High DNA Load Research Articles

Moving Beyond Oxford Nanopore Standard Procedures: New Insights from Water and Multiple Fish Microbiomes

Oxford Nanopore Technology (ONT) allows for the rapid profiling of aquaculture microbiomes. However, not all the experimental and downstream methodological possibilities have been benchmarked. Here, we aimed to offer novel insights into the use of different library preparation methods (standard-RAP and native barcoding-LIG), primers (V3–V4, V1–V3, and V1–V9), and basecalling models (fast-FAST, high-HAC, and super-accuracy-SUP) implemented in ONT to elucidate the microbiota associated with the aquatic environment and farmed fish, including faeces, skin, and intestinal mucus. Microbial DNA from water and faeces samples could be amplified regardless of the library–primer strategy, but only with LIG and V1–V3/V1–V9 primers in the case of skin and intestine mucus. Low taxonomic assignment levels were favoured by the use of full-length V1–V9 primers, though in silico hybridisation revealed a lower number of potential matching sequences in the SILVA database, especially evident with the increase in Actinobacteriota in real datasets. SUP execution allowed for a higher median Phred quality (24) than FAST (11) and HAC (17), but its execution time (6–8 h) was higher in comparison to the other models (0.6–7 h). Altogether, we optimised the use of ONT for water- and fish-related microbial analyses, validating, for the first time, the use of the LIG strategy. We consider that LIG–V1–V9-HAC is the optimal time/cost-effective option to amplify the microbial DNA from environmental samples. However, the use of V1–V3 could help to maximise the dataset microbiome diversity, representing an alternative when long amplicon sequences become compromised by microbial DNA quality and/or high host DNA loads interfere with the PCR amplification/sequencing procedures, especially in the case of gut mucus.

BK Polyomavirus DNAemia With a High DNA Load Is Associated With De Novo Donor-Specific HLA Antibodies in Kidney Transplant Recipients.

BK polyomavirus-associated nephropathy (BKPyVAN) is a well-known complication of kidney transplantation (KTx). The mainstay of prevention is the reduction of immunosuppression upon detection of BK polyomavirus (BKPyV) DNAemia, which precedes BKPyVAN. However, this reduction may inadvertently increase the risk of alloimmunity particularly in patients with a high BKPyV DNA load, where significant immunosuppression reduction is often necessary. This single-center, retrospective cohort study assesses the risk of de novo donor-specific antibodies (dnDSA) development and biopsy-proven acute rejection (BPAR) following high and low BKPyV DNAemia. All patients who underwent KTx at Leiden University Medical Center between 2011 and 2020 were included. Patients were grouped according to high (maximum BKPyV DNA load > 4log10 copies/mL), low (maximum serum BKPyV DNA load ≤ 10E4 copies/mL), and absent BKPyV DNAemia, and analyzed for the development of dnDSA and BPAR, using Cox regression. Of 1076 KTx recipients included, 108 (10%) developed a BKPyV DNAemia with a maximum DNA load below 4log10 copies/mL, whereas 121 (11.2%) developed a BKPyV DNAemia exceeding 4log10 copies/mL. The risk of dnDSA development was higher in patients with a high BKPyV DNAemia, compared to patients without DNAemia (adjusted hazard ratio of 1.9 (95% CI 1.1-3.2, p = 0.017). No significant difference in dnDSA risk was observed between patients with low and absent BKPyV DNAemia. Risk of BPAR did not differ between groups. Our study shows that higher BKPyV DNA loads in KTx patients are associated with a higher risk for dnDSA development, highlighting the importance of exploring additional strategies for the prevention and treatment of BKPyV infections in KTx recipients.

Unraveling the role of hepatitis B virus DNA integration in B-cell lymphomagenesis.

