Isolation and characterization of a pangolin-borne HKU4-related coronavirus that potentially infects human-DPP4-transgenic mice

We recently detected a HKU4-related coronavirus in subgenus Merbecovirus (named pangolin-CoV-HKU4-P251T) from a Malayan pangolin1. Here we report isolation and characterization of pangolin-CoV-HKU4-P251T, the genome sequence of which is closest to that of a coronavirus from the greater bamboo bat (Tylonycteris robustula) in Yunnan Province, China, with a 94.3% nucleotide identity. Pangolin-CoV-HKU4-P251T is able to infect human cell lines, and replicates more efficiently in cells that express human-dipeptidyl-peptidase-4 (hDPP4)-expressing and pangolin-DPP4-expressing cells than in bat-DPP4-expressing cells. After intranasal inoculation with pangolin-CoV-HKU4-P251, hDPP4-transgenic female mice are likely infected, showing persistent viral RNA copy numbers in the lungs. Progressive interstitial pneumonia developed in the infected mice, characterized by the accumulation of macrophages, and increase of antiviral cytokines, proinflammatory cytokines, and chemokines in lung tissues. These findings suggest that the pangolin-borne HKU4-related coronavirus has a potential for emerging as a human pathogen by using hDPP4.

Treatment of a patient with severe lactic acidosis and multiple organ failure due to mitochondrial myopathy: A case report

BACKGROUND

Mitochondrial myopathy is a rare genetic disease with maternal inheritance that may involve multiple organ systems. Due to the lack of typical characteristics, its clinical diagnosis is difficult, and it is often misdiagnosed or even missed.

CASE SUMMARY

The patient was a young college student. When he presented at the hospital, he had severe lactic acidosis, respiratory failure, and shock with multiple organ dysfunction syndrome (MODS). He was treated by mechanical ventilation, veno-arterial extracorporeal membrane oxygenation, and other organ support. However, his condition continued to worsen. After a thorough and detailed medical and family history was taken, a mitochondrial crisis was suspected. A muscle biopsy was taken. Further genetic testing confirmed a mitochondrial gene mutation (TRNL1 3243A>G). The final diagnosis of mitochondrial myopathy was made. Although there is no known specific treatment, intravenous methylprednisone and intravenous immunoglobulin were started. The patient's shock eventually improved. The further course was complicated by severe infection in multiple sites, severe muscle weakness, and recurrent MODS. After 2 mo of multidisciplinary management and intensive rehabilitation, the patient could walk with assistance 4 mo after admission and walk independently 6 mo after admission.

CONCLUSION

More attention should be paid to mitochondrial myopathy to avoid missed diagnosis and misdiagnosis.

Treatment of a patient with severe lactic acidosis and multiple organ failure due to mitochondrial myopathy: A case report

BACKGROUND

Mitochondrial myopathy is a rare genetic disease with maternal inheritance that may involve multiple organ systems. Due to the lack of typical characteristics, its clinical diagnosis is difficult, and it is often misdiagnosed or even missed.

CASE SUMMARY

The patient was a young college student. When he presented at the hospital, he had severe lactic acidosis, respiratory failure, and shock with multiple organ dysfunction syndrome (MODS). He was treated by mechanical ventilation, veno-arterial extracorporeal membrane oxygenation, and other organ support. However, his condition continued to worsen. After a thorough and detailed medical and family history was taken, a mitochondrial crisis was suspected. A muscle biopsy was taken. Further genetic testing confirmed a mitochondrial gene mutation (TRNL1 3243A>G). The final diagnosis of mitochondrial myopathy was made. Although there is no known specific treatment, intravenous methylprednisone and intravenous immunoglobulin were started. The patient’s shock eventually improved. The further course was complicated by severe infection in multiple sites, severe muscle weakness, and recurrent MODS. After 2 mo of multidisciplinary management and intensive rehabilitation, the patient could walk with assistance 4 mo after admission and walk independently 6 mo after admission.

CONCLUSION

More attention should be paid to mitochondrial myopathy to avoid missed diagnosis and misdiagnosis.

Parabrachial nucleus astrocytes regulate wakefulness and isoflurane anesthesia in mice

Background: The parabrachial nucleus (PBN) is an important structure regulating the sleep-wake behavior and general anesthesia. Astrocytes in the central nervous system modulate neuronal activity and consequential behavior. However, the specific role of the parabrachial nucleus astrocytes in regulating the sleep-wake behavior and general anesthesia remains unclear. Methods: We used chemogenetic approach to activate or inhibit the activity of PBN astrocytes by injecting AAV-GFAabc1d-hM3Dq-eGFP or AAV-GFAabc1d-hM4Di-eGFP into the PBN. We investigated the effects of intraperitoneal injection of CNO or vehicle on the amount of wakefulness, NREM sleep and REM sleep in sleep-wake behavior, and on the time of loss of righting reflex, time of recovery of righting reflex, sensitivity to isoflurane, electroencephalogram (EEG) power spectrum and burst suppression ratio (BSR) in isoflurane anesthesia. Results: The activation of PBN astrocytes increased wakefulness amount for 4 h, while the inhibition of PBN astrocytes decreased total amount of wakefulness during the 3-hour post-injection period. Chemogenetic activation of PBN astrocytes decreased isoflurane sensitivity and shortened the emergence time from isoflurane-induced general anesthesia. Cortical EEG recordings revealed that PBN astrocyte activation decreased the EEG delta power and BSR during isoflurane anesthesia. Chemogenetic Inhibition of PBN astrocytes increased the EEG delta power and BSR during isoflurane anesthesia. Conclusion: PBN astrocytes are a key neural substrate regulating wakefulness and emergence from isoflurane anesthesia.

