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1.
Viruses ; 13(2)2021 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-33567734

RESUMO

Human cytomegalovirus (HCMV) is a ubiquitous double-stranded DNA virus belonging to the ß-subgroup of the herpesvirus family. After the initial infection, the virus establishes latency in poorly differentiated myeloid precursors from where it can reactivate at later times to cause recurrences. In immunocompetent subjects, primary HCMV infection is usually asymptomatic, while in immunocompromised patients, HCMV infection can lead to severe, life-threatening diseases, whose clinical severity parallels the degree of immunosuppression. The existence of a strict interplay between HCMV and the immune system has led many to hypothesize that HCMV could also be involved in autoimmune diseases (ADs). Indeed, signs of active viral infection were later found in a variety of different ADs, such as rheumatological, neurological, enteric disorders, and metabolic diseases. In addition, HCMV infection has been frequently linked to increased production of autoantibodies, which play a driving role in AD progression, as observed in systemic lupus erythematosus (SLE) patients. Documented mechanisms of HCMV-associated autoimmunity include molecular mimicry, inflammation, and nonspecific B-cell activation. In this review, we summarize the available literature on the various ADs arising from or exacerbating upon HCMV infection, focusing on the potential role of HCMV-mediated immune activation at disease onset.


Assuntos
Doenças Autoimunes/imunologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Autoanticorpos/imunologia , Doenças Autoimunes/patologia , Doenças Autoimunes/virologia , Autoimunidade , Citomegalovirus/patogenicidade , Infecções por Citomegalovirus/patologia , Infecções por Citomegalovirus/virologia , Humanos , Hospedeiro Imunocomprometido , Inflamação , Doenças Vasculares/patologia
2.
Science ; 371(6532)2021 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-33361116

RESUMO

Immunoglobulin G (IgG) antibodies are crucial for protection against invading pathogens. A highly conserved N-linked glycan within the IgG-Fc tail, which is essential for IgG function, shows variable composition in humans. Afucosylated IgG variants are already used in anticancer therapeutic antibodies for their increased activity through Fc receptors (FcγRIIIa). Here, we report that afucosylated IgG (approximately 6% of total IgG in humans) are specifically formed against enveloped viruses but generally not against other antigens. This mediates stronger FcγRIIIa responses but also amplifies brewing cytokine storms and immune-mediated pathologies. Critically ill COVID-19 patients, but not those with mild symptoms, had high concentrations of afucosylated IgG antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), amplifying proinflammatory cytokine release and acute phase responses. Thus, antibody glycosylation plays a critical role in immune responses to enveloped viruses, including COVID-19.


Assuntos
Anticorpos Antivirais/imunologia , Imunoglobulina G/imunologia , /imunologia , Adulto , Idoso , Anticorpos Antivirais/sangue , Anticorpos Antivirais/química , Células Cultivadas , Estado Terminal , Citomegalovirus/imunologia , Feminino , Fucose/análise , Glicosilação , HIV/imunologia , Vacinas contra Hepatite B/imunologia , Humanos , Fragmentos Fc das Imunoglobulinas/química , Fragmentos Fc das Imunoglobulinas/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/química , Inflamação , Interleucina-6/biossíntese , Interleucina-6/imunologia , Macrófagos/imunologia , Masculino , Pessoa de Meia-Idade , Parvovirus B19 Humano/imunologia , Índice de Gravidade de Doença , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas de Subunidades/imunologia , Adulto Jovem
3.
PLoS Pathog ; 16(12): e1009169, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33370407

RESUMO

Human cytomegalovirus (HCMV) is the primary viral cause of congenital birth defects and causes significant morbidity and mortality in immune-suppressed transplant recipients. Despite considerable efforts in vaccine development, HCMV infection still represents an unmet clinical need. In recent phase II trials, a MF59-adjuvanted gB vaccine showed only modest efficacy in preventing infection. These findings might be attributed to low level of antibodies (Abs) with a neutralizing activity induced by this vaccine. Here, we analyzed the immunogenicity of each gB antigenic domain (AD) and demonstrated that domain I of gB (AD5) is the main target of HCMV neutralizing antibodies. Furthermore, we designed, characterized and evaluated immunogenic responses to two different nanoparticles displaying a trimeric AD5 antigen. We showed that mice immunization with nanoparticles induces sera neutralization titers up to 100-fold higher compared to those obtained with the gB extracellular domain (gBECD). Collectively, these results illustrate with a medically relevant example the advantages of using a general approach combining antigen discovery, protein engineering and scaffold presentation for modern development of subunit vaccines against complex pathogens.


