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1.
Cell Rep ; 40(1): 111033, 2022 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-35793624

RESUMO

The immune response of brain cells to invading bacteria in vivo and the mechanism used by pathogenic bacteria to escape brain immune surveillance remain largely unknown. It is believed that microglia eliminate bacteria by phagocytosis based on in vitro data. Here we find that a small percentage of microglia in the brain engulf neonatal meningitis-causing Escherichia coli (NMEC), but more microglia are activated to produce tumor necrosis factor alpha (TNFα), which activates astrocytes to secrete complement component 3 (C3) involved in anti-bacterial activity. To evade anti-bacterial activity of the immune system, NMEC senses low concentration of threonine in cerebrospinal fluid (CSF) to down-modulate the expression of flagellin and reduce microglial TNFα and astrocyte C3 production. Our findings may help develop strategies for bacterial meningitis treatment.


Assuntos
Astrócitos , Microglia , Astrócitos/metabolismo , Bactérias/metabolismo , Encéfalo/metabolismo , Flagelina/metabolismo , Flagelina/farmacologia , Humanos , Recém-Nascido , Microglia/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
2.
mBio ; 12(4): e0046321, 2021 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-34340542

RESUMO

Oropouche virus (OROV) infection of humans is associated with a debilitating febrile illness that can progress to meningitis or encephalitis. First isolated from a forest worker in Trinidad and Tobago in 1955, the arbovirus OROV has since been detected throughout the Amazon basin with an estimated 500,000 human infections over 60 years. Like other members of the family Peribunyaviridae, the viral genome exists as 3 single-stranded negative-sense RNA segments. The medium-sized segment encodes a viral glycoprotein complex (GPC) that is proteolytically processed into two viral envelope proteins, Gn and Gc, responsible for attachment and membrane fusion. There are no therapeutics or vaccines to combat OROV infection, and we have little understanding of protective immunity to infection. Here, we generated a replication competent chimeric vesicular stomatitis virus (VSV), in which the endogenous glycoprotein was replaced by the GPC of OROV. Serum from mice immunized by intramuscular injection with VSV-OROV specifically neutralized wild-type OROV, and using peptide arrays we mapped multiple epitopes within an N-terminal variable region of Gc recognized by the immune sera. VSV-OROV lacking this variable region of Gc was also immunogenic in mice producing neutralizing sera that recognize additional regions of Gc. Challenge of both sets of immunized mice with wild-type OROV shows that the VSV-OROV chimeras reduce wild-type viral infection and suggest that antibodies that recognize the variable N terminus of Gc afford less protection than those that target more conserved regions of Gc. IMPORTANCE Oropouche virus (OROV), an orthobunyavirus found in Central and South America, is an emerging public health challenge that causes debilitating febrile illness. OROV is transmitted by arthropods, and increasing mobilization has the potential to significantly increase the spread of OROV globally. Despite this, no therapeutics or vaccines have been developed to combat infection. Using vesicular stomatitis (VSV) as a backbone, we developed a chimeric virus bearing the OROV glycoproteins (VSV-OROV) and tested its ability to elicit a neutralizing antibody response. Our results demonstrate that VSV-OROV produces a strong neutralizing antibody response that is at least partially targeted to the N-terminal region of Gc. Importantly, vaccination with VSV-OROV reduces viral loads in mice challenged with wild-type virus. These data provide novel evidence that targeting the OROV glycoproteins may be an effective vaccination strategy to combat OROV infection.


Assuntos
Infecções por Bunyaviridae/prevenção & controle , Genoma Viral , Orthobunyavirus/genética , Vesiculovirus/genética , Vesiculovirus/imunologia , Proteínas do Envelope Viral/genética , Animais , Anticorpos Neutralizantes , Infecções por Bunyaviridae/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estomatite Vesicular/virologia , Replicação Viral
3.
Pathol Oncol Res ; 27: 602726, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34257561

