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Env protein

Bibek Parajuli, Kriti Acharya, Reina Yu, Brendon Ngo, Adel A Rashad, Cameron F Abrams, Irwin M Chaiken
We recently reported discovery of a recombinant chimera, denoted DAVEI (Dual Acting Virucidal Entry Inhibitor), which is able to selectively cause specific and potent lytic inactivation of both pseudotyped and fully infectious HIV-1 virions. The chimera is composed of the lectin cyanovirin-N (CVN) fused to the 20-residue membrane-proximal external region (MPER) of HIV-1 gp41. Since the Env gp120-binding CVN domain on its own is not lytic, we sought here to determine how the MPER(DAVEI) domain is able to endow the chimera with virolytic activity...
October 12, 2016: Biochemistry
Giuseppina Musumeci, Giacomo Magnani, Isabella Bon, Serena Longo, Alessia Bertoldi, Anna Maria Degli Antoni, Maria Rita Rossi, Alessandro Ruggeri, Vittorio Sambri, Simona Semprini, Laura Sighinolfi, Maria Alessandra Ursitti, Alessandro Zerbini, Vincenzo Colangeli, Leonardo Calza, Alba Carola Finarelli, Erika Massimiliani, Maria Carla Re
It is crucial to establish the timing of infection and distinguish between early and long-lasting HIV-1 infections not only for partner notification and epidemiological surveillance, but also to offer early drug treatment and contain the spread of infection. This study analyzed serum and/or plasma samples with a first positive HIV antibody/antigen result coming from different Medical Centers in the Emilia Romagna Region, North East Italy, using the avidity assay, Western Blotting, RNA viral load, CD4 cell counts and genotyping assay...
September 13, 2016: New Microbiologica
Cătălin Buiu, Mihai V Putz, Speranta Avram
The dependency between the primary structure of HIV envelope glycoproteins (ENV) and the neutralization data for given antibodies is very complicated and depends on a large number of factors, such as the binding affinity of a given antibody for a given ENV protein, and the intrinsic infection kinetics of the viral strain. This paper presents a first approach to learning these dependencies using an artificial feedforward neural network which is trained to learn from experimental data. The results presented here demonstrate that the trained neural network is able to generalize on new viral strains and to predict reliable values of neutralizing activities of given antibodies against HIV-1...
October 11, 2016: International Journal of Molecular Sciences
Jianhui Tian, Cesar A López, Cynthia A Derdeyn, Morris S Jones, Abraham Pinter, Bette Korber, S Gnanakaran
Heavy glycosylation of the envelope (Env) surface subunit, gp120, is a key adaptation of HIV-1; however, the precise effects of glycosylation on the folding, conformation and dynamics of this protein are poorly understood. Here we explore the patterns of HIV-1 Env gp120 glycosylation, and particularly the enrichment in glycosylation sites proximal to the disulfide linkages at the base of the surface-exposed variable domains. To dissect the influence of glycans on the conformation these regions, we focused on an antigenic peptide fragment from a disulfide bridge-bounded region spanning the V1 and V2 hyper-variable domains of HIV-1 gp120...
October 2016: PLoS Computational Biology
Karen P Coss, Snezana Vasiljevic, Laura K Pritchard, Stefanie A Krumm, Molly Glaze, Sharon Madzorera, Penny L Moore, Max Crispin, Katie J Doores
: The HIV envelope (Env) is extensively modified with host-derived N-linked glycans. The high density of glycosylation on the viral spike limits enzymatic processing resulting in numerous under-processed oligomannose-type glycans. This extensive glycosylation not only shields conserved regions of the protein from the immune system but also act as targets for HIV broadly neutralizing antibodies (bnAbs). In response to the host immune system, the HIV glycan shield is constantly evolving through mutations affecting both the positions and frequencies of potential N-linked glycans (PNGSs)...
