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Lu Cao, Mingui Fu, Santosh Kumar, Anil Kumar
Methamphetamine (METH), a commonly used controlled substance, is known to exacerbate neuropathological dysfunction in HIV-infected individuals. The neuropathological manifestation results from cell death or dysfunction in the central nervous system (CNS) wherein autophagy is expected to have an important role. Autophagy is generally considered protective during deprivation/stress. However, excessive autophagy can be destructive, leading to autophagic cell death. This study was designed to investigate if METH and HIV-1 gp120 interact to induce autophagy in SVGA astrocytes, and whether autophagy is epiphenomenal or it has a role in METH- and gp120-induced cytotoxicity...
October 20, 2016: Cell Death & Disease
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
Mohammed Asmal, Sophie Lane, Meijuan Tian, Gabrielle Nickel, Colin Venner, Brennan Dirk, Jimmy Dikeakos, Corinne Luedemann, Linh Mach, Harikrishnan Balachandran, Adam Buzby, Srinivas Rao, Norman Letvin, Yong Gao, Eric J Arts
For studies on vaccines and therapies for HIV disease, SIV-HIV chimeric viruses harboring the HIV-1 env gene (SHIVenv) remain the best virus in non-human primate models. However, there are still very few SHIVenv viruses that can cause AIDS in non-CD8-depleted animals. In the present study, a recently created CCR5-using SHIVenv_B3 virus with env gene derived from acute/early HIV-1 infections (AHI) successfully established pathogenic infection in macaques. Through a series of investigations on the evolution, mutational profile, and phenotype of the virus and the resultant humoral immune response in infected rhesus macaques, we found that the E32K mutation in the Env C1 domain was associated with macaque pathogenesis, and that the electrostatic interactions in Env may favor E32K at the gp120 N terminus and "lock" the binding to heptad repeat 1 of gp41 in the trimer and produce a SHIVenv with increased fitness and pathogenesis during macaque infections...
October 6, 2016: Virology
Kevin K Ariën, Françoise Baleux, Delphine Desjardins, Françoise Porrot, Yves-Marie Coïc, Johan Michiels, Kawthar Bouchemal, David Bonnaffé, Timothée Bruel, Olivier Schwartz, Roger Le Grand, Guido Vanham, Nathalie Dereuddre-Bosquet, Hugues Lortat-Jacob
The CD4 and the cryptic coreceptor binding sites of the HIV-1 envelope glycoprotein are key to viral attachment and entry. We developed new molecules comprising a CD4 mimetic peptide linked to anionic compounds (mCD4.1-HS12 and mCD4.1-PS1), that block the CD4-gp120 interaction and simultaneously induce the exposure of the cryptic coreceptor binding site, rendering it accessible to HS12- or PS1- mediated inhibition. Using a cynomolgus macaque model of vaginal challenge with SHIV162P3, we report that mCD4.1-PS1, formulated into a hydroxyethyl-cellulose gel provides 83% protection (5/6 animals)...
October 10, 2016: Scientific Reports
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
Francesca Curreli, Dmitry S Belov, Ranjith R Ramesh, Naisargi Patel, Andrea Altieri, Alexander V Kurkin, Asim K Debnath
Since our first discovery of a CD4-mimic, NBD-556, which targets the Phe43 cavity of HIV-1 gp120, we and other groups made considerable progress in designing new CD4-mimics with viral entry-antagonist property. In our continued effort to make further progress we have synthesized twenty five new analogs based on our earlier reported viral entry antagonist, NBD-11021. These compounds were tested first in HIV-1 Env-pseudovirus based single-cycle infection assay as well as in a multi-cycle infection assay. Four of these new compounds showed much improved antiviral potency as well as cytotoxicity...
