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1.
Pan Afr Med J ; 36: 167, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32952811

RESUMO

Coronavirus disease 2019 (COVID-19) has been reported as the possible cause of acute myocarditis. Myocarditis is an inflammatory heart disease mostly caused by viral infections. Cytomegalovirus (CMV) primary infection is often not suspected as a cause of myocarditis in immune-competent adults. We report the case of a 37-year-old male admitted with fever, cough and dyspnea. Chest CT showed typical ground-glass changes indicative of viral pneumonia. He was tested negative for COVID-19 but had biological markers that made us still suspect it. He had elevated troponin I level (up to 111.5 ng/mL) and diffuse myocardial dyskinesia along with a decreased left ventricular ejection fraction (LVEF). He was diagnosed with CMV myocarditis with cardiac insufficiency and totally recovered without antiviral therapy. During the COVID-19 pandemic patients may develop myocarditis, still every myocarditis is not a COVID infection. Myocarditis linked to CMV infection may be rare, but life-threatening.


Assuntos
Infecções por Coronavirus/diagnóstico , Infecções por Citomegalovirus/diagnóstico , Miocardite/diagnóstico , Pneumonia Viral/diagnóstico , Técnicas de Laboratório Clínico , Infecções por Coronavirus/epidemiologia , Tosse/etiologia , Infecções por Citomegalovirus/virologia , Diagnóstico Diferencial , Dispneia/etiologia , Febre/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Miocardite/diagnóstico por imagem , Miocardite/virologia , Pandemias , Pneumonia Viral/epidemiologia , Tomografia Computadorizada por Raios X
2.
Anticancer Res ; 40(10): 5909-5917, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988922

RESUMO

BACKGROUND/AIM: Cytomegalovirus (CMV) replication may cause life-threatening complications after allogeneic haematopoietic stem cell transplantation (allo-HSCT). The aim of the study was to characterize CMV events, and the outcome of letermovir (LTV) CMV prophylaxis. PATIENTS AND METHODS: In this retrospective analysis of patients treated with an allo-HSCT between 2010 and 2020, we determined plasma CMV events, as well as associated risk factors. RESULTS: We identified 423 patients who had undergone allo-HSCT between 2010 and 2020. CMV DNAemia was found in 130/423 (30.7%) of patients. CMV reactivation rate was significantly higher in patients with acute graft-versus-host disease, HLA mismatch, and CMV IgG seropositivity of donors and recipients. Among 42 patients receiving LTV prophylaxis those, 5 (11.9%) showed CMV DNAemia under LTV versus 87/353 (24.6%) in a control group. CONCLUSION: Despite the development of better approaches with weekly monitoring and early treatment initiation, CMV reactivations play an important role after allo-HSCT.


Assuntos
Acetatos/administração & dosagem , Infecções por Citomegalovirus/tratamento farmacológico , Citomegalovirus/efeitos dos fármacos , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Quinazolinas/administração & dosagem , Adulto , Idoso , Citomegalovirus/patogenicidade , Infecções por Citomegalovirus/sangue , Infecções por Citomegalovirus/etiologia , Infecções por Citomegalovirus/virologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transplante Homólogo/efeitos adversos , Replicação Viral/efeitos dos fármacos
3.
Virology ; 548: 168-173, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32838938

RESUMO

Clinical significance of the cytomegalovirus (CMV) genotypes in patients undergoing allogeneic hematopoietic stem cell transplant (HSCT) has been evaluated mostly in adults. The studies of diverse CMV glycoprotein B (gB) and N (gN) genotype variants in transplanted children and adolescents are lacking. We analyzed the investment of gB and gN genotype variants in the HSCTed children and their relation to clinical complications and disease outcome. The cohort included forty two pediatric recipients of the HSCT. Patients positive for CMV DNAemia (24/42, 57.1%) were genotyped. The gB4 and gN1 genotype variants predominated and were evidenced in 7/18 (38.9%) and 9/19 (47.4%) patients, respectively. The graft-versus-host disease (GvHD) predominated in children with viremia (p < 0.05). Frequencies of the gB and gN genotypes contrasted those reported in recent studies. The GvHD scaled strongly with CMV reactivation whereas viral loads were uncorrelated to medical complications and treatment outcomes.