[Safety and feasibility of stereotactic radiation therapy on porcine ventricular septum: a preliminary study]

Objective: To explore the safety and feasibility of stereotactic radiation therapy (SBRT) strategy for irradiating porcine ventricular septum, see if can provide a preliminary experimental evidence for clinical SBRT in patients with hypertrophic obstructive cardiomyopathy (HOCM). Methods: Five male pigs (39-49 kg, 6 months old) were used in this study. Pigs were irradiated at doses of 25 Gy (n=2) or 40 Gy (n=3). Delineation of the target volume was achieved under the guidance of 3-dimensional CT image reconstruction, and SBRT was then performed on defined target volume of porcine ventricular septum. Blood biomarkers, electrocardiogram and echocardiography parameters were monitored before and after SBRT. Pathological examination (HE staining, Masson staining) was performed on the target and non-target myocardium at 6 months post SBRT. Results: SBRT was successful and all animals survived to the designed study endpoint (6 months) after SBRT. Serum cardiac troponin T (cTnT) level was significantly higher than the baseline level at 1 day post SBRT, and reduced at 1 week after SBRT, but was still higher than the baseline level(P<0.05). Serum N-terminal pro-B type natriuretic peptide (NT-proBNP) was also significantly increased at 1 day post SBRT (P<0.05) and returned to baseline level at 1 week post SBRT. The serum NT-proBNP level was (249±78), (594±37) and (234±46) pg/ml, respectively, and the cTnT was (14±7), (240±40) and (46±34) pg/ml, respectively at baseline, 1 day and 1 week after SBRT in the 40 Gy dose group. The serum NT-proBNP level was (184±20), (451±49) and (209±36) pg/ml, respectively, the cTnT values ​​were (9±1), (176±29) and (89±27) pg/ml, respectively at baseline, 1 day and 1 week after SBRT in the 25 Gy dose group. Both NT-proBNP and cTnT values tended to be higher post SBRT in the 40 Gy dose group as compared with the 25 Gy dose group, but the difference was not statistically significant (P>0.05). The left ventricular ejection fraction and the left ventricular end-diastolic diameter remained unchanged before and after SBRT (P>0.05). The interventricular septum thickness showed a decreasing trend at 6 months after SBRT, but the difference was not statistically significant ((9.54±0.24) mm vs. (9.82±8.00) mm, P>0.05). The flow velocity of the left ventricular outflow tract, and the valve function and morphology were not affected by SBRT. At 6 months after SBRT, HE staining revealed necrosis in the irradiated target area of ​​the myocardium in the 40 Gy dose group and the 25 Gy dose group, and the degree of necrosis in the irradiated interventricular septum was more obvious in the 40 Gy dose group as compared with the 25 Gy group. The combined histological analysis of the two groups showed that the necrotic area of ​​the irradiated target area accounted for (26±9)% of the entire interventricular septum area, which was higher than that of the non-irradiated area (0) (P<0.05). There was no damage or necrosis of myocardial tissue outside the target irradiation area in both groups. The results of Masson staining showed that the percentage area of myocardial fibrosis was significantly higher in the irradiated target area than non-irradiated area ((12.6±5.3)% vs. (2.5±0.8)%, P<0.05). Conclusion: SBRT is safe and feasible for irradiating porcine ventricular septum.

Lipid nanoparticle-encapsulated mRNA antibody provides long-term protection against SARS-CoV-2 in mice and hamsters

Monoclonal antibodies represent important weapons in our arsenal to against the COVID-19 pandemic. However, this potential is severely limited by the time-consuming process of developing effective antibodies and the relative high cost of manufacturing. Herein, we present a rapid and cost-effective lipid nanoparticle (LNP) encapsulated-mRNA platform for in vivo delivery of SARS-CoV-2 neutralization antibodies. Two mRNAs encoding the light and heavy chains of a potent SARS-CoV-2 neutralizing antibody HB27, which is currently being evaluated in clinical trials, were encapsulated into clinical grade LNP formulations (named as mRNA-HB27-LNP). In vivo characterization demonstrated that intravenous administration of mRNA-HB27-LNP in mice resulted in a longer circulating half-life compared with the original HB27 antibody in protein format. More importantly, a single prophylactic administration of mRNA-HB27-LNP provided protection against SARS-CoV-2 challenge in mice at 1, 7 and even 63 days post administration. In a close contact transmission model, prophylactic administration of mRNA-HB27-LNP prevented SARS-CoV-2 infection between hamsters in a dose-dependent manner. Overall, our results demonstrate a superior long-term protection against SARS-CoV-2 conferred by a single administration of this unique mRNA antibody, highlighting the potential of this universal platform for antibody-based disease prevention and therapy against COVID-19 as well as a variety of other infectious diseases.

