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1.
BMJ Case Rep ; 14(1)2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33462001

RESUMO

A 75-year-old man was admitted with a 3-month history of worsening diarrhoea and weight loss. He was on long-term immunosuppression following cardiac transplantation. Investigations revealed herpes simplex oesophagitis and stool samples were positive for norovirus. Treatment with acyclovir and nitazoxanide resulted in a complete resolution of symptoms. Norovirus is a common cause of infectious gastroenteritis, but immunosuppressed patients may present with chronic diarrhoea rather than an acute illness. This case highlights the importance of a low clinical threshold for testing for norovirus infection in immunocompromised patients.


Assuntos
Infecções por Caliciviridae/imunologia , Diarreia/virologia , Gastroenterite/imunologia , Hospedeiro Imunocomprometido , Norovirus/isolamento & purificação , Complicações Pós-Operatórias/imunologia , Perda de Peso , Idoso , Infecções por Caliciviridae/complicações , Infecções por Caliciviridae/diagnóstico , Doença Crônica , Diarreia/imunologia , Gastroenterite/complicações , Gastroenterite/diagnóstico , Transplante de Coração , Humanos , Masculino , Complicações Pós-Operatórias/diagnóstico , Perda de Peso/imunologia
2.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 36(8): 734-739, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-32958131

RESUMO

Objective To prepare monoclonal antibodies (mAbs) against GII.4 norovirus P domain by multiple antigens in an immunization program. Methods BALB/c mice were immunized with the multiple GII.4 NoV P domain, namely 1996cluster (VA387), 2004cluster, 2006b cluster and 2010 cluster. The spleen cells from the immunized mice were fused with SP2/0 cells and the hybridoma cells were screened by ELISA. The supernatant of the mAbs was collected and purified by the limiting dilution assay. Its subtype was identified, and the specificity and neutralization were analyzed by indirect ELISA and HBGA blocking, respectively. Results We obtained thirteen hybridoma cell lines that stably secreted mAbs against GII.4 NoV P domain. Their titers reached above 10-4 after purification. The subtypes of the mAbs were identified as IgG1. Indirect ELISA showed that all the mAbs specifically bound to all GII.4 norovirus variants. Five mAbs specifically bound to GII.17, GII.3 and GII.6 variants. Three mAbs specifically bound to GII.2 variants and strongly blocked NoV P particle from binding to the histo-blood group antigen (HBGA) receptors. Conclusion The mAbs against GII.4 norovirus P domain have been obtained by combined antigens immunization program. Multi-antigen immunization can enhance immune response significantly and cross-react with other GII.4 norovirus variants. The findings provide a basis for further development of novel GII.4 norovirus vaccines and for the optimization of the immunization programs of combined multi-antigen vaccine candidates.


Assuntos
Anticorpos Monoclonais , Anticorpos Antivirais , Infecções por Caliciviridae , Norovirus , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Infecções por Caliciviridae/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Norovirus/genética , Norovirus/imunologia
3.
Sheng Wu Gong Cheng Xue Bao ; 36(8): 1536-1545, 2020 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-32924352

RESUMO

Moschus chrysogaster (sifanicus) viral hemorrhagic disease (McVHD) is an acute and highly lethal infectious disease caused by Moschus chrysogaster hemorrhagic disease virus (McHDV) whose genome sequence is highly homologous with rabbit hemorrhagic disease virus. To screen the protective antigen of McHDV and set the basis for study of McVHD vaccine, the antigen epitope of major structural protein VP60 of McHDV was analyzed, and the specific primers were designed to obtain three amplified DNA sequences encoding the main antigen epitope of VP60 from McHDV by using RT-PCR. Then the three DNA fragments were sequenced and cloned to prokaryotic expression vector with pET-28a(+) by using overlap extension PCR, and finally the prokaryotic expression plasmid pET-truncated-VP60 was constructed. Subsequently, the pET-truncated-VP60 was transformed into Escherichia coli BL21(DE3), and the recombinant proteins were expressed by IPTG induction. Finally, the expressed protein was purified and applied to immunize that without immunizing with RHD vaccine, then the antiserum titers were evaluated by the hemagglutination inhibition test, and the immune-protective efficacy of the recombinant proteins was observed and analyzed through animal challenge test. The results showed that the multi-epitope DNA fragments of VP60 of McHDV was successfully expressed in the form of inclusion bodies in E. coli, and the relative molecular weight of recombinant proteins is about 45 kDa. After immunized with the recombinant proteins, 100% of New Zealand white rabbits were resistant to attack of McHDV, which indicates efficient immune-protective efficacy of chosen epitope recombinant protein. The study laid a foundation for the development of the new subunit vaccines of McVHD.


