade, Toll-like receptor 7 (TLR7) activation with the agonist vesatolimod, or a combination of the two agents in chronically simian immunodeficiency virus (SIV)-infected macaques suppressed with ART for more than 2 years. Despite achieving extended anti-PD-1 antibody plasma exposure and TLR7-dependent immune activation after multiple administrations, neither individual treatment nor the combination resulted in changes to viral rebound kinetics following ART interruption or reduction in the SIV reservoir size. Our data in the context of other reports demonstrating improved viral control upon PD-1 blockade suggest that its therapeutic utility may be restricted to specific experimental conditions or treatment times during viral pathogenesis.

The Antimicrobial and Antiviral Activity of Polyphenols from Almond (Prunus dulcis L.) Skin.

Due to their antimicrobial and antiviral activity potential in vitro, polyphenols are gaining a lot of attention from the pharmaceutical and healthcare industries. A novel antiviral and antimicrobial approach could be based on the use of polyphenols obtained from natural sources. Here, we tested the antibacterial and antiviral effect of a mix of polyphenols present in natural almond skin (NS MIX). The antimicrobial potential was evaluated against the standard American Type Culture Collection (ATCC) and clinical strains of Staphylococcus aureus, including methicillin-resistant (MRSA) strains, by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Herpes simplex virus type I was used for the antiviral assessment of NS MIX by plaque assay. Furthermore, we evaluated the expression of viral cascade antigens. NS MIX exhibited antimicrobial (MIC values of 0.31–1.25 mg/ml) and antiviral activity (decrease in the viral titer ** p < 0.01, and viral DNA accumulation * p < 0.05) against Staphylococcus aureus and HSV-1, respectively. Amongst the isolated compounds, the aglycones epicatechin and catechin showed the greatest activity against S. aureus ATCC 6538P (MIC values of 0.078–0.15 and 0.15 mg/ml, respectively), but were not active against all the other strains. These results could be used to develop novel products for topical use.

Molecular Detection of Epstein-Barr Virus and Human Cytomegalovirus Antigen Expression in Breast Cancer in Khartoum State, Sudan 2018

Molecular Detection of Epstein-Barr Virus and Human Cytomegalovirus Antigen Expression in Breast Cancer in Khartoum State, Sudan 2018

Inhibition of H1N1 influenza virus infection by zinc oxide nanoparticles: another emerging application of nanomedicine

BackgroundCurrently available anti-influenza drugs are often associated with limitations such as toxicity and the appearance of drug-resistant strains. Therefore, there is a pressing need for the development of novel, safe and more efficient antiviral agents. In this study, we evaluated the antiviral activity of zinc oxide nanoparticles (ZnO-NPs) and PEGylated zinc oxide nanoparticles against H1N1 influenza virus.MethodsThe nanoparticles were characterized using the inductively coupled plasma mass spectrometry, x-ray diffraction analysis, and electron microscopy. MTT assay was applied to assess the cytotoxicity of the nanoparticles, and anti-influenza activity was determined by TCID50 and quantitative Real-Time PCR assays. To study the inhibitory impact of nanoparticles on the expression of viral antigens, an indirect immunofluorescence assay was also performed.ResultsPost-exposure of influenza virus with PEGylated ZnO-NPs and bare ZnO-NPs at the highest non-toxic concentrations could be led to 2.8 and 1.2 log10 TCID50 reduction in virus titer when compared to the virus control, respectively (P < 0.0001). At the highest non-toxic concentrations, the PEGylated and unPEGylated ZnO-NPs led to inhibition rates of 94.6% and 52.2%, respectively, which were calculated based on the viral loads. There was a substantial decrease in fluorescence emission intensity in viral-infected cell treated with PEGylated ZnO-NPs compared to the positive control.ConclusionsTaken together, our study indicated that PEGylated ZnO-NPs could be a novel, effective, and promising antiviral agent against H1N1 influenza virus infection, and future studies can be designed to explore the exact antiviral mechanism of these nanoparticles.