Assuntos
Infecções por Citomegalovirus/virologia , Citomegalovirus/isolamento & purificação , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Complicações Pós-Operatórias/virologia , Proteínas do Envelope Viral/genética , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Citomegalovirus/classificação , Citomegalovirus/genética , Citomegalovirus/metabolismo , Feminino , Genótipo , Doença Enxerto-Hospedeiro/virologia , Humanos , Masculino , Transplante Homólogo/efeitos adversos , Proteínas do Envelope Viral/metabolismo , Adulto Jovem
4.
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
5.
Virology ; 548: 49-58, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32838946

RESUMO

Human cytomegalovirus (HCMV) is a widespread herpesvirus that establishes latency in myeloid cells and persists by manipulating immune signaling. Chemokine receptor CXCR4 and its ligand CXCL12 regulate movement of myeloid progenitors into bone marrow and out into peripheral tissues. HCMV amplifies CXCL12-CXCR4 signaling through viral chemokine receptor US27 and cmvIL-10, a viral cytokine that binds the cellular IL-10 receptor (IL-10R), but precisely how these viral proteins influence CXCR4 is unknown. We used the proximity ligation assay (PLA) to examine association of CXCR4, IL-10R, and US27 in both transfected and HCMV-infected cells. CXCR4 and IL-10R colocalized to discrete clusters, and treatment with CXCL12 and cmvIL-10 dramatically increased receptor clustering and calcium flux. US27 was associated with CXCR4 and IL-10R in PLA clusters and further enhanced cluster formation and calcium signaling. These results indicate that CXCR4, IL-10R, and US27 form a novel virus-host signaling complex that enhances CXCL12 signaling during HCMV infection.


Assuntos
Infecções por Citomegalovirus/metabolismo , Citomegalovirus/metabolismo , Receptores CXCR4/metabolismo , Receptores de Quimiocinas/metabolismo , Receptores de Interleucina-10/metabolismo , Proteínas Virais/metabolismo , Quimiocina CXCL12/genética , Quimiocina CXCL12/metabolismo , Citomegalovirus/genética , Infecções por Citomegalovirus/genética , Infecções por Citomegalovirus/virologia , Interações Hospedeiro-Patógeno , Humanos , Ligação Proteica , Receptores CXCR4/genética , Receptores de Quimiocinas/genética , Receptores de Interleucina-10/genética , Transdução de Sinais , Proteínas Virais/genética
6.
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
7.
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
8.
Cancer Invest ; 38(7): 394-405, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32643440

RESUMO

The study investigated the human cytomegalovirus (HCMV) and human papillomavirus (HPV) in gliomas. A retrospective study was conducted on 112 samples. HCMV was investigated by PCR, in situ hybridization (ISH) and immunohistochemistry. HPV was tested by PCR and DNA ISH. HCMV was identified in 60 gliomas, including 55 GBM. However, RNA ISH and immunohistochemistry failed to detect HCMV positivity. HPV was identified in 44 GBM. No significant relationship was identified between HCMV and HPV and tumour characteristics (p > 0.05). Our findings support the HCMV and HPV presence in gliomas. Further assays are required to more explore the potential efficient antiviral management.


Assuntos
Neoplasias Encefálicas/virologia , Citomegalovirus/isolamento & purificação , Glioma/virologia , Papillomaviridae/isolamento & purificação , Adulto , Idoso , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Citomegalovirus/genética , Infecções por Citomegalovirus/virologia , Feminino , Glioma/mortalidade , Glioma/patologia , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Papillomaviridae/genética , Infecções por Papillomavirus/virologia , Reação em Cadeia da Polimerase , Estudos Retrospectivos , Tunísia , Adulto Jovem
9.
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
10.
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
11.
Proc Natl Acad Sci U S A ; 117(31): 18771-18779, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32690704