Assuntos
Anticorpos Antivirais/imunologia , Infecções por Citomegalovirus/imunologia , Vacinas contra Citomegalovirus/imunologia , Nanopartículas , Proteínas do Envelope Viral/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Citomegalovirus/imunologia , Infecções por Citomegalovirus/prevenção & controle , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Vacinas de Subunidades/imunologia
4.
BMC Infect Dis ; 20(1): 768, 2020 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-33069216

RESUMO

BACKGROUND: Cytomegalovirus (CMV) is a double stranded DNA virus and ubiquitous in nature. Association of Guillain-Barre syndrome (GBS) and CMV is well known but CMV acute myositis is a rare condition. Restriction of movements of limbs due to severe pain in myositis may obscure the diagnosis of GBS and this may easily miss. CASE PRESENTATION: Here we describe a 29-year-old male presenting with pain and swelling of bilateral lower limbs which progressed rapidly with increasing serum creatine kinase levels with positive IgM CMV antibodies. In view of no improvement in clinical condition, patient was further evaluated and found to have concurrent GBS. He was treated with plasmapheresis and improved. CONCLUSION: Cytomegalovirus infection presenting as acute myositis is a uncommon and further association with GBS is a rare occurrence.


Assuntos
Infecções por Citomegalovirus/complicações , Infecções por Citomegalovirus/diagnóstico , Citomegalovirus/imunologia , Síndrome de Guillain-Barré/complicações , Síndrome de Guillain-Barré/diagnóstico , Miosite/complicações , Miosite/diagnóstico , Doença Aguda , Adulto , Anticorpos Antivirais/sangue , Infecções por Citomegalovirus/terapia , Erros de Diagnóstico , Síndrome de Guillain-Barré/terapia , Humanos , Imunoglobulina M/sangue , Masculino , Miosite/terapia , Miosite/virologia , Dor , Plasmaferese , Resultado do Tratamento
5.
PLoS Pathog ; 16(8): e1008736, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32745149

RESUMO

Human cytomegalovirus (HCMV) is one of the main causative agents of congenital viral infection in neonates. HCMV infection also causes serious morbidity and mortality among organ transplant patients. Glycoprotein B (gB) is a major target for HCMV neutralizing antibodies, yet the underlying neutralization mechanisms remain largely unknown. Here we report that 3-25, a gB-specific monoclonal antibody previously isolated from a healthy HCMV-positive donor, efficiently neutralized 14 HCMV strains in both ARPE-19 cells and MRC-5 cells. The core epitope of 3-25 was mapped to a highly conserved linear epitope on antigenic domain 2 (AD-2) of gB. A 1.8 Å crystal structure of 3-25 Fab in complex with the peptide epitope revealed the molecular determinants of 3-25 binding to gB at atomic resolution. Negative-staining electron microscopy (EM) 3D reconstruction of 3-25 Fab in complex with de-glycosylated postfusion gB showed that 3-25 Fab fully occupied the gB trimer at the N-terminus with flexible binding angles. Functionally, 3-25 efficiently inhibited HCMV infection at a post-attachment step by interfering with viral membrane fusion, and restricted post-infection viral spreading in ARPE-19 cells. Interestingly, bivalency was required for HCMV neutralization by AD-2 specific antibody 3-25 but not the AD-4 specific antibody LJP538. In contrast, bivalency was not required for HCMV binding by both antibodies. Taken together, our results reveal the structural basis of gB recognition by 3-25 and demonstrate that inhibition of viral membrane fusion and a requirement of bivalency may be common for gB AD-2 specific neutralizing antibody.


Assuntos
Anticorpos Antivirais/imunologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Epitopos/imunologia , Proteínas do Envelope Viral/imunologia , Motivos de Aminoácidos , Anticorpos Neutralizantes/imunologia , Sequência Conservada , Citomegalovirus/química , Citomegalovirus/genética , Citomegalovirus/fisiologia , Infecções por Citomegalovirus/virologia , Epitopos/química , Epitopos/genética , Humanos , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética , Internalização do Vírus
6.
Proc Natl Acad Sci U S A ; 117(36): 22113-22121, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32843346

RESUMO

RNA polymerase (Pol) III has a noncanonical role of viral DNA sensing in the innate immune system. This polymerase transcribes viral genomes to produce RNAs that lead to induction of type I interferons (IFNs). However, the genetic and functional links of Pol III to innate immunity in humans remain largely unknown. Here, we describe a rare homozygous mutation (D40H) in the POLR3E gene, coding for a protein subunit of Pol III, in a child with recurrent and systemic viral infections and Langerhans cell histiocytosis. Fibroblasts derived from the patient exhibit impaired induction of type I IFN and increased susceptibility to human cytomegalovirus (HCMV) infection. Cultured cell lines infected with HCMV show induction of POLR3E expression. However, induction is not restricted to DNA virus, as sindbis virus, an RNA virus, enhances the expression of this protein. Likewise, foreign nonviral DNA elevates the steady-state level of POLR3E and elicits promoter-dependent and -independent transcription by Pol III. Remarkably, the molecular mechanism underlying the D40H mutation of POLR3E involves the assembly of defective initiation complexes of Pol III. Our study links mutated POLR3E and Pol III to an innate immune deficiency state in humans.