Role of heparinase in the gastrointestinal dysfunction of sepsis (Review)

Heparinase (HPA) is a β-D glucuronidase that belongs to the endoglycosidase enzyme family, and plays an important role in numerous pathological and physiological processes, including inflammation, angiogenesis and tumor metastasis. When the expression of HPA is abnormally high, the side chain of heparin sulfate proteoglycans degrades, destroying the cell barrier and leading to the occurrence and development of inflammation, with systemic inflammation occurring in severe cases. Sepsis is a major cause of mortality in critically ill patients. In sepsis, the gastrointestinal tract is the first and most frequently involved target organ, which often leads to gastrointestinal dysfunction. HPA overexpression has been determined to accelerate sepsis progression and gastrointestinal dysfunction; thus, it was hypothesized that HPA may play an important role and may serve as an index for the diagnosis of gastrointestinal dysfunction in sepsis. HPA inhibitors may therefore become applicable as targeted drugs for the treatment of gastrointestinal dysfunction in patients with sepsis. The present review mainly discussed the role of HPA in gastrointestinal dysfunction of sepsis.

Lasting antibody and T cell responses to SARS-CoV-2 in COVID-19 patients three months after infection

The dynamics, duration, and nature of immunity produced during SARS-CoV-2 infection are still unclear. Here, we longitudinally measured virus-neutralising antibody, specific antibodies against the spike (S) protein, receptor-binding domain (RBD), and the nucleoprotein (N) of SARS-CoV-2, as well as T cell responses, in 25 SARS-CoV-2-infected patients up to 121 days post-symptom onset (PSO). All patients seroconvert for IgG against N, S, or RBD, as well as IgM against RBD, and produce neutralising antibodies (NAb) by 14 days PSO, with the peak levels attained by 15-30 days PSO. Anti-SARS-CoV-2 IgG and NAb remain detectable and relatively stable 3-4 months PSO, whereas IgM antibody rapidly decay. Approximately 65% of patients have detectable SARS-CoV-2-specific CD4⁺ or CD8⁺ T cell responses 3-4 months PSO. Our results thus provide critical evidence that IgG, NAb, and T cell responses persist in the majority of patients for at least 3-4 months after infection.

Aerosol and Surface Distribution of Severe Acute Respiratory Syndrome Coronavirus 2 in Hospital Wards, Wuhan, China, 2020

To determine distribution of severe acute respiratory syndrome coronavirus 2 in hospital wards in Wuhan, China, we tested air and surface samples. Contamination was greater in intensive care units than general wards. Virus was widely distributed on floors, computer mice, trash cans, and sickbed handrails and was detected in air ≈4 m from patients.

Development and evaluation of serotype-specific recombinase polymerase amplification combined with lateral flow dipstick assays for the diagnosis of foot-and-mouth disease virus serotype A, O and Asia1

Background

Foot-and-mouth disease (FMD) caused by foot-and-mouth disease virus (FMDV) is one of the most highly infectious diseases in livestock, and leads to huge economic losses. Early diagnosis and rapid differentiation of FMDV serotype is therefore integral to the prevention and control of FMD. In this study, a series of serotype-specific reverse transcription recombinase polymerase amplification assays combined with lateral flow dipstick (RPA-LFD) were establish to differentiate FMDV serotypes A, O or Asia 1, respectively.

Results

The serotype-specific primers and probes of RPA-LFD were designed to target conserved regions of the FMDV VP1 gene sequence, and three primer and probe sets of serotype-specific RPA-LFD were selected for amplification of FMDV serotypes A, O or Asia 1, respectively. Following incubation at 38 °C for 20 min, the RPA amplification products could be visualized by LFD. Analytical sensitivity of the RPA assay was then determined with ten-fold serial dilutions of RNA of VP1 gene and the recombinant vector respectively containing VP1 gene from FMDV serotypes A, O or Asia1, the detection limits of these assays were 3 copies of plasmid DNA or 50 copies of viral RNA per reaction. Moreover, the specificity of the assay was assessed, and there was no cross reactions with other viruses leading to bovine vesicular lesions. Furthermore, 126 clinical samples were respectively detected with RPA-LFD and real-time PCR (rPCR), there was 98.41% concordance between the two assays, and two samples were positive by RPA-LFD but negative in rPCR, these were confirmed as FMDV-positive through viral isolation in BHK-21 cells. It showed that RPA-LFD assay was more sensitive than the rPCR method in this study.

