RESUMO
BACKGROUND: Human cytomegalovirus (HCMV) is the leading infectious cause of congenital disabilities. We designed a prospective study to investigate the rate, outcome, and risk factors of congenital CMV (cCMV) infection in neonates born to immune women, and the potential need and effectiveness of hygiene recommendations in this population. METHODS: The study was composed of 2 sequential parts: an epidemiology (part 1) and a prevention (part 2) study. Performance of part 2 depended upon a cCMV rate >0.4%. Women enrolled in part 1 did not receive hygiene recommendations. Newborns were screened by HCMV DNA testing in saliva and cCMV was confirmed by urine testing. RESULTS: Saliva swabs were positive for HCMV DNA in 45/9661 newborns and cCMV was confirmed in 18 cases. The rate of cCMV was .19% (95% confidence interval [CI]: .11-.29%), and 3 out of 18 infants with cCMV had symptoms of CMV at birth. Age, nationality, occupation, and contact with children were similar between mothers of infected and noninfected newborns. Twin pregnancy (odds ratio [OR]: 7.2; 95% CI: 1.7-32.2; P = .037) and maternal medical conditions (OR: 3.9; 95% CI: 1.5-10.1; P = .003) appeared associated with cCMV. Given the rate of cCMV was lower than expected, the prevention part of the study was cancelled. CONCLUSIONS: Newborns from women with preconception immunity have a low rate of cCMV, which appears to be mostly due to reactivation of the latent virus. Therefore, serological screening in childbearing age would be pivotal to identify HCMV-seropositive women, whose newborns have a low risk of cCMV. CLINICAL TRIALS REGISTRATION: www.clinicaltrials.gov (NCT03973359).
Assuntos
Infecções por Citomegalovirus , Complicações Infecciosas na Gravidez , Lactente , Gravidez , Recém-Nascido , Humanos , Feminino , Criança , Estudos Prospectivos , Prevalência , Infecções por Citomegalovirus/epidemiologia , Infecções por Citomegalovirus/prevenção & controle , Infecções por Citomegalovirus/diagnóstico , Citomegalovirus/genética , Fatores de RiscoRESUMO
OBJECTIVES: Human cytomegalovirus (HCMV) non-primary infections can occur in pregnant women and may result in congenital infection. Comprehensive studies investigating the frequency, characteristics, risk factors and immune response of non-primary infection in pregnancy are missing, while the rate of vertical transmission is not known. METHODS: HCMV non-primary infection was investigated prospectively in 250 pregnant women. Blood and urine samples as well as saliva and vaginal swabs were collected at 13, 21 and 31 weeks of gestation and at delivery. HCMV-DNA and specific IgG and IgM levels were determined. RESULTS: Overall, 105/250 pregnant women (42.0%) developed non-primary infection. HCMV-DNA was detected more frequently in vaginal secretions (84/250 of the women, 33.6%) than in urine (35/250, 14.0%), saliva (26/250, 10.4%) and blood (7/250, 3.0%). The rate of HCMV non-primary infection increased significantly with the progression of pregnancy (from 12.9% in the first trimesters of gestation to 21.9% at delivery, p < 0.01). IgM was detected in 25/250 of the women (10.0%), with no association with non-primary infection, while anti-gB IgG was significantly higher (p < 0.01) in women with non-primary infection. Age and close contact with children were not associated with non-primary infection. No woman with non-primary infection transmitted the infection to the fetus (95% confidence interval of transmission rate: 0-3.5%). DISCUSSION: Although HCMV non-primary infection is frequent during pregnancy, the rate of congenital infection as a consequence of non-primary infection is likely to be ≤ 3.5%.