Assuntos
Citomegalovirus/fisiologia , Fibroblastos/imunologia , Fibroblastos/virologia , RNA Polimerase III/metabolismo , Animais , Chlorocebus aethiops , Citomegalovirus/imunologia , Células Dendríticas , Regulação Enzimológica da Expressão Gênica , Humanos , Mutação , RNA Polimerase III/genética , Células Vero
7.
Virology ; 548: 182-191, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32838941

RESUMO

Human cytomegalovirus (HCMV) is the most common congenital infection. A glycoprotein B (gB) subunit vaccine (gB/MF59) is the most efficacious clinically tested to date, having achieved 50% protection against primary infection of HCMV-seronegative women. We previously identified that gB/MF59 vaccination primarily elicits non-neutralizing antibody responses, with variable binding to gB genotypes, and protection associated with binding to membrane-associated gB. We hypothesized that gB-specific non-neutralizing antibody binding breadth and function are dependent on epitope and genotype specificity, and ability to interact with membrane-associated gB. We mapped twenty-four gB-specific monoclonal antibodies (mAbs) from naturally HCMV-infected individuals for gB domain specificity, genotype preference, and ability to mediate phagocytosis or NK cell activation. gB-specific mAbs were primarily specific for Domain II and demonstrated variable binding to gB genotypes. Two mAbs facilitated phagocytosis with binding specificities of Domain II and AD2. This investigation provides novel understanding on the relationship between gB domain specificity and antigenic variability on gB-specific antibody effector functions.


Assuntos
Anticorpos Antivirais/imunologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Proteínas do Envelope Viral/imunologia , Adulto , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Especificidade de Anticorpos , Citomegalovirus/genética , Infecções por Citomegalovirus/sangue , Infecções por Citomegalovirus/virologia , Feminino , Humanos , Masculino , Proteínas do Envelope Viral/genética , Adulto Jovem
8.
Virology ; 548: 93-100, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32838950

RESUMO

Human cytomegalovirus (HCMV) infects the chorioamnion, but whether these infections cause fetal membrane dysfunction remains poorly understood. We sought to assess whether guinea pig cytomegalovirus (GPCMV) infects amnion-derived cells in vitro, compare the inflammatory response of amnion cells to GPCMV and HCMV, and determine if GPCMV infects the amnion in vivo. We found that GPCMV replicates in primary guinea pig amnion derived cells and HPV16 E6/E7-transduced amniotic epithelial cells (AEC[E6/E7]s). HCMV and GPCMV infection of amnion cells increased the transcription of the chemokines CCL5/Ccl5, CXCL8/Cxcl8, and CXCL10/Cxcl10. Myd88-knockdown decreased Ccl5 and Cxc8 transcription in GPCMV-infected AEC[E6/E7]s. GPCMV was detected in the guinea pig amnion after primary maternal infection, revealing that guinea pigs are an appropriate model to study fetal membrane physiology after cytomegalovirus infection. As inflammation is known to cause fetal membrane weakening, the amnion's response to cytomegalovirus infection may cause preterm birth and other adverse pregnancy outcomes.


Assuntos
Âmnio/imunologia , Quimiocinas/imunologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/fisiologia , Complicações na Gravidez/imunologia , Âmnio/virologia , Animais , Quimiocina CCL5/genética , Quimiocina CCL5/imunologia , Quimiocina CXCL10/genética , Quimiocina CXCL10/imunologia , Quimiocinas/genética , Citomegalovirus/genética , Citomegalovirus/imunologia , Infecções por Citomegalovirus/genética , Feminino , Cobaias , Humanos , Interleucina-8/genética , Interleucina-8/imunologia , Gravidez , Complicações na Gravidez/genética , Complicações na Gravidez/virologia
9.
Mol Immunol ; 126: 143-152, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32829203

RESUMO

A viral infection is detected through germline-encoded pattern-recognition receptors (PRRs) leading to the production of interferons (IFNs) and proinflammatory cytokines. The objective of this study was to investigate the expression of retinoic acid-inducible gene-I (RIG-I)-like receptors (RLRs) in response to viral infection and the selected cytokine responses in the human term placenta. Placental villi and decidual explants were infected with human cytomegalovirus (CMV) or vesicular stomatitis virus (VSV) and cultured ex vivo to study viral infection. To evaluate DDX58 (RIG-I), IFIH1 (MDA5), and DHX58 (LGP2) expression, quantitative real-time PCR (qRT-PCR) was used. The expression of RLRs was detected by Western blotting. Cytokine and chemokine production, as well as RLR protein levels, were quantified using ELISA. The increased expression of both RIG-I and MDA5 and the enhanced secretion of IFN-ß were observed in response to VSV infection compared to mock-infected tissues. CMV infection resulted in higher transcript levels of DDX58 and IFIH1, while no changes in the cytokine production were observed. Our results indicate that RIG-I and MDA5 are specifically expressed in chorionic villi and deciduae in response to VSV infection. These findings suggest that RLRs may play a key role in pathogen recognition and the immune response against intrauterine viral transmission.