Conclusion

The development of serotype-specific RPA-LFD assay provides a rapid, sensitive, and specific method for differentiation of FMDV serotype A, O or Asia1, respectively. It is possible that the serotype-specific RPA-LFD assay may be used as a integral protocol for field detection of FMDV.

Development and characterization of Rift Valley fever virus-like particles

Rift Valley fever (RVF) is an acute, febrile zoonotic disease that is caused by the RVF virus (RVFV) and spread by arthropod vectors. RVF is currently prevalent in Africa and the Arabian Peninsula, and causes substantial economic losses. Furthermore, this disease poses a serious threat to animal and human health in regions worldwide, making it a serious public health concern. However, RVFV vaccines for human use are still unavailable, and hence there is an urgent need for novel efficient vaccines against RVFV. Vaccine preparation techniques have become a crucial factor in developing new vaccines. In the current study, the N and G protein genes of RVFV were inserted into the pFastBacDual baculovirus expression vector downstream of the pP10 and pPH promoters. The resultant recombinant vector, pFastBacDual-S-M, was transfected into Sf9 insect cells by lipofection. The recombinant baculovirus, named rBac-N-G, was retrieved and infected into Sf9 insect cells to generate RVFV virus-like particles (VLPs). Using polyclonal antibodies against RVFV proteins in immunofluorescence and western blot analyses, we positively identified the presence of the RVFV proteins in VLP preparations. Sucrose density gradient centrifugation and transmission electron microscopy revealed that the morphology of the RVFV VLPs was consistent with previous reports of RVFV virions. This study describes a technique for efficient production of RVFV VLPs, and has laid the foundation for future VLP-based RVFV vaccines.

Therapeutic effect of double-filtration plasmapheresis combined with methylprednisolone to treat diffuse proliferative lupus nephritis

OBJECTIVE

The efficacy of double-filtration plasmapheresis (DFPP), combined with methylprednisolone, to treat diffuse proliferative lupus nephritis (LN) was studied.

METHODS

Twenty-four patients who were admitted to the hospital and diagnosed with diffuse proliferative LN (LN Class IV-G(A)) through renal biopsy from 2011 to 2013 were recruited as the study subjects. The patients' clinical manifestations were nephritic syndrome and/or renal insufficiency. The pathological features were glomerular diffuse proliferative lesions. The patients were divided into two groups: the treatment group and the control group, with 12 patients in each group. The patients in the treatment group were first treated with DFPP combined with methylprednisolone (0.8-1.0 mg/kg/day); subsequently, they were put on methylprednisolone therapy only. The patients in the control group were first put on methylprednisolone pulse therapy (500-1,000 mg) for 3 days; subsequently, they were treated with methylprednisolone (0.8-1.0 mg/kg/day) combined with mycophenolate mofetil (1.5 g/day). The patients were observed for 24 months. Levels of hemoglobin, platelet, albumin, serum creatinine, 24-h urinary protein, serum C3 , antinuclear antibody (ANA), anti-dsDNA, and anti-Smith were measured at 0, 3, 6, 12, and 24 months. Complete remission and recurrence standards were established. The total dosages of methylprednisolone were calculated. Repeated renal biopsy was performed on several patients.

RESULTS

There was no statistical significance in the baseline conditions of the treatment and the control groups. For the treatment group, no plasmapheresis-related complications occurred. The two groups showed no significant difference in complete remission. The patients' edema and serous effusion resolved, urine volume, serum creatinine, and albumin levels returned to normal, urine protein decreased in treatment group more rapidly than the patients in the control group. The mean dose of methylprednisolone received in the treatment group was lower than in the control group. The complement C3 levels in the treatment group were significantly higher than in the control group. The recurrence rate in the treatment group was lower than in the control group. Repeated renal biopsies on several patients in the treatment group indicated that their pathology improved significantly, changing from LN (IV) to LN(II-III).

CONCLUSIONS

Appropriate application of DFPP combined with glucocorticoid therapy could accelerate the remission of diffuse proliferative LN, reduce overall glucocorticoid dosage, prevent recurrence, and maintain C3 level in a higher level. J. Clin. Apheresis 31:375-380, 2016. © 2015 Wiley Periodicals, Inc.

A meta-analysis of the effects of angiotensin converting enzyme inhibitors and angiotensin II receptor blockers on insulin sensitivity in hypertensive patients without diabetes

AIMS

This study sought to compare the effects of angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB) on insulin sensitivity (IS) in hypertensive patients without diabetes.

METHODS

Studies on the observation of IS in hypertensive patients without diabetes who received ACEI and ARB prior to December 2013 was collected using computer-based retrieval of the PUBMED, EMBASE, and COCHRANE databases. The primary indicators included IS, fasting plasma glucose (FPG), and fasting plasma insulin (FPI). The secondary indicators included systolic blood pressure (SBP) and diastolic blood pressure (DBP). A meta-analysis was performed using the STATA and Review Manager 5.2 software. The effects of these two drugs on IS in hypertensive patients without diabetes were analyzed using the fixed effect model and the random effect model.