Assuntos
Infecções por Caliciviridae , Expressão Gênica , Vírus da Doença Hemorrágica de Coelhos , Proteínas Estruturais Virais , Animais , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/virologia , Epitopos/genética , Escherichia coli/genética , Coelhos , Proteínas Estruturais Virais/genética , Proteínas Estruturais Virais/metabolismo
4.
Proc Natl Acad Sci U S A ; 117(38): 23782-23793, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32907944

RESUMO

Human noroviruses (HuNoVs) are the leading cause of viral gastroenteritis worldwide; yet currently, no vaccines or FDA-approved antiviral drugs are available to counter these pathogens. To understand HuNoV biology and the epithelial response to infection, we performed transcriptomic analyses, RT-qPCR, CRISPR-Cas9 modification of human intestinal enteroid (HIE) cultures, and functional studies with two virus strains (a pandemic GII.4 and a bile acid-dependent GII.3 strain). We identified a predominant type III interferon (IFN)-mediated innate response to HuNoV infection. Replication of both strains is sensitive to exogenous addition of IFNs, suggesting the potential of IFNs as therapeutics. To obtain insight into IFN pathway genes that play a role in the antiviral response to HuNoVs, we developed knockout (KO) HIE lines for IFN alpha and lambda receptors and the signaling molecules, MAVS, STAT1, and STAT2 An unexpected differential response of enhanced replication and virus spread was observed for GII.3, but not the globally dominant GII.4 HuNoV in STAT1-knockout HIEs compared to parental HIEs. These results indicate cellular IFN responses restrict GII.3 but not GII.4 replication. The strain-specific sensitivities of innate responses against HuNoV replication provide one explanation for why GII.4 infections are more widespread and highlight strain specificity as an important factor in HuNoV biology. Genetically modified HIEs for innate immune genes are useful tools for studying immune responses to viral or microbial pathogens.


Assuntos
Infecções por Caliciviridae , Interações Hospedeiro-Patógeno/imunologia , Interferons , Intestinos , Norovirus , Sistemas CRISPR-Cas , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/virologia , Humanos , Interferons/genética , Interferons/metabolismo , Intestinos/imunologia , Intestinos/virologia , Modelos Biológicos , Norovirus/genética , Norovirus/imunologia , Norovirus/patogenicidade , Organoides/imunologia , Organoides/virologia , Análise de Sequência de RNA , Transcriptoma/genética , Replicação Viral
5.
Virology ; 546: 109-121, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32452409

RESUMO

The inflammasome machinery has recently been recognized as an emerging pillar of innate immunity. However, little is known regarding the interaction between the classical interferon (IFN) response and inflammasome activation in response to norovirus infection. We found that murine norovirus (MNV-1) infection induces the transcription of IL-1ß, a hallmark of inflammasome activation, which is further increased by inhibition of IFN response, but fails to trigger the release of mature IL-1ß. Interestingly, pharmacological inflammasome inhibitors do not affect viral replication, but slightly reverse the inflammasome activator lipopolysaccharide (LPS)-mediated inhibition of MNV replication. LPS efficiently stimulates the transcription of IFN-ß through NF-ĸB, which requires the transcription factors IRF3 and IRF7. This activates downstream antiviral IFN-stimulated genes (ISGs) via the JAK-STAT pathway. Moreover, inhibition of NF-ĸB and JAK-STAT signaling partially reverse LPS-mediated anti-MNV activity, suggesting additional antiviral mechanisms activated by NF-ĸB. This study reveals additional insight in host defense against MNV infection.


Assuntos
Antivirais/farmacologia , Infecções por Caliciviridae/imunologia , Janus Quinases/imunologia , Lipopolissacarídeos/farmacologia , Macrófagos/imunologia , NF-kappa B/imunologia , Norovirus/efeitos dos fármacos , Fatores de Transcrição STAT/imunologia , Animais , Infecções por Caliciviridae/genética , Infecções por Caliciviridae/virologia , Humanos , Inflamassomos/genética , Inflamassomos/imunologia , Fator Regulador 3 de Interferon/genética , Fator Regulador 3 de Interferon/imunologia , Janus Quinases/genética , Macrófagos/virologia , Camundongos , NF-kappa B/genética , Norovirus/genética , Norovirus/fisiologia , Fatores de Transcrição STAT/genética , Transdução de Sinais/efeitos dos fármacos
6.
J Virol ; 94(10)2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32161178