RESUMO

Human cytomegalovirus (HCMV) is an important human pathogen and a paradigm of intrinsic, innate, and adaptive viral immune evasion. Here, we employed multiplexed tandem mass tag-based proteomics to characterize host proteins targeted for degradation late during HCMV infection. This approach revealed that mixed lineage kinase domain-like protein (MLKL), a key terminal mediator of cellular necroptosis, was rapidly and persistently degraded by the minimally passaged HCMV strain Merlin but not the extensively passaged strain AD169. The strain Merlin viral inhibitor of apoptosis pUL36 was necessary and sufficient both to degrade MLKL and to inhibit necroptosis. Furthermore, mutation of pUL36 Cys131 abrogated MLKL degradation and restored necroptosis. As the same residue is also required for pUL36-mediated inhibition of apoptosis by preventing proteolytic activation of procaspase-8, we define pUL36 as a multifunctional inhibitor of both apoptotic and necroptotic cell death.


Assuntos
Apoptose/fisiologia , Citomegalovirus , Necroptose/fisiologia , Proteínas Virais/metabolismo , Células Cultivadas , Citomegalovirus/química , Citomegalovirus/metabolismo , Citomegalovirus/patogenicidade , Infecções por Citomegalovirus/metabolismo , Infecções por Citomegalovirus/virologia , Humanos , Ligação Proteica , Proteólise
12.
Proc Natl Acad Sci U S A ; 117(31): 18764-18770, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32694203

RESUMO

Human progenitor cells (HPCs) support human cytomegalovirus (HCMV) latency, and their differentiation along the myeloid lineage triggers cellular cues that drive reactivation. A key step during HCMV reactivation in latently infected HPCs is reexpression of viral major immediate early (MIE) genes. We recently determined that the major immediate early promoter (MIEP), which is primarily responsible for MIE gene expression during lytic replication, remains silent during reactivation. Instead, alternative promoters in the MIE locus are induced by reactivation stimuli. Here, we find that forkhead family (FOXO) transcription factors are critical for activation of alternative MIE promoters during HCMV reactivation, as mutating FOXO binding sites in alternative MIE promoters decreased HCMV IE gene expression upon reactivation and significantly decreased the production of infectious virus from latently infected primary CD34+ HPCs. These findings establish a mechanistic link by which infected cells sense environmental cues to regulate latency and reactivation, and emphasize the role of contextual activation of alternative MIE promoters as the primary drivers of reactivation.


Assuntos
Citomegalovirus , Fatores de Transcrição Forkhead/metabolismo , Regiões Promotoras Genéticas/genética , Proteínas Virais/metabolismo , Citomegalovirus/genética , Citomegalovirus/metabolismo , Citomegalovirus/fisiologia , Infecções por Citomegalovirus/virologia , Genes Precoces/genética , Células HeLa , Humanos , Latência Viral
13.
Arch Virol ; 165(8): 1827-1835, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32507978

RESUMO

Human cytomegalovirus (HCMV) infection causes high morbidity and mortality among immunocompromised patients and can remain in a latent state in host cells. Expression of the immediate-early (IE) genes sustains HCMV replication and reactivation. As a novel genome-editing tool, the clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) system has been extensively utilized to modify and edit genomic DNA. In the present study, the CRISPR/Cas9 system was used to target the IE region of the HCMV genome via specific single-guide RNAs (sgRNAs). Infection with CRISPR/Cas9/sgRNA lentiviral constructs significantly reduced viral gene expression and virion production in HFF primary fibroblasts and inhibited viral DNA production and reactivation in the THP-1 monocytic cell line. Thus, the CRISPR/Cas9/sgRNA system can accurately and efficiently target HCMV replication and reactivation and represents a novel therapeutic strategy against latent HCMV infection.