Assuntos
Proteína DEAD-box 58/metabolismo , Transmissão Vertical de Doença Infecciosa , Helicase IFIH1 Induzida por Interferon/metabolismo , Placenta/imunologia , Complicações Infecciosas na Gravidez/imunologia , Animais , Linhagem Celular , Citomegalovirus/imunologia , Feminino , Humanos , Interferon beta/imunologia , Interferon beta/metabolismo , Camundongos , Placenta/metabolismo , Placenta/virologia , Gravidez , Complicações Infecciosas na Gravidez/virologia , Terceiro Trimestre da Gravidez , RNA Helicases/metabolismo , Técnicas de Cultura de Tecidos , Vesiculovirus/imunologia
10.
BMC Infect Dis ; 20(1): 470, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32615937

RESUMO

BACKGROUND: Strongyloidiasis is a gastrointestinal parasitic infection caused by percutaneous infection with Strongyloides stercoralis. Digestive symptoms such as diarrhea and abdominal pain are the main manifestation, but serious infections such as septicemia, purulent meningitis, and bacterial pneumonia may occur in individuals harboring human T-lymphotropic virus type 1 (HTLV-1) or who are immunocompromised. Although coinfection with Strongyloides stercoralis and HTLV-1 can lead to chronic strongyloidiasis and a disseminated form of the disease, there is a high rate of response to the anthelmintic ivermectin. CASE PRESENTATION: We report a case of strongyloidiasis infection syndrome that was difficult to differentiate from immune reconstitution inflammatory syndrome (IRIS) for various reasons. The patient had been treated with the corticosteroids tacrolimus (Tac) and mycophenolate mofetil (MMF) for systemic lupus erythematosus (SLE) with lupus nephritis and pancytopenia. When the steroid was reduced, she developed cytomegalovirus (CMV) enteritis, and her respiratory status rapidly deteriorated immediately after the withdrawal of Tac and MMF. It was difficult to distinguish immune reconstitution inflammatory syndrome from strongyloidiasis infection syndrome because stool cultures were negative and eosinophils were not increased. Bronchoscopy revealed viable Strongyloides, leading to a diagnosis of strongyloidiasis infection syndrome, but the patient died despite treatment. CONCLUSIONS: Both corticosteroid therapy and HTLV-1 infection can be associated with a decrease of eosinophils, despite the presence of parasitic infection. In conclusion, even if multiple culture tests are negative, the risk of parasitic infection should be assessed in patients receiving immunosuppressants and steroids even in non-endemic areas.


Assuntos
Infecções por Citomegalovirus/complicações , Citomegalovirus/imunologia , Infecções por HTLV-I/complicações , Vírus Linfotrópico T Tipo 1 Humano/isolamento & purificação , Imunossupressão/efeitos adversos , Imunossupressores/uso terapêutico , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Strongyloides stercoralis/isolamento & purificação , Estrongiloidíase/complicações , Idoso , Animais , Anti-Helmínticos/uso terapêutico , Antivirais/uso terapêutico , Coinfecção/tratamento farmacológico , Citomegalovirus/isolamento & purificação , Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/tratamento farmacológico , Infecções por Citomegalovirus/virologia , Evolução Fatal , Feminino , Ganciclovir/uso terapêutico , Infecções por HTLV-I/diagnóstico , Infecções por HTLV-I/tratamento farmacológico , Infecções por HTLV-I/virologia , Humanos , Hospedeiro Imunocomprometido , Imunossupressores/efeitos adversos , Ivermectina/uso terapêutico , Estrongiloidíase/diagnóstico , Estrongiloidíase/tratamento farmacológico , Estrongiloidíase/parasitologia , Síndrome
11.
Nat Commun ; 11(1): 3548, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32669541

RESUMO

Congenital CMV infection (cCMVi) affects 0.5-1% of all live births worldwide, making it the leading cause of sensorineural hearing loss (SNHL) in childhood. The majority of infants with cCMVi have normal hearing at birth, but are at risk of developing late-onset SNHL. Currently, we lack reliable biomarkers to predict the development of SNHL in these infants. Here, we evaluate blood transcriptional profiles in 80 infants with cCMVi (49 symptomatic, 31 asymptomatic), enrolled in the first 3 weeks of life, and followed for 3 years to assess emergence of late-onset SNHL. The biosignatures of symptomatic and asymptomatic cCMVi are indistinguishable, suggesting that immune responses of infants with asymptomatic and symptomatic cCMVi are not different. Random forest analyses of initial samples in infants with cCMVi, irrespective of their clinical classification, identify a 16-gene classifier signature associated with the development of SNHL with 92% accuracy, suggesting its potential value as a biomarker.