Assuntos
Infecções por Citomegalovirus , Complicações Infecciosas na Gravidez , Anticorpos Antivirais , Formação de Anticorpos , Criança , Citomegalovirus , Infecções por Citomegalovirus/epidemiologia , Feminino , Humanos , Imunoglobulina G , Imunoglobulina M , Recém-Nascido , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Fatores de RiscoRESUMO
BACKGROUND: Strain-specific antibodies to human cytomegalovirus (HCMV) glycoproteins B and H (gB and gH) have been proposed as a potential diagnostic tool for identifying reinfection. We investigated genotype-specific IgG antibody responses in parallel with defining the gB and gH genotypes of the infecting viral strains. METHODS: Subjects with primary (n = 20) or non-primary (n = 25) HCMV infection were studied. The seven gB (gB1-7) and two gH (gH1-2) genotypes were determined by real-time PCR and whole viral genome sequencing, and genotype-specific IgG antibodies were measured by a peptide-based enzyme-linked immunosorbent assay (ELISA). RESULTS: Among subjects with primary infection, 73% (n = 8) infected by gB1-HCMV and 63% (n = 5) infected by gB2/3-HCMV had genotype-specific IgG antibodies to gB (gB2 and gB3 are similar in the region tested). Peptides from the rarer gB4-gB7 genotypes had nonspecific antibody responses. All subjects infected by gH1-HCMV and 86% (n = 6) infected by gH2-HCMV developed genotype-specific responses. Among women with non-primary infection, gB and gH genotype-specific IgG antibodies were detected in 40% (n = 10) and 80% (n = 20) of subjects, respectively. CONCLUSIONS: Peptide-based ELISA is capable of detecting primary genotype-specific IgG responses to HCMV gB and gH, and could be adopted for identifying reinfections. However, about half of the subjects did not have genotype-specific IgG antibodies to gB.
Assuntos
Anticorpos Antivirais/sangue , Infecções por Citomegalovirus/imunologia , Imunoglobulina G/sangue , Proteínas do Envelope Viral/imunologia , Citomegalovirus/genética , Citomegalovirus/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Genótipo , Humanos , MasculinoRESUMO
OBJECTIVES: The immunologic profile and opportunistic viral DNA increase were monitored in Italian patients with COVID-19 in order to identify markers of disease severity. METHODS: A total of 104 patients infected with SARS-CoV-2 were evaluated in the study. Of them, 42/104 (40.4%) were hospitalized in an intensive care unit (ICU) and 62/104(59.6%) in a sub-intensive care unit (SICU). Human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV), Parvovirus B19 and Human Herpesvirus 6 virus reactivations were determined by real-time PCR, and lymphocyte subpopulation counts were determined by flow cytometry. RESULTS: Among opportunistic viruses, only EBV was consistently detected. EBV DNA was observed in 40/42 (95.2%) of the ICU patients and in 51/61 (83.6%) of the SICU patients. Comparing the two groups of patients, the EBV DNA median level among ICU patients was significantly higher than that observed in SICU patients. In parallel, a significant reduction of CD8 T cell and NK count in ICU patients as compared with SICU patients was observed (p<0.05). In contrast, B cell count was significantly increased in ICU patients (p=0.0172). CONCLUSIONS: A correlation between reduced CD8+ T cells and NK counts, EBV DNA levels and COVID-19 severity was observed. Other opportunistic viral infections were not observed. The relationship between EBV load and COVID-19 severity should be further evaluated in longitudinal studies.