RESUMO

The rabbit hemorrhagic disease virus (RHDV), which belongs to the family Caliciviridae and the genus Lagovirus, causes lethal fulminant hepatitis in rabbits. RHDV decreases the activity of antioxidant enzymes regulated by Nrf2 in the liver. Antioxidants are important for the maintenance of cellular integrity and cytoprotection. However, the mechanism underlying the regulation of the Nrf2-antioxidant response element (ARE) signaling pathway by RHDV remains unclear. Using isobaric tags for relative and absolute quantification (iTRAQ) technology, the current study demonstrated that RHDV inhibits the induction of ARE-regulated genes and increases the expression of the p50 subunit of the NF-κB transcription factor. We showed that RHDV replication causes a remarkable increase in reactive oxygen species (ROS), which is simultaneously accompanied by a significant decrease in Nrf2. It was found that nuclear translocation of Keap1 plays a key role in the nuclear export of Nrf2, leading to the inhibition of Nrf2 transcriptional activity. The p50 protein partners with Keap1 to form the Keap1-p50/p65 complex, which is involved in the nuclear translocation of Keap1. Moreover, upregulation of Nrf2 protein levels in liver cell nuclei by tert-butylhydroquinone (tBHQ) delayed rabbit deaths due to RHDV infection. Considered together, our findings suggest that RHDV inhibits the Nrf2-dependent antioxidant response via nuclear translocation of Keap1-NF-κB complex and nuclear export of Nrf2 and provide new insight into the importance of oxidative stress during RHDV infection.IMPORTANCE Recent studies have reported that rabbit hemorrhagic disease virus (RHDV) infection reduced Nrf2-related antioxidant function. However, the regulatory mechanisms underlying this process remain unclear. The current study showed that the NF-κB p50 subunit partners with Keap1 to form the Keap1-NF-κB complex, which plays a key role in the inhibition of Nrf2 transcriptional activity. More importantly, upregulated Nrf2 activity delayed the death of RHDV-infected rabbits, strongly indicating the importance of oxidative damage during RHDV infection. These findings may provide novel insights into the pathogenesis of RHDV.


Assuntos
Antioxidantes/metabolismo , Infecções por Caliciviridae/metabolismo , Vírus da Doença Hemorrágica de Coelhos/imunologia , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Animais , Elementos de Resposta Antioxidante , Antioxidantes/farmacologia , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/patologia , Núcleo Celular/metabolismo , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Regulação da Expressão Gênica , Células HEK293 , Vírus da Doença Hemorrágica de Coelhos/patogenicidade , Humanos , Hidroquinonas , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Fígado/lesões , Fígado/metabolismo , Fígado/patologia , Fator 2 Relacionado a NF-E2/genética , Estresse Oxidativo , Proteômica , Coelhos , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição RelA , Replicação Viral
7.
Braz J Microbiol ; 51(1): 183-187, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31656022

RESUMO

Noroviruses (NoV) cause the majority of non-bacterial gastroenteritis cases worldwide, with genotype II.4 being the most common. The aim of our study was to quantitate norovirus-specific IgG in immunocompromised patients before and after laboratory-confirmed norovirus infection. A quantitative ELISA was developed by coating ELISA plates with recombinantly expressed P domain of GII.1 capsid protein. After testing mouse sera drawn before and after immunization with GII.1- and GII.4 P domain, sera from GII.1- and GII.4 infected patients were tested. The assay reliably detected preexisting NoV-specific IgG antibodies. Sera drawn after infection showed increased antibody concentrations. Antibodies elicited by GII.1- and GII.4 infections could be detected with coated GII.1 capsid protein. IgG levels remained constant during the first week and then increased in the second week after laboratory diagnosis. The results show that immunocompromised patients elicited IgG responses to NoV infections that could be reliably detected with our quantitative ELISA.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Caliciviridae/imunologia , Hospedeiro Imunocomprometido , Imunoglobulina G/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Infecções por Caliciviridae/virologia , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Norovirus
8.
Nat Microbiol ; 5(1): 84-92, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31768030

RESUMO

Evidence has accumulated to demonstrate that the intestinal microbiota enhances mammalian enteric virus infections1. For example, we and others previously reported that commensal bacteria stimulate acute and persistent murine norovirus infections2-4. However, in apparent contradiction of these results, the virulence of murine norovirus infection was unaffected by antibiotic treatment. This prompted us to perform a detailed investigation of murine norovirus infection in microbially deplete mice, revealing a more complex picture in which commensal bacteria inhibit viral infection of the proximal small intestine while simultaneously stimulating the infection of distal regions of the gut. Thus, commensal bacteria can regulate viral regionalization along the intestinal tract. We further show that the mechanism underlying bacteria-dependent inhibition of norovirus infection in the proximal gut involves bile acid priming of type III interferon. Finally, the regional effects of the microbiota on norovirus infection may result from distinct regional expression profiles of key bile acid receptors that regulate the type III interferon response. Overall, these findings reveal that the biotransformation of host metabolites by the intestinal microbiota directly and regionally impacts infection by a pathogenic enteric virus.


