Host proteins interact with viral elements and affect the life cycle of highly pathogenic avian influenza A virus H7N9.

Host-virus interactions can significantly impact the viral life cycle and pathogenesis; however, our understanding of the specific host factors involved in highly pathogenic avian influenza A virus H7N9 (HPAI H7N9) infection is currently restricted. Herein, we designed and synthesized 65 small interfering RNAs targeting host genes potentially associated with various aspects of RNA virus life cycles. Afterward, HPAI H7N9 viruses were isolated and RNA interference was used to screen for host factors likely to be involved in the life cycle of HPAI H7N9. Moreover, the research entailed assessing the associations between host proteins and HPAI H7N9 proteins. Twelve key host proteins were identified: Annexin A (ANXA)2, ANXA5, adaptor related protein complex 2 subunit sigma 1 (AP2S1), adaptor related protein complex 3 subunit sigma 1 (AP3S1), ATP synthase F1 subunit alpha (ATP5A1), COPI coat complex subunit alpha (COP)A, COPG1, heat shock protein family A (Hsp70) member 1A (HSPA)1A, HSPA8, heat shock protein 90 alpha family class A member 1 (HSP90AA1), RAB11B, and RAB18. Co-immunoprecipitation revealed intricate interactions between viral proteins (hemagglutinin, matrix 1 protein, neuraminidase, nucleoprotein, polymerase basic 1, and polymerase basic 2) and these host proteins, presumably playing a crucial role in modulating the life cycle of HPAI H7N9. Notably, ANXA5, AP2S1, AP3S1, ATP5A1, HSP90A1, and RAB18, were identified as novel interactors with HPAI H7N9 proteins rather than other influenza A viruses (IAVs). These findings underscore the significance of host-viral protein interactions in shaping the dynamics of HPAI H7N9 infection, while highlighting subtle variations compared with other IAVs. Deeper understanding of these interactions holds promise to advance disease treatment and prevention strategies.

Integrated fixed-film activated sludge systems in continuous-flow and batch mode acclimated from low to high aniline concentrations: Performance, mechanism and metabolic pathways.

Integrated fixed-film activated sludge (IFAS) system has considerable advantages in treating aniline wastewater economically and efficiently. However, the response mechanism of IFAS to aniline needs further study. Herein, IFAS in continuous-flow (CF-IFAS) and batch mode (B-IFAS) were set up to investigate it. The removal efficiency of aniline exceeded 99% under different stress intensities. At low stress intensity (aniline ≈ 200 mg/L), the total nitrogen removal efficiency of B-IFAS was approximately 37.76% higher than CF-IFAS. When the stress intensity increased (aniline ≥ 400 mg/L), both were over 82%. CF-IFAS was restrained by denitrification while nitrification in B-IFAS. The legacy effect of perturbation of B-IFAS made microflora quickly reach new stability. The closer interspecific relationship in B-IFAS and more key species: Leucobacter, Rhodococcus, Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, Ellin6067 and norank_f_NS9_marine_group. Metabolic and Cell growth and death were the most abundant metabolic pathways, resulting both systems the excellent pollutant removal and stability under high stress intensity.

Development of a multi-recombinase polymerase amplification assay for rapid identification of COVID-19, influenza A and B.