RESULTS

A total of 203 cases of patients involved in 4 clinical studies were included. As compared to ARB, ACEI treatment resulted in more effective improvement of IS in hypertensive patients without diabetes (SMD: 0.45, 95% CI 0.17-0.73), although these two drugs did not show significant differences with regards to FPG (WMD: 0.00, 95% CI -0.19-0.20), FPI (WMD: -0.34, 95% CI -1.31-0.63), SBP (WMD: 2.85, 95% CI -1.55-7.24), and DBP (WMD: 0.81, 95% CI -1.12-2.75).

CONCLUSION

In patients showing no significant difference in blood pressure control, the comparison between ACEI and ARB showed that the former type of drug more effectively relieved IS in hypertensive patients without diabetes.

Characterization of a novel reassortant influenza A virus (H2N2) from a domestic duck in Eastern China

While H2N2 viruses have been sporadically isolated from wild and domestic birds, H2N2 viruses have not been detected among human populations since 1968. Should H2N2 viruses adapt to domestic poultry they may pose a risk of infection to people, as most anyone born after 1968 would likely be susceptible to their infection. We report the isolation of a novel influenza A virus (H2N2) cultured in 2013 from a healthy domestic duck at a live poultry market in Wuxi City, China. Sequence data revealed that the novel H2N2 virus was similar to Eurasian avian lineage avian influenza viruses, the virus had been circulating for ≥ two years among poultry, had an increase in α2,6 binding affinity, and was not highly pathogenic. Approximately 9% of 100 healthy chickens sampled from the same area had elevated antibodies against the H2 antigen. Fortunately, there was sparse serological evidence that the virus was infecting poultry workers or had adapted to infect other mammals. These findings suggest that a novel H2N2 virus has been circulating among domestic poultry in Wuxi City, China and has some has increased human receptor affinity. It seems wise to conduct better surveillance for novel influenza viruses at Chinese live bird markets.

Potential role of high-mobility group box 1 protein in the pathogenesis of influenza H5N1 virus infection

During influenza A virus (IAV) (H5N1) infection, the levels of inflammatory cytokines are markedly elevated in the lungs of infected hosts. One of them, high-mobility group box 1 protein (HMGB1) functions in regulation of cellular transcription and activation of proinflammatory responses, but little is known about its role in viral infection. In this study, we attempted to address this question. Using an IAV (H5N1) - mouse model, lung tissues were analyzed for virus titer, expression of HMGB1 and other inflammatory cytokines and histopathological changes. Moreover, the effect of administration of HMGB1-specific antibody to the infected mice on these parameters was investigated. The results showed that the HMGB1 expression was induced on days 3-7 post infection (p.i.) and primarily localized to epithelial cells of alveoli and bronchioles. The HMGB1-specific antibody reduced the levels of inflammatory cytokines and chemokines and the survival rate, but did not influence the virus titer. Summing up, these data suggest that HMGB1 contributes to the pathogenesis of IAV (H5N1) infection in mice by inducing extensive inflammatory responses and severe pneumonia.

Aptamers targeting rabies virus-infected cells inhibit street rabies virus in vivo

Rabies is a viral infection of the CNS that is almost always fatal once symptoms occur. No effective treatment of the disease is available and novel antiviral strategies are urgently required. Street rabies viruses are field isolates known to be highly neurotropic. Aptamers are single-stranded oligonucleotides that bind their targets with high affinity and specificity and thus have potential for use in diagnostic and therapeutic applications. In this study, we demonstrate that the aptamers FO24 and FO21, which target RABV-infected cells, can significantly protect mice from a lethal dose of the street rabies virus FJ strain in vivo. Groups receiving preexposure prophylaxis had higher survival rates than the groups receiving postexposure prophylaxis. When mice were inoculated with aptamers (4 nmol) for 24h by intracranial or intramuscular injection prior to intramuscular inoculation with the FJ strain, approximately 60% of the mice survived. These results indicate that the FO21 and FO24 aptamers may be used to develop preventative antiviral therapy against rabies disease.

Selection of an aptamer against rabies virus: a new class of molecules with antiviral activity

Rabies is a fatal central nervous system (CNS) disease caused by the neurotropic rabies virus (RABV). The therapeutic management of RABV infections is still problematic, and novel antiviral strategies are urgently required. We established the RVG-BHK-21 cell line, which expresses RABV glycoprotein on the cell surface, to select aptamers. Through 28 iterative rounds of selection, single-stranded DNA (ssDNA) aptamers were generated by exponential enrichment (SELEX). A virus titer assay and a real-time quantitative reverse transcription PCR (qRT-PCR) assay revealed that four aptamers could inhibit the replication of RABV in cultured baby hamster kidney (BHK)-21 cells. However, the aptamers did not inhibit the replication of other virus, e.g., canine distemper virus (CDV) and canine parvovirus (CPV). In addition, the GE54 aptamer was found to effectively protect mice against lethal RABV challenge. After inoculation with aptamers for 24h or 48h, followed by inoculation with CVS-11, approximately 25-33% of the mice survived. In summary, we selected aptamers that could significantly protect from a lethal dose of RABV in vitro and in vivo.