Assuntos
Ácidos e Sais Biliares/metabolismo , Infecções por Caliciviridae/imunologia , Microbioma Gastrointestinal , Interferons/metabolismo , Intestinos/imunologia , Animais , Infecções por Caliciviridae/microbiologia , Linhagem Celular , Interações Hospedeiro-Patógeno , Humanos , Intestinos/microbiologia , Intestinos/virologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Norovirus/crescimento & desenvolvimento , Norovirus/patogenicidade , Especificidade de Órgãos
9.
Front Immunol ; 10: 2654, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31798584

RESUMO

Environmental factors contribute to Type 1 diabetes (T1D) susceptibility. The gut microbiome, which includes bacteria, viruses, and fungi, contributes to this environmental influence, and can induce immunological changes. The gut viral component of the microbiome, related to T1D has mostly focused on coxsackieviruses and rotavirus. The role of norovirus, another common enteric virus, in susceptibility to T1D was hitherto unknown. Norovirus is highly infectious and encountered by many children. We studied the mouse norovirus 4 (MNV4), related to human noroviruses, in the Non-obese diabetic (NOD) mouse model, to determine its role in influencing susceptibility to T1D. We infected MNV-free NOD mice with MNV4 by exposing the mice to MNV4-positive bedding from an endemically-infected mouse colony to mimic a natural infection. Control MNV-free NOD mice were exposed to MNV-free bedding from the same colony. Interestingly, MNV4 infection protected NOD mice from the development of T1D and was associated with an expansion of Tregs and reduced proinflammatory T cells. We also found MNV4 significantly modified the gut commensal bacteria composition, promoting increased α-diversity and Firmicutes/Bacteroidetes ratio. To elucidate whether T1D protection was directly related to MNV4, or indirectly through modulating gut microbiota, we colonized germ-free (GF) NOD mice with the MNV4-containing or non-MNV4-containing viral filtrate, isolated from filtered fecal material. We found that MNV4 induced significant changes in mucosal immunity, including altered Tuft cell markers, cytokine secretion, antiviral immune signaling markers, and the concentration of mucosal antibodies. Systemically, MNV4-infection altered the immune cells including B cell subsets, macrophages and T cells, and especially induced an increase in Treg number and function. Furthermore, in vitro primary exposure of the norovirus filtrate to naïve splenocytes identified significant increases in the proportion of activated and CTLA4-expressing Tregs. Our data provide novel knowledge that norovirus can protect NOD mice from T1D development by inducing the expansion of Tregs and reducing inflammatory T cells. Our study also highlights the importance of distinguishing the mucosal immunity mediated by bacteria from that by enteric viruses.


Assuntos
Infecções por Caliciviridae/imunologia , Diabetes Mellitus Tipo 1/imunologia , Suscetibilidade a Doenças/virologia , Microbioma Gastrointestinal/imunologia , Linfócitos T/imunologia , Animais , Suscetibilidade a Doenças/imunologia , Camundongos , Camundongos Endogâmicos NOD , Norovirus/imunologia
10.
Viruses ; 11(11)2019 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-31684058

RESUMO

Human noroviruses (NoVs) are a genetically diverse, constantly evolving group of viruses. Here, we studied the effect of NoV pre-existing immunity on the success of NoV vaccinations with genetically close and distant genotypes. A sequential immunization as an alternative approach to multivalent NoV virus-like particles (VLPs) vaccine was investigated. Mice were immunized with NoV GI.3, GII.4-1999, GII.17, and GII.4 Sydney as monovalent VLPs or as a single tetravalent mixture combined with rotavirus VP6-protein. Sequentially immunized mice were primed with a trivalent vaccine candidate (GI.3 + GII.4-1999 + VP6) and boosted, first with GII.17 and then with GII.4 Sydney VLPs. NoV serum antibodies were analyzed. Similar NoV genotype-specific immune responses were induced with the monovalent and multivalent mixture immunizations, and no immunological interference was observed. Multivalent immunization with simultaneous mix was found to be superior to sequential immunization, as sequential boost induced strong blocking antibody response against the distant genotype (GII.17), but not against GII.4 Sydney, closely related to GII.4-1999, contained in the priming vaccine. Genetically close antigens may interfere with the immune response generation and thereby immune responses may be differently formed depending on the degree of NoV VLP genotype identity.