Studies have shown that hepatitis B virus (HBV)-associated B-cell non-Hodgkin lymphoma (NHL) constitutes a unique subgroup with distinct clinical features. It still leaves open the question of whether the integration of HBV DNA into the B-cell genome is a causal mechanism in the development of lymphoma. Using the hybridisation capture-based next generation sequencing and RNA sequencing, we characterised the HBV integration pattern in 45 HBV-associated B-cell NHL tumour tissues. A total of 354 HBV integration sites were identified in 13 (28.9%) samples, indicating the relatively low integration frequency in B-cell NHLs. High plasma HBV DNA loads were not associated with the existence of HBV integration. The insertion sites distributed randomly across all the lymphoma genome without any preferential hotspot neither at the chromosomal level nor at the genetic level. Intriguingly, most HBV integrations were nonclonal in B-cell NHLs, implying that they did not confer a survival advantage. Analysis of the paired diagnosis-relapse samples showed the unstable status of HBV integrations during disease progression. Furthermore, transcriptomic analysis revealed the limited biological impact of HBV integration. Our study provides an unbiased HBV integration map in B-cell NHLs, revealing the insignificant role of HBV DNA integration in B-cell lymphomagenesis.

The plasma EBV DNA load with IL-6 and VEGF levels as predictive and prognostic biomarker in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is often diagnosed at a very advanced stage due to its location and non-specific initial symptoms. Moreover, no clinically useful serological marker has been established so far for early detection of NPC. In this study, we have investigated the clinical significance of plasma Epstein–Barr virus DNA load along with interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) levels to evaluate if these three all together can be useful as a strong serological marker for early detection and prediction of treatment response in patients with NPC. Plasma EBV DNA load, IL-6 level, VEGF expressions were measured in 24 patients with NPC at presentation and various time points during and after treatment. There was a positive correlation between high plasma EBV DNA load with higher IL-6 and VEGF expression, which was closely associated with therapeutic response as well. Persistent or recurrent plasma EBV load with higher IL-6 and VEGF levels can potentially predict disease progression and may be useful to select patients for additional therapy and longer follow-up.

Dual stimuli-responsive upconversion nanoparticle-poly-N-isopropylacrylamide/DNA core-shell microgels.

Stimuli-responsive upconversion nanoparticle (UCNP)-poly-N-isopropylacrylamide (pNIPAM)/DNA core-shell microgels with tunable sizes and programmable functions have been prepared. Thanks to the near-infrared (NIR)-responsive UCNP cores and thermosensitive polymeric shells, functional DNA-incorporated microgels with high DNA activity and loading efficiency are obtained, and the activity of the loaded DNA structures can be smartly regulated by NIR illumination and temperature simultaneously.

Efficacy of combined antiretroviral therapy (cART) in Hepatitis B and C associated hepatocellular carcinoma (HCC): a narrative review

Introduction: HCC is the 3rd leading cancers in the world. Majority of HCC are due to chronic viral hepatitis including HBV, HCV, and HDV. Progression to cirrhosis and HCC in HBV and HCV infection is linked to level of replication and high serum viral DNA load. The use of antiviral agents is an effective strategy of treating HBV- and HCV- associated HCC. Aim: To assess the effectiveness of combined antiretroviral therapy on HBV and HCV-associated HCC Method: A narrative review of literature involving RCT and observational studies was performed. Blinding scores was used to evaluate the quality of the studies. This review was informed by one of the author’s experience with hepatitis virus in Africa. Discussion: The five studies were found to be useful in reducing viral load and improving the pathology of HBV- and HCV- associated cirrhosis, HCC, and decompensated liver disease. The combinations are sofosbuvir plus ledipasvir, declatasvir plus asunaprevir, grazoprevir plus elbasvir with or without ribavirin, ombitasvir, paritaprevir, ritonavir plus ribavirin, sofosbuvir plus ribavirin. However, resistance to either drug or both is a problem that needs to be addressed.

Comparative analysis of clinicopathologic characteristics and prognosis between nasal and nonnasal extranodal NK/T-cell lymphoma.