The coronavirus disease 2019 (COVID-19) pandemic caused extensive loss of life worldwide. Further, the COVID-19 and influenza mix-infection had caused great distress to the diagnosis of the disease. To control illness progression and limit viral spread within the population, a real-time reverse-transcription PCR (RT-PCR) assay for early diagnosis of COVID-19 was developed, but detection was time-consuming (4-6 h). To improve the diagnosis of COVID-19 and influenza, we herein developed a recombinase polymerase amplification (RPA) method for simple and rapid amplification of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19 and Influenza A (H1N1, H3N2) and B (influenza B). Genes encoding the matrix protein (M) for H1N1, and the hemagglutinin (HA) for H3N2, and the polymerase A (PA) for Influenza B, and the nucleocapsid protein (N), the RNA-dependent-RNA polymerase (RdRP) in the open reading frame 1ab (ORF1ab) region, and the envelope protein (E) for SARS-CoV-2 were selected, and specific primers were designed. We validated our method using SARS-CoV-2, H1N1, H3N2 and influenza B plasmid standards and RNA samples extracted from COVID-19 and Influenza A/B (RT-PCR-verified) positive patients. The method could detect SARS-CoV-2 plasmid standard DNA quantitatively between 102 and 105 copies/ml with a log linearity of 0.99 in 22 min. And this method also be very effective in simultaneous detection of H1N1, H3N2 and influenza B. Clinical validation of 100 cases revealed a sensitivity of 100% for differentiating COVID-19 patients from healthy controls when the specificity was set at 90%. These results demonstrate that this nucleic acid testing method is advantageous compared with traditional PCR and other isothermal nucleic acid amplification methods in terms of time and portability. This method could potentially be used for detection of SARS-CoV-2, H1N1, H3N2 and influenza B, and adapted for point-of-care (POC) detection of a broad range of infectious pathogens in resource-limited settings.

The viral distribution and pathological characteristics of BALB/c mice infected with highly pathogenic Influenza H7N9 virus.

BACKGROUND: The highly pathogenic Influenza H7N9 virus is believed to cause multiple organ infections. However, there have been few systematic animal experiments demonstrating the virus distribution after H7N9 virus infection. The present study was carried out to investigate the viral distribution and pathological changes in the main organs of mice after experimental infection with highly pathogenic H7N9 virus. METHODS: Infection of mice with A/Guangdong/GZ8H002/2017(H7N9) virus was achieved via nasal inoculation. Mice were killed at 2, 3, and 7 days post infection. The other mice were used to observe their illness status and weight changes. Reverse transcription polymerase chain reaction and viral isolation were used to analyse the characteristics of viral invasion. The pathological changes of the main organs were observed using haematoxylin and eosin staining and immunohistochemistry. RESULTS: The weight of H7N9 virus-infected mice increased slightly in the first two days. However, the weight of the mice decreased sharply in the following days, by up to 20%. All the mice had died by the 8th day post infection and showed multiple organ injury. The emergence of viremia in mice was synchronous with lung infection. On the third day post infection, except in the brain, the virus could be isolated from all organs (lung, heart, kidney, liver, and spleen). On the seventh day post infection, the virus could be detected in all six organs. Brain infection was detected in all mice, and the viral titre in the heart, kidney, and spleen infection was high. CONCLUSION: Acute diffuse lung injury was the initial pathogenesis in highly pathogenic H7N9 virus infection. In addition to lung infection and viremia, the highly pathogenic H7N9 virus could cause multiple organ infection and injury.

Highly pathogenic H7N9 avian influenza virus infection associated with up-regulation of PD-1/PD-Ls pathway-related molecules.

To investigate the main transcriptional and biological changes of human host during low and highly pathogenic avian H7N9 influenza virus infection and to analyze the possible causes of escalated virulence and the systematic progression of H7N9 virus infection, we utilized whole transcriptome sequencing (RNA-chip and RNA-seq) and other biomolecular methods to analyze and verify remarkable changes of host cells during these two subtypes of H7N9 influenza viruses infection. Whole transcriptome analysis showed the global profiles of differentially expressed genes (DEGs) and identified 458 DEGs associated with major changes in biological processes of the host cells after infection with 2017 HPAI H7N9 virus versus 2013 LPAI H7N9 virus, mainly including drastically increased defense responses to viruses (e.g. negative regulation of viral gene replication), IFNs related pathways, immune response/native immune response, and inflammatory response. Genes of programmed cell death 1 (PD-1) pathways were found changed remarkably and several highly correlated non-coding RNAs were identified. The results suggested that HPAI H7N9 virus induces stronger immune response and suppressing response than LPAI H7N9. Meanwhile, PD-1/PD-Ls signaling pathways work together in regulating host responses including antiviral defense, lethal inflammation caused by the virus and immune response, thus contribute to the high pathogenicity of 2017H7N9 virus that can be regulated by non-coding RNAs. The present study represents a comprehensive understanding and good reference of regulation of pathogenicity of H7N9 virus even other fatal viruses and correlated host immune responses.

