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The maintenance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among wildlife populations poses a potential risk for the emergence of novel variants. Therefore, monitoring SARS-CoV-2 infection among animals is crucial. As urban rodents live in close proximity to human habitats, there is concern that they may be a potential source of zoonoses. To examine the prevalence of SARS-CoV-2 in rodent populations, we analyzed 128 serum samples and 129 oral swabs collected from 128 brown rats (Rattus norvegicus) and 2 black rats (Rattus rattus) captured for pest control purposes in Tokyo, Japan, between May and December 2023. A virus-neutralizing test using the Omicron variant revealed no evidence of SARS-CoV-2 infection in these populations. Real-time RT-PCR from oral swabs did not detect any SARS-CoV-2 RNA-positive rats. These results indicate the low probability of SARS-CoV-2 circulation among rat populations in Tokyo.
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Tibroviruses are novel rhabdoviruses detected in humans, cattle, and arthropods. Four tibroviruses are known to infect humans: Bas-Congo virus (BASV), Ekpoma virus 1 (EKV-1), Ekpoma virus 2, and Mundri virus. However, since none of them has been isolated, their biological properties are largely unknown. We aimed to characterize the human tibrovirus glycoprotein (G), which likely plays a pivotal role in viral tropism and pathogenicity. Human tibrovirus Gs were found to share some primary structures and display 14 conserved cysteine residues, although their overall amino acid homology was low (29%-48%). Multiple potential glycosylation sites were found on the G molecules, and endoglycosidase H- and peptide-N-glycosidase F-sensitive glycosylation was confirmed. AlphaFold-predicted three-dimensional (3D) structures of human tibrovirus Gs were overall similar. Membrane fusion mediated by these tibrovirus Gs was induced by acidic pH. The low pH-induced conformational change that triggers fusion was reversible. Virus-like particles (VLPs) were produced by transient expression of Gs in cultured cells and used to produce mouse antisera. Using vesicular stomatitis Indiana virus pseudotyped with Gs, we found that the antisera to the respective tibrovirus VLPs showed limited cross-neutralizing activity. It was also found that human C-type lectins and T-cell immunoglobulin mucin 1 acted as attachment factors for G-mediated entry into cells. Interestingly, BASV-G showed the highest ability to utilize these molecules. The viruses infected a wide range of cell lines with preferential tropism for human-derived cells whereas the preference of EKV-1 was unique compared with the other human tibroviruses. These findings provide fundamental information to understand the biological properties of the human tibroviruses. IMPORTANCE: Human tibroviruses are poorly characterized emerging rhabdoviruses associated with either asymptomatic infection or severe disease with a case fatality rate as high as 60% in humans. However, the extent and burden of human infection as well as factors behind differences in infection outcomes are largely unknown. In this study, we characterized human tibrovirus glycoproteins, which play a key role in virus-host interactions, mainly focusing on their structural and antigenic differences and cellular tropism. Our results provide critical information for understanding the biological properties of these novel viruses and for developing appropriate preparedness interventions such as diagnostic tools, vaccines, and effective therapies.
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Proteínas do Envelope Viral , Humanos , Animais , Proteínas do Envelope Viral/metabolismo , Proteínas do Envelope Viral/genética , Camundongos , Glicosilação , Internalização do Vírus , Tropismo Viral , Linhagem Celular , Mucina-1/metabolismo , Células HEK293 , Anticorpos Antivirais/imunologia , Sequência de AminoácidosRESUMO
Rabies virus (RABV) causes fatal neurological disease. Pre-exposure prophylaxis (PrEP) and post-exposure prophylaxis (PEP) using inactivated-virus vaccines are the most effective measures to prevent rabies. In Japan, HEP-Flury, the viral strain, used as a human rabies vaccine, has historically been propagated in primary fibroblast cells derived from chicken embryos. In the present study, to reduce the cost and labor of vaccine production, we sought to adapt the original HEP-Flury (HEP) to Vero cells. HEP was repeatedly passaged in Vero cells to generate ten- (HEP-10V) and thirty-passaged (HEP-30V) strains. Both HEP-10V and HEP-30V grew significantly better than HEP in Vero cells, with virulence and antigenicity similar to HEP. Comparison of the complete genomes with HEP revealed three non-synonymous mutations in HEP-10V and four additional non-synonymous mutations in HEP-30V. Comparison among 18 recombinant HEP strains constructed by reverse genetics and vesicular stomatitis viruses pseudotyped with RABV glycoproteins indicated that the substitution P(L115H) in the phosphoprotein and G(S15R) in the glycoprotein improved viral propagation in HEP-10V, while in HEP-30V, G(V164E), G(L183P), and G(A286V) in the glycoprotein enhanced entry into Vero cells. The obtained recombinant RABV strain, rHEP-PG4 strain, with these five substitutions, is a strong candidate for production of human rabies vaccine.