RESUMO

Genotyping epidermal growth factor receptor (EGFR) gene in patients with advanced non-small cell lung cancers (NSCLC) is essential for identifying those patients who may benefit from targeted therapies. Systemically evaluating EGFR mutation detection rates of different methods currently used in clinical setting will provide valuable information to clinicians and laboratory scientists who take care of NSCLC patients. This study retrospectively reviewed the EGFR data obtained in our laboratory in last 10 years. A total of 21,324 NSCLC cases successfully underwent EGFR genotyping for clinical therapeutic purpose, including 5,244 cases tested by Sanger sequencing, 13,329 cases tested by real-time PCR, and 2,751 tested by next-generation sequencing (NGS). The average EGFR mutation rate was 45.1%, with 40.3% identified by Sanger sequencing, 46.5% by real-time PCR and 47.5% by NGS. Of these cases with EGFR mutations identified, 93.3% of them harbored a single EGFR mutation (92.1% with 19del or L858R, and 7.9% with uncommon mutations) and 6.7% harbored complex EGFR mutations. Of the 72 distinct EGFR variants identified in this study, 15 of them (single or complex EGFR mutations) were newly identified in NSCLC. For these cases with EGFR mutations tested by NGS, 65.3% of them also carried tumor-related variants in some non-EGFR genes and about one third of them were considered candidates of targeted drugs. NGS method showed advantages over Sanger sequencing and real-time PCR not only by providing the highest mutation detection rate of EGFR but also by identifying actionable non-EGFR mutations with targeted drugs in clinical setting.


Assuntos
Povo Asiático/genética , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Laboratórios/normas , Mutação , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/epidemiologia , Carcinoma Pulmonar de Células não Pequenas/genética , China/epidemiologia , Receptores ErbB/genética , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Adulto Jovem
4.
Exp Ther Med ; 19(4): 3143-3149, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32256802

RESUMO

The incidence of gastric hyperplastic polyps (HPs) has been on the rise in recent years. The contribution of Helicobacter pylori infection to this trend has remained to be elucidated. The present study aimed to explore the association between HPs and H. pylori in China, an area with a high infection rate of H. pylori. In order to study trends of HPs and H. pylori infection over the past decades, cases encountered from 2009 to 2018 were assessed and a total of 109,150 consecutive patients who underwent esophagogastroduodenoscopy at Qingdao Municipal Hospital (Qingdao, China) were enrolled. The incidence of HPs and the prevalence of H. pylori were determined and their correlation was explored. Gastric HPs were detected in 1,497 patients (1.6%) who received gastric biopsies. The incidence of HPs exhibited a rising trend, with a ~4-fold increase in the annual detection rate from 2009 to 2018. The prevalence of H. pylori infection was inversely associated with the prevalence of HPs (adjusted odds ratio, 0.66). The prevalence of H. pylori in the examined cohort decreased with time (r=-0.76, P=0.011). The decreasing trend of H. pylori infection was negatively correlated with the rising trend of HPs (r=-0.64, P=0.048), further indicating an inverse association between them. The difference in the prevalence of HPs between H. pylori-negative and -positive patients increased with age (r=0.80, P=0.018). The age-associated increase was slower in H. pylori-infected patients. The decline in H. pylori infection with time appeared to not be associated with the birth cohort effect, suggesting the decline was not caused by exposure to environmental factors during an early period of life. The present results indicated that the incidence of gastric HPs increased with the decline in H. pylori infection, demonstrating an inverse association between the occurrence of HPs and the infection.