Assuntos
Sistemas CRISPR-Cas/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Citomegalovirus/genética , Endonucleases/genética , Genes Virais/genética , Replicação Viral/genética , Linhagem Celular , Infecções por Citomegalovirus/virologia , DNA Viral/genética , Fibroblastos/virologia , Edição de Genes/métodos , Expressão Gênica/genética , Células HEK293 , Humanos , RNA Guia/genética , Células THP-1
14.
PLoS One ; 15(5): e0233096, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32421725

RESUMO

Congenital cytomegalovirus (cCMV) infection is the most common intrauterine infection. A non-specific immune response is the first line of host defense mechanism against human cytomegalovirus (HCMV). There is limited data on associations between Single Nucleotide Polymorphisms (SNPs) in genes involving innate immunity and the risk and clinical manifestation of cCMV infection. The aim of the study was to investigate association between selected SNPs in genes encoding cytokines and cytokine receptors, and predisposition to cCMV infection including symptomatic course of disease and symptoms. A panel of eight SNPs: IL1B rs16944, IL12B rs3212227, IL28B rs12979860, CCL2 rs1024611, DC-SIGN rs735240, TLR2 rs5743708, TLR4 rs4986791, TLR9 rs352140 was analyzed in 233 infants (92 cCMV-infected and 141 healthy controls). Associations between genotyped SNPs and predisposition to cCMV infection and symptoms were analyzed. The association analysis was performed using SNPStats software. No statistically significant association was found between any genotyped SNPs and predisposition to cCMV infection and symptomatic course of disease. In relation to particular symptoms, polymorphism of IL12B rs3212227 was linked to decreased risk of prematurity (OR = 0.37;95%CI,0.14-0.98;p = 0.025), while polymorphism of IL1B rs16944 was linked to reduced risk of splenomegaly (OR = 0.36;95%CI,0.14-0.98; p = 0.034) in infants with cCMV infection. An increased risk of thrombocytopenia was associated with IL28B rs12979860 polymorphism (OR = 2.55;95%CI,1.03-6.32;p = 0.042), while hepatitis was associated with SNP of TLR4rs4986791 (OR = 7.80;95%CI,1.49-40,81; p = 0.024). This is the first study to demonstrate four new associations between SNPs in selected genes (IL1B, IL12B, IL28B, TLR4) and particular symptoms in cCMV disease. Further studies on the role of SNPs in the pathogenesis of cCMV infection and incorporation of selected SNPs in the clinical practice might be considered in the future.


Assuntos
Infecções por Citomegalovirus/genética , Interferons/genética , Interleucina-12/genética , Interleucina-1beta/genética , Polimorfismo de Nucleotídeo Único/genética , Receptor 4 Toll-Like/genética , Adulto , Infecções por Citomegalovirus/virologia , Feminino , Frequência do Gene/genética , Genótipo , Técnicas de Genotipagem , Humanos , Masculino , Trombocitopenia/genética , Trombocitopenia/virologia
15.
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
16.
PLoS Pathog ; 16(4): e1008402, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32251483

RESUMO

Herpesvirus late promoters activate gene expression after viral DNA synthesis has begun. Alphaherpesviruses utilize a viral immediate-early protein to do this, whereas beta- and gammaherpesviruses primarily use a 6-member set of viral late-acting transcription factors (LTF) that are drawn to a TATT sequence in the late promoter. The betaherpesvirus, human cytomegalovirus (HCMV), produces three immediate-early 2 protein isoforms, IE2-86, IE2-60, IE2-40, late in infection, but whether they activate late viral promoters is unknown. Here, we quickly degrade the IE2 proteins in late infection using dTag methodology and analyze effects on transcription using customized PRO-Seq and computational methods combined with multiple validation methods. We discover that the IE2 proteins selectively drive RNA Pol II transcription initiation at a subset of viral early-late and late promoters common to different HCMV strains, but do not substantially affect Pol II transcription of the 9,942 expressed host genes. Most of the IE2-activated viral late infection promoters lack the TATT sequence bound by the HCMV UL87-encoded LTF. The HCMV TATT-binding protein is not mechanistically involved in late RNA expression from the IE2-activated TATT-less UL83 (pp65) promoter, as it is for the TATT-containing UL82 (pp71) promoter. While antecedent viral DNA synthesis is necessary for transcription from the late infection viral promoters, continued viral DNA synthesis is unnecessary. We conclude that in late infection the IE2 proteins target a distinct subset of HCMV early-late and late promoters for transcription initiation by RNA Pol II. Commencement of viral DNA replication renders the HCMV genome late promoters susceptible to late-acting viral transcription factors.


