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Abstract: human immunodeficiency virus type 1 (HIV-1) is the etiological agent of acquired immunodeficiency syndrome (AIDS), a pandemic with high economic and social costs. The envelope glycoprotein (ENV) of the virus mediates the infectious process by binding to and entering the host cell, one of the main target components of studies since its discovery. Its endodomain or C-terminal tail (CTT) participates in late replicative cycle processes, such as intracellular trafficking, activation, and cell death, which occurs because it interacts with multiple cellular factors through motifs or signal sequences present throughout its structure. Although these interactions have not been fully understood at specific levels, studies over more than three decades leave no doubtthatthis domain plays a fundamental role in the biology of the virus and probably the development of the disease. This review describes the studies carried out to date that demonstrate the importance of the CTT, focusing on the motifs responsible for its interactions and its possible roles in the pathogenicity of the infection.
Resumen: el virus de la inmunodeficiencia humana tipo 1 (VIH-1) es el agente etiológico del síndrome de inmunodeficiencia adguirida (SIDA), una pandemia con altos costos económicos y sociales. La glicoproteína de la envoltura (ENV) del virus media el proceso infeccioso al unirse a la célula huésped y entrar en ella, uno de los principales componentes objetivo de los estudios desde su descubrimiento. Su endodominio o cola C-terminal (CTT) participa en procesos tardíos del ciclo replicativo, como tráfico intracelular, activación y muerte celular, lo que ocurre porque interactúa con múltiples factores celulares a través de motivos o secuencias señal presentes en toda su estructura. Aunque estas interacciones no se han entendido completamente a niveles específicos, los estudios durante más de tres décadas no dejan dudas de que este campo juega un papel fundamental en la biología del virus y probablemente en el desarrollo de la enfermedad. Esta revisión describe los estudios realizados hasta la fecha que demuestran la importancia de la CTT, centrándose en los motivos responsables de sus interacciones y sus posibles roles en la patogenicidad de la infección.
Resumo: o vírus da imunodeficiência humana tipo 1 (HIV-1) é o agente etiológico da síndrome da imunodeficiência adquirida (AUXILIA), urna pandemia com elevados custos económicos e sociais. A glicoproteína do envelope (ENV) do vírus media o processo infeccioso ligando-se e entrando na célula hospedeira, um dos principais componentes alvo dos estudos desde sua descoberta. Seu endo domínio ou cauda C-terminal (CTT) participa de processos do ciclo replicativo tardio, como tráfego intracelular, ativação e morte celular, que ocorre porque interage com múltiplos fatores celulares por meio de motivos ou sequências-sinal presentes em toda a sua estrutura. Embora essas interações não tenham sido totalmente compreendidas em níveis específicos, estudos ao longo de mais de três décadas não deixam dúvidas de que esse domínio desempenha um papel fundamental na biologia do vírus e provavelmente no desenvolvimento da doença. Esta revisão descreve os estudos realizados até o momento que demonstram a importância da CTT, com foco nos motivos responsáveis por suas interações e seus possíveis papéis na patogenicidade da infecção.
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Mayaro virus (MAYV) is a mosquito-transmitted alphavirus that produces an acute, usually non-fatal, febrile illness including Mayaro fever. Like other alphaviruses, the MAYV E1 and E2 envelope glycoproteins are major viral surface antigens that play a key role in host recognition and infection. Here, we report expression and purification methods for recombinant MAYV E1 (rE1) and rE2 using a baculovirus system. Enzyme-linked immunosorbent assays (ELISA) revealed that rE1 and rE2 were antigenic and reacted with human anti-MAYV IgG and IgM. Cross-reactivity was also confirmed with human anti-Chikungunya virus (CHIKV) IgG and IgM. Furthermore, we developed an immunochromatographic strip test (IST) with rE2 to diagnose MAYV infection. Thus, purified rE2 may be valuable tool for rapidly diagnosing MAYV infection.