Novel pathogenic characteristics of highly pathogenic avian influenza virus H7N9: viraemia and extrapulmonary infection.

The H7N9 virus mutated in 2017, resulting in new cases of highly pathogenic avian influenza (HPAI) H7N9 virus infection. H7N9 was found in a viraemic patient in Guangdong province, China. The present study aimed to clarify the pathogenic characteristics of HPAI H7N9. Virus was isolated from the plasma and sputum of the patient with HPAI H7N9. Liquid phase chip technology was used to detect the plasma cytokines from the infected patient and healthy controls. Mice were infected with strains A/Guangdong/GZ8H002/2017(H7N9) and A/Zhejiang/DTID-ZJU01/2013(H7N9) to observe the virus's pathogenic characteristics. Serum and brain tissue were collected at 2, 4, and 6 days after infection. The viruses in serum and brain tissue were detected and isolated. The two strains were infected into A549 cells, exosomes were extracted, and virus genes in the exosomes were assessed. Live virus was isolated from the patient's plasma. An acute cytokine storm was detected during the whole course of the disease. In animal experiments, A/Guangdong/GZ8H002/2017(H7N9) was more pathogenic than A/Zhejiang /DTID-ZJU01/2013(H7N9) and resulted in the death of mice. Live virus was isolated from infected mouse serum. Virus infection was also detected in the brain of mice. Under viral stress, A549 cells secreted exosomes containing the entire viral genome. The viraemic patient was confirmed to have an HPAI H7N9 infection. A/Guangdong/GZ8H002/2017(H7N9) showed significantly enhanced toxicity. Patient deaths might result from cytokine storms and brain infections. Extrapulmonary tissue infection might occur via the exosome pathway. The determined pathogenic characteristics of HPAI H7N9 will contribute to its future treatment.

Increased expression of BCL11B and its recruited chromatin remodeling factors during highly active antiretroviral therapy synergistically represses the transcription of human immunodeficiency virus type 1 and is associated with residual immune activation.

Persistence of human immunodeficiency virus 1 (HIV-1) latency and residual immune activation remain major barriers to treatment in patients receiving highly active antiretroviral therapy (HAART). In the present study, we investigated the molecular mechanisms of persistent HIV infection and residual immune activation in HAART-treated patients. We showed that the expression level of B-cell CLL/lymphoma 11B (BCL11B) was significantly increased in CD4+T cells from HIV-infected patients undergoing HAART, and this was accompanied by increased expression of BCL11B-associated chromatin modifiers and inflammatory factors in comparison to healthy controls and untreated patients with HIV. In vitro assays showed that BCL11B significantly inhibited HIV-1 long terminal repeat (LTR)-mediated transcription. Knockdown of BCL11B resulted in the activation of HIV latent cells, and dissociation of BCL11B and its related chromatin remodeling factors from the HIV LTR. Our findings suggested that increased expression of BCL11B and its related chromatin modifiers contribute to HIV-1 transcriptional silencing, and alteration of BCL11B levels might lead to abnormal transcription and inflammation.

Molecular Characteristics, Functions, and Related Pathogenicity of MERS-CoV Proteins.

Middle East respiratory syndrome (MERS) is a viral respiratory disease caused by a de novo coronavirus-MERS-CoV-that is associated with high mortality. However, the mechanism by which MERS-CoV infects humans remains unclear. To date, there is no effective vaccine or antibody for human immunity and treatment, other than the safety and tolerability of the fully human polyclonal Immunoglobulin G (IgG) antibody (SAB-301) as a putative therapeutic agent specific for MERS. Although rapid diagnostic and public health measures are currently being implemented, new cases of MERS-CoV infection are still being reported. Therefore, various effective measures should be taken to prevent the serious impact of similar epidemics in the future. Further investigation of the epidemiology and pathogenesis of the virus, as well as the development of effective therapeutic and prophylactic anti-MERS-CoV infections, is necessary. For this purpose, detailed information on MERS-CoV proteins is needed. In this review, we describe the major structural and nonstructural proteins of MERS-CoV and summarize different potential strategies for limiting the outbreak of MERS-CoV. The combination of computational biology and virology can accelerate the advanced design and development of effective peptide therapeutics against MERS-CoV. In summary, this review provides important information about the progress of the elimination of MERS, from prevention to treatment.