CpG/Poly (I:C) mixed adjuvant priming enhances the immunogenicity of a DNA vaccine against eastern equine encephalitis virus in mice

Eastern equine encephalitis virus (EEEV) poses a serious public health threat in many countries. Therefore, developing efficient vaccine against EEEV remains an important challenge in the field of disease control. To identify immunogenic proteins in EEEV, we constructed an expression vector containing the protein coding genes C, E3, E2, 6k, and E1 (pcDNA3.1-C-E). After verifying the target gene expression in 293 T cells, we immunized BALB/c mice with the pcDNA3.1-C-E vector as a DNA vaccine in conjunction with either CpG or poly (I:C) or a mixture of both adjuvants and monitored various aspects of the immune response. After two immunizations, the mice vaccinated with antigen plus mixed CpG/poly (I:C) adjuvant exhibited significantly stronger IFN-gamma responses and generated high-level CD4(+) cell responses for the cytokines IL-2, IL-4, and IFN-γ and CD8(+) T cell responses for the cytokines IL-2 and IFN-γ compared to the mice vaccinated with the corresponding antigen plus CpG or poly(I:C) alone. In addition, the higher antibody titers against EEEV effectively neutralized the EEEV pseudoviruses in the group immunized with antigen plus mixed CpG/poly (I:C) adjuvant after tertiary immunization. This study demonstrates that the pcDNA3.1-C-E plasmids in conjunction with mixed CpG/poly (I:C) adjuvant priming maximize the cellular immune response and specific antibody generation in mice. Moreover, this mixed adjuvant priming provides a promising strategy for enhancing the immune effectiveness of a DNA vaccine against EEEV.

Adeno-associated viruses serotype 2-mediated RNA interference efficiently inhibits rabies virus replication in vitro and in vivo

To investigate the potential of adeno-associated viruses serotype 2 (AAV2)-mediated RNA interference (RNAi) as an antiviral agent against rabies, recombinant AAV2 vectors expressing siRNA targeting the nucleoprotein (N) gene of rabies virus (RABV) (rAAV-N796) were constructed and evaluated. When NA cells pretreated with rAAV-N796 were challenged with RABV, there was a 37.8 ± 3.4% to 55.1 ± 5.3% reduction in RABV virus titer. When cells pre-challenged with RABV were treated with rAAV-N796, there was a 4.4 ± 1.4 to 28.8 ± 3.2% reduction in RABV virus titer. Relative quantification of RABV transcripts using real-time PCR and Western blot revealed that the knockdown of RABV-N gene transcripts was based on the rAAV-N796 inoculation titer. When any NA cells were treated with rAAV-N796 before or after challenged with RABV, significant reduction in virus titer was observed in both administrations. Mice treated intracerebrally with rAAV-N796 exhibited 50 ± 5.3 and 62.5 ± 4.7% protection when challenged intracerebrally or intramuscally, respectively, with lethal RABV. When mice treated intramuscularly with rAAV-N796 were challenged intramuscularly with lethal RABV, they exhibited 37.5 ± 3.7% protection. When mice were intracerebrally and intramuscularly with rAAV-N796 24 hr after exposure to RABV infection, they exhibited 25 ± 4.1% protection The N gene mRNA levels in the brains of challenged mice with three different administrations were reduced (55, 68, 32 and 25%, respectively). These results indicated that AAV2 vector-mediated siRNA delivery in vitro in NA cells inhibited RABV multiplication, inhibited RABV multiplication in vivo in the mice brain and imparted partial protection against lethal rabies. So, it may have a potential to be used as an alternative antiviral approach against rabies.

Isolation of ssDNA aptamers that inhibit rabies virus

Aptamers, functional nucleic acids, capable of binding a variety of molecular targets with high affinity and specificity, have emerged as promising therapeutic agents. In this study, the cell surface-systematic evolution of ligands by exponential enrichment (Cell-SELEX) strategy was used to generate DNA aptamers which targeted to the intact rabies virus-infected live cells. Through 35 iterative rounds of selection, five high-affinity single-stranded DNA (ssDNA) aptamers were generated by cell-SELEX. Virus titer assay and real-time quantitative reverse transcription PCR (qRT-PCR) assay revealed that all five aptamers could inhibit replication of rabies virus (RABV) in cultured baby hamster kidney (BHK)-21 cells; and T14 and F34 aptamers were most effective. The qRT-PCR also showed a dose-dependent inhibitory effect in BHK-21 cells. Collectively, these data show the feasibility of generating functionally effective aptamers against rabies virus-infected cells by the Cell-SELEX iterative procedure. These aptamers may prove clinically useful as therapeutic molecules with specific antiviral potential against RABV infections.