Assuntos
Infecções por Citomegalovirus/sangue , Citomegalovirus/imunologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/imunologia , Perda Auditiva Neurossensorial/epidemiologia , Infecções Assintomáticas , Biomarcadores/sangue , Estudos de Casos e Controles , Pré-Escolar , Citomegalovirus/isolamento & purificação , Infecções por Citomegalovirus/complicações , Infecções por Citomegalovirus/congênito , Infecções por Citomegalovirus/virologia , Feminino , Perda Auditiva Neurossensorial/genética , Perda Auditiva Neurossensorial/imunologia , Perda Auditiva Neurossensorial/virologia , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Masculino , Estudos Prospectivos , Medição de Risco/métodos , Transcriptoma/genética
12.
Rev Med Virol ; 30(5): e2144, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32671966

RESUMO

The significantly higher mortality rates seen in the elderly compared with young children during the coronavirus disease 2019 (Covid-19) pandemic is likely to be driven in part by an impaired immune response in older individuals. Cytomegalovirus (CMV) seroprevalence approaches 80% in the elderly. CMV has been shown to accelerate immune ageing by affecting peripheral blood T cell phenotypes and increasing inflammatory mediated cytokines such as IL-6. The elderly with pre-existing but clinically silent CMV infection may therefore be particularly susceptible to severe Covid-19 disease and succumb to a cytokine storm which may have been promoted by CMV. Here, we evaluate the potential role of CMV in those with severe Covid-19 disease and consider how this relationship can be investigated in current research studies.


Assuntos
Betacoronavirus/patogenicidade , Infecções por Coronavirus/epidemiologia , Síndrome da Liberação de Citocina/epidemiologia , Infecções por Citomegalovirus/epidemiologia , Citomegalovirus/patogenicidade , Imunossenescência , Pandemias , Pneumonia Viral/epidemiologia , Fatores Etários , Idoso , Betacoronavirus/imunologia , Criança , Coinfecção , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/virologia , Síndrome da Liberação de Citocina/imunologia , Síndrome da Liberação de Citocina/mortalidade , Síndrome da Liberação de Citocina/virologia , Citocinas/genética , Citocinas/imunologia , Citomegalovirus/imunologia , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/mortalidade , Infecções por Citomegalovirus/virologia , Progressão da Doença , Humanos , Pneumonia Viral/imunologia , Pneumonia Viral/mortalidade , Pneumonia Viral/virologia , Estudos Soroepidemiológicos , Índice de Gravidade de Doença , Análise de Sobrevida , Linfócitos T/imunologia , Linfócitos T/patologia , Linfócitos T/virologia
13.
PLoS Pathog ; 16(7): e1008560, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32667948

RESUMO

Human cytomegalovirus (HCMV) causes serious complications to immune compromised hosts. Dendritic cells (iDCgB) expressing granulocyte-macrophage colony-stimulating factor, interferon-alpha and HCMV-gB were developed to promote de novo antiviral adaptive responses. Mice reconstituted with a human immune system (HIS) were immunized with iDCgB and challenged with HCMV, resulting into 93% protection. Immunization stimulated the expansion of functional effector memory CD8+ and CD4+ T cells recognizing gB. Machine learning analyses confirmed bone marrow T/CD4+, liver B/IgA+ and spleen B/IgG+ cells as predictive biomarkers of immunization (≈87% accuracy). CD8+ and CD4+ T cell responses against gB were validated. Splenic gB-binding IgM-/IgG+ B cells were sorted and analyzed at a single cell level. iDCgB immunizations elicited human-like IgG responses with a broad usage of various IgG heavy chain V gene segments harboring variable levels of somatic hypermutation. From this search, two gB-binding human monoclonal IgGs were generated that neutralized HCMV infection in vitro. Passive immunization with these antibodies provided proof-of-concept evidence of protection against HCMV infection. This HIS/HCMV in vivo model system supported the validation of novel active and passive immune therapies for future clinical translation.


Assuntos
Anticorpos Antivirais/imunologia , Infecções por Citomegalovirus/imunologia , Vacinas contra Citomegalovirus/imunologia , Imunização Passiva , Imunoglobulina G/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/farmacologia , Antígenos Virais/imunologia , Citomegalovirus/imunologia , Células Dendríticas/imunologia , Modelos Animais de Doenças , Humanos , Imunoglobulina G/farmacologia , Camundongos
14.
J Occup Health ; 62(1): e12112, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32515872