October 5, 2016: Journal of Virology
Xunqing Jiang, Max Totrov, Wei Li, Jared M Sampson, Constance Williams, Hong Lu, Xueling Wu, Shan Lu, Shixia Wang, Susan Zolla-Pazner, Xiang-Peng Kong
: The V1V2 region of HIV-1 gp120 harbors a major vulnerable site targeted by a group of broadly neutralizing mAbs such as PG9 through strand-strand recognition. However, this epitope region is structurally polymorphic, as it can also form a helical conformation recognized by RV144 vaccine-induced mAb CH58. This structural polymorphism is a potential mechanism for masking the V1V2 vulnerable site. Designing immunogens that can induce conformation-specific Ab responses may lead to vaccines targeting this vulnerable site...
October 5, 2016: Journal of Virology
Y Liu, Y F Zhang, X L Sun, S Y Liu
The envelope protein (Env) of the Jaagsiekte sheep retrovirus (JSRV) is known to be a unique oncoprotein responsible for inducing ovine pulmonary adenocarcinoma (OPA). The objective of this study was to prepare a specific monoclonal antibody (mAb) against the JSRV Env protein using bioinformatic analysis. According to the structure and epitope prediction results of JSRV Env, the JSRV-Env572-615 antigen was prepared via peptide synthesis (amino acid sequence 572-615, denoted as JSRV-Env572-615). BALB/c mice were immunized to prepare the anti-JSRV-Env572-615 mAb...
August 29, 2016: Genetics and Molecular Research: GMR
Magdalena Janina Laskaj, Anne Troldborg, Ellen-Margrethe Hauge, Shervin Bahrami, Kristian Stengaard-Pedersen
OBJECTIVES: Human Endogenous Retroviruses (HERVs) are remnants of past retroviral infections in the human genome and have been implicated in different aspects of human biology. The aim of this study was to identify HERVs which are associated with the pathogenesis of Rheumatoid diseases represented by Systemic Lupus Erythematosus (SLE). METHODS: The study subjects included 45 female patients with SLE and 50 geographically and age matched healthy. Real-time RT-PCR analysis was used to examine the transcription levels of 11 genes with coding capacity for complete envelope protein in these individuals...
October 1, 2016: Arthritis & Rheumatology
Y Shi, Y M Wan, J Chen, J Wang, Y Q Ren, Q Wei, Z Cong, J Q Xu
Objective: To investigate the number and distribution of N-linked glycosylation sites of simian/human immunodeficiency virus envelope proteins(SHIVSF162P3)and SHIV transmission. Methods: Two female adult Chinese rhesus macaques(4 years old)were intravenously inoculated with 300 TCID50 SHIVSF162P3. The macaques weighed 4 and 5 kg and were identified as Rh1 and Rh2. We collected plasma samples at days 3, 7, 10, 14, 17, 21, 24, 28, 35, 42, 49, 56, 63, 70 and 77 post-challenge. Subsequently, we monitored plasma viral load by real-time PCR after viral RNA isolation and cDNA synthesis...
October 6, 2016: Zhonghua Yu Fang Yi Xue za Zhi [Chinese Journal of Preventive Medicine]
Sunil Kannanganat, Linda S Wyatt, Sailaja Gangadhara, Venkatesarlu Chamcha, Lynette S Chea, Pamela A Kozlowski, Celia C LaBranche, Lakshmi Chennareddi, Benton Lawson, Pradeep B J Reddy, Tiffany M Styles, Thomas H Vanderford, David C Montefiori, Bernard Moss, Harriet L Robinson, Rama Rao Amara
We tested, in rhesus macaques, the effects of a 500-fold range of an admixed recombinant modified vaccinia Ankara (MVA) expressing rhesus GM-CSF (MVA/GM-CSF) on the immunogenicity and protection elicited by an MVA/SIV macaque 239 vaccine. High doses of MVA/GM-CSF did not affect the levels of systemic envelope (Env)-specific Ab, but it did decrease the expression of the gut-homing receptor α4β7 on plasmacytoid dendritic cells (p < 0.01) and the magnitudes of Env-specific IgA (p = 0.01) and IgG (p < 0...