Assuntos
Infecções por Caliciviridae/prevenção & controle , Imunização/métodos , Norovirus/imunologia , Vacinas Virais/administração & dosagem , Animais , Anticorpos Bloqueadores/sangue , Anticorpos Antivirais/sangue , Antígenos Virais/imunologia , Infecções por Caliciviridae/imunologia , Proteínas do Capsídeo/imunologia , Reações Cruzadas , Feminino , Genótipo , Esquemas de Imunização , Camundongos , Camundongos Endogâmicos BALB C , Norovirus/genética , Vacinas Combinadas/administração & dosagem , Vacinas Combinadas/imunologia , Vacinas de Partículas Semelhantes a Vírus/administração & dosagem , Vacinas de Partículas Semelhantes a Vírus/imunologia , Vacinas Virais/imunologia
11.
Nat Immunol ; 20(12): 1681-1691, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31636462

RESUMO

Much attention has focused on commensal bacteria in health and disease, but the role of commensal viruses is understudied. Although metagenomic analysis shows that the intestine of healthy humans and animals harbors various commensal viruses and the dysbiosis of these viruses can be associated with inflammatory diseases, there is still a lack of causal data and underlying mechanisms to understand the physiological role of commensal viruses in intestinal homeostasis. In the present study, we show that commensal viruses are essential for the homeostasis of intestinal intraepithelial lymphocytes (IELs). Mechanistically, the cytosolic viral RNA-sensing receptor RIG-I in antigen-presenting cells can recognize commensal viruses and maintain IELs via a type I interferon-independent, but MAVS-IRF1-IL-15 axis-dependent, manner. The recovery of IELs by interleukin-15 administration reverses the susceptibility of commensal virus-depleted mice to dextran sulfate sodium-induced colitis. Collectively, our results indicate that commensal viruses maintain the IELs and consequently sustain intestinal homeostasis via noncanonical RIG-I signaling.


Assuntos
Células Apresentadoras de Antígenos/imunologia , Infecções por Caliciviridae/imunologia , Colite/imunologia , Proteína DEAD-box 58/metabolismo , Intestinos/imunologia , Linfócitos Intraepiteliais/imunologia , Norovirus/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Infecções por Caliciviridae/virologia , Células Cultivadas , Colite/induzido quimicamente , Colite/virologia , Proteína DEAD-box 58/genética , Sulfato de Dextrana , Suscetibilidade a Doenças , Homeostase , Fator Regulador 1 de Interferon/genética , Fator Regulador 1 de Interferon/metabolismo , Interleucina-15/metabolismo , Intestinos/virologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais , Simbiose/imunologia
12.
Vet Microbiol ; 238: 108429, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31648721

RESUMO

Viral haemorrhagic disease (VHD) and colibacillosis are common diseases in rabbits that cause economic losses worldwide. The effect of colibacillosis on the immune response of vaccinated rabbits against rabbit haemorrhagic disease virus (RHDV) was studied. Four groups (G1-G4) were included. G1 was the negative control group; G2 was the RHDV vaccine group; G3 was the E. coli-infected group; and G4 was the E. coli-infected + RHDV vaccine group. The E. coli infection and RHDV vaccination were simultaneously performed, with another previous infection, 3 days before vaccination. At 28 days post-vaccination (PV), the rabbits (G2-G4) were challenged intramuscularly with 0.5 ml of RHDV at a dose of 103 50% median lethal dose (LD50)/rabbit. The rabbits were observed for clinical signs, body weight gain and mortality rates. Tissue, blood, serum, and faecal samples and rectal swabs were collected at 3, 5, 7, 14, 21 and 28 days PV. Significant clinical signs and mortality and a decrease in BW were observed in the infected + RHDV vaccine group. On the 3rd day post-infection (PI), compared with all the other groups, the vaccinated group (G2) had significantly upregulated hepatic tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels; however, the infected + RHDV vaccine group had significantly higher intestinal levels of TNF-α and IL-6 than the other groups. Furthermore, E. coli infection in vaccinated rabbits led to immunosuppression, as shown by significant decreases (P < 0.05) in heterophil phagocytic activity, the CD4+/CD8+ ratio, and HI antibody responses to RHDV and a significant increase in the heterophil to lymphocyte (H/L) ratio. In conclusion, colibacillosis leads to immunosuppression involving a shift in the equilibrium of cytokines and reduced weight gain and mortality in vaccinated rabbits and could be a contributing factor in RHDV vaccination failure in rabbit farming.


Assuntos
Infecções por Caliciviridae/veterinária , Infecções por Escherichia coli/veterinária , Coelhos/imunologia , Vacinação/veterinária , Vacinas Virais/imunologia , Animais , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/mortalidade , Citocinas/genética , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/mortalidade , Infecções por Escherichia coli/fisiopatologia , Regulação da Expressão Gênica/imunologia , Vírus da Doença Hemorrágica de Coelhos/imunologia , Coelhos/microbiologia , Coelhos/virologia , Vacinação/normas
13.
Front Immunol ; 10: 2334, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632406