The clinicopathologic characteristics and prognosis of nasal and nonnasal extranodal natural killer T-cell lymphoma (ENKTL) are considered to be different. However, the underlying features responsible for these differences are not well clarified especially in the era of asparaginase therapy. In total, 1007 newly diagnosed ENKTL patients from 11 medical centers were included in this study. Clinicopathologic characteristics and survival data were collected. The chi-squared test and Kruskal-Wallis test were utilized for the comparison of different groups. Univariable and multivariable Cox proportional hazards models were used to screen prognostic factors. Overall, 869 (86.3%) patients were nasal forms. Compared to patients with nasal ENKTL, nonnasal patients were at more advanced stages and had poor performance status, bone marrow involvement, elevated serum lactate dehydrogenase (LDH), and CD56-negative status (p < 0.05). The 5-year overall survival (OS) for nasal and nonnasal patients were 65.6% and 45.0%, respectively. The OS of nasal forms patients were superior to nonnasal patients, especially in Eastern Cooperative Oncology Group performance status (ECOG PS) (≥2), advanced stage, KPI (HIR/HR), IPI (HIR/HR), PINK (HR), and high EBV DNA load groups. In patients treated with pegaspargase/L-asparaginase-based regimens, the OS of nasal patients was better than that of nonnasal patients. After adjusting the covariates of age, stage, ECOG PS score, LDH, B symptoms, and BM involvement, results showed that the nonnasal site was associated with poor survival of ENKTL. The clinicopathologic characteristics and prognosis of nasal and nonnasal ENKTL patients are different. Nasal forms patients had superior OS than nonnasal patients, especially in the era of asparaginase.

The Dynamic Change in Plasma Epstein-Barr Virus DNA Load over a Long-Term Follow-Up Period Predicts Prognosis in Nasopharyngeal Carcinoma.

The current study was designed to investigate the changes in the circulating Epstein-Barr virus DNA load (EBV DNA) at various time points before and after treatment and its clinical significance in nasopharyngeal carcinoma (NPC). A total of 142 patients with NPC were prospectively enrolled in this study. The plasma EBV DNA concentration was measured before and after treatment using qPCR. The prognostic values of the EBV DNA load were analyzed using the Kaplan-Meier and Cox regression tests. Following multivariate analysis, our data showed that high pre-EBV DNA loads were associated with significantly poorer distant metastasis free survival (DMFS) and progression free survival (PFS); detectable end-EBV DNA loads were associated with significantly worse loco-regional recurrence free survival (LRRFS) and PFS, and the detecTable 6 months-post-EBV DNA loads were associated with significantly poorer overall survival (OS), DMFS and PFS (p &lt; 0.05). Additionally, combining the pre-EBV DNA load and the stage of the disease, our results showed that patients at stage III-IVA with a low pre-EBV DNA load had similar survival rates as patients at stage II with a low or high pre-EBV DNA load, but had better survival rates than those at stage III-IVA with a high pre-EBV DNA load. Taken together, we showed that the change of the EBV DNA load measured at several time points was more valuable than at any single time point for predicting patients' survival for NPC. Furthermore, combining the pre-EBV DNA load and the TNM classification could help to formulate an improved prognostic model for this cancer.

Functionalized photosensitive metal-organic framework as a theranostic nanoplatform for turn-on detection of MicroRNA and photodynamic therapy

Developing a theranostic platform integrating precise diagnostic and efficient treatment is significant but challenging. Here, we reported a new theranostic platform - hairpin probe - photosensitizing MOFs (HPMOF) composed of photosensitizing MOFs (PMOFs) and hairpin probes labeled with fluorophore and quencher, in which PMOF played the role of photosensitizer and nanocarrier of the hairpin probe. The HPMOF was covered with a layer of ZIF-8 to achieve the dual-layered nanotheranostics (HPMOF@ZIF-8). The HPMOF@ZIF-8 achieved high DNA loading capacity and intracellular delivery for tumor-related miRNA imaging. Moreover, HPMOF@ZIF-8 could generate reactive oxygen species with high efficiency, which induced cell apoptosis, leading to efficient photodynamic therapy. Due to the different expression of miRNA between normal cells and cancer cells, the HPMOF@ZIF-8 could recognize cancer cells through imaging of miRNA, leading to more accurate treatment of cancer, providing a promising theranostic nanoplatform.

DNA Nanostructure-Guided Plasmon Coupling Architectures

DNA Nanostructure-Guided Plasmon Coupling Architectures

Effect of infection with hepatitis B virus on the survival outcome of diffuse large B-cell lymphoma in the prophylactic antiviral era.