September 28, 2016: Journal of Immunology: Official Journal of the American Association of Immunologists
Elodie Cassan, Anne-Muriel Arigon-Chifolleau, Jean-Michel Mesnard, Antoine Gross, Olivier Gascuel
Recent experiments provide sound arguments in favor of the in vivo expression of the AntiSense Protein (ASP) of HIV-1. This putative protein is encoded on the antisense strand of the provirus genome and entirely overlapped by the env gene with reading frame -2. The existence of ASP was suggested in 1988, but is still controversial, and its function has yet to be determined. We used a large dataset of ∼23,000 HIV-1 and SIV sequences to study the origin, evolution, and conservation of the asp gene. We found that the ASP ORF is specific to group M of HIV-1, which is responsible for the human pandemic...
October 11, 2016: Proceedings of the National Academy of Sciences of the United States of America
Chia-Yen Chen, Masashi Shingai, Sarah Welbourn, Malcolm A Martin, Pedro Borrego, Nuno Taveira, Klaus Strebel
: Although HIV-2 does not encode a vpu gene, the ability to antagonize BST-2 is conserved in some HIV-2 isolates where it is controlled by the Env glycoprotein. We previously reported that a single amino acid difference between the lab-adapted ROD10 and ROD14 Envs controlled the enhancement of virus release (referred to here as Vpu-like) activity. Here we investigated how conserved the Vpu-like activity is in primary HIV-2 isolates. We found that almost half of the 35 tested primary HIV-2 Env isolates obtained from 7 different patients enhanced virus release...
September 28, 2016: Journal of Virology
Silvia Angeletti, Alessandra Lo Presti, Marta Giovanetti, Alba Grifoni, Massimo Amicosante, Marco Ciotti, Luiz-Carlos J Alcantara, Eleonora Cella, Massimo Ciccozzi
Zika virus (ZIKV) is an emerging Flavivirus that have recently caused an outbreak in Brazil and rapid spread in several countries. In this study, the consequences of ZIKV evolution on protein recognition by the host immune system have been analyzed. Evolutionary analysis was combined with homology modeling and T-B cells epitope predictions. Two separate clades, the African one with the Uganda sequence, as the most probable ancestor, and the second one containing all the most recent sequences from the equatorial belt were identified...
September 27, 2016: Pathogens and Global Health
Xifeng Jiang, Qiyan Jia, Lu Lu, Fei Yu, Jishen Zheng, Weiguo Shi, Lifeng Cai, Shibo Jiang, Keliang Liu
HIV-1 fusion with the target cell is initiated by the insertion of the gp41 fusion peptide (FP) into the target cell membrane and the interaction between the gp41 N- and C-terminal heptad repeats (NHR and CHR), followed by the formation of the six-helix bundle (6-HB) fusion core. Therefore, both FP and NHR are important targets for HIV-1 fusion inhibitors. Here, we designed and synthesized a dual-target peptidic HIV-1 fusion inhibitor, 4HR-LBD-VIRIP, in which 4HR-LBD is able to bind to the gp41 NHR domain, while VIRIP is able to interact with gp41 FP...
September 8, 2016: Amino Acids
Susan Zolla-Pazner, Rebecca Powell, Sara Yahyaei, Constance Williams, Xunqing Jiang, Wei Li, Shan Lu, Shixia Wang, Chitra Upadhyay, Catarina E Hioe, Max Totrov, Xiangpeng Kong
: Strong antibody (Ab) responses against V1V2 epitopes of the HIV-1 gp120 envelope (Env) correlated with reduced infection rates in studies of HIV, SHIV, and SIV. In order to focus the Ab response on V1V2, we used six V1V2 sequences and nine scaffold proteins to construct immunogens which were tested using various immunization regimens for their ability to induce cross-reactive and biologically active V2 Abs in rabbits. A prime/boost immunization strategy was employed using gp120 DNA and various V1V2-scaffold proteins...
September 14, 2016: Journal of Virology
Matthew Costa, Justin Pollara, Regina Whitney Edwards, Michael Seaman, Miroslaw K Gorny, David Montefiori, Hua-Xin Liao, Guido Ferrari, Shan Lu, Shixia Wang
: HIV-1 is able to elicit broadly potent neutralizing antibodies in a very small subset of individuals only after several years' infection and, therefore, vaccines that elicit these types of antibodies have been difficult to design. The RV144 trial showed that a moderate protection is possible, which may correlate with ADCC activity. Our previous studies demonstrated that in an HIV vaccine phase I trial, DP6-001, a polyvalent Env DNA prime-protein boost formulation, could elicit potent and broadly reactive, gp120-specific antibodies with positive neutralization activities...