Assuntos
COVID-19/complicações , Infecções por Vírus Epstein-Barr/virologia , Herpesvirus Humano 4/isolamento & purificação , SARS-CoV-2 , Carga Viral , Idoso , Idoso de 80 Anos ou mais , Linfócitos T CD8-Positivos/virologia , COVID-19/virologia , DNA Viral/análise , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/diagnóstico , Feminino , Herpesvirus Humano 4/genética , Humanos , Unidades de Terapia Intensiva , Células Matadoras Naturais/virologia , Contagem de Linfócitos , Subpopulações de Linfócitos/virologia , Masculino , Pessoa de Meia-Idade , Infecções Oportunistas , Reação em Cadeia da Polimerase em Tempo RealRESUMO
BACKGROUND: Direct-acting antiviral agents (DAAs) combined with pegylated-interferon (PegIFN) and ribavirin (RBV) are still a standard treatment in patients with genotype 1HCV infection. However, virologic response could be impaired by baseline or early selection of resistant HCV strains. OBJECTIVES: The aim of this study was to determine the onset and persistence of resistance-associated mutations (RAMs) in the NS3 and NS5B genes of DAA-naïve patients failing treatment. STUDY DESIGN: Direct sequencing of HCV NS3 was performed in 49 DAA-naïve patients with HCV genotype 1 infection. RESULTS: Eight out of 23 patients (34.7%) failed PegIFN/RBV/telaprevir during the 12-weeks of therapy. Treatment failure was associated with the development of RAMs at amino-acids 36,54,80 and 155 of the HCV protease in 6/8 patients (75%). Among patients treated with PegIFN/RBV/boceprevir treatment, 4/18 (22.2%) failed therapy. Of these, 2 (50%) carried virus strains which developed a RAM at amino-acids 54 and 155. Among HCV strains with RAMs, 7 belonged to genotype 1a and 1 to 1b. Finally, in 6/10 (60%) patients, drug-resistant variants could still be detected for up to 3-7 months after stopping therapy. CONCLUSIONS: A higher rate (p=0.49) of treatment failure was observed in patients receiving telaprevir- compared to the boceprevir-based combination. In addition, compared with genotype 1b, genotype 1a was associated with higher rates (p=0.01) of treatment failure due to virus resistant strains. Resistance testing at baseline and during DAA treatment should be taken into consideration when treating patients with new HCV combination therapies.
Assuntos
Antivirais/administração & dosagem , Antivirais/farmacologia , Farmacorresistência Viral , Hepacivirus/genética , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/virologia , Mutação de Sentido Incorreto , Genótipo , Hepacivirus/classificação , Hepacivirus/efeitos dos fármacos , Hepacivirus/isolamento & purificação , Humanos , Oligopeptídeos/administração & dosagem , Oligopeptídeos/farmacologia , Prolina/administração & dosagem , Prolina/análogos & derivados , Prolina/farmacologia , Análise de Sequência de DNA , Falha de Tratamento , Proteínas não Estruturais Virais/genéticaRESUMO
The identification of a putative novel type human papillomaviruses (HPV) strain related to HPV-RTRX3 in a subject with penile skin warts and glans lichen sclerosus is reported. A beta-HPV-RTRX3-like strain was detected in a immunocompetent patient with glans lichen sclerosus. HPV screening was performed by PCR in L1 gene. The MY fragment showed 99% nt identity with HPV-RTRX3 and 64.5% nt identity with HPV-37. The remaining part of the L1 gene showed similarity with HPV 80, 15, 17, and 37. Based on the presence of penile lichen sclerosus and the HPV-RTRX3-like strain found in our patient, a potential correlation was hypothesized.
Assuntos
Proteínas do Capsídeo/genética , Líquen Escleroso e Atrófico/virologia , Proteínas Oncogênicas Virais/genética , Papillomaviridae/genética , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/virologia , Adulto , Humanos , Imunocompetência , Líquen Escleroso e Atrófico/imunologia , Masculino , Dados de Sequência Molecular , Papillomaviridae/classificação , Infecções por Papillomavirus/imunologia , FilogeniaRESUMO
Human immunodeficiency virus type 1 (HIV-1) circulating recombinant form (CRF) 02_AG is a major recombinant variant in different geographic areas and is predominant in West and Central Africa. Of particular interest is the increased frequency of CRF02_AG in patients living in Italy. In the present study, phylogenetic analyses were performed on gag, pol (integrase), and env (gp120 and gp41) gene sequences from 34 CRF02_AG-infected patients living in Italy. Thirty out of 34 (89.4%) patients were from western Africa, 3/34 (8.8%) were born in Italy, and 1/34 (2.9%) was from Cuba. Phylogenetic analysis revealed the presence of a well-supported clade (aLRT score>0.75) of sequences only in gp120 and gp41 trees. Evolutionary rate estimation showed a faster evolution for the gp120 gene with respect to the gag, integrase, and gp41 genes. This finding was confirmed by the analysis of interpatient variability. Intrapatient variability was greater in gp120 gene sequences; 10/19 (52.6%; p<0.001) patients had a ratio of dN/dS>1 as compared with gag, integrase, and gp41 gene sequences with dN/dS ratios<1. In summary, phylogenetic analyses of CRF02_AG strains offer a perspective on intrapatient and interpatient variability among CRF02_AG-infected patients living in Italy. In addition, divergent phylogenetic relationships were observed among different genomic regions.