RESUMO

OBJECTIVE: The aim of the study was to determine and compare the prevalence of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) antibodies and DNA among nurses working in different profiles of healthcare activity. MATERIAL AND METHODS: The study population comprised 120 women (90 exposed healthcare workers and 30 controls). Blood samples were investigated using chemiluminescent microparticle immunoassays (CMIA) tests to detect the presence of EBV VCA IgM, IgG, and CMV IgM, IgG. Plasma CMV and EBV DNA levels were assessed using real-time polymerase chain reaction (PCR). RESULTS: CMV IgG antibodies were present in 87.80% nurses (86.70% in controls), EBV IgG were present in all the nurses studied and in the control group. No statistically significant differences were noted between the subgroups of nurses and the control group as regards IgG CMV, VCA IgG EBV. CMV IgM/EBV IgM antibodies were negative in all the nurses. CMV/EBV DNA was reported only in the study group. It was not found in any of control group participants. CONCLUSIONS: The positive PCR CMV/EBV markers only in the study group can be indicative of the exposure of nurses to these pathogens being greater than in other people not being professionally involved in patient care. In addition, it was observed that the level of CMV IgG antibodies as well as EBV VCA IgG antibodies tended to be linked to the age and the length of work of nurses working in pediatrics.


Assuntos
Anticorpos Antivirais/sangue , Citomegalovirus/imunologia , DNA Viral/isolamento & purificação , Herpesvirus Humano 4/imunologia , Enfermeiras e Enfermeiros , Exposição Ocupacional/análise , Adulto , Idoso , Estudos de Casos e Controles , Infecções por Citomegalovirus/epidemiologia , Infecções por Vírus Epstein-Barr/epidemiologia , Feminino , Humanos , Pessoa de Meia-Idade , Enfermeiras Pediátricas , Transplante de Órgãos , Prevalência , Enfermagem de Atenção Primária
15.
Acta Virol ; 64(2): 117-130, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32551781

RESUMO

Viruses have evolved sophisticated strategies to subvert immunity to benefit overall viral fitness. Human cytomegalovirus (HCMV, ß-herpesvirus) represents a paradigm of very effective hijacking of gene functions that imitate host encoded immunomodulatory proteins. This co-evolution with the host immune system allowed for establishment of lifelong persistence. The HCMV infection is largely asymptomatic in healthy persons; however, it can induce serious disease in immunocompromised individuals. For this reason, great attention is paid to the development of therapeutics based on HCMV immunomodulatory 'tricks' as well as to the search for active vaccine against HCMV. While comparing the HCMV clinical isolates with extensively passaged laboratory strains, the unique long (UL) b' locus was commonly found to be deleted in HCMV genome while adapted to replication in human fibroblasts in vitro. This missing region, called UL/b' region, encodes up to 22 canonical genes with different functions, as of targeting cellular tropism (e.g. UL133-UL138); viral entry and assembly (e.g. UL128, UL130, UL131A); regulation of immunological synapses (e.g. UL135); inhibition of NK and T cell function (e.g. UL141, UL142, UL148, UL144), ablating activity (e.g. UL146, UL147), but mainly aimed at manipulating the host immune response. Moreover, the presence of UL/b' genomic region dramatically correlates with adverse effects in vaccinated persons, indicating that viral genes in this region play a significant role in controlling virulence. Here, we review how HCMV shapes our immunity by hijacked genes originated from UL/b' locus, discuss their impact in immunomodulation mechanism and how this knowledge may translate to clinical applications. Keywords: immunomodulation; HCMV genes; UL/b' locus; NK cell function; HCMV vaccine; immunity; immunotherapeutics.


Assuntos
Infecções por Citomegalovirus/imunologia , Citomegalovirus , Genes Virais , Deleção de Sequência , Citomegalovirus/genética , Citomegalovirus/imunologia , Humanos , Glicoproteínas de Membrana/genética , Proteínas Virais/genética , Tropismo Viral/genética , Internalização do Vírus
16.
Sheng Wu Gong Cheng Xue Bao ; 36(6): 1223-1231, 2020 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-32597072

RESUMO

In order to prepare human-mouse chimeric cytomegalovirus-immunoglobulin M (CMV-IgM) in vitro and study the effects of different signal peptides on the secretion of CMV-IgM, genes were amplified from hybridoma cell line using RLM-RACE to construct the expression vector of chimeric CMV-IgM. Then, the signal peptide of SigF itself was replaced by five different secreted signal peptides (SigA-SigE) by PCR method, and the CHO cell was chosen as host cell for in vitro expression. SDS-PAGE, SEC-HPLC and ELISA experiments were carried out to evaluate the protein expression level and immunoreactivity of the purified CMV-IgM. A 910 kDa recombinant protein was successfully prepared and signal peptides (SigA-SigE) had an increased expressed CMV-IgM, which were 6.72, 5.19, 1.44, 1.85 and 1.98 times higher than that of the CMV 6# cell signal peptide SigF. In summary, this work provides a theoretical basis for the development of human-mouse chimeric CMV-IgM, and a novel route to increase the expression level of CMV-IgM.