Expression of bovine leukemia virus antigen in breast cancer tissue

Breast cancer is a serious medical and social problem for most developed countries of the world. The search for new prognostic factors and targets for targeted therapy currently continues to be a pressing issue, as there are forms of breast cancer with uncertain targets for any type of therapy. The purpose of this work is to conduct an immunohistochemical study to detect and evaluate the expression of the antigen of the cow leukemia virus in the tissue of various types of breast cancer.&#x0D; Method. 100 cases of breast cancer were investigated, divided into subgroups, the studied parameters: steroid hormone receptors, HER2 / neu, VEGF, BLV expression, molecular genetic research on BRCA1/BRCA2 mutations.&#x0D; Results. In the group of triple negative breast cancer, 4 cases were detected expressing a cow leukosis virus antigen. Expression was represented by grains and clumps in the cytoplasm and on the surface of the tumor cell membrane, the wall of microvessels. Also in these cases, increased expression of VEGF was detected.&#x0D; Conclusion. The results indicate that expression of the BLV antigen was observed only in cases of poorly differentiated triple negative breast cancer. It is also noteworthy that the same type of BRCA1 gene mutation (5382insC) and increased expression of vascular endothelial growth factor were detected in these tumors. The authors first used the immunohistochemical method for detecting the antigen of the BLV virus, which made it possible to reliably confirm its presence in breast tumors with similar molecular genetic and immunohistochemical profiles.

Human Cytomegalovirus Compromises Development of Cerebral Organoids.

Congenital human cytomegalovirus (HCMV) infection causes a broad spectrum of central and peripheral nervous system disorders, ranging from microcephaly to hearing loss. These ramifications mandate the study of virus-host interactions in neural cells. Neural progenitor cells are permissive for lytic infection. We infected two induced pluripotent stem cell (iPSC) lines and found these more primitive cells to be susceptible to infection but not permissive. Differentiation of infected iPSCs induced de novo expression of viral antigens. iPSCs can be cultured in three dimensions to generate cerebral organoids, closely mimicking in vivo development. Mock- or HCMV-infected iPSCs were subjected to a cerebral organoid generation protocol. HCMV IE1 protein was detected in virus-infected organoids at 52 days postinfection. Absent a significant effect on organoid size, infection induced regions of necrosis and the presence of large vacuoles and cysts. Perhaps more in parallel with the subtler manifestations of HCMV-induced birth defects, infection dramatically altered neurological development of organoids, decreasing the number of developing and fully formed cortical structure sites, with associated changes in the architectural organization and depth of lamination within these structures, and manifesting aberrant expression of the neural marker β-tubulin III. Our observations parallel published descriptions of infected clinical samples, which often contain only sparse antigen-positive foci yet display areas of focal necrosis and cellular loss, delayed maturation, and abnormal cortical lamination. The parallels between pathologies present in clinical specimens and the highly tractable three-dimensional (3D) organoid system demonstrate the utility of this system in modeling host-virus interactions and HCMV-induced birth defects.IMPORTANCE Human cytomegalovirus (HCMV) is a leading cause of central nervous system birth defects, ranging from microcephaly to hearing impairment. Recent literature has provided descriptions of delayed and abnormal maturation of developing cortical tissue in infected clinical specimens. We have found that infected induced pluripotent stem cells can be differentiated into three-dimensional, viral protein-expressing cerebral organoids. Virus-infected organoids displayed dramatic alterations in development compared to those of mock-infected controls. Development in these organoids closely paralleled observations in HCMV-infected clinical samples. Infection induced regions of necrosis, the presence of larger vacuoles and cysts, changes in the architectural organization of cortical structures, aberrant expression of the neural marker β-tubulin III, and an overall reduction in numbers of cortical structure sites. We found clear parallels between the pathologies of clinical specimens and virus-infected organoids, demonstrating the utility of this highly tractable system for future investigations of HCMV-induced birth defects.