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Humans , Alphavirus , Antigens, Surface , Baculoviridae , Enzyme-Linked Immunosorbent Assay , Fever , Glycoproteins , Immunoglobulin G , Immunoglobulin MABSTRACT
Aim To investigate whether osthole can alleviate neuropathic pain induced by HIV gpl20 and its mechanism. Methods The paw withdrawal threshold and the paw withdrawal latency were observed to assess pain behaviors in four groups of the rats, including sham group, sham combined with osthole treatment group, gpl20 treatment group, and gpl20 combined with osthole treatment group. The protein expression levels of the P2X3 receptor, tumor necrosis factor-a receptor (TNF-aR), ERK, p-ERK in the L4-L6 dorsal root ganglia (DRG) were measured by Western blot. The mRNA expression level of P2X3 receptor was assessed by real-time quantitative polymerase chain reaction ( qPCR). The whole path clamp recording was used to measure HEK293 cell current activated by ATP. Results Osthole attenuated the mechanical and thermal hyperalgesia in gpl20 treated rats and down-regulated P2X3 receptor mRNA and protein expression in L4-L6 DRGs of gpl20 treated rats. Additionally, osthole simultaneously decreased the expression of TNF-ctR protein in L4-L6 DRGs and inhibited the phosphorylated ERK1/2 protein expression. Moreover, osthole reduced ATP activated current of HEK293 cells transfected with hP2X3R. Conclusion Osthole decreases the mechanical and thermal hyperalgesia induced by gpl20 through inhibiting P2X3R in DRG.
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Objective@#To study the relationship between human cytomegalovirus (HCMV) envelope glycoprotein gene H and clinical features of children with congenital cytomegalovirus infection.@*Methods@#A cohort study was conducted. Newborns diagnosed with congenital cytomegalovirus infection, hospitalized in the Department of Neonatology and Neonatal Intensive Care Unit (NICU) of the Children′s Hospital, Zhejiang University School of Medicine, were included from July 2013 to December 2015.HCMV-DNA gH typing in urine, sputum or blood was conducted. Patients then were divided into gH1 group and gH2 group according to gH genotypes. Patients′ data during hospitalization in newborn and 3-5 years of follow-up were collected.The relationships between gH genotype and clinical manifestations, laboratory examinations, hearing loss and neurological prognosis were analyzed by chi-square test, t test and non-parametric test.@*Results@#A total of 21 cases were enrolled as congenital HCMV infection and followed-up for 3-5 years. Among them, 14 (67%) were gH1 type and 7 (33%) were gH2 type. No mixed infection was found. In the two groups, there were no significant differences in the ratio of males (9/14 vs. 3/7,P=0.397), or birth weight ((2 609±686) vs. (3 021±451) g, t=-1.436, P=0.167). Gestational age of gH1 group was younger than that of gH2 group (38 (29-40) vs. 39(38-40) weeks, Z=-2.18, P=0.029). Moderate to severe hearing loss detected by neonatal auditory brainstem response were found in 40 ears (20 cases). It was higher in gH1 group than that in gH2 group (4/22 vs.0/18, χ2=5.145, P=0.023). In the imaging examination of the nervous system, the Alarcon score of gH1 group was lower than that of gH2 group (0.4±0.3 vs. 1.3±1.1, t=-2.459,P=0.024).No significant statistical difference was found in the probability of motor or language development lag in gH2 group and gH1 group (4/7 vs.4/14, P=0.346).@*Conclusions@#Compared with gH2 infection, gH1 infection in children has a younger gestational age. The major type of hearing loss in neonatal period is gH1 infection. Children with gH2 congenital infections are more likely to suffer from nervous systems damage.