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Substituição de Aminoácidos , Vacina Antirrábica , Vírus da Raiva , Animais , Células Vero , Chlorocebus aethiops , Vacina Antirrábica/genética , Vacina Antirrábica/imunologia , Vírus da Raiva/genética , Vírus da Raiva/imunologia , Humanos , Raiva/prevenção & controle , Raiva/virologia , Genoma ViralRESUMO
Tissue stem cells often exhibit developmental stage-specific and sexually dimorphic properties, but the underlying mechanism remains largely elusive. By characterizing IGF1R signaling in hematopoietic cells, here we report that its disruption exerts sex-specific effects in adult hematopoietic stem and progenitor cells (HSPCs). Loss of IGF1R decreases the HSPC population in females but not in males, in part due to a reduction in HSPC proliferation induced by estrogen. In addition, the adult female microenvironment enhances engraftment of wild-type but not Igf1r-null HSPCs. In contrast, during gestation, when both female and male fetuses are exposed to placental estrogens, loss of IGF1R reduces the numbers of their fetal liver HSPCs regardless of sex. Collectively, these data support the interplay of IGF1R and estrogen pathways in HSPCs and suggest that the proliferation-promoting effect of estrogen on HSPCs is in part mediated via IGF1R signaling.
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We report a draft genome sequence of Yersinia pseudotuberculosis isolated from the spleen of a wild rat from Mikura-shima Island, Japan. The bacterium was identified as serotype O:4b using PCR-based O-genotyping. These genomic data provide insights into the pathogenic potential of this strain in spontaneous outbreaks among wild animals.
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BACKGROUND: Bas-Congo virus (BASV), an emerging tibrovirus, was associated with an outbreak of acute haemorrhagic fever in Mangala, Democratic Republic of the Congo, in 2009. In 2012, neutralising antibodies to BASV were detected in the lone survivor and one of his close contacts. However, subsequent serological and molecular surveys were unsuccessful as neither BASV antibodies nor its RNA were detected. In this study, we determined the seroprevalence of BASV infection in Mangala 13 years after the initial outbreak. METHODS: We conducted a population-based serological survey from Jan 17 to Jan 23, 2022. Consenting individuals at least 5 years of age, living in Mangala for at least 4 weeks, and who had no contraindication to venepuncture were enrolled. Participants were interviewed using a pre-tested questionnaire for sociodemographic and clinical characteristics. We supplemented the collected serum samples with 284 archived samples from Matadi and Kinshasa. All samples were tested for antibodies to BASV and other tibroviruses using a pseudovirus-based neutralisation test. FINDINGS: Among the 267 individuals from Mangala, the prevalence of BASV antibodies was 55% (95% CI 49-61; n=147). BASV seropositivity odds significantly increased with age (5·2 [95% CI 2·1-12·9] to 83·9 [20·8-337·7] times higher in participants aged 20 years or older than participants aged 5-19 years). Some occupational categories (eg, farmer or public servant) were associated with seropositivity. Only nine (6%) of 160 samples from Matadi and one (<1%) of 124 samples from Kinshasa had neutralising antibodies to BASV. Moreover, we also detected neutralising antibodies to other tibroviruses-Ekpoma virus 1, Ekpoma virus 2, and Mundri virus-in 84 (31%), 251 (94%), and 219 (82%) of 267 Mangala samples; 14 (9%), 62 (39%), and 120 (75%) of 160 Matadi samples; and six (5%), five (4%), and 33 (27%) of 124 Kinshasa samples, respectively. INTERPRETATION: Human infection with BASV and other tibroviruses seems common in Mangala, although no deadly outbreak has been reported since 2009. Exposure to BASV might be highly restricted to Mangala and the increasing prevalence of neutralising antibodies with age suggests regular contact with the virus in this city. Altogether, our findings suggest that human infection with tibroviruses could be common in the study areas and not associated with deadly haemorrhagic or debilitating syndromes. FUNDING: Japan Agency for Medical Research and Development (AMED) and Japan International Cooperation Agency (JICA) under the Science and Technology Research Partnership for Sustainable Development (SATREPS) and Japan Program for Infectious Diseases Research and Infrastructure from AMED.