Assuntos
Anticorpos Antivirais , Citomegalovirus , Imunoglobulina M , Proteínas Recombinantes de Fusão , Animais , Anticorpos Antivirais/genética , Anticorpos Antivirais/imunologia , Cricetinae , Citomegalovirus/imunologia , Ensaio de Imunoadsorção Enzimática , Expressão Gênica , Humanos , Imunoglobulina M/imunologia , Camundongos , Sinais Direcionadores de Proteínas , Proteínas Recombinantes de Fusão/imunologia
17.
BMC Infect Dis ; 20(1): 418, 2020 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-32546244

RESUMO

BACKGROUND: Cytomegalovirus infection is the most frequent viral congenital infection, with possible consequences such as deafness, or psychomotor retardation. In 2016, the French High Council of Public Health was mandated to update recommendations regarding prevention of cytomegalovirus infection in pregnant women. We summarize a critical appraisal of knowledge and deterministic decision analysis comparing the current no-screening situation to serological screening during pregnancy, and to hygiene promotion. METHODS: Screening was defined as systematic serological testing, during the first trimester, with repeated tests as needed, to all pregnant women. Outcomes were: 1) severe sequela: intellectual deficiency with IQ ≤ 50 or hearing impairment < 70 dB or sight impairment (≤ 3/10 at best eye); 2) moderate sequela: any level of intellectual, hearing or sight deficiency; and 3) death or termination of pregnancy. We simulated the one-year course of cytomegalovirus infection in a cohort of 800,000 pregnant women. We developed a deterministic decision model, using best and min-max estimates, extracted from systematic reviews or original studies. RESULTS: Relevant data were scarce or imprecise. We estimated that 4352 maternal primary infections would result in 1741 foetal infections, and an unknown number of maternal reinfections would result in 1699 foetal infections. There would be 788 cytomegalovirus-related consequences, including 316 foetal deaths or terminations of pregnancy, and 424 moderate and 48 severe sequelae. Screening would result in a 1.66-fold increase of poor outcomes, mostly related to a 2.93-fold increase in deaths and terminations of pregnancy, not compensated by the decrease in severe symptomatic newborns. The promotion of hygiene would result in a 0.75-fold decrease of poor outcomes, related to both a decrease in severe sequelae among symptomatic newborns (RR = 0.75; min-max: 1.00-0.68), and in deaths and terminations of pregnancy (RR = 0.75; min-max: 0.97-0.68). CONCLUSIONS: Prevention of cytomegalovirus infection during pregnancy should promote hygiene; serological screening should not be recommended.


Assuntos
Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/prevenção & controle , Citomegalovirus/imunologia , Doenças Fetais/diagnóstico , Higiene , Programas de Rastreamento/métodos , Complicações Infecciosas na Gravidez/virologia , Estudos de Coortes , Técnicas de Apoio para a Decisão , Feminino , Doenças Fetais/virologia , Humanos , Recém-Nascido , Modelos Biológicos , Gravidez , Testes Sorológicos
18.
Hematol Oncol ; 38(4): 554-559, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32583904

RESUMO

Ruxolitinib is effective in myeloproliferative neoplasms (MPN) but can cause reactivation of silent infections. We aimed at evaluating viral load and T-cell responses to human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) in a cohort of 25 MPN patients treated with ruxolitinib. EBV-DNA and HCMV-DNA were quantified monthly using real-time polimerase chain reaction (PCR) on peripheral blood samples, and T-cell subsets were analyzed by flowcytometry. HCMV and EBV-directed T-cell responses were evaluated using the IFN-γ ELISPOT assay. Most patients had CD4+ and/or CD8+ T-cells below the normal range; these reductions were related to the duration of ruxolitinib treatment. In fact, reduced T-lymphocytes' subsets were found in 93% of patients treated for ≥5 years and in 45% of those treated for <5 years (P = .021). The former also had lower median numbers of CD4+ and CD8+ cells. Subclinical reactivation of EBV and HCMV occurred in 76% and 8% of patients. We observed a trend to an inverse relationship between EBV and CMV-specific CD4+ and CD8+ T-cell responses and viral load, and a trend to an inverse correlation with ruxolitinib dose. Therefore, our data suggest that the ruxolitinib treatment may interfere with immunosurveillance against EBV and HCMV.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Infecções por Citomegalovirus/imunologia , Infecções por Vírus Epstein-Barr/imunologia , Transtornos Mieloproliferativos/imunologia , Pirazóis/farmacologia , Ativação Viral/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/virologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/virologia , Citomegalovirus/efeitos dos fármacos , Citomegalovirus/imunologia , Infecções por Citomegalovirus/tratamento farmacológico , Infecções por Citomegalovirus/virologia , Infecções por Vírus Epstein-Barr/tratamento farmacológico , Infecções por Vírus Epstein-Barr/virologia , Feminino , Seguimentos , Herpesvirus Humano 4/efeitos dos fármacos , Herpesvirus Humano 4/imunologia , Humanos , Interferon gama/metabolismo , Masculino , Pessoa de Meia-Idade , Transtornos Mieloproliferativos/tratamento farmacológico , Transtornos Mieloproliferativos/virologia , Prognóstico , Taxa de Sobrevida , Carga Viral , Ativação Viral/efeitos dos fármacos
19.
BMC Med Genet ; 21(1): 113, 2020 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-32450795

