ABSTRACT
Immunizing mice with Crimean-Congo hemorrhagic fever virus (CCHFV) nucleoprotein (NP), glycoprotein precursor (GPC), or with the GP38 domain of GPC, can be protective when the proteins are delivered with viral vectors or as a DNA or RNA vaccine. Subunit vaccines are a safe and cost-effective alternative to some vaccine platforms, but Gc and Gn glycoprotein subunit vaccines for CCHFV fail to protect despite eliciting high levels of neutralizing antibodies. Here, we investigated humoral and cellular immune responses and the protective efficacy of recombinant NP, GP38, and GP38 forms (GP85 and GP160) associated with the highly glycosylated mucin-like (MLD) domain, as well as the NP + GP38 combination. Vaccination with GP160, GP85, or GP38 did not confer protection, and vaccination with the MLD-associated GP38 forms blunted the humoral immune responses to GP38, worsened clinical chemistry, and increased viral RNA in the blood compared to the GP38 vaccination. In contrast, NP vaccination conferred 100% protection from lethal outcome and was associated with mild clinical disease, while the NP + GP38 combination conferred even more robust protection by reducing morbidity compared to mice receiving NP alone. Thus, recombinant CCHFV NP alone is a promising vaccine candidate conferring 100% survival against heterologous challenge. Moreover, incorporation of GP38 should be considered as it further enhances subunit vaccine efficacy by reducing morbidity in surviving animals.
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ABSTRACTNipah virus (NiV) is an emerging zoonotic RNA virus that can cause fatal respiratory and neurological disease in animals and humans. Accurate NiV diagnostics and surveillance tools are crucial for the identification of acute and resolved infections and to improve our understanding of NiV transmission and circulation. Here, we have developed and validated a split NanoLuc luciferase NiV glycoprotein (G) biosensor for detecting antibodies in clinical and animal samples. This assay is performed by simply mixing reagents and measuring luminescence, which depends on the complementation of the split NanoLuc luciferase G biosensor following its binding to antibodies. This anti-NiV-G "mix-and-read" assay was validated using the WHO's first international standard for anti-NiV antibodies and more than 700 serum samples from the NiV-endemic country of Bangladesh. Anti-NiV antibodies from survivors persisted for at least 8 years according to both âºNiV-G mix-and-read and NiV neutralization assays. The âºNiV-G mix-and-read assay sensitivity (98.6%) and specificity (100%) were comparable to anti-NiV IgG ELISA performance but failed to detect anti-NiV antibodies in samples collected less than a week following the appearance of symptoms. Overall, the anti-NiV-G biosensor represents a simple, fast, and reliable tool that could support the expansion of NiV surveillance and retrospective outbreak investigations.
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BACKGROUND: The rVSVΔG-ZEBOV-GP Ebola vaccine (rVSV-ZEBOV) has been used in response to Ebola disease outbreaks caused by Ebola virus (EBOV). Understanding Ebola knowledge, attitudes, and practices (KAP) and the long-term immune response following rVSV-ZEBOV are critical to inform recommendations on future use. METHODS: We administered surveys and collected blood samples from healthcare workers (HCWs) from seven Ugandan healthcare facilities. Questionnaires collected information on demographic characteristics and KAP related to Ebola and vaccination. IgG ELISA, virus neutralization, and interferon gamma ELISpot measured immunological responses against EBOV glycoprotein (GP). RESULTS: Overall, 37 % (210/565) of HCWs reported receiving any Ebola vaccination. Knowledge that rVSV-ZEBOV only protects against EBOV was low among vaccinated (32 %; 62/192) and unvaccinated (7 %; 14/200) HCWs. Most vaccinated (91 %; 192/210) and unvaccinated (92 %; 326/355) HCWs wanted to receive a booster or initial dose of rVSV-ZEBOV, respectively. Median time from rVSV-ZEBOV vaccination to sample collection was 37.7 months (IQR: 30.5, 38.3). IgG antibodies against EBOV GP were detected in 95 % (61/64) of HCWs with vaccination cards and in 84 % (162/194) of HCWs who reported receiving a vaccination. Geometric mean titer among seropositive vaccinees was 0.066 IU/mL (95 % CI: 0.058-0.076). CONCLUSION: As Uganda has experienced outbreaks of Sudan virus and Bundibugyo virus, for which rVSV-ZEBOV does not protect against, our findings underscore the importance of continued education and risk communication to HCWs on Ebola and other viral hemorrhagic fevers. IgG antibodies against EBOV GP were detected in most vaccinated HCWs in Uganda 2â4 years after vaccination; however, the duration and correlates of protection warrant further investigation.