RESUMO

Noroviruses and Sapoviruses, classified in the Caliciviridae family, are small positive-stranded RNA viruses, considered nowadays the leading cause of acute gastroenteritis globally in both children and adults. Although most noroviruses have been associated with gastrointestinal disease in humans, almost 50 years after its discovery, there is still a lack of comprehensive evidence regarding its biology and pathogenesis mainly because they can be neither conveniently grown in cultured cells nor propagated in animal models. However, other members of this family such as Feline calicivirus (FCV), Murine norovirus (MNV), Rabbit hemorrhagic disease virus (RHDV), and Porcine sapovirus (PS), from which there are accessible propagation systems, have been useful to study the calicivirus replication strategies. Using cell cultures and animal models, many of the functions of the viral proteins in the viral replication cycles have been well-characterized. Moreover, evidence of the role of viral proteins from different members of the family in the establishment of infection has been generated and the mechanism of their immunopathogenesis begins to be understood. In this review, we discuss different aspects of how caliciviruses are implicated in membrane rearrangements, apoptosis, and evasion of the immune responses, highlighting some of the pathogenic mechanisms triggered by different members of the Caliciviridae family.


Assuntos
Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/virologia , Caliciviridae/imunologia , Interações Hospedeiro-Patógeno/imunologia , Imunidade , Imunomodulação , Imunidade Adaptativa , Animais , Peptídeos Catiônicos Antimicrobianos , Apoptose , Caliciviridae/genética , Infecções por Caliciviridae/metabolismo , Membrana Celular/metabolismo , Membrana Celular/virologia , Efeito Citopatogênico Viral , Suscetibilidade a Doenças , Regulação Viral da Expressão Gênica , Genoma Viral , Humanos , Evasão da Resposta Imune , Imunidade Inata , Interações Microbianas , Microbiota , Replicação Viral
14.
Vaccine ; 37(51): 7509-7518, 2019 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-31585726

RESUMO

Enteric viruses cause diverse infections with substantial morbidity and mortality in children, rotavirus (RV) and norovirus (NoV) being the leading agents of severe pediatric gastroenteritis. Coxsackie B viruses (CVB) are common enteroviruses (EV), associated with increased incidence of severe neonatal CVB disease with potentially fatal consequences. To prevent majority of childhood gastroenteritis, we have developed a non-live NoV-RV combination vaccine consisting of NoV virus-like particles (VLPs) and RV oligomeric rVP6 protein that induced protective immune responses to NoV and RV in mice. Moreover, rVP6 acted as an adjuvant for NoV VLPs. Here, we investigated a possibility to include a third enteric virus-derived antigen in the candidate NoV-RV vaccine, by adding recombinant nanoparticles derived from EV CVB1. To examine immunogenicity of EV-NoV-RV vaccine, BALB/c mice were immunized intramuscularly twice with 10 µg CVB1 VLPs, GII.4 VLPs and rVP6 nanotubes, either separately or combined. To evaluate the adjuvant effect of rVP6 on EV responses, mice received 0.3 µg CVB1 VLPs with or without 10 µg rVP6. Comparable serum IgG antibodies were detected whether the antigens were administered separately or in combination. Each formulation generated IgG1 and IgG2a antibodies, indicating a mixed Th2/Th1-type response. CVB1 VLPs skewed the isotype distribution slightly towards IgG1 subtype, while EV-NoV-RV combination vaccine induced unbiased Th1/Th2 responses to CVB1. Each antigen also induced T cell mediated immunity measured by IFN-γ secretion to specific stimulants ex vivo. Antisera raised by single antigens and combined formulation also exhibited strong neutralizing ability against CVB1 and NoV GII.4. Further, rVP6 showed an adjuvant effect on CVB1 responses, sparing the VLP dose and homogenizing the responses. Finally, the results support inclusion of additional antigens in the candidate NoV-RV combination vaccine to combat severe childhood infections and confirm adjuvant effect of rVP6 nanostructures.


Assuntos
Infecções por Caliciviridae/prevenção & controle , Infecções por Enterovirus/prevenção & controle , Gastroenterite/prevenção & controle , Infecções por Rotavirus/prevenção & controle , Vacinação/métodos , Vacinas de Partículas Semelhantes a Vírus/administração & dosagem , Vacinas Virais/administração & dosagem , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Antígenos Virais/química , Antígenos Virais/imunologia , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/virologia , Proteínas do Capsídeo/química , Proteínas do Capsídeo/imunologia , Criança , Enterovirus Humano B/química , Enterovirus Humano B/efeitos dos fármacos , Enterovirus Humano B/imunologia , Infecções por Enterovirus/imunologia , Infecções por Enterovirus/virologia , Feminino , Gastroenterite/imunologia , Gastroenterite/virologia , Humanos , Esquemas de Imunização , Imunogenicidade da Vacina , Imunoglobulina G/sangue , Imunoglobulina G/classificação , Camundongos , Camundongos Endogâmicos BALB C , Norovirus/química , Norovirus/efeitos dos fármacos , Norovirus/imunologia , Rotavirus/química , Rotavirus/efeitos dos fármacos , Rotavirus/imunologia , Infecções por Rotavirus/imunologia , Infecções por Rotavirus/virologia , Vacinas Sintéticas , Vacinas de Partículas Semelhantes a Vírus/biossíntese , Vacinas Virais/biossíntese , Vírion/química , Vírion/imunologia
15.
Mucosal Immunol ; 12(6): 1259-1267, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31501514