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Anticorpos Antivirais , Humanos , República Democrática do Congo/epidemiologia , Masculino , Estudos Soroepidemiológicos , Adulto , Estudos Transversais , Adolescente , Feminino , Pessoa de Meia-Idade , Criança , Adulto Jovem , Anticorpos Antivirais/sangue , Pré-Escolar , Anticorpos Neutralizantes/sangue , Idoso , Surtos de DoençasRESUMO
Rabies is a fatal zoonotic, neurological disease caused by rabies lyssavirus (RABV) and other lyssaviruses. In this study, we established novel serological neutralizing tests (NT) based on vesicular stomatitis virus pseudotypes possessing all 18 known lyssavirus glycoproteins. Applying this system to comparative NT against rabbit sera immunized with current RABV vaccines, we showed that the current RABV vaccines fail to elicit sufficient neutralizing antibodies against lyssaviruses other than to those in phylogroup I. Furthermore, comparative NT against rabbit antisera for 18 lyssavirus glycoproteins showed glycoproteins of some lyssaviruses elicited neutralizing antibodies against a broad range of lyssaviruses. This novel testing system will be useful to comprehensively detect antibodies against lyssaviruses and evaluate their cross-reactivities for developing a future broad-protective vaccine.
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Lyssavirus , Vacina Antirrábica , Vírus da Raiva , Raiva , Animais , Coelhos , Raiva/veterinária , Anticorpos Antivirais , Pseudotipagem Viral/veterinária , Anticorpos Neutralizantes , Glicoproteínas , ZoonosesRESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among pets owned by coronavirus disease 2019 (COVID-19) patients has been reported around the world. However, how often the animals are exposed to SARS-CoV-2 by their owners is still unclear. We have collected swab samples from COVID-19 patients' pets and performed real-time RT-PCR to detect the viral genome. In total, 8 of 53 dogs (15.1%) and 5 of 34 cats (14.7%) tested positive for the SARS-CoV-2 N gene. The result of a virus neutralization (VN) test also showed VN antibodies in four cats and six dogs. Our results indicate that the virus often passed from infected owners to their pets, which then excreted the virus despite having no or mild clinical signs.
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COVID-19 , Doenças do Gato , Doenças do Cão , Humanos , Animais , Cães , Gatos , SARS-CoV-2/genética , Genoma Viral , Testes Sorológicos , Manejo de EspécimesRESUMO
Mpox virus (formerly monkeypox virus [MPXV]) is a neglected zoonotic pathogen that caused a worldwide outbreak in May 2022. Given the lack of an established therapy, the development of an anti-MPXV strategy is of vital importance. To identify drug targets for the development of anti-MPXV agents, we screened a chemical library using an MPXV infection cell assay and found that gemcitabine, trifluridine, and mycophenolic acid (MPA) inhibited MPXV propagation. These compounds showed broad-spectrum anti-orthopoxvirus activities and presented lower 90% inhibitory concentrations (0.026 to 0.89 µM) than brincidofovir, an approved anti-smallpox agent. These three compounds have been suggested to target the postentry step to reduce the intracellular production of virions. Knockdown of IMP dehydrogenase (IMPDH), the rate-limiting enzyme of guanosine biosynthesis and a target of MPA, dramatically reduced MPXV DNA production. Moreover, supplementation with guanosine recovered the anti-MPXV effect of MPA, suggesting that IMPDH and its guanosine biosynthetic pathway regulate MPXV replication. By targeting IMPDH, we identified a series of compounds with stronger anti-MPXV activity than MPA. This evidence shows that IMPDH is a potential target for the development of anti-MPXV agents. IMPORTANCE Mpox is a zoonotic disease caused by infection with the mpox virus, and a worldwide outbreak occurred in May 2022. The smallpox vaccine has recently been approved for clinical use against mpox in the United States. Although brincidofovir and tecovirimat are drugs approved for the treatment of smallpox by the U.S. Food and Drug Administration, their efficacy against mpox has not been established. Moreover, these drugs may present negative side effects. Therefore, new anti-mpox virus agents are needed. This study revealed that gemcitabine, trifluridine, and mycophenolic acid inhibited mpox virus propagation and exhibited broad-spectrum anti-orthopoxvirus activities. We also suggested IMP dehydrogenase as a potential target for the development of anti-mpox virus agents. By targeting this molecule, we identified a series of compounds with stronger anti-mpox virus activity than mycophenolic acid.