Assuntos
Genes Virais , Variação Genética , Infecções por HIV/virologia , HIV-1/classificação , HIV-1/genética , África Ocidental , Análise por Conglomerados , Cuba , Emigrantes e Imigrantes , Evolução Molecular , Genótipo , HIV-1/isolamento & purificação , Humanos , Itália , Dados de Sequência Molecular , Taxa de Mutação , Filogenia , Análise de Sequência de DNARESUMO
BACKGROUND: Environmental factors may play a role in colon cancer. In this view, several studies investigated tumor samples for the presence of various viral DNA with conflicting results. FINDINGS: We undertook a systematic DNA analysis of 44 consecutive, prospectively collected primary tumor samples by real time and qualitative PCR for viruses of known or potential oncogenic role in humans, including polyomavirus (JCV, BKV, Merkel cell polyomavirus), HPV, HTLV, HHV-8 and EBV. Negative controls consisted of surgical resection margins. No evidence of genomic DNA fragments from tested virus were detected, except for EBV, which was found in a significant portion of tumors (23/44, 52%). Real-time PCR showed that EBV DNA was present at a highly variable content (median 258 copies in 10(5) cells, range 15-4837). Presence of EBV DNA had a trend to be associated with high lymphocyte infiltration (p = 0.06, χ2 test), and in situ hybridization with EBER1-2 probes revealed latency in a fraction of these lymphoid cells, with just a few scattered plasma cells positive for BZLF-1, an immediate early protein expressed during lytic replication. LMP-1 expression was undetectable by immunohistochemistry. CONCLUSIONS: These results argue against a significant involvement of the tested oncogenic viruses in established colon cancer.
RESUMO
BACKGROUND: Direct-acting antiviral (DAA) agents target HCV proteins; some of these have already been approved for the treatment of HCV infection, while others are in development. However, selection of DAA-resistant viral variants may hamper treatment. The aim of this study was to illustrate potential natural DAA-resistance mutations in the HCV NS5A and NS5B regions of HCV genotypes 1a and 1b from DAA-naïve patients. METHODS: Direct sequencing of HCV NS5A and NS5B regions was performed in 32 patients infected with HCV genotype 1a and 30 patients infected with HCV genotype 1b; all subjects were naïve to DAAs. RESULTS: In genotype 1a strains, resistance mutations in NS5A (M28V, L31M and H58P) were observed in 4/32 (12.5%) patients, and resistance mutations in NS5B (V321I, M426L, Y448H, Y452H) were observed in 4/32 (12.5%) patients. In genotype 1b, resistance mutations in NS5A (L28V, L31M, Q54H, Y93H and I280V) were observed in 16/30 (53.3%) patients, while resistance mutations in NS5B (L159F, V321I, C316N, M426L, Y452H, R465G and V499A) were observed in 27/30 (90%) patients. CONCLUSIONS: Mutations conferring DAA resistance were detected in NS5A and NS5B of HCV genotypes 1a and 1b from DAA-naïve patients. Although some mutations confer only a low level of resistance, the presence at baseline of mutated HCV variants should be taken into consideration in the context of DAA therapy.