5.
Oncol Lett ; 16(3): 3917-3922, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30128008

RESUMO

Circulating follicular helper T (cTfh) cells are a novel subset of cluster of differentiation (CD)4+ helper T cells. Interleukin (IL)-21 and C-X-C motif chemokine ligand (CXCL)13 are the principal effectors and chemotactic regulatory factors of Tfh. However, the roles of IL-21 and CXCL13 in gastric cancer have not yet been completely elucidated. The aim of the present study was to investigate the distribution of cTfh cells, and the expression of IL-21 and CXCL13 in patients with gastric cancer was evaluated in order to ascertain the significance and potential mechanisms of these effectors in gastric cancer. A total of 50 patients with gastric cancer were enrolled as the study subjects, with 30 healthy individuals selected as controls. The percentage of cTfh cells (cTfh%) in the peripheral blood was calculated using flow cytometry. They are identified in the present study as CD4+ chemokine C-X-C receptor (CXCR)5+ inducible T cell co-stimulator (ICOS)+ cells. The serum levels of IL-21 and CXCL13 were determined by ELISA. The cTfh% in the peripheral blood and the concentration of IL-21 and CXCL13 in the serum were significantly higher in patients with gastric cancer compared with the control group. cTfh% was significantly higher in patients with lymph node metastasis, Tumor-Node-Metastasis (TNM) stage III-IV and low differentiation. The concentrations of IL-21 and CXCL13 in patients with lymph node metastasis and/or TNM III-IV were significantly higher than in those without lymph node metastasis or with TNM I-II. There was a positive correlation between cTfh%/CXCL13 and IL-21/CXCL13, while there was no correlation between cTfh%/IL-21. cTfh cells and associated factors (IL-21/CXCL13) may be involved in the development and progression of gastric cancer. There may be mutual regulation among cTfh cells, IL-21 and CXCL13.

6.
Turk J Gastroenterol ; 29(1): 45-51, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29391307

RESUMO

BACKGROUND/AIMS: The function of regulatory T cells (Treg) and helper T cells 17 (Th17) related indexes, such as interleukin (IL)-6, IL-17, transforming growth factor (TGF)-ß1, and forkhead box protein 3(FoxP3) in gastric adenocarcinoma tissues remains undefined. We investigated and analyzed the relevance of the proteins with the clinicopathological characteristics and the interactions among them in gastric cancer. MATERIALS AND METHODS: A total 68 gastric cancer patients and 40 healthy controls were enrolled. Immunohistochemistry (IHC) as well as quantitative real-time reverse transcription- polymerase chain reaction (RT-PCR) was used to determine the expression levels of IL-6, TGF-ß1, IL-17, and FoxP3 in the prepared tissues. Statistical analysis included ANOVA and chi-square test. RESULTS: The expression levels of IL-6, IL-17, FoxP3, and TGF-ß1 had significantly increased in cancer tissues compared to controls. Clinical staging of gastric cancer were correlated with the rise of IL-6, IL-17, FoxP3, and TGF-ß1 levels expressed in cancer tissues. The expression level of TGF-ß1 and IL-6 was positively related to that of IL-17 and FoxP3, similar to FoxP3 and IL-17 in gastric cancer tissues. CONCLUSION: IL-6, TGF-ß1, FoxP3, and IL-17 may promote the progression of gastric cancer individually or jointly and have complex interactions.


Assuntos
Fatores de Transcrição Forkhead/metabolismo , Interleucina-17/metabolismo , Interleucina-6/metabolismo , Neoplasias Gástricas/genética , Fator de Crescimento Transformador beta1/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Reação em Cadeia da Polimerase em Tempo Real , Neoplasias Gástricas/imunologia , Neoplasias Gástricas/patologia , Linfócitos T Reguladores/metabolismo , Células Th17/metabolismo
7.
World J Gastroenterol ; 22(42): 9437-9444, 2016 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-27895432

RESUMO

AIM: To investigate the prevalence of depression and anxiety in patients with chronic digestive system diseases. METHODS: A total of 1736 patients with chronic digestive system diseases were included in this cross-sectional study, including 871 outpatients and 865 in-patients. A self-designed General Information for Patients of the Department of Gastroenterology of General Hospitals questionnaire was used to collect each patient's general information, which included demographic data (including age, sex, marital status, and education) and disease characteristics (including major diseases, disease duration, principal symptoms, chronic pain, sleep disorder, and limited daily activities). RESULTS: The overall detection rate was 31.11% (540/1736) for depression symptoms alone, 27.02% (469/1736) for anxiety symptoms alone, 20.68% (359/1736) for both depression and anxiety symptoms, and 37.44% (650/1736) for either depression or anxiety symptoms. Subjects aged 70 years or above had the highest detection rate of depression (44.06%) and anxiety symptoms (33.33%). χ2 trend test showed: the higher the body mass index (BMI), the lower the detection rate of depression and anxiety symptoms (χ2trend = 13.697, P < 0.001; χ2trend = 9.082, P = 0.003); the more severe the limited daily activities, the higher the detection rate of depression and anxiety symptoms (χ2trend = 130.455, P < 0.001, χ2trend = 108.528, P < 0.001); and the poorer the sleep quality, the higher the detection rate of depression and anxiety symptoms (χ2trend = 85.759, P < 0.001; χ2trend = 51.969, P < 0.001). Patients with digestive system tumors had the highest detection rate of depression (57.55%) and anxiety (55.19%), followed by patients with liver cirrhosis (41.35% and 48.08%). Depression and anxiety symptoms were also high in subjects with comorbid hypertension and coronary heart disease. CONCLUSION: Depression and anxiety occur in patients with tumors, liver cirrhosis, functional dyspepsia, and chronic viral hepatitis. Elderly, divorced/widowed, poor sleep quality, and lower BMI are associated with higher risk of depression and anxiety.