September 14, 2016: Journal of Virology
Barbara Richichi, Claudia Pastori, Stefano Gherardi, Assunta Venuti, Antonella Cerreto, Francesca Sanvito, Lucio Toma, Lucia Lopalco, Cristina Nativi
Glycosphingolipids (GSLs) are involved in HIV-1 entry. GM-3 ganglioside, a widespread GSL, affects HIV entry and infection in different ways, depending on the concentration, through its anchoring activity in lipid rafts. This explains why the induction of an altered GSLs metabolism was a tempting approach to reducing HIV-1 cell infection. This study assayed the biological properties of a synthetic GM-3 lactone mimetic, 1, aimed at blocking HIV-1 infection without inducing the adverse events expected by an altered metabolism of GLSs in vivo...
August 12, 2016: ACS Infectious Diseases
Gaudensia Mutua, Bashir Farah, Robert Langat, Jackton Indangasi, Simon Ogola, Brian Onsembe, Jakub T Kopycinski, Peter Hayes, Nicola J Borthwick, Ambreen Ashraf, Len Dally, Burc Barin, Annika Tillander, Jill Gilmour, Jan De Bont, Alison Crook, Drew Hannaman, Josephine H Cox, Omu Anzala, Patricia E Fast, Marie Reilly, Kundai Chinyenze, Walter Jaoko, Tomáš Hanke, The Hiv-Core 004 Study Group
We are developing a pan-clade HIV-1 T-cell vaccine HIVconsv, which could complement Env vaccines for prophylaxis and be a key to HIV cure. Our strategy focuses vaccine-elicited effector T-cells on functionally and structurally conserved regions (not full-length proteins and not only epitopes) of the HIV-1 proteome, which are common to most global variants and which, if mutated, cause a replicative fitness loss. Our first clinical trial in low risk HIV-1-negative adults in Oxford demonstrated the principle that naturally mostly subdominant epitopes, when taken out of the context of full-length proteins/virus and delivered by potent regimens involving combinations of simian adenovirus and poxvirus modified vaccinia virus Ankara, can induce robust CD8(+) T cells of broad specificities and functions capable of inhibiting in vitro HIV-1 replication...
2016: Molecular Therapy. Methods & Clinical Development
Nicole Grandi, Marta Cadeddu, Jonas Blomberg, Enzo Tramontano
BACKGROUND: Human endogenous retroviruses (HERVs) are ancient sequences integrated in the germ line cells and vertically transmitted through the offspring constituting about 8 % of our genome. In time, HERVs accumulated mutations that compromised their coding capacity. A prominent exception is HERV-W locus 7q21.2, producing a functional Env protein (Syncytin-1) coopted for placental syncytiotrophoblast formation. While expression of HERV-W sequences has been investigated for their correlation to disease, an exhaustive description of the group composition and characteristics is still not available and current HERV-W group information derive from studies published a few years ago that, of course, used the rough assemblies of the human genome available at that time...
2016: Retrovirology
Fangyuan DU, Dayong Chen, Yufei Zhang, Xiaolin Sun, Wenqing Guo, Shuying Liu
Objective To explore the influence of the exogenous Jaagsiekte sheep retrovious (exJSRV) envelope protein (Env) on NIH3T3 cell proliferation. Methods A recombinant plasmid pcDNA4/myc-His/exJSRV- env carrying exJSRV- env gene was constructed, and then the correctness of the recombinant plasmid was identified by PCR, restriction enzyme digestion and sequencing. The recombinant plasmid pcDNA4/myc-His/exJSRV- env was transiently transfected into NIH3T3 cells by Lipofectamine(TM) LTX. After the transfection of the recombinant plasmid, the expression of exJSRV- env was detected by reverse transcription PCR and Western blotting...
September 2016: Xi Bao Yu Fen Zi Mian Yi Xue za Zhi, Chinese Journal of Cellular and Molecular Immunology
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