Generation and characterization of a fusion protein of single-chain fragment variable antibody against hemagglutinin antigen of avian influenza virus and truncated protamine

The hemagglutinin antigen (HA) of avian influenza virus (AIV) is an immunogen abundant on the surfaces of infected cells, and can be used as a target for specific antibodies to clear viral infection. Protamine has been demonstrated to deliver DNA into cells effectively. Accordingly, a fusion protein of anti-HA single-chain fragment variable (scFv) and truncated protamine (tP) may be used as a vehicle for delivering the anti-AIV siRNA into the AIV-infected cells for gene therapy. To test this hypothesis, we constructed a novel recombinant plasmid, pET28-scFv-tP, by connecting the genes for anti-H5N1 AIV HA-specific scFv with synthesized oligonucleotides encoding the 22 amino acids of human tP and a linker. Furthermore, the recombinant scFV-tP was expressed and purified, with a yield of 7-8mg of scFv-tP and a purity of >92% from 1L of bacterial culture. Characterization of its bioactivity revealed that scFv-tP recognized HA, similar to its scFv control, in a dose-dependent manner and that the scFv-tP, but not its scFv control, bound to DNA and delivered plasmid and oligonucleotide DNA into the AIV-infected MDCK cells effectively. More importantly, transfection with the mixture of the scFv-tP and plasmid for the NP-specific siRNA significantly inhibited the replication of AIV in MDCK cells, as compared with that transfection with the scFv-plasmid mixture, even with the plasmid in liposome. Our data demonstrated that the recombinant scFv-tP retained the functions of both scFv and tP, and might be potentially used for delivering genetic materials for targeting therapy of AIV infection in vivo.

Role of macrophage migration inhibitory factor in influenza H5N1 virus pneumonia

The severe and often fatal disease in humans and birds caused by H5N1 influenza viruses has been attributed to aberrant pulmonary inflammatory responses. We investigated the role of macrophage migration inhibitory factor (MIF), a proinflammatory cytokine and a pivotal regulator of innate immunity, in H5N1 influenza virus pneumonia in murine model. We found increased MIF mRNA levels in the lungs and MIF protein levels in the serum of infected mice. Although the inhibition of MIF action by isoxazolone-1 (ISO-1) did not render mice more resistant to the lethality of infection, it caused a significant reduction in pulmonary inflammatory cytokines interleukin-1 beta (IL-1beta), IL-6 and tumor necrosis factor alpha (TNF-alphalfa) and chemokine interferon-inducible protein-10 (IP-10). These results indicate the involvement of MIF in inflammatory responses to H5N1 influenza virus infections by induction of pulmonary inflammatory cytokines and chemokines, and suggest that pharmacotherapeutic approaches targeting MIF may hold promise for the treatment of H5N1 influenza virus pneumonia.

Isolation and identification of a canine coronavirus strain from giant pandas (Ailuropoda melanoleuca)

Two giant pandas (Ailuropoda melanoleuca) died of unknown causes in a Chinese zoo. The clinical disease profile suggested that the pandas may have suffered a viral infection. Therefore, a series of detection including virus isolation, electron microscopy, cytobiological assay, serum neutralization and RT-PCR were used to identify the virus. It was determined that the isolated virus was a canine coronavirus (CCV), on the basis of coronavirus, neutralization by canine anti-CCV serum, and 84.3% to 100% amino acid sequence similarity with CCV. The results suggest that the affected pandas had been infected with CCV.

[Pathogenesis of H5N1 avian influenza virus in C57BL/6 mice]

C57BL/6 mice were inoculated intranasally (50 microl) with serial 10-fold dilution of HAB/01 H5N1 virus. Three and five days later, three mice of each group were euthanized. Lung injury was assessed by observation of lung histopathology, virus titers and MCD50 were also measured. Our data showed that H5N1 viral infection in mice resulted in mainly epithelial injury and interstitial pneumonia, featuring significant weight loss, dramatically increased lung wet weight:body weight ratio, inflammatory cellular infiltration, alveolar and interstitial edema, hemorrhage in lungs with high virus titers, and MCD50 was 10(-6.5)/ 0.05 mL. These results suggested that a mouse model of H5N1 viral infection was successfully established which may benefit study of H5N1 avian influenza virus and pathogenic mechanism of host.