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Monkeypox virus , Ácido Micofenólico , Guanosina/farmacologia , IMP Desidrogenase/genética , IMP Desidrogenase/metabolismo , Ácido Micofenólico/farmacologia , Trifluridina , Monkeypox virus/efeitos dos fármacosRESUMO
Purpose: The starting time for probiotic supplementation in preterm infants after birth varies widely. This study aimed to investigate the optimal time for initiating probiotics to reduce adverse outcomes in preterm or very low birth weight (VLBW) infants. Methods: Medical records of preterm infants born at a gestational age (GA) of <32 weeks or VLBW infants in 2011-2020 were reviewed respectively. The infants who received Saccharomyces boulardii probiotics within 7 days of birth were grouped into an early introduction (EI) group, and those who received supplemented probiotics after 7 days of birth were part of the late introduction (LI) group. Clinical characteristics were compared between the two groups and analyzed statistically. Results: A total of 370 infants were included. The mean GA (29.1 weeks vs. 31.2 weeks, p<0.001) and birth weight (1,235.9 g vs. 1491.4 g, p<0.001) were lower in the LI group (n=223) than in the EI group. The multivariate analysis indicated that factors affecting the LI of probiotics were GA at birth (odds ratio [OR], 1.52; p<0.001) and the enteral nutrition start day (OR, 1.47; p<0.001). The late probiotic introduction was associated with a risk of late-onset sepsis (OR, 2.85; p=0.020), delayed full enteral nutrition (OR, 5.44; p<0.001), and extrauterine growth restriction (OR, 1.67; p=0.033) on multivariate analyses after adjusting for GA. Conclusion: Early supplementation of probiotics within a week after birth may reduce adverse outcomes among preterm or VLBW infants.
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BACKGROUND: In clinical practice, the importance of interactive engagement behaviors is overlooked in children with developmental problems other than autism spectrum disorder (ASD). Parenting stress affects children's development but lacks attention from clinicians. PURPOSE: This study aimed to identify the characteristics of interactive engagement behaviors and parenting stress among non-ASD children with developmental delays (DDs). We also analyzed whether engagement behaviors affect parenting stress. METHODS: At Gyeongsang National University Hospital, between May 2021 and October 2021, we retrospectively enrolled 51 consecutive patients diagnosed with DDs in language or cognition (but not ASD) in the delayed group and 24 typically developing children in the control group. The Korean version of the Parenting Stress Index-4 and Child Interactive Behavior Test were used to assess the participants. RESULTS: The median age of the delayed group was 31.0 months (interquartile range, 25.0-35.5 months); this group included 42 boys (82.4%). There were no intergroup differences in child age, child sex, parental age, parental educational background, mother's employment status, or marital status. Higher parenting stress (P<0.001) and fewer interactive engagement behaviors (P<0.001) were observed in the delayed group. Low parental acceptance and competence had the largest effects on total parenting stress in the delayed group. A mediation analysis revealed that DDs did not directly affect total parenting stress (ß=3.49, P=0.440). Instead, DDs contributed to total parenting stress, which was mediated by children's overall interactive engagement behaviors (ß=57.30, P<0.001). CONCLUSION: Interactive engagement behaviors were significantly reduced in non-ASD children with DDs and significantly mediated parenting stress. The importance of parenting stress and interactive behaviors in children with DDs should be further examined in clinical practice.