RESUMO

Noroviruses are major causes of gastroenteritis, with epidemic outbreaks occurring frequently. They are an important global health concern, especially for pediatric and immunocompromised populations, and are challenging pathogens to target immunologically due to their rapid rates of genetic and antigenic evolution and failure to stimulate durable protective immunity. In this Review, we summarize our current understanding of norovirus pathogenesis, noting the prominent role of murine norovirus as a small animal model for norovirus research. We highlight intriguing data supporting the possible involvement of norovirus in sequelae including irritable bowel syndrome and inflammatory bowel diseases, and describe the innate and adaptive immune mechanisms involved in control of both human and murine norovirus infection. Furthermore, we discuss the potential implications of recent discoveries regarding norovirus interactions with the gut microbiota, and briefly detail current understanding of noroviral evolution and its influence on viral pathogenesis. Our mechanistic understanding of norovirus pathogenesis continues to improve with increasing availability of powerful model systems, which will ultimately facilitate development of effective preventive and therapeutic approaches for this pathogen.


Assuntos
Infecções por Caliciviridae/virologia , Gastroenterite/virologia , Imunidade nas Mucosas , Mucosa Intestinal/virologia , Norovirus/patogenicidade , Imunidade Adaptativa , Animais , Infecções por Caliciviridae/imunologia , Modelos Animais de Doenças , Gastroenterite/imunologia , Microbioma Gastrointestinal , Interações Hospedeiro-Patógeno , Humanos , Imunidade Inata , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Norovirus/imunologia
16.
Am J Clin Nutr ; 110(6): 1456-1464, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31504095

RESUMO

BACKGROUND: To accurately assess micronutrient status, it is necessary to characterize the effects of inflammation and the acute-phase response on nutrient biomarkers. OBJECTIVE: Within a norovirus human challenge study, we aimed to model the inflammatory response of C-reactive protein (CRP) and α-1-acid glycoprotein (AGP) by infection status, model kinetics of micronutrient biomarkers by inflammation status, and evaluate associations between inflammation and micronutrient biomarkers from 0 to 35 d post-norovirus exposure. METHODS: Fifty-two healthy adults were enrolled into challenge studies in a hospital setting and followed longitudinally; all were exposed to norovirus, half were infected. Post hoc analysis of inflammatory and nutritional biomarkers was performed. Subjects were stratified by inflammation resulting from norovirus exposure. Smoothed regression models analyzed the kinetics of CRP and AGP by infection status, and nutritional biomarkers by inflammation. Linear mixed-effects models were used to analyze the independent relations between CRP, AGP, and biomarkers for iron, vitamin A, vitamin D, vitamin B-12, and folate from 0 to 35 d post-norovirus exposure. RESULTS: Norovirus-infected subjects had median (IQR) peak concentrations for CRP [16.0 (7.9-29.5) mg/L] and AGP [0.9 (0.8-1.2) g/L] on day 3 and day 4 postexposure, respectively. Nutritional biomarkers that differed (P < 0.05) from baseline within the inflamed group were ferritin (elevated day 3), hepcidin (elevated days 2, 3), serum iron (depressed days 2-4), transferrin saturation (depressed days 2-4), and retinol (depressed days 3, 4, and 7). Nutritional biomarker concentrations did not differ over time within the uninflamed group. In mixed models, CRP was associated with ferritin (positive) and serum iron and retinol (negative, P < 0.05). CONCLUSION: Using an experimental infectious challenge model in healthy adults, norovirus infection elicited a time-limited inflammatory response associated with altered serum concentrations of certain iron and vitamin A biomarkers, confirming the need to consider adjustments of these biomarkers to account for inflammation when assessing nutritional status. These trials were registered at clinicaltrials.gov as NCT00313404 and NCT00674336.


Assuntos
Biomarcadores/sangue , Infecções por Caliciviridae/sangue , Micronutrientes/sangue , Adulto , Proteína C-Reativa/análise , Proteína C-Reativa/imunologia , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/virologia , Feminino , Ferritinas/sangue , Ácido Fólico/sangue , Humanos , Ferro/sangue , Estudos Longitudinais , Masculino , Norovirus/fisiologia , Vitamina A/sangue , Vitamina D/sangue
17.
Viruses ; 11(8)2019 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-31370359