Assuntos
Infecções por Citomegalovirus/virologia , Citomegalovirus/metabolismo , Replicação do DNA , Proteínas Imediatamente Precoces/metabolismo , Regiões Promotoras Genéticas , RNA Polimerase II/metabolismo , Transativadores/metabolismo , Proteínas Virais/genética , Citomegalovirus/genética , Infecções por Citomegalovirus/genética , Infecções por Citomegalovirus/metabolismo , DNA Viral/genética , Regulação Viral da Expressão Gênica , Humanos , Proteínas Imediatamente Precoces/genética , RNA Polimerase II/genética , Transativadores/genética , Iniciação da Transcrição Genética , Proteínas Virais/metabolismo , Replicação Viral
17.
New Microbiol ; 43(2): 58-63, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32310297

RESUMO

Up to now, the UL16-17 region of human cytomegalovirus (HCMV) has not been well characterized at the level of mRNA and protein, especially for the Han strain, the first clinical HCMV strain in China. In previous studies, three transcripts were detected from the UL16-17 region by northern blot analysis for Merlin strain. Transcriptions of UL16 and UL17 were also studied by 5' rapid amplification of cDNA ends (5'RACE) and deep sequencing for AD169 and Towne strains, respectively. However, details of 3' end of UL16 and UL17 transcripts have never been confirmed by 3'RACE. The expressing phage of the UL16-17 region needs further research by northern blot, too. In the present study, cDNA library screening, northern blot and RACE were used to identify the transcription characteristics of the UL16-17 region. Mainly, 3 clusters of transcripts with the same 3' end were found to be expressed from the UL16-17 region in both Han and AD169 strains. The lengths of the core transcripts among the 3 clusters were 1,254nt, 718nt and 468nt, respectively. The corresponding 5' ends are at nt23119, nt23655, nt23905 in the HCMV Han genome. The consistent 3' end is located at nt24372 in the Han genome. The 1,254nt and 468nt transcripts are transcribed in early and late phases, and the 718nt transcript is transcribed only in the late phase.


Assuntos
Citomegalovirus , Proteínas Virais , China , Citomegalovirus/genética , Infecções por Citomegalovirus/virologia , Biblioteca Gênica , Humanos , RNA Mensageiro/química , Proteínas Virais/química , Proteínas Virais/genética
18.
New Microbiol ; 43(2): 93-95, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32310302

RESUMO

Cytomegalovirus is the primary viral cause of congenital infection. However, diagnosis may be difficult for clinical and technical reasons. Currently, evaluation of CMV DNA on dried blood spot (DBS) is an important instrument to define a congenital infection. The aim of this study was to identify a clinically and technically suitable diagnostic work-flow for CMV DNA evaluation on DBS. Sensitivity was not significantly influenced by storage time of up to 12 months and extraction technique; however, analysis in triplicate was crucial to obtain reliable results. Considering viral load in an infected foetus at risk of developing disease, a threshold value of approximately 104 copies/mL was characterized by high operating characteristics for detection of positivity at 12 months on DBS.


Assuntos
Infecções por Citomegalovirus , Citomegalovirus , DNA Viral , Teste em Amostras de Sangue Seco , Citomegalovirus/genética , Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/virologia , DNA Viral/química , Teste em Amostras de Sangue Seco/normas , Humanos , Sensibilidade e Especificidade , Testes Sorológicos , Carga Viral
19.
PLoS Pathog ; 16(4): e1008426, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32282833