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BACKGROUND: Mpox virus (MPXV) is a zoonotic orthopoxvirus and caused an outbreak in 2022. Although tecovirimat and brincidofovir are approved as anti-smallpox drugs, their effects in mpox patients have not been well documented. In this study, by a drug repurposing approach, we identified potential drug candidates for treating mpox and predicted their clinical impacts by mathematical modeling. METHODS: We screened 132 approved drugs using an MPXV infection cell system. We quantified antiviral activities of potential drug candidates by measuring intracellular viral DNA and analyzed the modes of action by time-of-addition assay and electron microscopic analysis. We further predicted the efficacy of drugs under clinical concentrations by mathematical simulation and examined combination treatment. RESULTS: Atovaquone, mefloquine, and molnupiravir exhibited anti-MPXV activity, with 50% inhibitory concentrations of 0.51-5.2 µM, which was more potent than cidofovir. Whereas mefloquine was suggested to inhibit viral entry, atovaquone and molnupiravir targeted postentry processes. Atovaquone was suggested to exert its activity through inhibiting dihydroorotate dehydrogenase. Combining atovaquone with tecovirimat enhanced the anti-MPXV effect of tecovirimat. Quantitative mathematical simulations predicted that atovaquone can promote viral clearance in patients by 7 days at clinically relevant drug concentrations. CONCLUSIONS: These data suggest that atovaquone would be a potential candidate for treating mpox.
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Mefloquina , Monkeypox virus , Humanos , Atovaquona/farmacologia , Atovaquona/uso terapêutico , Mefloquina/farmacologia , Mefloquina/uso terapêutico , Monkeypox virus/efeitos dos fármacosRESUMO
Epithelial ovarian cancer (EOC) can originate from either fallopian tube epithelial (FTE) or ovarian surface epithelial (OSE) cells, but with different latencies and disease outcomes. To address the basis of these differences, we performed single cell RNA-sequencing of mouse cells isolated from the distal half of fallopian tube (FT) and surface layer of ovary. We find at the molecular level, FTE secretory stem/progenitor cells and OSE cells resemble mammary luminal progenitors and basal cells, respectively. An FT stromal subpopulation, enriched with Pdgfra + and Esr1 + cells, expresses multiple secreted factor (e.g., IGF1) and Hedgehog pathway genes and may serve as a niche for FTE cells. In contrast, Lgr5 + OSE cells express similar genes largely by themselves, raising a possibility that they serve as their own niche. The differences in intrinsic expression programs and niche organizations of FTE and OSE cells may contribute to their different courses toward the development of EOCs.
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PURPOSE: Renal tumors account for approximately 7% of all childhood cancers. These include Wilms tumor (WT), clear cell sarcoma of the kidney (CCSK), malignant rhabdoid tumor of the kidney (MRTK), renal cell carcinoma (RCC), congenital mesoblastic nephroma (CMN) and other rare tumors. We investigated the epidemiology of pediatric renal tumors in Korea. MATERIALS AND METHODS: From January 2001 to December 2015, data of pediatric patients (0-18 years) newly-diagnosed with renal tumors at 26 hospitals were retrospectively analyzed. RESULTS: Among 439 patients (male, 240), the most common tumor was WT (n=342, 77.9%), followed by RCC (n=36, 8.2%), CCSK (n=24, 5.5%), MRTK (n=16, 3.6%), CMN (n=12, 2.7%), and others (n=9, 2.1%). Median age at diagnosis was 27.1 months (range 0-225.5) and median follow-up duration was 88.5 months (range 0-211.6). Overall, 32 patients died, of whom 17, 11, 1, and 3 died of relapse, progressive disease, second malignant neoplasm, and treatment-related mortality. Five-year overall survival and event free survival were 97.2% and 84.8% in WT, 90.6% and 82.1% in RCC, 81.1% and 63.6% in CCSK, 60.3% and 56.2% in MRTK, and 100% and 91.7% in CMN, respectively (p < 0.001). CONCLUSION: The pediatric renal tumor types in Korea are similar to those previously reported in other countries. WT accounted for a large proportion and survival was excellent. Non-Wilms renal tumors included a variety of tumors and showed inferior outcome, especially MRTK. Further efforts are necessary to optimize the treatment and analyze the genetic characteristics of pediatric renal tumors in Korea.