[Study on the histopathology of cats inoculated with H5N1 subtype high pathogenic avian influenza virus originated from tigers]

In this study, the HPAIV A/Tiger/Harbin/01/2002 (H5N1) used was originated from tigers and propagated in SPF embryonated hen eggs. TCID5, of the virus was 10(-7.36)/0. 05mL on MDCK cell. The cats were inoculated through bronchus route and then, the cats of dead and control were collected for histopathological and immunohistochemistry examination. Meanwhile, the emulsion supernatant fluid of organs and the pharyngeal swab samples of the dead cats were collected for RT-PCR, survived cats and the control cats were tested for the presence of HI antibody by standard method. The results indicated that the damage of lungs from the dead cats were most obvious, the wide range of red consolidation focus emerged on the lobus pulmonis, the fused focus of infection caused injury of lungs. Histology under the microscope revealed diffuse alveolar damage, confluence phlegmasia pathology, infiltration of lymphomonocytes, sackful of infiltration of macrophages and manipulus protein-like effusion in the alveolar. By immunohistochemistry, the positively stained virus particles were found on the epithelial cells of bronchus and alveolus, and also in the endochylema of lymphomonocytes. The specific electophoretic band of 464bp amplified by RT-PCR from samples of pharyngeal swabs, lungs, kidneys, hearts and brains was as same as the theory value. HI antibody titers of the survived cat were 1:32.

[Construction and experimental immunity of recombinant replication-competent canine adenovirus type 2 expressing hemagglutinin gene of H5N1 subtype tiger influenza virus]

H5N1 highly pathogenic avian influenza virus was highly pathogenic and sometimes even fatal for tigers and cats. To develop a new type of vaccine for Felidae influenza prevention, recombinant replication-competent canine adenovirus Type 2 expressing hemagglutinin gene of H5N1 subtype tiger influenza virus was constructed. A/tiger/Harbin/01/2003 (HSN1) HA gene was cloned into PVAX1. The HA expression cassette which included CMV and HA and PolyA was ligated into the E3 deletion region of pVAXdeltaE. The recombinant plasmid was named pdeltaEHA. The pdelta EHA and the pPoly2-CAV2 were digested with Nru I /Sal I, respectively. The purified Nru I/Sal I DNA fragment containing the HA expression cassette was cloned into pPoly2-CAV2 to generate the recombinant plasmid pCAV-2/HA. The recombinant genome was released from pCAV-2/HA, and was transfected into MDCK cells by Lipofectamine. The recombinant virus named CAV2/HA was gained. Anti-H5N1 influenza virus HI antibody (1:8 - 1:16) was detected in the cat immunized with CAV-2/HA.

Cross-host evolution of severe acute respiratory syndrome coronavirus in palm civet and human

The genomic sequences of severe acute respiratory syndrome coronaviruses from human and palm civet of the 2003/2004 outbreak in the city of Guangzhou, China, were nearly identical. Phylogenetic analysis suggested an independent viral invasion from animal to human in this new episode. Combining all existing data but excluding singletons, we identified 202 single-nucleotide variations. Among them, 17 are polymorphic in palm civets only. The ratio of nonsynonymous/synonymous nucleotide substitution in palm civets collected 1 yr apart from different geographic locations is very high, suggesting a rapid evolving process of viral proteins in civet as well, much like their adaptation in the human host in the early 2002-2003 epidemic. Major genetic variations in some critical genes, particularly the Spike gene, seemed essential for the transition from animal-to-human transmission to human-to-human transmission, which eventually caused the first severe acute respiratory syndrome outbreak of 2002/2003.

Regime shift signatures from stable oxygen isotopic records of otoliths of Atlantic cod (Gadus morhua)

The sudden collapse of Atlantic cod (Gadus morhua) may relate to ocean climate, or regime shifts as demonstrated in production of Pacific salmon. This paper reports the results of stable oxygen isotope ratio analyses (18O/16O or delta18OA) from 91 otoliths of cod over a period of about 20 years. Seasonal delta18OA variations of individual otoliths started at an initial value of about -0.5 to 0 per thousand VPDB, and then reached a stable level in the range of +2.5 to +3.5 per thousand VPDB after 4-5 years. The initial low values correspond to the natal sources of mature cod, while the higher delta18OA values represent the water conditions before the cod was caught. This pattern of delta18OA variation was observed over the life history of all cod examined. Furthermore, the calculated isotopic temperatures agreed with those obtained from summer bottom trawl survey, indicating that delta18OA of otoliths could be used as a thermometer in determining the ambient seawater temperature where the cod lived. Comparison of long-term delta18OA records and biological and meteorological observations suggested that decadal-scale ecosystem changes did occur in the late 1970s and early 1990s in Atlantic Canada, comparable to regime shifts occurred in the North Pacific.

[Clinical and experimental study on oral liquor night-cough tranquiller in treating infantile cough]

Oral Liquor of Night-Cough Tranquiller (NCT) was used in treating infantile cough and 128 patients have been treated. The result revealed that the total effective rate was 95.3%. In comparing with other group of patients treated with the common cold cough syrup and Caps. cephalexini, the latter has a clinical effective rate of 81.0%. A significant difference existed between the above-mentioned two groups (P < 0.05). According to the animal experiment, the NCT has some outstanding pharmacologic functions such as anti-tussive function, phlegm reducing and sedation, etc. While the LD50 of NCT has not been detected which indicated that this preparation has negligible side effect.