Corrigendum: Chaperones, Membrane Trafficking and Signal Transduction Proteins Regulate Zaire Ebola Virus trVLPs and Interact With trVLP Elements.

[This corrects the article DOI: 10.3389/fmicb.2018.02724.].

Chaperones, Membrane Trafficking and Signal Transduction Proteins Regulate Zaire Ebola Virus trVLPs and Interact With trVLP Elements.

Ebolavirus (EBOV) life cycle involves interactions with numerous host factors, but it remains poorly understood, as does pathogenesis. Herein, we synthesized 65 siRNAs targeting host genes mostly connected with aspects of the negative-sense RNA virus life cycle (including viral entry, uncoating, fusion, replication, assembly, and budding). We produced EBOV transcription- and replication-competent virus-like particles (trVLPs) to mimic the EBOV life cycle. After screening host factors associated with the trVLP life cycle, we assessed interactions of host proteins with trVLP glycoprotein (GP), VP40, and RNA by co-immunoprecipitation (Co-IP) and chromatin immunoprecipitation (ChIP). The results demonstrate that RNAi silencing with 11 siRNAs (ANXA5, ARFGAP1, FLT4, GRP78, HSPA1A, HSP90AB1, HSPA8, MAPK11, MEK2, NTRK1, and YWHAZ) decreased the replication efficiency of trVLPs. Co-IP revealed nine candidate host proteins (FLT4, GRP78, HSPA1A, HSP90AB1, HSPA8, MAPK11, MEK2, NTRK1, and YWHAZ) potentially interacting with trVLP GP, and four (ANXA5, GRP78, HSPA1A, and HSP90AB1) potentially interacting with trVLP VP40. Ch-IP identified nine candidate host proteins (ANXA5, ARFGAP1, FLT4, GRP78, HSPA1A, HSP90AB1, MAPK11, MEK2, and NTRK1) interacting with trVLP RNA. This study was based on trVLP and could not replace live ebolavirus entirely; in particular, the interaction between trVLP RNA and host proteins cannot be assumed to be identical in live virus. However, the results provide valuable information for further studies and deepen our understanding of essential host factors involved in the EBOV life cycle.

Development and Characterization of Neutralizing Antibodies Against Zaire Ebolavirus Glycoprotein and Protein 40.

BACKGROUND/AIMS: Monoclonal antibodies (mAbs) are presently the most promising treatment against Ebola virus disease (EVD), and cocktail of two or more antibodies likely confers protection through complementary mechanisms. Zaire Ebolavirus (EBOV) glycoprotein (GP) and viral protein 40 (VP40) are targets for designing neutralizing antibodies. Currently, the antiviral therapeutics of mAb-cocktails are still limited solely to anti-GP antibodies，there is no Abs cocktail against Zaire EBOV GP and VP40, which both have important interactions with host cellular membrane. METHODS: We used hybridoma technology to produce anti-Zaire EBOV GP mAb against GP receptor binding domain, and anti-Zaire EBOV VP40 mAbs against the N-terminal domain, the C-terminal domain, respectively; synthesized Zaire EBOV transcription and replication competent virus like particles (trVLPs), which model even all aspects of the EBOV life cycles in order to evaluate the anti-viral effect of mAbs. Then, we characterized the anti- Zaire EBOV trVLPs effect of anti-GP and VP40 mAbs in vitro by real time-PCR, immunofluorescence assay and western blot analysis. RESULTS: Our results demonstrate that anti-GP or anti-VP40 mAbs effectively inhibit trVLPs replication. The cocktails of anti-GP and anti-VP40 mAbs, or between anti-VP40 mAbs, had synergistic anti-trVLPs effect. Meanwhile, the detailed DNA and amino acid sequences of the mAbs were checked. CONCLUSION: The study verifies neutralizing efficacy of anti-GP or anti-VP40 mAb, report promising cocktail of anti-GP and anti-VP40 mAb, or cocktail of two anti-VP40 mAbs. To our knowledge, this is the first account to report the important anti-viral effect of cocktails of anti-GP and anti-VP40 mAbs in vitro.