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Carcinoma de Células Renais , Neoplasias Renais , Nefroma Mesoblástico , Tumor Rabdoide , Sarcoma , Tumor de Wilms , Criança , Humanos , Masculino , Carcinoma de Células Renais/epidemiologia , Estudos Retrospectivos , Recidiva Local de Neoplasia , Neoplasias Renais/terapia , Neoplasias Renais/tratamento farmacológico , Nefroma Mesoblástico/congênito , Nefroma Mesoblástico/metabolismo , Nefroma Mesoblástico/patologia , Tumor Rabdoide/patologia , República da Coreia/epidemiologiaRESUMO
Introduction: Severe fever with thrombocytopenia syndrome (SFTS) is a fatal viral disease characterized by high fever, thrombocytopenia, leukopenia, and multi-organ haemorrhage. Disruption of the humoral immune response and decreased lymphocyte numbers are thought to contribute to the disease severity. These findings have been obtained through the analysis of peripheral blood leukocytes in human patients, whereas analysis of lymph nodes has been limited. Thus, in this study, we characterized the germinal centre response and apoptosis in the lymph nodes of cats with fatal SFTS, because SFTS in cats well mimics the pathology of human SFTS. Methods: Lymph node tissue sections collected during necropsy from seven fatal SFTS patients and five non-SFTS cases were used for histopathological analysis. Additionally, lymph node tissue sections collected from cats with experimental infection of SFTS virus (SFTSV) were also analysed. Results: In the lymphoid follicles of cats with SFTS, a drastic decrease in Bcl6- and Ki67-positive germinal centre B cells was observed. Together, the number of T cells in the follicles was also decreased in SFTS cases. In the paracortex, a marked increase in cleaved-caspase3 positivity was observed in T cells. These changes were independent of the number of local SFTS virus-positive cell. Furthermore, the analysis of cats with experimental SFTSV infection revealed that the intrafollicular Bcl6- and CD3-positive cell numbers in cats with low anti-SFTSV antibody production were significantly lower than those in cats with high anti-SFTSV antibody production. Discussion: These results suggest that dysfunction of the humoral response in severe SFTS was caused by the loss of germinal centre formation and massive apoptosis of T cells in the lymph nodes due to systemically circulating viruses.
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Lysophosphatidic acid (LPA) is a bioactive lipid enriched in the tumor microenvironment of immunosuppressive malignancies such as ovarian cancer. Although LPA enhances the tumorigenic attributes of cancer cells, the immunomodulatory activity of this phospholipid messenger remains largely unexplored. Here, we report that LPA operates as a negative regulator of type I interferon (IFN) responses in ovarian cancer. Ablation of the LPA-generating enzyme autotaxin (ATX) in ovarian cancer cells reprogrammed the tumor immune microenvironment, extended host survival, and improved the effects of therapies that elicit protective responses driven by type I IFN. Mechanistically, LPA sensing by dendritic cells triggered PGE2 biosynthesis that suppressed type I IFN signaling via autocrine EP4 engagement. Moreover, we identified an LPA-controlled, immune-derived gene signature associated with poor responses to combined PARP inhibition and PD-1 blockade in patients with ovarian cancer. Controlling LPA production or sensing in tumors may therefore be useful to improve cancer immunotherapies that rely on robust induction of type I IFN. SIGNIFICANCE: This study uncovers that ATX-LPA is a central immunosuppressive pathway in the ovarian tumor microenvironment. Ablating this axis sensitizes ovarian cancer hosts to various immunotherapies by unleashing protective type I IFN responses. Understanding the immunoregulatory programs induced by LPA could lead to new biomarkers predicting resistance to immunotherapy in patients with cancer. See related commentary by Conejo-Garcia and Curiel, p. 1841. This article is highlighted in the In This Issue feature, p. 1825.
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Interferon Tipo I , Lisofosfolipídeos , Neoplasias Ovarianas , Feminino , Humanos , Lisofosfolipídeos/genética , Lisofosfolipídeos/metabolismo , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Receptores de Ácidos Lisofosfatídicos/genética , Receptores de Ácidos Lisofosfatídicos/metabolismo , Microambiente TumoralRESUMO
A two-year-old male domestic cat showed lethargy, tonic-clonic convulsion, and mucosal jaundice. Upon admission, blood examination indicated severe neutropenia and thrombocytopenia, and ultrasonography revealed diffuse splenomegaly with a honeycomb appearance and abdominal lymph nodes enlargement in addition to a decrease in cardiac blood flow indicating a shock condition. Cytology of the spleen showed a cell population composed of immature large lymphoid cells with distinct nucleoli, suggesting lymphoma. The cat received symptomatic treatments but died four hours later. Reverse transcriptase polymerase chain reaction assay of the spleen sample indicated the presence of severe fever with thrombocytopenia syndrome (SFTS) virus S gene segment. Clinical features of this case that was diagnose as SFTS were similar to lymphoma. Therefore, pet owners and veterinary workers should be protected against infection of SFTS.