September 24, 2016: Bioorganic & Medicinal Chemistry
Gautam Srivastava, Adi Moseri, Naama Kessler, Sabine R Akabayov, Boris Arshava, Fred Naider, Jacob Anglister
Weak protein-protein and protein-ligand interactions play important roles in biological recognition. In many cases, simplification of structural studies of large protein complexes is achieved by investigation of the interaction between the protein and a weakly binding segment of its protein ligand. Detection of pairwise interactions in such complexes is a major challenge for both X-ray crystallography and NMR. We demonstrate that transferrednuclear Overhauser effect, TRNOE, in combination with asymmetric deuteration of a protein and a peptide ligand can be used to detect intermolecular interactions in large protein complexes with molecular weights up to ~100 kDa...
October 4, 2016: FEBS Journal
Muntasir Alam, Takeo Kuwata, Kazuya Shimura, Masaru Yokoyama, Kristel Paola Ramirez Valdez, Kazuki Tanaka, Yasuhiro Maruta, Shinya Oishi, Nobutaka Fujii, Hironori Sato, Masao Matsuoka, Shuzo Matsushita
BACKGROUND: HIV-1 typically develops resistance to any single antiretroviral agent. Combined anti-retroviral therapy to reduce drug-resistance development is necessary to control HIV-1 infection. Here, to assess the utility of a combination of antibody and fusion inhibitor treatments, we investigated the potency of monoclonal antibodies at neutralizing HIV-1 variants that are resistant to fusion inhibitors. RESULTS: Mutations that confer resistance to four fusion inhibitors, enfuvirtide, C34, SC34, and SC34EK, were introduced into the envelope of HIV-1JR-FL, a CCR5-tropic tier 2 strain...
September 27, 2016: Retrovirology
Sabrina Lusvarghi, Katheryn Lohith, Jeanne Morin-Leisk, Rodolfo Ghirlando, Jenny E Hinshaw, Carole A Bewley
Carbohydrate binding proteins such as griffithsin, cyanovirin-N, and BanLec are potent HIV entry inhibitors and promising microbicides. Each binds to high-mannose glycans on the surface envelope glycoprotein gp120, yet the mechanisms by which they engage viral spikes and exhibit inhibition constants ranging from nanomolar to picomolar are not understood. To determine the structural and mechanistic basis for recognition and potency, we selected a panel of lectins possessing different valencies per subunit, oligomeric states, and relative orientations of carbohydrate binding sites to systematically probe their contributions to inhibiting viral entry...
October 3, 2016: ACS Infectious Diseases
Ana B Sanchez, Kathryn E Medders, Ricky Maung, Paloma Sánchez-Pavón, Daniel Ojeda-Juárez, Marcus Kaul
BACKGROUND: The chemokine receptor CXCR4 (CD184) and its natural ligand CXCL12 contribute to many physiological processes, including decisions about cell death and survival in the central nervous system. In addition, CXCR4 is a co-receptor for human immunodeficiency virus (HIV)-1 and mediates the neurotoxicity of the viral envelope protein gp120. However, we previously observed that CXCL12 also causes toxicity in cerebrocortical neurons but the cellular mechanism remained incompletely defined...
2016: Journal of Neuroinflammation
Nicolò Mauro, Paolo Ferruti, Elisabetta Ranucci, Amedea Manfredi, Angela Berzi, Mario Clerici, Valeria Cagno, David Lembo, Alessandro Palmioli, Sara Sattin
The initial steps of viral infections are mediated by interactions between viral proteins and cellular receptors. Blocking the latter with high-affinity ligands may inhibit infection. DC-SIGN, a C-type lectin receptor expressed by immature dendritic cells and macrophages, mediates human immunodeficiency virus (HIV) infection by recognizing mannose clusters on the HIV-1 gp120 envelope glycoprotein. Mannosylated glycodendrimers act as HIV entry inhibitors thanks to their ability to block this receptor. Previously, an amphoteric, but prevailingly cationic polyamidoamine named AGMA1 proved effective as infection inhibitor for several heparan sulfate proteoglycan-dependent viruses, such as human papilloma virus HPV-16 and herpes simplex virus HSV-2...