The Protective Effects of the A/ZJU01/ PR8/2013 Split H7N9 Avian Influenza Vaccine Against Highly Pathogenic H7N9 in BALB/c Mice.

BACKGROUND/AIMS: Since the first case of novel H7N9 infection was reported, China has experienced five epidemics of H7N9. During the fifth wave, a highly pathogenic H7N9 strain emerged. In order to assess whether the H7N9 vaccine based on A/Zhejiang/DTID-ZJU01/2013(H7N9) was effective in protecting against highly pathogenic H7N9, we conducted this study. METHODS: Groups of mice were immunized twice by intraperitoneal injection with 500 µl of either split vaccine alone or MF59-adjuvanted vaccine. Serum was collected 2 weeks after the second vaccine booster. The hemagglutinin inhibition test was conducted on vaccine seed and highly pathogenic H7N9 to evaluate the neutralization of highly pathogenic H7N9. We also immunized mice and challenged them with highly pathogenic H7N9. Mice were observed for illness, weight loss, and death at 1 week and 2 weeks post-infection. Then, the mice were sacrificed and lungs were removed. Antibody responses were assessed and pathological changes in the lung tissue were evaluated. RESULTS: The ability of serum to neutralize highly pathogenic H7N9 was reduced. In mice, highly pathogenic H7N9 was more virulent than A/Zhejiang/DTID-ZJU01/2013(H7N9). After challenge with highly pathogenic H7N9, all mice died while mice challenged with A/Zhejiang/DTID-ZJU01/2013(H7N9) all recovered. The A/ZJU01/PR8/2013 split H7N9 avian influenza vaccine was able to protect against infection with highly pathogenic H7N9 in mice, with or without MF59. Moreover, H7N9 vaccine adjuvanted with MF59 produced high antibody levels, which lead to better protection. CONCLUSIONS: The A/ZJU01/PR8/2013 split H7N9 avian influenza vaccine based on A/Zhejiang/DTID-ZJU01/2013(H7N9) is effective in protecting against highly pathogenic H7N9. H7N9 vaccine adjuvanted with MF59 offers better protection against infection with highly pathogenic H7N9. In order to make the H7N9 vaccine applicable to humans, further clinical trials are required to evaluate MF59 adjuvanted vaccine. Meanwhile, the vaccine strain should be updated based on the highly pathogenic H7N9 gene sequence.

The lifecycle of the Ebola virus in host cells.

Ebola haemorrhagic fever causes deadly disease in humans and non-human primates resulting from infection with the Ebola virus (EBOV) genus of the family Filoviridae. However, the mechanisms of EBOV lifecycle in host cells, including viral entry, membrane fusion, RNP formation, GP-tetherin interaction, and VP40-inner leaflet association remain poorly understood. This review describes the biological functions of EBOV proteins and their roles in the lifecycle, summarizes the factors related to EBOV proteins or RNA expression throughout the different phases, and reviews advances with regards to the molecular events and mechanisms of the EBOV lifecycle. Furthermore, the review outlines the aspects remain unclear that urgently need to be solved in future research.

Ebolavirus Vaccines: Progress in the Fight Against Ebola Virus Disease.

Ebolaviruses are highly infectious pathogens that cause lethal Ebola virus disease (EVD) in humans and non-human primates (NHPs). Due to their high pathogenicity and transmissibility, as well as the potential to be misused as a bioterrorism agent, ebolaviruses would threaten the health of global populations if not controlled. In this review, we describe the origin and structure of ebolaviruses and the development of vaccines from the beginning of the 1980s, including conventional ebolavirus vaccines, DNA vaccines, Ebola virus-like particles (VLPs), vaccinia virus-based vaccines, Venezuelan equine encephalitis virus (VEEV)-like replicon particles, Kunjin virus-based vaccine, recombinant Zaire Ebolavirusx2206;VP30, recombinant cytomegalovirus (CMV)-based vaccines, recombinant rabies virus (RABV)-based vaccines, recombinant paramyxovirus-based vaccines, adenovirus-based vaccines and vesicular stomatitis virus (VSV)-based vaccines. No licensed vaccine or specific treatment is currently available to counteract ebolavirus infection, although DNA plasmids and several viral vector approaches have been evaluated as promising vaccine platforms. These vaccine candidates have been confirmed to be successful in protecting NHPs against lethal infection. Moreover, these vaccine candidates were successfully advanced to clinical trials. The present review provides an update of the current research on Ebola vaccines, with the aim of providing an overview on current prospects in the fight against EVD.