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Background & objectives: Kyasanur Forest disease (KFD) is a febrile illness characterized by haemorrhages and caused by KFD virus (KFDV), which belongs to the Flaviviridae family. It is reported to be an endemic disease in Shimoga district of Karnataka State, India, especially in forested and adjoining areas. Several outbreaks have been reported in newer areas, which raised queries regarding the changing nature of structural proteins if any. The objective of the study was to investigate amino acid composition and antigenic variability if any, among the envelope glycoprotein (E-proteins) from old and new strains of KFDV. Methods: Bioinformatic tools and techniques were used to predict B-cell epitopes and three-dimensional structures and to compare envelope glycoprotein (E-proteins) between the old strains of KFDV and those from emerging outbreaks till 2015. Results: The strain from recent outbreak in Thirthahalli, Karnataka State (2014), was similar to the older strain of KFDV (99.2%). Although mutations existed in strains from 2015 in Kerala KFD sequences, these did not alter the epitopes. Interpretation & conclusions: The study revealed that though mutations existed, there were no drastic changes in the structure or antigenicity of the E-proteins from recent outbreaks. Hence, no correlation could be established between the mutations and detection in new geographical areas. It seems that KFDV must be present earlier also in many States and due to availability of testing system and alertness coming into notice now.
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Objective:To build the DNA vaccine encoding hantavirus glycoprotein fused with lysosome-associated membrane protein (LAMP) and assess its immune response.Methods:BALB/c mice were immuned with the previous experimental expressing purified recombinant plasmids pVAX-Gn,pVAX-Gc,pVAX-LAMP/Gn,pVAX-LAMP/Gc,and inactivated vaccine.Indirect ELISA and neutralization test was used to detect specific antibody and neutralizing antibody in the serum of mice.The mice were tested to detect the protective effects in vivo.Results:Indirect ELISA results showed that the pVAX-LAMP/Gc group was the highest,followed by pVAX-Gc,pVAX-LAMP/Gn,and PVAX-Gn,and inactivated vaccine group.In neutralization test,there were significantly higher serum antibodies in LAMP group than those in conventional DNA group,which were higher than the inactivated vaccine group.The mice immuned had good protective effect in vivo without the specific antigen of hantavirus in vivo.Conclusion:Chimeric DNA vaccines induced higher levels of antibody in BALB/c mice and produced better protective efficacy,which illustrate the targeting strategy is expected to be an effective way to improve the DNA vaccine efficacy.
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AIDS is an infectious disease caused by human immunodeficiency virus(HIV)and has done great harm to human beings. The envelope glycoprotein surface subunit gp120 and its receptor CD4 and coreceptor CXCR4 play important roles in HIV-1 en?try. The Phe43 pocket and Arg59 of gp120 are two important regions that interact with CD4. Recently,HIV small-molecule entry inhib?itors have become a hot topic in anti-HIV drug research,which are able to inhibit the virus before the cells are infected. The Phe43 pocket is an attractive target and the study of Phe43 pocket-targeting small-molecule entry inhibitors is underway,including BMS-378806,BHS-488043 and its analogs,and NBD-556 and its analogs. Besides,CXCR4 antagonist is another important approach.
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AIDS is an infectious disease caused by human immunodeficiency virus (HIV) and has done great harm to human beings. The envelope glycoprotein surface subunit gp120 and its receptor CD4 and coreceptor CXCR4 play important roles in HIV-1 entry. The Phe43 pocket and Arg59 of gp120 are two important regions that interact with CD4. Recently, HIV small-molecule entry inhibitors have become a hot topic in anti-HIV drug research, which are able to inhibit the virus before the cells are infected. The Phe43 pocket is an attractive target and the study of Phe43 pocket-targeting small-molecule entry inhibitors is underway, including BMS-378806, BHS-488043 and its analogs, and NBD-556 and its analogs. Besides, CXCR4 antagonist is another important approach.
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The drug searching for combating the present outbreak of Ebola virus infection is the urgent activity at present. Finding the new effective drug at present must base on the molecular analysis of the pathogenic virus. The in-depth analysis of the viral protein to find the binding site, active pocket is needed. Here, the authors analyzed the envelope glycoprotein GP2 from Ebola virus. Identification of active pocket and protein druggability within envelope glycoprotein GP2 from Ebola virus was done. According to this assessment, 7 active pockets with varied druggability could be identified.