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BACKGROUND: Pneumatosis cystoides intestinalis (PCI), characterized by a collection of gas-filled cysts in the intestinal wall, is an uncommon but well-known condition in gastroenterology. Abdominal pain is the most frequent symptom associated with PCI. Intussusception represents a potential cause of recurrent abdominal pain or emergency presentation. However, the occurrence of colonic intussusception secondary to PCI is very unusual in adulthood. CASE SUMMARY: A 52-year-old male, known with idiopathic PCI, presented seventeen months after initial diagnosis with a new right upper quadrant pain. A computed tomography-scan demonstrated a colonic intussusception at the hepatic flexure. PCI did not progress compared with initial investigation. The patient underwent an emergency right hemicolectomy. CONCLUSION: Resection was recommended in this case because PCI proved to be persisting with no identified curable cause. Surgery allowed to address the underlying pathology, the potential relapse of intussusception, and the likely cause of recurrent abdominal pain, either invagination or PCI itself.
ABSTRACT
Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne nairovirus with a wide geographic spread that can cause severe and lethal disease. No specific medical countermeasures are approved to combat this illness. The CCHFV L protein contains an ovarian tumor (OTU) domain with a cysteine protease thought to modulate cellular immune responses by removing ubiquitin and ISG15 post-translational modifications from host and viral proteins. Viral deubiquitinases like CCHFV OTU are attractive drug targets, as blocking their activity may enhance cellular immune responses to infection, and potentially inhibit viral replication itself. We previously demonstrated that the engineered ubiquitin variant CC4 is a potent inhibitor of CCHFV replication in vitro. A major challenge of the therapeutic use of small protein inhibitors such as CC4 is their requirement for intracellular delivery, e.g., by viral vectors. In this study, we examined the feasibility of in vivo CC4 delivery by a replication-deficient recombinant adenovirus (Ad-CC4) in a lethal CCHFV mouse model. Since the liver is a primary target of CCHFV infection, we aimed to optimize delivery to this organ by comparing intravenous (tail vein) and intraperitoneal injection of Ad-CC4. While tail vein injection is a traditional route for adenovirus delivery, in our hands intraperitoneal injection resulted in higher and more widespread levels of adenovirus genome in tissues, including, as intended, the liver. However, despite promising in vitro results, neither route of in vivo CC4 treatment resulted in protection from a lethal CCHFV infection.
Subject(s)
Adenoviridae , Disease Models, Animal , Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Virus Replication , Animals , Hemorrhagic Fever Virus, Crimean-Congo/genetics , Hemorrhagic Fever, Crimean/virology , Mice , Adenoviridae/genetics , Viral Proteins/genetics , Viral Proteins/metabolism , Genetic Vectors/genetics , Antiviral Agents/pharmacology , Female , Liver/virology , HumansABSTRACT
Crimean-Congo hemorrhagic fever virus (CCHFV) can cause severe human disease and is considered a WHO priority pathogen due to the lack of efficacious vaccines and antivirals. A CCHF virus replicon particle (VRP) has previously shown protective efficacy in a lethal Ifnar-/- mouse model when administered as a single dose at least 3 days prior to challenge. Here, we determine that non-specific immune responses are not sufficient to confer short-term protection, since Lassa virus VRP vaccination 3 days prior to CCHFV challenge was not protective. We also investigate how CCHF VRP vaccination confers protective efficacy by examining viral kinetics, histopathology, clinical analytes and immunity early after challenge (3 and 6 days post infection) and compare to unvaccinated controls. We characterize how these effects differ based on vaccination period and correspond to previously reported CCHF VRP-mediated protection. Vaccinating Ifnar-/- mice with CCHF VRP 28, 14, 7, or 3 days prior to challenge, all known to confer complete protection, significantly reduced CCHFV viral load, mucosal shedding, and markers of clinical disease, with greater reductions associated with longer vaccination periods. Interestingly, there were no significant differences in innate immune responses, T cell activation, or antibody titers after challenge between groups of mice vaccinated a week or more before challenge, but higher anti-NP antibody avidity and effector function (ADCD) were positively associated with longer vaccination periods. These findings support the importance of antibody-mediated responses in VRP vaccine-mediated protection against CCHFV infection.