RESUMO

This study evaluated the prevalence of feline calicivirus (FCV) antibodies and response to vaccination in healthy adult cats. Cats >1 year (n = 111) that had not been vaccinated within 12 months of enrollment in the study received a vaccine containing inactivated FCV antigen strains 431 and G1. Antibodies were determined on Days 0, 7, and 28 by virus neutralization (VN) using FCV isolate KS20, and by broad spectrum blocking FCV enzyme-linked immunosorbent assay (ELISA). Factors associated with the presence of antibodies and vaccine response were determined by uni- and multivariate analysis. Pre-vaccination antibodies were detected in 62.2% of cats (CI95%: 52.9-70.1) by VN and in 77.2% (CI95%: 67.5-84.6) by ELISA. A ≥4-fold titer increase after vaccination was observed in 13.6% (CI95%: 8.3-21.4) of cats with VN and 33.7% (CI95%: 24.5-44.5) with ELISA. Factors associated with the presence of pre-vaccination VN antibodies were age (≥2 years; OR: 7.091; p = 0.022) and lack of previous vaccination (OR: 3.472; p = 0.014). The presence of pre-vaccination ELISA antibodies was associated with time since last vaccination (OR: 5.672; p = 0.043). Outdoor cats were more likely to have a ≥4-fold ELISA titer increase (OR: 5.556; p = 0.005). Many cats had pre-vaccination FCV antibodies, and their presence depended on previous vaccinations and increases with age. A ≥4-fold titer increase was rarely observed and was influenced by the lifestyle of the cat.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Caliciviridae/veterinária , Calicivirus Felino/imunologia , Doenças do Gato/prevenção & controle , Vacinação/veterinária , Animais , Infecções por Caliciviridae/epidemiologia , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/prevenção & controle , Doenças do Gato/epidemiologia , Doenças do Gato/imunologia , Gatos , Feminino , Alemanha/epidemiologia , Masculino , Prevalência , Vacinas Virais/administração & dosagem
19.
Curr Opin Infect Dis ; 32(5): 445-452, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31335438

RESUMO

PURPOSE OF REVIEW: Gastroenteritis results in substantial morbidity and mortality worldwide, especially in young children in low-and-middle-income settings. Rotavirus and norovirus are the leading causes of viral gastroenteritis. Although introduction of rotavirus vaccines into childhood immunization programmes has reduced disease burden, vaccine effectiveness remains low in developing countries. Norovirus is replacing rotavirus as the most common cause of diarrhea hospitalization in settings where rotavirus vaccines are highly effective. Genetically determined host factors, such as expression of histo blood group antigens (HBGAs) are hypothesized to play key roles in susceptibility to infections and gastroenteritis caused by these virus, as well as influence vaccine take. RECENT FINDINGS: Epidemiology studies provide strong support for virus genotype-dependent effects of host HBGA expression, specifically secretor status on susceptibility to rotavirus and norovirus. Secretor-positive persons are significantly more susceptible to gastroenteritis caused by rotavirus P[8] genotype, and to infection with the GII.4 genotype of human norovirus. There is increasing data on the role of secretor status on rotavirus vaccine take but results are currently conflicting. For analyses involving young infants, maternal HBGA status is an important factor to be considered in future studies. SUMMARY: Genetically determined HBGA expression influences susceptibility to enteric viruses of public health importance.


Assuntos
Antígenos de Grupos Sanguíneos/biossíntese , Infecções por Caliciviridae/epidemiologia , Suscetibilidade a Doenças , Gastroenterite/epidemiologia , Infecções por Rotavirus/epidemiologia , Infecções por Caliciviridae/imunologia , Gastroenterite/imunologia , Gastroenterite/virologia , Expressão Gênica , Humanos , Infecções por Rotavirus/imunologia
20.
Immunol Lett ; 215: 40-44, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31154053

RESUMO

Norovirus (NoV) is now recognized as a major cause of gastroenteritis outbreaks, worldwide. Norovirus replication mechanisms are still poorly understood, mainly because a reliable cell culture system is still lacking. The present study aims at understanding some aspects of the immune response against norovirus, and particularly the capacity of virus like particles (VLPs) from an Italian strain, belonging to the GII.4 genotype predominating worldwide, to interact with target cells via Toll Like Receptors (TLRs). The capacity of GII.4 NoV VLPs to interact and cause the activation of TLR2, 4 and 5 was studied in recombinant HEK cells. The results obtained show the ability of GII.4 NoV VLPs to induce activation of TLR2 and 5. The results on TLRs activation confirm that GII.4 NoV VLPs interact with TLR2 and 5, that may represent putative receptors and play a role in NoV infection of intestinal cells.


Assuntos
Norovirus/imunologia , Receptor 2 Toll-Like/imunologia , Receptor 5 Toll-Like/imunologia , Vírion/imunologia , Infecções por Caliciviridae/genética , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/patologia , Células HEK293 , Humanos , Norovirus/genética , Receptor 2 Toll-Like/genética , Receptor 5 Toll-Like/genética , Vírion/genética
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