Assuntos
Ansiedade/epidemiologia , Depressão/epidemiologia , Doenças do Sistema Digestório/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Ansiedade/diagnóstico , Ansiedade/fisiopatologia , Ansiedade/psicologia , Índice de Massa Corporal , Distribuição de Qui-Quadrado , China/epidemiologia , Doença Crônica , Comorbidade , Estudos Transversais , Depressão/diagnóstico , Depressão/fisiopatologia , Depressão/psicologia , Doenças do Sistema Digestório/diagnóstico , Doenças do Sistema Digestório/fisiopatologia , Doenças do Sistema Digestório/psicologia , Feminino , Nível de Saúde , Humanos , Masculino , Estado Civil , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Sono , Inquéritos e Questionários , Adulto Jovem
8.
PLoS One ; 7(10): e46714, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23071620

RESUMO

Herpes simplex virus type 2 (HSV-2) is a sexually transmitted virus that is highly prevalent worldwide, causing a range of symptoms that result in significant healthcare costs and human suffering. ACAM529 is a replication-defective vaccine candidate prepared by growing the previously described dl5-29 on a cell line appropriate for GMP manufacturing. This vaccine, when administered subcutaneously, was previously shown to protect mice from a lethal vaginal HSV-2 challenge and to afford better protection than adjuvanted glycoprotein D (gD) in guinea pigs. Here we show that ACAM529 given via the intramuscular route affords significantly greater immunogenicity and protection in comparison with subcutaneous administration in the mouse vaginal HSV-2 challenge model. Further, we describe a side-by-side comparison of intramuscular ACAM529 with a gD vaccine across a range of challenge virus doses. While differences in protection against death are not significant, ACAM529 protects significantly better against mucosal infection, reducing peak challenge virus shedding at the highest challenge dose by over 500-fold versus 5-fold for gD. Over 27% (11/40) of ACAM529-immunized animals were protected from viral shedding while 2.5% (1/40) were protected by the gD vaccine. Similarly, 35% (7/20) of mice vaccinated with ACAM529 were protected from infection of their dorsal root ganglia while none of the gD-vaccinated mice were protected. These results indicate that measuring infection of the vaginal mucosa and of dorsal root ganglia over a range of challenge doses is more sensitive than evaluating survival at a single challenge dose as a means of directly comparing vaccine efficacy in the mouse vaginal challenge model. The data also support further investigation of ACAM529 for prophylaxis in human subjects.


Assuntos
Herpes Genital/prevenção & controle , Vacinas contra o Vírus do Herpes Simples/administração & dosagem , Herpesvirus Humano 2/imunologia , Adjuvantes Imunológicos/administração & dosagem , Compostos de Alúmen/administração & dosagem , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Modelos Animais de Doenças , Feminino , Gânglios Espinais/virologia , Herpes Genital/imunologia , Vacinas contra o Vírus do Herpes Simples/imunologia , Humanos , Injeções Intramusculares , Camundongos , Camundongos Endogâmicos BALB C , Oligodesoxirribonucleotídeos/administração & dosagem , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/imunologia , Vacinas de Subunidades Antigênicas/administração & dosagem , Vacinas de Subunidades Antigênicas/imunologia , Vagina/virologia , Proteínas do Envelope Viral/administração & dosagem , Proteínas do Envelope Viral/imunologia
9.
Chin J Cancer ; 29(3): 288-93, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20193112