Viral genome and antiviral drug sensitivity analysis of two patients from a family cluster caused by the influenza A(H7N9) virus in Zhejiang, China, 2013.

OBJECTIVES: In the winter of 2013, people were facing the risk of human-to-human transmission of the re-emerging influenza A(H7N9) virus. We report herein information on the clinical features of two patients from the same family infected with this virus, the genomic sequences of the viruses harbored, and antiviral drug sensitivity. METHODS: Clinical and epidemiological data of two patients from the same family were collected and analyzed. Sequencing was done for the viruses isolated from these two patients and one epidemiologically related chicken, and the sequences of the eight gene segments of the viruses were analyzed phylogenetically. The sensitivity of the viruses to antiviral drug treatment was determined by neuraminidase inhibitor susceptibility test. RESULTS: The two patients from one family cluster shared the same symptoms but had different outcomes, and had a strong epidemiological link. Three strains, two from these two patients and one from the chicken, were isolated. Genome sequencing and analyses of phylogenetic trees demonstrated that the two viruses were almost identical. We noted the presence of the PB2 E627K amino acid substitution that was not present in isolates from the first wave, as well as two new mutations in the NA gene and six in the PB2 gene. Drug sensitivity testing showed that the new isolates were resistant to oseltamivir but sensitive to peramivir. CONCLUSIONS: The two patients from one family cluster were probable human-to-human transmission cases. The new isolates were sensitive to peramivir but showed reduced sensitivity to oseltamivir.

[Highly active antiretroviral therapy on liver function in HIV-positive children with HBV/HCV co-infection].

OBJECTIVE: To assess changes of liver function in HIV-positive children with/without HBV/ HCV co-infection after 1 year of highly active antiretroviral therapy (HARRT). METHODS: Seventy-eight pediatric AIDS patients with HBV/HCV co-infection,19 pediatric AIDS patients with HBV co-infection and 44 pediatric AIDS patients without HBV/HCV co-infection who received HAART at least for 1 year were enrolled. HIV-1 viral load was quantitatively detected using a standardized reverse transcriptase-polymerase chain reaction assay, and blood cells were determined by three-color flow cytometry. Anti-HCV antibody and HBsAg was detected using an enzyme-linked immunosorbent technique, and ALT, AST and TBIL were detected by automatic biochemical analyzer. RESULTS: After 1 year-HAART, the viral load was decreased to the lowest limit of detection in 90.34% patients (t=2.61, P<0.01), and CD4+ T cell counts were increased from 170.187±132.405/ µl to 796.014±158.491/ µl (t=3.17, P<0.01). The levels of ALT and AST were elevated (t=2.02, P<0.05), while the ALT and AST levels in patients receiving nevirapine (NVP) based HAART increased from 18.28±13.74 U/L and 24.23±8.09 U/L to 55.35±22.40 U/L and 69.97±26.72 U/L, respectively(t=3.80,t=4.11;Ps<0.01). The increment of ALT and AST in NVP based HAART were significantly higher than that in the efavirenz based HAART (ALT:46.28±13.35 U/L vs 37.70±15.25 U/L and AST:19.53±7.23 U/L vs 1.25±0.21 U/L, respectively; t=4.53, t=5.79; Ps<0.01), particularly in patients co-infected with HIV/HBV/HCV (ALT:54.32±22.85 U/L vs 16.89±14.42 U/L and AST:41.71±19.26 U/L vs -3.44±15.59 U/L, respectively; t=3.42, t=2.98, Ps<0.01). CONCLUSION: HARRT can repress HIV-1 replication effectively, but it also cause the damage of liver function, especially in patients with HBV and/or HCV co-infection.