Assuntos
Antivirais/farmacologia , Farmacorresistência Viral , Hepacivirus/efeitos dos fármacos , Hepacivirus/genética , Mutação de Sentido Incorreto , Proteínas não Estruturais Virais/genética , Feminino , Genótipo , Hepacivirus/isolamento & purificação , Hepatite C/virologia , Humanos , Masculino , Dados de Sequência Molecular , RNA Viral/genética , Análise de Sequência de DNARESUMO
Human enterovirus 104 (EV-C104) is a member of the Human Enterovirus species C (Family Picornaviridae, Genus Enterovirus) and has been associated with mild respiratory syndromes. At present, only two EV-C104 complete genome sequences from strains detected in Switzerland and Japan have been deposited in GenBank. In this study a complete genome analysis of seven Italian EV-C104 strains was carried out. In addition, VP1 sequence analysis was performed in an additional 5 Italian strains (for a total of 12 strains). The genome length of the seven strains was 7406 nucleotides (nt). The seven genomes showed 91.0-96.9% nucleotide identity with respect to other available EV-C104 complete genomes. The P1 and P2 regions of the Italian strains were closely related to EV-C104 identified in Switzerland, while the P3 region was closely related to the EV-C117 strain. In addition, bootscan analysis showed the presence of one putative recombination breakpoint between the P2 and P3 regions. Based on the trees constructed with partial VP1/2A nucleotide sequences, as well as the 3D partial coding region tree, the Italian strains appear to form a single and independent cluster together with the EV-C104 Japanese strain. In conclusion, a complete phylogenetic analysis of the relationship between EV-C104 and other known HEV-C strains was achieved. In addition, the recombinant origin of EV-C104, which has circulated in Italy and Japan, was demonstrated.
Assuntos
Enterovirus Humano C/genética , Infecções por Enterovirus/virologia , Genoma Viral/genética , RNA Viral/genética , Sequência de Bases , Enterovirus Humano C/classificação , Enterovirus Humano C/isolamento & purificação , Variação Genética , Humanos , Itália , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Proteínas Virais/genéticaRESUMO
The molecular characterization of circulating influenza A viruses is crucial to detect mutations potentially involved in increased virulence, drug resistance and immune escape. A molecular and phylogenetic analysis of A(H1N1)pdm09 neuraminidase (NA) gene sequences from different patient categories defined according to the severity of influenza infection were analyzed. A total of 126 influenza A(H1N1)pdm09 positive samples from patients with severe infections in comparison with those with moderate and mild infections was performed in Lombardy (Northern Italy, nearly 10 million inhabitants) during the 2010-2011 season. NA sequences included in this study segregated into five distinct clusters. Nineteen amino acid substitutions were detected exclusively in NA sequences of viruses identified in patients with severe or moderate influenza infection. Three of them (F74S, S79P, E287K) were observed in virus strains with the 222G/N hemagglutinin mutation. None of NA sequences under study had mutations related to the resistance to the NA inhibitors. Four out of 126 (3.2%) NA sequences from patients with severe infection lost a N-linked glycosylation site due to the change from N to K at residue 386. Two additional N-linked glycosylation sites in the NA stalk region (residues 42 and 44) were found in 12 (9.5%) NA sequences. Sporadic NA mutations were detected in NA viral sequences from critically ill patients, and no variants with reduced sensitivity to NA inhibitors were observed either in treated or untreated patients.
Assuntos
Genes Virais , Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/virologia , Mutação , Neuraminidase/genética , Filogenia , Sequência de Aminoácidos , Antivirais/uso terapêutico , Glicosilação , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Influenza Humana/tratamento farmacológico , Dados de Sequência Molecular , Família Multigênica , Oseltamivir/uso terapêutico , Estações do Ano , Índice de Gravidade de DoençaRESUMO
BACKGROUND: Protease inhibitors (PIs) to treat hepatitis C (HCV) virus infection have been approved and others are under development. RESULTS: The aims of this study were to illustrate natural polymorphisms in the HCV protease and measure the frequency of PI resistance mutations in different HCV genotypes from PI-naïve patients.Direct sequencing of HCV NS3/4A protease was performed in 156 HCV patients naïve to PIs who were infected with genotype 1a (n = 31), 1b (n = 39), 2 (n = 30), 3 (n = 33) and 4 (n = 23).Amino acid (aa) substitutions associated with HCV PI resistance were found in 17/156 (10.8%) sequences. Mutations V36L, T54S, V55A/I, and Q80K/L were observed in 29% of patients with genotype 1a, and V55F, Q80L/N and M175L in 10% of patients with genotype 1b. The mutation V158M was found in 3% of patients with genotype 2, D168Q was present in 100% of patients with genotype 3 and D168E was observed in 13% of patients with genotype 4. In addition, multiple aa polymorphisms not associated with PI resistance were detected in patients with genotypes 1a, 1b and 4. CONCLUSIONS: Although major PI resistance mutations were not detected, other resistance mutations conferring low level resistance to PIs together with a number of natural polymorphisms were observed in proteases of PI naïve HCV patients. A more extensive analysis is needed to better evaluate the impact of baseline resistance and compensatory mutations in the efficacy of HCV PI treatment.