Patients with lymphoma who are also infected with Hepatitis B virus (HBV) have a poor prognosis. This could be partly explained by the delay or premature termination of anti-tumor treatment because of HBV reactivation. However, there is limited data on the survival outcome of patients HBV-related lymphoma in the era of prophylactic antivirals. Data for 128 patients with HBV surface antigen-positive diffuse large B-cell lymphoma was collected. The median age was 54 years and the ratio of men to women was 1.2:1. All patients received immune-chemotherapy and prophylactic antiviral therapy. The median number of cycles of immune-chemotherapy was six. The overall response rate was 82%, with a complete remission rate of 75%. With a median follow-up of 58.4 months, the 5-year progression-free survival and overall survival rates were 75.7% and 74.7%, respectively. Nine patients experienced HBV reactivation but none experienced HBV-associated hepatitis. Patients with low and high HBV DNA loads had comparable survival outcomes. In conclusion, HBV infection had no negative effect on the prognosis of DLBCL in the era of prophylactic antiviral therapy.

Quantitative assessment of viral load in the blood and urine of patients with congenital cytomegalovirus infection using droplet digital PCR.

Congenital cytomegalovirus infection (cCMV) is a common cause of congenital infections, leading to neurodevelopmental sequelae. Real-time quantitative polymerase chain reaction (qPCR) has been widely used for the diagnosis and assessment of cCMV; however, the correlation between CMV DNA load and the severity of cCMV symptoms has been inconclusive. Droplet digital PCR (ddPCR) offers an improvement over the current qPCR methods through the absolute quantification of viral loads. We compared ddPCR and qPCR results for the quantification of CMV DNA in blood and urine specimens from 39 neonates with cCMV (21 symptomatic and 18 asymptomatic). There was no significant difference in blood CMV DNA loads measured by ddPCR and qPCR, with or without any clinical findings. However, developmental delays at 36 months were significantly more frequently observed in patients with high CMV DNA loads (≥2950 copies/ml), as measured by ddPCR at diagnosis, than in those with lower CMV DNA loads. The association of urine CMV DNA load with symptoms and developmental delay was not observed. CMV DNA loads in the blood might be used as a predictor of developmental outcomes in cCMV patients, and absolute quantitation of viral loads by ddPCR assay could contribute to the standardization of CMV load measurement.

Occurrence of Chlamydiae in Corvids in Northeast Italy.

Simple SummaryThe continuous improvement of next-generation sequencing techniques has led to an expansion of the number of Chlamydia species, as well as their host range. Recent studies performed on wild birds have detected Chlamydia strains with characteristics intermediate between Chlamydia psittaci and Chlamydia abortus. In this study, 12/108 corvids tested positive for Chlamydia by real-time PCR. Molecular characterisation at the species level was possible for eight samples, with one positive for C. psittaci and seven for C. abortus. Considering the well-known zoonotic role of C. psittaci and that a potential zoonotic role of avian C. abortus strains cannot be excluded, people who may have professional or other contact with wild birds should take appropriate preventive measures.Chlamydiaceae occurrence has been largely evaluated in wildlife, showing that wild birds are efficient reservoirs for avian chlamydiosis. In this study, DNA extracted from cloacal swabs of 108 corvids from Northeast Italy was screened for Chlamydiaceae by 23S real-time (rt)PCR. The positive samples were characterised by specific rtPCRs for Chlamydia psittaci, Chlamydia abortus, Chlamydia gallinacea, Chlamydia avium, Chlamydia pecorum and Chlamydia suis. Cloacal shedding of Chlamydiaceae was detected in 12 out of 108 (11.1%, 5.9%–18.6% 95% CI) corvids sampled. Molecular characterisation at the species level was possible in 8/12 samples, showing C. psittaci positivity in only one sample from a hooded crow and C. abortus positivity in seven samples, two from Eurasian magpies and five from hooded crows. Genotyping of the C. psittaci-positive sample was undertaken via PCR/high-resolution melting, clustering it in group III_pigeon, corresponding to the B genotype based on former ompA analysis. For C. abortus genotyping, multilocus sequence typing was successfully performed on the two samples with high DNA load from Eurasian magpies, highlighting 100% identity with the recently reported Polish avian C. abortus genotype 1V strain 15-58d44. To confirm the intermediate characteristics between C. psittaci and C. abortus, both samples, as well as two samples from hooded crows, showed the chlamydial plasmid inherent in most C. psittaci and avian C. abortus, but not in ruminant C. abortus strains. The plasmid sequences were highly similar (≥99%) to those of the Polish avian C. abortus genotype 1V strain 15-58d44. To our knowledge, this is the first report of avian C. abortus strains in Italy, specifically genotype 1V, confirming that they are actively circulating in corvids in the Italian region tested.