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The drug searching for combating the present outbreak of Ebola virus infection is the urgent activity at present. Finding the new effective drug at present must base on the molecular analysis of the pathogenic virus. The in-depth analysis of the viral protein to find the binding site, active pocket is needed. Here, the authors analyzed the envelope glycoprotein GP2 from Ebola virus. Identification of active pocket and protein druggability within envelope glycoprotein GP2 from Ebola virus was done. According to this assessment, 7 active pockets with varied druggability could be identified.
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HIV-1 gp41 is an envelope protein that plays an essential role in virus entry. The mutation of gp41 affects HIV-1 entry and susceptibility to the fusion inhibitor T-20. Therefore, we analyzed the natural polymorphism of gp41 of 163 HIV-1 isolates from T-20-naive Koreans infected with HIV-1. This study of gp41 polymorphisms showed that insertions in the fourth threonine (74.8%) and L7M substitutions (85.3%) were more frequent in the fusion peptide motif in Korean HIV-1 isolates compared with those from other countries. Minor T-20 resistance mutations such as L45M (1.2%), N126K (1.2%), and E137K (6.7%) were detected, but the critical T-20 resistance mutations were not detected in the gp41 HR1 and HR2 regions. In addition, the N42S mutation (12.9%) associated with T-20 hypersusceptibility was detected at a high frequency. These results may serve as useful data for studies considering T-20 for use in the development of a more effective anti-retroviral treatment in Korea.
Subject(s)
Humans , Anti-HIV Agents/pharmacology , Drug Resistance, Viral/genetics , HIV Envelope Protein gp41/genetics , HIV Infections/virology , HIV-1/genetics , Peptide Fragments/pharmacology , Polymorphism, Genetic , Protein Structure, Tertiary/genetics , Republic of Korea , Virus InternalizationABSTRACT
Infection by the human immunodeficiency virus (HIV) is characterized by a progressive depletion of CD4 T lymphocytes, which leads to dysfunction of the immune system. Although a variety of mechanisms may contribute to the gradual T cell decline that occurs in HIV-infected patients, abnormal apoptosis of infected or bystander T lymphocytes is an important event leading to immunodeficiency. The HIV envelope glycoprotein plays a crucial role in HIV associated apoptosis through both death receptor-mediated and mitochondria-dependent pathways. This review summarizes current knowledge of Env-mediated T lymphocyte apoptosis.
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Objective To establish antigen capture ELISA methed to detect Kaposi's sarcoma-as-sociated herpesvirus(KSHV)antigen,and to evaluate its feasibility for clinical application.Methods The BALB/c mice and New Zealand white rabbits were injected with purified recombinant KSHV gpK8.1 proteins to prepare the monoclonal antibody(McAb)and polyclonal antibody(PcAb)anti-gpK8.1,respectively.A new antigen capture ELISA method was established for KSHV antigen detection.The detection reproducibili-ty as well as the sensitivity and specificity of this new assay were determined by the optimization test,which antibody pairs were analyzed to choose the best coating antibody and detecting antibody.The 3 KSHV posi-tive patients sera and 257 patients sera from sexually transmitted disease,cancers or gynecological diseases were detected with this assay to evaluate its value for clinical application.Results When the McAb as coat-ing antibody at concentration of 5 μg/ml and PcAb as detecting antibody at concentration of 1.6μg/ml were selected,the highest P/N value could be obtained.The sensitive analysis of this test could detect recombi-nant KSHV gpK8.1 antigen of 31.28 ng/ml.Meanwhile,it is highly specific to detect KSHV antigen with-out cross reaction to Epstein-Barr vims(EBV),herpes simplex virus(HSV)-1 or HSV-2.All of three KSHV-positive sera and 4 sera from 257 clinical samples were positive with this new assay.which indicated that it could be used for capturing KSHV antigen.Conclusion A sensitive and specific McAb-based anti-gen capture ELISA method to detect KSHV antigen were established successfully.It is of great potential val-ue to develop reagent for KSHV clinical serologic dingnosis.