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Nairoviridae is a family for negative-sense RNA viruses with genomes of about 17.2-21.1 kb. These viruses are maintained in and/or transmitted by arthropods among birds, reptiles and mammals. Norwaviruses and orthonairoviruses can cause febrile illness in humans. Several orthonairoviruses can infect mammals, causing mild, severe and sometimes, fatal diseases. Nairovirids produce enveloped virions containing two or three single-stranded RNA segments with open reading frames that encode a nucleoprotein (N), sometimes a glycoprotein precursor (GPC), and a large (L) protein containing an RNA-directed RNA polymerase (RdRP) domain. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) report on the family Nairoviridae, which is available at www.ictv.global/report/nairoviridae.
Subject(s)
Genome, Viral , Animals , Humans , Open Reading Frames , Viral Proteins/genetics , Nairovirus/genetics , Nairovirus/classification , Nairovirus/isolation & purification , RNA, Viral/genetics , Phylogeny , Virion/ultrastructure , RNA-Dependent RNA Polymerase/geneticsABSTRACT
Crimean-Congo hemorrhagic fever virus (CCHFV) is a WHO priority pathogen. Antibody-based medical countermeasures offer an important strategy to mitigate severe disease caused by CCHFV. Most efforts have focused on targeting the viral glycoproteins. However, glycoproteins are poorly conserved among viral strains. The CCHFV nucleocapsid protein (NP) is highly conserved between CCHFV strains. Here, we investigate the protective efficacy of a CCHFV monoclonal antibody targeting the NP. We find that an anti-NP monoclonal antibody (mAb-9D5) protected female mice against lethal CCHFV infection or resulted in a significant delay in mean time-to-death in mice that succumbed to disease compared to isotype control animals. Antibody protection is independent of Fc-receptor functionality and complement activity. The antibody bound NP from several CCHFV strains and exhibited robust cross-protection against the heterologous CCHFV strain Afg09-2990. Our work demonstrates that the NP is a viable target for antibody-based therapeutics, providing another direction for developing immunotherapeutics against CCHFV.
Subject(s)
Hemorrhagic Fever Virus, Crimean-Congo , Hemorrhagic Fever, Crimean , Female , Animals , Mice , Hemorrhagic Fever Virus, Crimean-Congo/metabolism , Nucleocapsid Proteins/metabolism , Antibodies, Monoclonal , Hemorrhagic Fever, Crimean/prevention & control , Glycoproteins/metabolism , Antibodies, ViralABSTRACT
Nipah virus (NiV) is a highly pathogenic paramyxovirus. The Syrian hamster model recapitulates key features of human NiV disease and is a critical tool for evaluating antivirals and vaccines. Here we describe longitudinal humoral immune responses in NiV-infected Syrian hamsters. Samples were obtained 1-28 days after infection and analyzed by ELISA, neutralization, and Fc-mediated effector function assays. NiV infection elicited robust antibody responses against the nucleoprotein and attachment glycoprotein. Levels of neutralizing antibodies were modest and only detectable in surviving animals. Fc-mediated effector functions were mostly observed in nucleoprotein-targeting antibodies. Antibody levels and activities positively correlated with challenge dose.