RESUMO

BACKGROUND: Maternal cytomegalovirus (CMV) infection and/or reactivation in pregnancy is associated with a myriad of adverse infant outcomes. However, the role of host genetic polymorphisms in modulating maternal CMV status is inconclusive. This study investigated the possible association of single nucleotide polymorphisms in toll-like receptor (TLR) and cytokine genes with maternal plasma CMV DNA status in black Zimbabweans. METHODS: In a cross-sectional study, 110 women in late gestation who included 36 CMV infected cases and 74 CMV uninfected, age and HIV status matched controls were enrolled. Twenty single nucleotide polymorphisms in 10 genes which code for proteins involved in immunity against CMV were genotyped using Iplex GOLD SNP genotyping protocol on the Agena MassARRAY® system. Statistical analyses were performed using Stata SE and the 'Genetics' and 'SNPassoc' packages of the statistical package R. RESULTS: The TLR7 rs179008A > T (p < 0.001) polymorphism was associated while the TLR9 rs352139T > C (p = 0.049) polymorphism was on the borderline for association with CMV positive (CMV+) status. In contrast, the interleukin (IL)-6 rs10499563T > C (p < 0.001) and TLR2 rs1816702C > T (p = 0.001) polymorphisms were associated with CMV negative (CMV-) status. Furthermore, allele frequencies of SNPs in TLR2, TLR4, TLR9, TLR7, IL-6, IL-10, IL-28B, IL-1A and interferon AR1 (IFNAR1) genes are being reported here for the first time in a Zimbabwean population. The allele frequencies in the Zimbabwean population are generally comparable to other African populations but different when compared to European and Asian populations. CONCLUSIONS: Toll-like receptor and interleukin genetic polymorphisms influence CMV status in late gestation among black Zimbabweans. This is attributable to possible modulation of immune responses to CMV reactivation in a population previously exposed to CMV infection.


Assuntos
Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/etiologia , Citomegalovirus , Variação Genética , Interleucina-6/genética , Complicações Infecciosas na Gravidez , Receptores Toll-Like/genética , Adolescente , Adulto , Alelos , Citomegalovirus/imunologia , Suscetibilidade a Doenças , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Razão de Chances , Polimorfismo de Nucleotídeo Único , Gravidez , Receptor 2 Toll-Like/genética , Receptor 7 Toll-Like/genética , Receptor Toll-Like 9/genética , Adulto Jovem
20.
Proc Natl Acad Sci U S A ; 117(23): 12961-12968, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32444487

RESUMO

Viral immune evasion is currently understood to focus on deflecting CD8 T cell recognition of infected cells by disrupting antigen presentation pathways. We evaluated viral interference with the ultimate step in cytotoxic T cell function, the death of infected cells. The viral inhibitor of caspase-8 activation (vICA) conserved in human cytomegalovirus (HCMV) and murine CMV (MCMV) prevents the activation of caspase-8 and proapoptotic signaling. We demonstrate the key role of vICA from either virus, in deflecting antigen-specific CD8 T cell-killing of infected cells. vICA-deficient mutants, lacking either UL36 or M36, exhibit greater susceptibility to CD8 T cell control than mutants lacking the set of immunoevasins known to disrupt antigen presentation via MHC class I. This difference is evident during infection in the natural mouse host infected with MCMV, in settings where virus-specific CD8 T cells are adoptively transferred. Finally, we identify the molecular mechanism through which vICA acts, demonstrating the central contribution of caspase-8 signaling at a point of convergence of death receptor-induced apoptosis and perforin/granzyme-dependent cytotoxicity.


Assuntos
Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Interações entre Hospedeiro e Microrganismos/imunologia , Evasão da Resposta Imune , Linfócitos T Citotóxicos/imunologia , Animais , Apoptose/imunologia , Caspase 8/genética , Caspase 8/metabolismo , Linhagem Celular , Técnicas de Cocultura , Citomegalovirus/patogenicidade , Infecções por Citomegalovirus/virologia , Modelos Animais de Doenças , Fibroblastos , Granzimas/metabolismo , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Camundongos , Camundongos Knockout , Muromegalovirus/genética , Muromegalovirus/imunologia , Muromegalovirus/metabolismo , Mutagênese , Perforina/genética , Perforina/metabolismo , Receptores de Morte Celular/metabolismo , Transdução de Sinais/imunologia , Linfócitos T Citotóxicos/metabolismo , Imagem com Lapso de Tempo , Proteínas Virais/genética , Proteínas Virais/imunologia , Proteínas Virais/metabolismo
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