Assuntos
Antivirais/farmacologia , Hepacivirus/efeitos dos fármacos , Hepatite C/virologia , Mutação de Sentido Incorreto , Inibidores de Proteases/farmacologia , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Substituição de Aminoácidos , Análise por Conglomerados , Farmacorresistência Viral , Feminino , Hepacivirus/enzimologia , Hepacivirus/genética , Hepacivirus/isolamento & purificação , Humanos , Masculino , Filogenia , Polimorfismo Genético , Homologia de SequênciaAssuntos
Colite/diagnóstico , Colite/patologia , Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/patologia , Citomegalovirus/isolamento & purificação , Idoso , Antivirais/administração & dosagem , Colite/tratamento farmacológico , Colite/virologia , Colo Sigmoide/patologia , Colonoscopia , Infecções por Citomegalovirus/tratamento farmacológico , Infecções por Citomegalovirus/virologia , Feminino , Ganciclovir/administração & dosagem , Humanos , Imuno-Histoquímica , Microscopia , Resultado do Tratamento , Proteínas Virais/análiseRESUMO
A single nucleotide polymorphism (SNP) upstream of the IL28 gene (rs12979860) has been reported to predict sustained virological response to peginterferon-ribavirin therapy in chronic HCV patients. In addition, two functionally deficient variants (rs1127354 and rs7270101) of inosine triphosphatase (ITPA) were shown to protect against ribavirin (RBV) - induced hemolytic anemia during early stages of treatment. In this study, three methods for detecting IL28 and ITPA mutations were compared to evaluate accuracy, sensitivity costs and turn-around time. IL28 and ITPA variants were detected using genomic DNA from peripheral blood mononuclear cells (PBMCs) of 61 patients with chronic HCV infection by denaturing high-performance liquid chromatography (DHPLC), direct DNA sequencing analysis and Taq Man Real-Time SNP analysis. Complete concordance in the IL28 polymorphism analysis was observed among the three methods. As for ITPA polymorphisms, 60/61 (98.4%) samples were consistent among the three methods, while results for 1/61 (1.64%) samples were concordant by DHPLC and sequencing, and discordant by real-time SNP. All three methods are suitable for routine testing. On the other hand, screening by real-time SNP detection was less expensive and more rapid.
Assuntos
Antivirais/administração & dosagem , Hepatite C Crônica/tratamento farmacológico , Interleucinas/genética , Polimorfismo de Nucleotídeo Único , Pirofosfatases/genética , Virologia/métodos , Humanos , Interferons/administração & dosagem , Leucócitos Mononucleares , Ribavirina/administração & dosagem , Resultado do TratamentoRESUMO
A panel of human sera exhibited a >or=128-fold higher neutralizing potency against a human cytomegalovirus (HCMV) clinical isolate propagated and tested in endothelial (or epithelial) cells than against the same virus infecting human fibroblasts. In a group of 18 primary infections, the reverse geometric mean titre was in the range of 10-15 in human fibroblasts within the first 3 months after the onset of infection, whereas the endothelial cell infection-neutralizing activity was already present within the first 10 days, reaching median levels of 122, 320 and 545 at respectively 30, 60 and 90 days after onset, then declining slowly. This difference was also confirmed in the majority of reactivated and remote HCMV infections, as well as in a hyperimmune globulin preparation. The antibody response to HCMV pUL131A, pUL130 and pUL128 locus products, which are required for endothelial/epithelial cell infection, provided a potential molecular basis for such a differential neutralizing activity. In addition, monoclonal/monospecific antibodies raised against the pUL131A, pUL130 and pUL128 proteins were found to display an inhibitory activity on HCMV plaque formation and HCMV leukocyte transfer from HCMV-infected cells. Hence, conventional determination of the neutralizing activity of human sera in fibroblasts is misleading. Antibodies to pUL131A, pUL130 and pUL128 appear to display a major HCMV-neutralizing and dissemination-inhibiting activity.