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Doenças do Gato , Linfoma , Phlebovirus , Febre Grave com Síndrome de Trombocitopenia , Animais , Doenças do Gato/diagnóstico , Gatos , Linfoma/veterinária , Masculino , Phlebovirus/genética , Febre Grave com Síndrome de Trombocitopenia/veterináriaRESUMO
Effective vaccines are essential for the control of the coronavirus disease 2019 (COVID-19) pandemic. Currently developed vaccines inducing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S)-antigen-specific neutralizing antibodies (NAbs) are effective, but the appearance of NAb-resistant S variant viruses is of great concern. A vaccine inducing S-independent or NAb-independent SARS-CoV-2 control may contribute to containment of these variants. Here, we investigate the efficacy of an intranasal vaccine expressing viral non-S antigens against intranasal SARS-CoV-2 challenge in cynomolgus macaques. Seven vaccinated macaques exhibit significantly reduced viral load in nasopharyngeal swabs on day 2 post-challenge compared with nine unvaccinated controls. The viral control in the absence of SARS-CoV-2-specific NAbs is significantly correlated with vaccine-induced, viral-antigen-specific CD8+ T cell responses. Our results indicate that CD8+ T cell induction by intranasal vaccination can result in NAb-independent control of SARS-CoV-2 infection, highlighting a potential of vaccine-induced CD8+ T cell responses to contribute to COVID-19 containment.
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Administração Intranasal/métodos , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Linfócitos T CD8-Positivos/imunologia , Vacinas contra COVID-19/administração & dosagem , COVID-19/imunologia , COVID-19/prevenção & controle , SARS-CoV-2/imunologia , Vacinação/métodos , Animais , COVID-19/epidemiologia , COVID-19/virologia , Vacinas contra COVID-19/imunologia , Chlorocebus aethiops , Proteínas do Envelope de Coronavírus/imunologia , Proteínas M de Coronavírus/imunologia , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Modelos Animais de Doenças , Feminino , Macaca fascicularis , Masculino , Pandemias/prevenção & controle , Fosfoproteínas/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Resultado do Tratamento , Células Vero , Carga ViralRESUMO
Heartland bandavirus (HRTV), which is an emerging tick-borne virus first identified in Missouri in 2009, causes fever, fatigue, decreased appetite, headache, nausea, diarrhea, and muscle or joint pain in humans. HRTV is genetically close to Dabie bandavirus, which is the causative agent of severe fever with thrombocytopenia syndrome (SFTS) in humans and is known as SFTS virus (SFTSV). The generation of infectious HRTV entirely from cloned cDNAs has not yet been reported. The absence of a reverse genetics system for HRTV has delayed efforts to understand its pathogenesis and to generate vaccines and antiviral drugs. Here, we developed a reverse genetics system for HRTV, which employs an RNA polymerase I-mediated expression system. A recombinant nonstructural protein (NSs)-knockout HRTV (rHRTV-NSsKO) was generated. We found that NSs interrupted signaling associated with innate immunity in HRTV-infected cells. The rHRTV-NSsKO was highly attenuated, indicated by the apparent absence of symptoms in a mouse model of HRTV infection. Moreover, mice immunized with rHRTV-NSsKO survived a lethal dose of HRTV. These findings suggest that NSs is a virulence factor of HRTV and that rHRTV-NSsKO could be a vaccine candidate for HRTV. IMPORTANCE Heartland bandavirus (HRTV) is a tick-borne virus identified in the United States in 2009. HRTV causes fever, fatigue, decreased appetite, headache, nausea, diarrhea, and muscle or joint pain in humans. FDA-approved vaccines and antiviral drugs are unavailable. The lack of a reverse genetics system hampers efforts to develop such antiviral therapeutics. Here, we developed a reverse genetics system for HRTV that led to the generation of a recombinant nonstructural protein (NSs)-knockout HRTV (rHRTV-NSsKO). We found that NSs interrupted signaling associated with innate immunity in HRTV-infected cells. Furthermore, rHRTV-NSsKO was highly attenuated and immunogenic in a mouse model. These findings suggest that NSs is a virulence factor of HRTV and that rHRTV-NSsKO could be a vaccine candidate for HRTV.