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Ebola disease outbreaks are major public health events because of human-to-human transmission and high mortality. These outbreaks are most often caused by Ebola virus, but at least three related viruses can also cause the disease. In 2022, Sudan virus re-emerged causing more than 160 confirmed and probable cases. This report describes generation of a recombinant Sudan virus and demonstrates its utility by quantifying antibody cross-reactivity between Ebola and Sudan virus glycoproteins after human infection or vaccination with a licensed Ebola virus vaccine.
Subject(s)
Ebolavirus , Hemorrhagic Fever, Ebola , Humans , Hemorrhagic Fever, Ebola/prevention & control , Antibodies, Viral , Ebolavirus/genetics , Vaccination , Glycoproteins/geneticsABSTRACT
BACKGROUND: The recurrence of common bile duct stones and other biliary events after endoscopic retrograde cholangiopancreatography (ERCP) is frequent. Despite recommendations for early cholecystectomy, intervention during the same admission is carried out inconsistently. METHODS: We reviewed the records of patients who underwent ERCP for gallstone disease and common bile duct clearance followed by cholecystectomy between July 2012 and June 2022. Patients were divided into 2 groups: the index group underwent cholecystectomy during the same admission and the delayed group was discharged and had their cholecystectomy postponed. Data on demographics and prognosis factors were collected and analyzed. RESULTS: The study population was composed of 268 patients, with 71 (26.6%) having undergone cholecystectomy during the same admission after common bile duct clearance with ERCP. A greater proportion of patients aged 80 years and older were in the index group than in the delayed group. The American Society of Anesthesiologists score was significantly higher in the index group. There was no significant difference between groups regarding surgical complications, open cholecystectomy and death. The operative time was significantly longer in the delayed group. Among patients with delayed cholecystectomy, 18.3% had at least 1 recurrence of common bile duct stones (CBDS) and 38.6% had recurrence of any gallstone-related events before cholecystectomy. None of these events occurred in the the index group. There was no difference in the recurrence of CBDS and other biliary events after initial diagnosis associated with stone disease. CONCLUSION: Cholecystectomy during the same admission after common bile duct clearance is safe, even in older adults with comorbidities. Compared with delayed cholecystectomy, it was not associated with adverse outcomes and may have prevented recurrence of biliary events.
Subject(s)
Cholangiopancreatography, Endoscopic Retrograde , Common Bile Duct , Humans , Aged , Common Bile Duct/surgery , Hospitalization , Patient Discharge , Cholecystectomy/adverse effectsABSTRACT
BACKGROUND: Gallstone disease will affect 15% of the adult population with concomitant common bile duct stone (CBDS) occurring in up to 30%. Endoscopic retrograde cholangiopancreatography (ERCP) is the mainstay of management for removal of CBDS, as cholecystectomy for the prevention of recurrent biliary event (RBE). RBE occurs in up to 47% if cholecystectomy is not done. The goal of this study was to evaluate the timing of occurrence of RBE after common bile duct clearance with ERCP and associated outcomes. METHODS: The records of all patients who underwent ERCP for gallstone disease followed by cholecystectomy, in a single center from 2010 to 2022, were reviewed. All RBE were identified. Actuarial incidence of RBE was built. Patients with and without RBE were compared. RESULTS: The study population is composed of 529 patients. Mean age was 58.0 (18-95). There were 221 RBE in 151 patients (28.5%), 39/151 (25.8%) having more than one episode. The most frequent RBE was acute cholecystitis (n = 104) followed by recurrent CBDS (n = 95). Median time for first RBE was 34 days. Actuarial incidence of RBE started from 2.5% at 7 days to reach 53.3% at 1 year. Incidence-rate of RBE was 2.9 per 100 person-months. Patients with RBE had significant longer hospitalisation time (11.7 vs 6.4 days; P < 0.0001), longer operative time (66 vs 48 min; P < 0.0001), longer postoperative stay (2.9 vs 0.9 days; P < 0.0001), higher open surgery rate (7.9% vs 1.3%; P < 0.0001), and more complicated pathology (23.8% vs 5.8%; P < 0.0001) and cholecystitis (64.2% vs 25.9%; P < 0.0001) as final diagnoses. CONCLUSIONS: RBE occurred in 28.5% of the subjects at a median time of 34 days, with an incidence of 2.5% as early as 1 week. Cholecystectomy should be done preferably within 7 days after common bile duct clearance in order to prevent RBE and adverse outcomes.