2016: Scientific Reports
Anne-Marie C Andersson, Emeline Ragonnaud, Kelly E Seaton, Sheetal Sawant, Antonella Folgori, Stefano Colloca, Celia Labranche, David C Montefiori, Georgia D Tomaras, Peter J Holst
The low number of envelope (Env) spikes presented on native HIV-1 particles is a major impediment for HIV-1 prophylactic vaccine development. We designed virus-like particle encoding adenoviral vectors utilizing SIVmac239 Gag as an anchor for full length and truncated HIV-1 M consensus Env. Truncated Env overexpressed VRC01 and 17b binding antigen on the surface of transduced cells while the full length Env vaccine presented more and similar amounts of antigen binding to the trimer conformation sensitive antibodies PGT151 and PGT145, respectively...
October 17, 2016: Vaccine
Jing Deng, Yu-Ya Mitsuki, Guomiao Shen, Jocelyn Ray, Claudia Cicala, James Arthos, Michael L Dustin, Catarina E Hioe
: HIV is transmitted most efficiently from cell to cell and productive infection occurs mainly in activated CD4 T cells. It is postulated that HIV exploits immunological synapses formed between CD4 T cells and antigen-presenting cells to facilitate the targeting and infection of activated CD4 T cells. This study sought to evaluate how the presence of the HIV envelope (Env) in the CD4 T cell immunological synapse affects synapse formation and intracellular signaling to impact the downstream T cell activation events...
September 14, 2016: Journal of Virology
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
Zhiying Liu, Yunjin Zang, Luxin Qiao, Kai Liu, Yabo Ouyang, Yulin Zhang, Dexi Chen
The mechanisms behind HIV-1-associated neurocognitive disorders are still unclear. Apoptosis-stimulating protein 2 of p53 (ASPP2) is a damage-inducible p53-binding protein that stimulates p53-mediated apoptosis and transactivates proapoptotic and cell cycle regulatory genes. It has been reported that ASPP2 has a specific regulatory function in the death of retinal ganglion cells and the development of Alzheimer's disease. In this study, we used p53 and ASPP2 knockout mice and primary cerebrocortical neuron culture to analyze the role of the interaction between ASPP2 with p53 in HIV-1 envelope glycoprotein gp120-induced neurotoxicity...
2016: Scientific Reports
Ming Tian, Cheng Cheng, Xuejun Chen, Hongying Duan, Hwei-Ling Cheng, Mai Dao, Zizhang Sheng, Michael Kimble, Lingshu Wang, Sherry Lin, Stephen D Schmidt, Zhou Du, M Gordon Joyce, Yiwei Chen, Brandon J DeKosky, Yimin Chen, Erica Normandin, Elizabeth Cantor, Rita E Chen, Nicole A Doria-Rose, Yi Zhang, Wei Shi, Wing-Pui Kong, Misook Choe, Amy R Henry, Farida Laboune, Ivelin S Georgiev, Pei-Yi Huang, Suvi Jain, Andrew T McGuire, Eric Georgeson, Sergey Menis, Daniel C Douek, William R Schief, Leonidas Stamatatos, Peter D Kwong, Lawrence Shapiro, Barton F Haynes, John R Mascola, Frederick W Alt
The design of immunogens that elicit broadly reactive neutralizing antibodies (bnAbs) has been a major obstacle to HIV-1 vaccine development. One approach to assess potential immunogens is to use mice expressing precursors of human bnAbs as vaccination models. The bnAbs of the VRC01-class derive from the IGHV1-2 immunoglobulin heavy chain and neutralize a wide spectrum of HIV-1 strains via targeting the CD4 binding site of the envelope glycoprotein gp120. We now describe a mouse vaccination model that allows a germline human IGHV1-2(∗)02 segment to undergo normal V(D)J recombination and, thereby, leads to the generation of peripheral B cells that express a highly diverse repertoire of VRC01-related receptors...
September 8, 2016: Cell
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