Genetic characterization of subtype H1 avian influenza viruses isolated from live poultry markets in Zhejiang Province, China, in 2011.

Nine avian influenza A viruses (AIVs), H1N2 (n = 2) and H1N3 (n = 7), were isolated from domestic ducks in live poultry markets in Zhejiang Province, Eastern China, in 2011. All viruses were characterized by whole genome sequencing with subsequent phylogenetic analysis and genetic comparison. Phylogenetic analysis of all eight viral genes showed that the viruses clustered in the Eurasian lineage of influenza A viruses. The hemagglutinin cleavage site of all viruses displayed features of a monobasic cleavage site. Although there was no evidence of re-assortment in subtype H1 AIVs among the avian species and mammalian hosts in this study, continued surveillance is needed considering the important role of the domestic duck in the dissemination and re-assortment of AIVs.

Rapid identification of YVDD mutants of hepatitis B virus using smart amplification process with competition probe.

Accurate and timely detection of drug-associated viral mutants is important during antiviral therapy. Combining Smart Amplification Process (SMAP) with competition probe, an assay specifically designed to detect point mutation at codon 204 of the hepatitis B virus (HBV) polymerase gene was developed. This assay was sensitive to detect 20 copies of mutant/reaction and recognize as little as 1% of minor mutants in the viral population. The comparison of direct sequencing and SMAP method on 35 clinical specimens showed the concordance in 88% of the cases. This method provides an efficient alternative for rapid identification of HBV mutation associated with lamivudine resistance.

Detection of hepatitis C virus by an improved loop-mediated isothermal amplification assay.

An improved, sensitive, specific, and rapid one-step reverse transcription loop-mediated isothermal amplification (LAMP) assay targeting the 5' untranslated region (UTR) was developed to detect hepatitis C virus (HCV) infection. Based on an accelerating primer (AP), the present assay, named AP-LAMP, has the advantages of rapidity and sensitivity over the routine LAMP method. The possible AP-based amplification pathway during the reaction was revealed by restriction enzyme digestion and eletrophoresis. The detection limit of the AP-LAMP assay was approximately 84 IU/ml, and no cross-detection was observed. The assay was evaluated further with 126 clinical specimens, and the results indicated the suitability and simplicity of the test as a rapid diagnostic tool for detection of HCV RNA.

[Expression of CD38 and HLA-DR on CD8+ T cells in pediatric AIDS patients receiving highly active antiretroviral therapy (HAART)].

OBJECTIVE: To study the expression of CD38 and HLA-DR on CD8(+) T cells in pediatric AIDS patients receiving highly active antiretroviral therapy (HAART) and the relationship of immune activation and disease progression. METHODS: A cross-section study of 194 pediatric AIDS patients receiving HAART was carried out and 52 age-matched healthy children were recruited as control. The percentage of CD4(+), CD8(+), CD8(+)/CD38(+) and CD8(+)/HLA-DR(+) T cells was tested using flow cytometry, and HIV-RNA in plasma was detected by quantitative RT-PCR. RESULTS: One hundred and ninety-four pediatric AIDS patients were divided into two groups according to the viral load: 59 patients with VL ≥ 400 copies/ml and 135 patients with VL < 400 copies/ml. The percentage of CD8(+)/CD38(+) and CD8(+)/HLA-DR(+) T cells of patients with VL ≥ 400 copies/ml was significantly higher than that of patients with VL < 400 copies/ml (P < 0.05). Of patients with VL < 400 copies/ml, the percentage of CD8(+)/CD38(+) T cells was nearly normal, and the percentage of CD8(+)/HLA-DR(+) T cells was higher than normal level (P < 0.05). There was a positive correlation between percentage of CD8(+)/CD38(+) and of CD8(+)/HLA-DR(+)T cells and viral load (R = 0.403, P = 0.03 for the former and R = 0.569, P = 0.09 for the later). CONCLUSIONS: Effective HAART could decrease immune activation of HIV-infected children significantly. And there was a positive correlation between percentage of CD8(+)/CD38(+) and of CD8(+)/HLA-DR(+)T cells and viral load, suggesting that the two indicators might be used as the substitution of viral load in resource-limited areas.