Subject(s)
Cholecystectomy, Laparoscopic , Choledocholithiasis , Gallstones , Running , Adult , Humans , Middle Aged , Cholangiopancreatography, Endoscopic Retrograde , Sphincterotomy, Endoscopic , Common Bile Duct/surgery , Cholecystectomy/adverse effects , Gallstones/surgery , Choledocholithiasis/surgery , Retrospective StudiesABSTRACT
[This corrects the article DOI: 10.3389/fmed.2023.1178696.].
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In April 2023, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by one new family, 14 new genera, and 140 new species. Two genera and 538 species were renamed. One species was moved, and four were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.
Subject(s)
Negative-Sense RNA Viruses , RNA Viruses , RNA Viruses/genetics , RNA-Dependent RNA Polymerase/geneticsABSTRACT
Nipah virus (NiV) is a highly pathogenic paramyxovirus with a high case fatality rate. Due to its high pathogenicity, pandemic potential, and lack of therapeutics or approved vaccines, its study requires biosafety level 4 (BSL4) containment. In this report, we developed a novel neutralization assay for use in biosafety level 2 laboratories. The assay uses a recombinant vesicular stomatitis virus expressing NiV glycoprotein and a fluorescent protein. The recombinant virus propagates as a replication-competent virus in a cell line constitutively expressing NiV fusion protein, but it is restricted to a single round of replication in wild-type cells. We used this system to evaluate the neutralization activity of monoclonal and polyclonal antibodies, plasma from NiV-infected hamsters, and serum from human patients. Therefore, this recombinant virus could be used as a surrogate for using pathogenic NiV and may constitute a powerful tool to develop therapeutics in low containment laboratories.
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Nipah virus (NiV) causes a highly lethal disease in humans who present with acute respiratory or neurological signs. No vaccines against NiV have been approved to date. Here, we report on the clinical impact of a novel NiV-derived nonspreading replicon particle lacking the fusion (F) protein gene (NiVΔF) as a vaccine in three small animal models of disease. A broad antibody response was detected that included immunoglobulin G (IgG) and IgA subtypes with demonstrable Fc-mediated effector function targeting multiple viral antigens. Single-dose intranasal vaccination up to 3 days before challenge prevented clinical signs and reduced virus levels in hamsters and immunocompromised mice; decreases were seen in tissues and mucosal secretions, critically decreasing potential for virus transmission. This virus replicon particle system provides a vital tool to the field and demonstrates utility as a highly efficacious and safe vaccine candidate that can be administered parenterally or mucosally to protect against lethal Nipah disease.
Subject(s)
Henipavirus Infections , Nipah Virus , Viral Vaccines , Cricetinae , Humans , Animals , Mice , Henipavirus Infections/prevention & control , Henipavirus Infections/genetics , Vaccination , Disease Models, Animal , Nipah Virus/genetics , RepliconABSTRACT
Bouveret syndrome is a gastric outlet obstruction, and biliary ileus is an obstruction of the small bowel, and both are caused by a gallstone that escaped the gallbladder through a bilio-enteric fistula. The concurrent occurrence of obstruction at both sites is encountered very rarely, and only two such cases associated with Bouveret syndrome were reported before. We now present a case involving a 78-year-old female with simultaneous obstruction at both the duodenum and jejunum. The literature is reviewed to evaluate the incidence of such a situation and to discuss the management of the case.