REPEATED SAMPLING OF WILD INDIVIDUALS REVEALS OPHIDIOMYCES OPHIDIICOLA INFECTION DYNAMICS IN A PENNSYLVANIA SNAKE ASSEMBLAGE.

Ophidiomyces ophidiicola is an emerging fungal pathogen associated with infections in snakes across North America. Although documented in Pennsylvania, O. ophidiicola has not been found at Powdermill Nature Reserve (PNR) in southwestern Pennsylvania, where the snake assemblage has been studied since 2002 and several species have recently declined. We surveyed for O. ophidiicola and putative ophidiomycosis at PNR. We screened five species of free-ranging, wild snakes (n=34) for suspected ophidiomycosis by visually checking for dermatitis and swabbing for the presence of O. ophidiicola DNA. We found a moderate prevalence of snakes with skin lesions (n=15) but a low prevalence of snakes with O. ophidiicola DNA in traditional PCR assays (n=2). Both positive snakes belonged to the same species and only one presented with lesions. When quantitative PCR screens were performed on duplicate swabs, 19 snakes were positive for O. ophidiicola DNA, with positive individuals in two species. Mark-recapture methods revealed seasonal variability in disease dynamics for sampled snakes. One individual presented with less than five skin lesions and tested negative in May 2020, had more than five lesions with a high fungal DNA load in June 2020, and no lesions with a low fungal DNA load in July 2020. We also found that snakes sampled from under the same cover object at the same time either all tested positive or all negative, including one instance involving two species. Our results underscore the value of using multiple screening techniques for O. ophidiicola surveillance and repeated sampling of individuals to understand the dynamics of ophidiomycosis in wild populations as compared to single method and single timepoint approaches.

Chitosan-Crosslinked Low Molecular Weight PEI-Conjugated Iron Oxide Nanoparticle for Safe and Effective DNA Delivery to Breast Cancer Cells.

Breast cancer has attracted tremendous research interest in treatment development as one of the major threats to public health. The use of non-viral carriers for therapeutic DNA delivery has shown promise in treating various cancer types, including breast cancer, due to their high DNA loading capacity, high cell transfection efficiency, and design versatility. However, cytotoxicity and large sizes of non-viral DNA carriers often raise safety concerns and hinder their applications in the clinic. Here we report the development of a novel nanoparticle formulation (termed NP-Chi-xPEI) that can safely and effectively deliver DNA into breast cancer cells for successful transfection. The nanoparticle is composed of an iron oxide core coated with low molecular weight (800 Da) polyethyleneimine crosslinked with chitosan via biodegradable disulfide bonds. The NP-Chi-xPEI can condense DNA into a small nanoparticle with the overall size of less than 100 nm and offer full DNA protection. Its biodegradable coating of small-molecular weight xPEI and mildly positive surface charge confer extra biocompatibility. NP-Chi-xPEI-mediated DNA delivery was shown to achieve high transfection efficiency across multiple breast cancer cell lines with significantly lower cytotoxicity as compared to the commercial transfection agent Lipofectamine 3000. With demonstrated favorable physicochemical properties and functionality, NP-Chi-xPEI may serve as a reliable vehicle to deliver DNA to breast cancer cells.