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Objective To explore the effects of glycosylation in E2 and E1 protein on specific cell fusion in rubella virus(RV)strain JR23.Methods Site-directed mutagenesis was used tO obtain mutants containing new enzyme sites on the E2 and E1 gene of RV JR23.All the mutants and wild type proteins were expressed in BHK21 cells and treated with acid medium to induce specific cell fusion.The fusion functions were assayed with Giemsa staining and reporter gene method for qualitative and quantitative analysis,respectively.Expression efficieneies of mutant proteins on cell surface were quantified with fluorescence-activated cell sorter(FACS).Hemadsorption assays were performed to detect binding activity of mutant proteins qualitatively and quantitatively.Results Mutant proteins E2 N53G,S73I and S131V had 62.73%,66.66%and 55.12% of fusion activities,and E1 T78A,T179A and T211A had 66.93%,87.33%and 90.18%of fusion activities,respectively,as compared with the wild type protein.The FACS indicated that the expression efficiencies of all the mutant proteins except E2 S131V were lower than that of the wild type protein.Hemadsorption assays demonstrated that binding abilities of E2 S73I and E1 T78A decreased slightly,but that of the other four mutant proteins Wns almost same as the wild type protein. Conclusion Glycosylation on E2 N53,N71,N129 and E1 N76 were important for the specific cell fusion,but E1 N177 and N209 were almost not.
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HIV-1 envelope glycoprotein gp120 and gp41 are considered as two important parts in viral entry.In the process of virus entry,CD4 first binds to gp120 and causes the conformation of gp120 to change.Furthermore the conformation of gp41 has also been changed.Many peptides,macromolecular compounds and small molecule compounds which bind to gp120 or gp41 can deter the progress of virus entry.These compounds can play an important role in halting the spread of HIV-1 in this way.The structure and interaction of gp120 and gp41 are reviewed here,as well as the anti-HIV agents blocking the HIV entry by targeting the HIV-1 envelope glycoprotein.
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Considerable effort has been directed at understanding the structure and function of HIV-1 envelope glycoproteins. It has been difficult to characterize HIV-1 envelope glycoproteins due to the limited availability of these proteins from virus particles or infected cells. To facilitate the structural and functional analysis of HIV-1 envelope glycoproteins, recombinant baculoviruses were generated to express wild type or mutant HIV-1 envelope glycoproteins. The gp160 precursor protein as well as the gp120 glycoprotein were detected in the cell infected with recombinant BacENVw.t containing wild type HIV-1 envelope gene. In the insect cells infected with recombinant BacENVc with mutations at the cleavage site of gp160, a precursor form of envelope glycoprotein was produced, but not secreted into the culture medium. However, the insect cells infected with recombinant BacENVc/t containing both mutations at the cleavage site and membrane spanning region produced mutant envelope glycoproteins that were efficiently secreted into the culture medium in the form of precursor. Therefore the recombinant HIV-1 envelope glycoproteins produced in this system would be useful as immunogens in the development of a vaccine against AIDS.
Subject(s)
Humans , Baculoviridae , Glycoproteins , HIV , HIV-1 , Insecta , Membranes , Staphylococcal Protein A , VirionABSTRACT
Human immunodeficiency virus type 1(HIV-1) envelope glycoprotein is synthesized as a 160KDa precursor, gp160, that is cleaved by a cellular protease to form the gp120 and gp41 subunits. Mammalian expression vectors were designed that are capabae of efficient expression of various mutant envelope glycoproteins derived from a molecular clone of HIV-1. To construct these vectors, one type of mutation was made at the gp120-gp41 cleavage site by oligonucleotide directed mutagenesis. And another mutation was made to change amino acids in the membrane spanning region of HIV-1 gp41 important for membrane anchorage. Next, these two mutations were combined to generate a vector to have double mutations in cleavage site and membrane spanning region. These mutants were transiently expressed in mammalian cells. The effect of these mutations on envelope glycoprotein synthesis, proteolytic processing and secretion was determined. In addition, cell surface expression and ability of the glycoprotein to induce syncytium formation were examined. This study provides a mammalian expression system that is capable of efficient expression and secretion of soluble gp160.