RESUMO

Human cytomegalovirus (HCMV) is the most frequent viral cause of congenital defects and can trigger devastating disease in immune-suppressed patients. Cytotoxic lymphocytes (CD8+ T cells and NK cells) control HCMV infection by releasing interferon-γ and five granzymes (GrA, GrB, GrH, GrK, GrM), which are believed to kill infected host cells through cleavage of intracellular death substrates. However, it has recently been demonstrated that the in vivo killing capacity of cytotoxic T cells is limited and multiple T cell hits are required to kill a single virus-infected cell. This raises the question whether cytotoxic lymphocytes can use granzymes to control HCMV infection in a noncytotoxic manner. Here, we demonstrate that (primary) cytotoxic lymphocytes can block HCMV dissemination independent of host cell death, and interferon-α/ß/γ. Prior to killing, cytotoxic lymphocytes induce the degradation of viral immediate-early (IE) proteins IE1 and IE2 in HCMV-infected cells. Intriguingly, both IE1 and/or IE2 are directly proteolyzed by all human granzymes, with GrB and GrM being most efficient. GrB and GrM cleave IE1 after Asp398 and Leu414, respectively, likely resulting in IE1 aberrant cellular localization, IE1 instability, and functional impairment of IE1 to interfere with the JAK-STAT signaling pathway. Furthermore, GrB and GrM cleave IE2 after Asp184 and Leu173, respectively, resulting in IE2 aberrant cellular localization and functional abolishment of IE2 to transactivate the HCMV UL112 early promoter. Taken together, our data indicate that cytotoxic lymphocytes can also employ noncytotoxic ways to control HCMV infection, which may be explained by granzyme-mediated targeting of indispensable viral proteins during lytic infection.


Assuntos
Infecções por Citomegalovirus/enzimologia , Citomegalovirus/metabolismo , Granzimas/metabolismo , Proteínas Imediatamente Precoces/metabolismo , Células Matadoras Naturais/enzimologia , Transativadores/metabolismo , Motivos de Aminoácidos , Citomegalovirus/genética , Infecções por Citomegalovirus/virologia , Granzimas/genética , Interações Hospedeiro-Patógeno , Humanos , Proteínas Imediatamente Precoces/genética , Proteólise , Linfócitos T Citotóxicos/enzimologia , Transativadores/genética
20.
Cancer Immunol Immunother ; 69(8): 1535-1548, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32300857

RESUMO

With an infection rate of 60-90%, the human cytomegalovirus (HCMV) is very common among adults but normally causes no symptoms. When T cell-mediated immunity is compromised, HCMV reactivation can lead to increased morbidity and mortality. HCMV antigens are processed and presented as peptides on the cell surface via HLA I complexes to the T cell receptor (TCR) of T cells. The generation of antibodies against HCMV peptides presented on HLA complexes (TCR-like antibodies) has been described, but is without therapeutic applications to date due to the polygenic and polymorphic nature of HLA genes. We set out to obtain antibodies specific for HLA/HCMV-peptides, covering the majority of HLA alleles present in European populations. Using phage display technology, we selected 10 Fabs, able to bind to HCMV-peptides presented in the 6 different HLA class I alleles A*0101, A*0201, A*2402, B*0702, B*0801 and B*3501. We demonstrate specific binding of all selected Fabs to HLA-typed lymphoblastoid cell lines (EBV-transformed B cells) and lymphocytes loaded with HCMV-peptides. After infection with HCMV, 4/10 tetramerized Fabs restricted to the alleles HLA-A*0101, HLA-A*0201 and HLA-B*0702 showed binding to infected primary fibroblasts. When linked to the pseudomonas exotoxin A, these Fab antibodies induce highly specific cytotoxicity in HLA matched cell lines loaded with HCMV peptides. TCR-like antibody repertoires therefore represent a promising new treatment modality for viral infections and may also have applications in the treatment of cancers.


Assuntos
Infecções por Citomegalovirus/prevenção & controle , Citomegalovirus/imunologia , Fibroblastos/imunologia , Antígenos HLA/imunologia , Fragmentos Fab das Imunoglobulinas/administração & dosagem , Fragmentos de Peptídeos/imunologia , Linfócitos T Citotóxicos/imunologia , Antígenos Virais/imunologia , Sobrevivência Celular , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/metabolismo , Infecções por Citomegalovirus/virologia , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Fragmentos Fab das Imunoglobulinas/imunologia , Fragmentos Fab das Imunoglobulinas/metabolismo , Imunotoxinas/administração & dosagem , Melanoma/imunologia , Melanoma/metabolismo , Melanoma/patologia , Melanoma/prevenção & controle , Receptores de Antígenos de Linfócitos T/imunologia , Proteínas Virais/imunologia
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