Application of hepatitis B immunoglobulin in prevention of mother-to-child transmission of chronic hepatitis B in HBsAg- and HBeAg-positive mother

The aim of our study was to compare the efficacy of two dosages of hepatitis B immunoglobulin (HBIG) combined with HBV vaccine (HBVac) to prevent mother-to-child transmission (MTCT) of hepatitis B in HBsAg- and HBeAg-positive mother. We enrolled 331 mother-infant pairs with HBsAg- and HBeAg-positive maternal state from the Women’s Hospital School of Medicine of Zhejiang University. Newborns were randomly distributed into two groups according to the dosages of HBIG injection: 100 IU and 200 IU. Newborns from both groups were injected with HBVac in the same doses. We compared the immune outcomes between the two groups and explore the influencing factors of immune outcomes through regression analysis. There was no statistically significant relationship between HBsAg serological transmission of newborns and dosages of HBIG in HBsAg- and HBeAg-positive mother (p > .05). The Logistic regression showed that high DNA load is a risk factor for passive-active immunoprophylaxis failure for both 100 IU and 200 IU group, but higher-dosage HBIG is not necessary for higher-viral-load pregnant women with HBsAg- and HBeAg-positive. In conclusion, combined application of HBVac and a single dose of 100 IU HBIG can achieve the ideal MTCT interruption results for HBsAg- and HBeAg-positive pregnant women. IMPACT STATEMENT What is already known on this subject? Passive-active immunoprophylaxis is proved to be effective in preventing mother-to-child transmission of hepatitis B. Hepatitis B vaccine combined with 100 IU or 200 IU immunoglobulin is mostly recommended in China. What do the results of this study add? At present, there is still a lack scientific basis for improving existing strategies and measures to prevent mother-to-child transmission of hepatitis B in China. What are the implications of these findings for clinical practice and/or further research? 100 IU and 200 IU immunoglobulin show equivalent blocking effect, and combined use of hepatitis B vaccine and 100 IU immunoglobulin is more cost-effective.

Controlled DNA Delivery Using Poly(lactide) Nanoparticles and Understanding the Binding Interactions.

Cationic polymer-based gene delivery vectors suffer from several limitations such as low DNA-loading capacity, poor transfection, toxicity, environmental degradations, etc. Again, very limited works are available addressing the binding interactions in detail at the atomic level explaining the loading capacity, protection ability against harsh environments, and controlled release behavior of the DNA-encapsulated vehicles. Here, a poly(l-lactide) (PLA) nanoparticle-based controlled DNA release system is proposed. The developed vehicle possesses a high DNA-loading capacity and can release the loaded DNA in a controlled manner. Spectroscopic, physicochemical, and molecular simulation techniques (AM1 and atomistic molecular dynamics) have been employed to understand the binding interactions between PLA and DNA molecules enabling high DNA loading, protection against external harsh environments, and controlled DNA release behavior. Methyl thiazolyl tetrazolium (MTT) assay experiments confirm the biocompatible nature of the vehicle. Cellular uptake efficiency and endo-lysosomal escape capabilities have been investigated against HeLA cells. This study, therefore, demonstrates the development of a promising nonviral DNA delivery vector and includes a detailed investigation of the atomic-level interaction behavior between PLA and DNA molecules.

Hydroa vacciniforme‐like lymphoproliferative disorder: A clinicopathological, immunohistochemical, and prognostic study of 24 cases in China

Hydroa vacciniforme‐like lymphoproliferative disorder (HV‐LPD) is a rare cutaneous disease associated with Epstein–Barr virus infection. We retrospectively analyzed the clinical presentation, histopathological characteristics, and prognostic study of HV‐LPD in 24 Chinese patients. All patients presented with recurrent papulovesicular and necrotic eruptions on the face, neck, and extremities, with 11 showing systemic symptoms. Twenty patients were diagnosed with HV‐LPD in childhood (age < 18 years) and four in adulthood (age ≥ 18 years). The median age at diagnosis was 8.5 years old (range, 2–50). Histopathology revealed variably dense lymphocyte infiltration throughout the dermis. All cases were strongly positive for CD3 and Epstein–Barr encoding region based on in situ hybridization. Of 18 cases with a T‐cell phenotype, 15 harbored monoclonal rearrangements in T‐cell receptor (TCR) genes. Four cases with a natural killer cell phenotype carried polyclonal rearrangements in TCR genes. Among 24 patients, eight (33.3%) received chemotherapy, two (8.3%) allogeneic hematopoietic stem cell transplantation, and both are currently alive without disease. The median follow‐up period was 24 months (range, 7–120) and 23 patients were available: 15 (62.5%) were alive, and eight (33.3%) had died. Fourteen cases had a relapse of disease and three developed lymphoma within 24 months of diagnosis. The mean survival time of childhood‐onset patients was longer than that of adult‐onset patients (36.4 vs. 20.8 months). In summary, the wide clinical course and representative presentation of cases in our center reflect the pedigree characteristics of HV‐LPD. Allogeneic hematopoietic stem cell transplantation should be a preferred choice for relapse and refractory patients due to the poor effect of chemotherapy. Adult‐onset and high serum EBV DNA loads may indicate an increased risk of aggressive disease in patients with HV‐LPD.