RESUMO

BACKGROUND AND OBJECTIVE: Invasion and metastasis are the most common causes of mortality for patients with colorectal neoplasms, and blocking invasion and metastasis in a timely fashion has become a hot research focus. We investigated the expression of the messenger RNA of Syndecan-1 and HPA-1 in colorectal cancer, and their correlation with invasion and metastasis. METHODS: Real-time fluorescent quantitative polymerase chain reaction (PCR) was used to detect the expression of Syndecan-1 and HPA-1 in specimens from 49 patients with colorectal cancer, 49 paired adjacent colorectal neoplasms (2 cm from the carcinoma), and 49 surgical margins of paired normal colorectal mucosa tissue (5 cm from the carcinoma), to analyze their correlation with clinicopathologic characteristics of colorectal neoplasm. RESULTS: The expression of HPA-1 mRNA was significantly higher in colorectal cancer (40.56 +/- 11.75) than that in the paired adjacent colorectal neoplasms (18.28 +/- 11.33) and normal colorectal mucosa tissue (10.80 +/- 10.20) (all P < 0.001). The expression of HPA-1 mRNA was significantly higher in paired adjacent colorectal neoplasms than that in normal colorectal mucosa (P < 0.05). The expression of Syndecan-1 mRNA was significantly higher in normal colorectal mucosa (61.21 +/- 12.96) than in the paired adjacent mucosa (14.35 +/- 11.06) or colorectal cancer (10.12 +/- 8.58) (all P < 0.001). The expression of Syndecan-1 mRNA was significantly higher in the paired adjacent mucosa than that in colorectal cancer (P < 0.05). The decreased expression of Syndecan-1 mRNA and the increased expression of HPA-1 were closely associated with the degree of differentiation, the depth of infiltration, lymph node metastasis, vessel metastasis, and TNM staging of colorectal cancer (all P < 0.05). Spearman rank correlation analysis demonstrated a significant correlation between Syndecan-1 and HPA-1(r = -0.405, P < 0.05). CONCLUSIONS: The expression of Syndecan-1 mRNA was significantly highest in normal colorectal mucosa and the expression of HPA-1 mRNA was significantly highest in colorectal cancer. At the same time, the decreased expression of Syndecan-1 mRNA and the increased expression of HPA-1 mRNA can promote the invasion and metastasis of colorectal cancer. The determination of Syndecan-1 and HPA-1 may be of value in the treatment as well as in the prognosis of patients with colorectal cancer.


Assuntos
Adenocarcinoma/metabolismo , Neoplasias Colorretais/metabolismo , Glucuronidase/metabolismo , Sindecana-1/metabolismo , Adenocarcinoma/patologia , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica , Glucuronidase/genética , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Metástase Linfática , Invasividade Neoplásica , Estadiamento de Neoplasias , Prognóstico , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Sindecana-1/genética
10.
Leuk Res ; 28(1): 71-82, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14630083