Assuntos
Anticorpos Antivirais/imunologia , Infecções por Citomegalovirus/virologia , Citomegalovirus/fisiologia , Células Endoteliais/virologia , Fibroblastos/virologia , Adulto , Idoso , Anticorpos Monoclonais/imunologia , Células Cultivadas , Infecções por Citomegalovirus/sangue , Feminino , Humanos , Soros Imunes/imunologia , Pessoa de Meia-Idade , Testes de Neutralização , Especificidade de Órgãos , Veias Umbilicais , Proteínas Virais/imunologia , Replicação ViralRESUMO
Human cytomegalovirus (HCMV) growth in endothelial cells (EC) requires the expression of the UL131A-128 locus proteins. In this study, the UL130 protein (pUL130), the product of the largest gene of the locus, is shown to be a luminal glycoprotein that is inefficiently secreted from infected cells but is incorporated into the virion envelope as a Golgi-matured form. To investigate the mechanism of the UL130-mediated promotion of viral growth in EC, we performed a complementation analysis of a UL130 mutant strain. To provide UL130 in trans to viral infections, we constructed human embryonic lung fibroblast (HELF) and human umbilical vein endothelial cell (HUVEC) derivative cell lines that express UL130 via a retroviral vector. When the UL130-negative virus was grown in UL130-complementing HELF, the infectivity of progeny virions for HUVEC was restored to the wild-type level. In contrast, the infectivity of the UL130-negative virus for UL130-complementing HUVEC was low and similar to that of the same virus infecting control noncomplementing HUVEC. The UL130-negative virus, regardless of whether or not it had been complemented in the prior cycle, could form plaques only on UL130-complementing HUVEC, not control HUVEC. Because (i) both wild-type and UL130-transcomplemented virions maintained their infectivity for HUVEC after purification, (ii) UL130 failed to complement in trans the UL130-negative virus when it was synthesized in a cell separate from the one that produced the virions, and (iii) pUL130 is a virion protein, models are favored in which pUL130 acquisition in the producer cell renders HCMV virions competent for a subsequent infection of EC.
Assuntos
Citomegalovirus/fisiologia , Endotélio Vascular/virologia , Glicoproteínas de Membrana/fisiologia , Proteínas do Envelope Viral/fisiologia , Proteínas Virais/fisiologia , Vírion/fisiologia , Sequência de Aminoácidos , Sequência de Bases , Endotélio Vascular/fisiologia , Células HeLa , Humanos , Glicoproteínas de Membrana/genética , Dados de Sequência Molecular , Mapeamento por Restrição , Proteínas do Envelope Viral/genética , Proteínas Virais/genéticaRESUMO
Human cytomegalovirus (HCMV) encodes a protein related to the large (R1) subunit of ribonucleotide reductase (RR), but does not encode the corresponding small (R2) subunit. The R1 homologue, UL45, lacks many catalytic residues, and its impact on deoxyribonucleotide (dNTP) production remains unknown. Here, UL45 is shown to accumulate at late stages of infection and to be a virion tegument protein. To study UL45 function in its genome context, UL45 was disrupted by transposon insertion. The UL45-knockout (UL45-KO) mutant exhibited a growth defect in fibroblasts at a low m.o.i. and also a cell-to-cell spread defect. This did not result from a reduced dNTP supply because dNTP pools were unchanged in resting cells infected with the mutant virus. Irrespective of UL45 expression, all cellular RR subunits - S-phase RR subunits, and the p53-dependent p53R2 - were induced by infection. p53R2 was targeted to the infected cell nucleus, suggesting that HCMV diverts a mechanism normally activated by DNA damage response. Cells infected with the UL45-KO mutant were moderately sensitized to Fas-induced apoptosis relative to those infected with the parental virus. Together with the report on the UL45-KO endotheliotropic HCMV mutant (Hahn et al., J Virol 76, 9551-9555, 2002), these data suggest that UL45 does not share the prominent antiapototic role attributed to the mouse cytomegalovirus homologue M45 (Brune et al., Science 291, 303-305, 2001).