Association of an IFN-γ variant with susceptibility to chronic hepatitis B by the enhancement of HBV DNA replication

Interferon gamma (IFN-γ) is a crucial cytokine in host immune response to hepatitis B virus (HBV) infection. This study aimed to determine whether a functional polymorphism +874T/A in IFN-γ gene linked to high and low producer phenotypes [IFN-γ (+874Thigh → Alow)] may alter the outcomes of chronic HBV infection in Tunisian population.The +874T/A was analysed by ARMS-PCR method in the group of 200 patients chronically infected with HBV and 200 healthy controls.We observed that minor +874A allele, minor +874AA and +874TA genotypes were significantly more frequent in the chronic hepatitis B group in comparison to the control group [49 vs. 31%, P < 10−4; 24 vs. 13%, P < 10−4; 52 vs. 38%, P < 10−4; respectively]. Besides, they were associated with susceptibility to hepatitis B infection [OR = 2.15, 3.87 and 2.84, respectively].The minor +874A allele and +874AA genotype were statistically more representative in the sub-group of patients with high viral DNA load when compared with the sub-group of patients with low HBV DNA load [(57% vs. 43%, P = 0.003, OR = 1.79); (33% vs. 14%, P = 0.003, OR = 3.59), respectively].Collectively, our study suggests an association between the IFN-γ +874T/A SNP and persistence of HBV by the enhancement of HBV DNA replication.

Experimental infection of indigenous North African goats with goatpox virus

BackgroundGoatpox is a viral disease caused by infection with goatpox virus (GTPV) of the genus Capripoxvirus, Poxviridae family. Capripoxviruses cause serious disease to livestock and contribute to huge economic losses. Goatpox and sheeppox are endemic to Africa, particularly north of the Equator, the Middle East and many parts of Asia. GTPV and sheeppox virus are considered host-specific; however, both strains can cause clinical disease in either goats or sheep with more severe disease in the homologous species and mild or sub-clinical infection in the other. Goatpox has never been reported in Morocco, Algeria or Tunisia despite the huge population of goats living in proximity with sheep in those countries. To evaluate the susceptibility and pathogenicity of indigenous North African goats to GTPV infection, we experimentally inoculated eight locally bred goats with a virulent Vietnamese isolate of GTPV. Two uninfected goats were kept as controls. Clinical examination was carried out daily and blood was sampled for virology and for investigating the antibody response. After necropsy, tissues were collected and assessed for viral DNA using real-time PCR.ResultsFollowing the experimental infection, all inoculated goats displayed clinical signs characteristic of goatpox including varying degrees of hyperthermia, loss of appetite, inactivity and cutaneous lesions. The infection severely affected three of the infected animals while moderate to mild disease was noticed in the remaining goats. A high antibody response was developed. High viral DNA loads were detected in skin crusts and nodules, and subcutaneous tissue at the injection site with cycle threshold (Ct) values ranging from 14.6 to 22.9, while lower viral loads were found in liver and lung (Ct = 35.7 and 35.1). The results confirmed subcutaneous tropism of the virus.ConclusionClinical signs of goatpox were reproduced in indigenous North African goats and confirmed a high susceptibility of the North African goat breed to GTPV infection. A clinical scoring system is proposed that can be applied in GTPV vaccine efficacy studies.