RESUMO

Adult T-cell leukemia (ATL) is an aggressive malignancy that is associated with human T-cell lymphotropic virus I (HTLV-I) infection. HTLV-I transformed T-cell lines and fresh ATL cells are characterized by constitutive activation of the interleukin-2 receptor (IL-2R) signaling pathway however, the mechanism(s) responsible for constitutive IL-2R activation are unknown. To further examine the cause of this signaling pathway deregulation, we measured mRNA and protein expression levels by real-time PCR and Western blots, respectively, of four negative regulators of the IL-2R signaling pathway including src homology 2 (SH2)-containing phosphatase (SHP1), cytokine-inducible (CIS) SH2-containing protein, suppressor of cytokine signaling-1 (SOCS1) and protein inhibitor of activated signal transducer and activator of transcription 3 (STAT3) (PIAS3) in six HTLV-1 negative and seven HTLV-1 positive T-cell leukemia lines. The activation status of the JAK/STAT pathway was also examined. SHP1 mRNA and protein expression levels were selectively down regulated in all HTLV-1-infected transformed cell lines, while CIS, SOCS1, and PIAS3 protein expression were markedly but variably upregulated and the cells showed evidence of constitutive STAT3 activation. In acutely HTLV-1 infected primary CD4+ T-cells there was a gradual loss of SHP1 expression over 10 weeks in culture which correlated with progression from immortalization to transformation and loss of IL-2 dependence for growth. Two transformed cell lines that were established following HTLV-1 infection showed loss of SHP1 expression and overexpression of CIS, SOCS1, PIAS3. However, this overexpression was not adequate to block constitutive activation of the JAK/STAT pathway. Thus, multiple levels of IL-2 receptor signal deregulation are found in HTLV-1 transformed cells, which may be a result of early loss of SHP1 expression.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Proteínas de Ligação a DNA/metabolismo , Vírus Linfotrópico T Tipo 1 Humano/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular , Leucemia-Linfoma de Células T do Adulto/metabolismo , Proteínas Tirosina Fosfatases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Transativadores/metabolismo , Adulto , Linfócitos T CD4-Positivos/virologia , Proteínas de Transporte/metabolismo , Linhagem Celular Transformada , Transformação Celular Viral , Regulação para Baixo , Infecções por HTLV-I/virologia , Humanos , Proteínas Imediatamente Precoces/metabolismo , Janus Quinase 1 , Janus Quinase 3 , Leucemia-Linfoma de Células T do Adulto/patologia , Proteína Tirosina Fosfatase não Receptora Tipo 6 , Proteínas Tirosina Fosfatases/genética , RNA Mensageiro/genética , Receptores de Interleucina-2/metabolismo , Proteínas Repressoras/metabolismo , Fator de Transcrição STAT3 , Transdução de Sinais , Proteína 1 Supressora da Sinalização de Citocina , Proteínas Supressoras da Sinalização de Citocina , Regulação para Cima
11.
J Virol ; 76(12): 5893-904, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12021322

RESUMO

Herpes simplex virus 1 (HSV-1) infection causes the shutoff of host gene transcription and the induction of a transcriptional program of viral gene expression. Cellular RNA polymerase II is responsible for transcription of all the viral genes, but several viral proteins stimulate viral gene transcription. ICP4 is required for all delayed-early and late gene transcription, ICP0 stimulates transcription of viral genes, and ICP27 stimulates expression of some early genes and transcription of at least some late viral genes. The early DNA-binding protein, ICP8, also stimulates late gene transcription. We therefore investigated which HSV proteins interact with RNA polymerase II. Using immunoprecipitation and Western blotting methods, we observed the coprecipitation of ICP27 and ICP8 with RNA polymerase II holoenzyme. The association of ICP27 with RNA polymerase II was detectable as early as 3 h postinfection, while ICP8 association became evident by 5 h postinfection, and the association of both was independent of viral DNA synthesis. Infections with ICP27 gene mutant viruses revealed that ICP27 is required for the association of ICP8 with RNA polymerase II, while studies with ICP8 gene deletion mutants showed no apparent role for ICP8 in the association of ICP27 with RNA polymerase II. The association of ICP27 and ICP8 with RNA polymerase II holoenzyme appeared to be independent of nucleic acids. We hypothesize that the interaction of ICP27 with RNA polymerase II holoenzyme reflects its role in stimulating early and late gene expression and/or its role in inhibiting host transcription and that the interaction of ICP8 with RNA polymerase II holoenzyme reflects its role in stimulating late gene transcription.


Assuntos
Regulação Viral da Expressão Gênica , Herpesvirus Humano 1 , Proteínas Imediatamente Precoces/metabolismo , RNA Polimerase II/metabolismo , Proteínas Virais/metabolismo , Animais , Western Blotting , Proteínas de Ligação a DNA , Herpesvirus Humano 1/patogenicidade , Herpesvirus Humano 1/fisiologia , Holoenzimas/genética , Holoenzimas/metabolismo , Humanos , Proteínas Imediatamente Precoces/genética , Camundongos , Testes de Precipitina , RNA Polimerase II/genética , Coelhos , Transcrição Gênica , Células Tumorais Cultivadas , Proteínas Virais/genética
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