Read by QxMD icon Read


Xiujuan Zhang, Yuanmei Zhu, Hao Hu, Senyan Zhang, Pengfei Wang, Huihui Chong, Jinsheng He, Xinquan Wang, Yuxian He
The deep hydrophobic pocket of HIV-1 gp41 has been considered a drug target, but short-peptides targeting this site usually lack potent antiviral activity. By applying the M-T hook structure, we previously generated highly potent short-peptide fusion inhibitors that specifically targeted the pocket site, such as MT-SC22EK, HP23L, and LP-11. Here, the crystal structures of HP23L and LP-11 bound to the target mimic peptide N36 demonstrated the critical intrahelical and interhelical interactions, especially verifying that the hook-like conformation was finely adopted while the methionine residue was replaced by the oxidation-less prone residue leucine, and that addition of an extra glutamic acid significantly enhanced the binding and inhibitory activities...
2018: Frontiers in Cellular and Infection Microbiology
Quang N Nguyen, David R Martinez, Jonathon E Himes, R Whitney Edwards, Qifeng Han, Amit Kumar, Riley Mangan, Nathan I Nicely, Guanhua Xie, Nathan Vandergrift, Xiaoying Shen, Justin Pollara, Sallie R Permar
BACKGROUND: The initial envelope (Env)-specific antibody response in acutely HIV-1-infected individuals and simian immunodeficiency virus (SIV)-infected rhesus monkeys (RMs) is dominated by non-neutralizing antibodies targeting Env gp41. In contrast, natural primate SIV hosts, such as African green monkeys (AGMs), develop a predominant Env gp120-specific antibody response to SIV infection. However, the fine-epitope specificity and function of SIV Env-specific plasma IgG, and their potential role on autologous virus co-evolution in SIV-infected AGMs and RMs remain unclear...
March 9, 2018: Retrovirology
Vani G S Narasimhulu, Anna K Bellamy-McIntyre, Annamarie E Laumaea, Chan-Sien Lay, David N Harrison, Hannah A D King, Heidi E Drummer, Pantelis Poumbourios
HIV-1 is spread by cell-free virions and by cell-cell viral transfer. We asked whether the structure and function of a broad neutralizing antibody (bNAb) epitope, the membrane-proximal ectodomain region (MPER) of the viral gp41 transmembrane glycoprotein, differ in cell-free and cell-cell transmitted viruses and whether this difference could be related to Ab neutralization sensitivity. Whereas cell-free viruses bearing W666A and I675A substitutions in the MPER lacked infectivity, cell-associated mutant viruses were able to initiate robust spreading infection...
March 1, 2018: Journal of Biological Chemistry
Lara Ajamian, Luca Melnychuk, Patrick Jean-Pierre, Gerasimos J Zaharatos
Flagellin's potential as a vaccine adjuvant has been increasingly explored over the last three decades. Monomeric flagellin proteins are the only known agonists of Toll-like receptor 5 (TLR5). This interaction evokes a pro-inflammatory state that impacts upon both innate and adaptive immunity. While pathogen associated molecular patterns (PAMPs) like flagellin have been used as stand-alone adjuvants that are co-delivered with antigen, some investigators have demonstrated a distinct advantage to incorporating antigen epitopes within the structure of flagellin itself...
February 27, 2018: Viruses
Victoria Oakes, Johana Torralba, Edurne Rujas, José L Nieva, Carmen Domene, Beatriz Apellaniz
The 10E8 antibody achieves near-pan neutralization of HIV-1 by targeting the remarkably conserved gp41 membrane-proximal external region (MPER) and the connected transmembrane domain (TMD) of the HIV-1 envelope glycoprotein (Env). Thus, recreating the structure that generates 10E8-like antibodies is a major goal of the rational design of anti-HIV vaccines. Unfortunately, high-resolution information of this segment in the native Env is lacking, limiting our understanding of the behavior of the crucial 10E8 epitope residues...
February 22, 2018: Biochimica et Biophysica Acta
Alexander M Andrianov, Ivan A Kashyn, Alexander V Tuzikov
An integrated computational approach to in silico drug design was used to identify novel HIV-1 fusion inhibitor scaffolds mimicking broadly neutralizing antibody (bNab) 10E8 targeting the membrane proximal external region (MPER) of the HIV-1 gp41 protein. This computer-based approach included (i) generation of pharmacophore models representing 3D-arrangements of chemical functionalities that make bNAb 10E8 active towards the gp41 MPER segment, (ii) shape and pharmacophore-based identification of the 10E8-mimetic candidates by a web-oriented virtual screening platform pepMMsMIMIC, (iii) high-throughput docking of the identified compounds with the gp41 MPER peptide, and (iv) molecular dynamics simulations of the docked structures followed by binding free energy calculations...
January 15, 2018: Journal of Bioinformatics and Computational Biology
Wei Liu, Xiaohong An, Jiao Wang, Xiaoguang Zhang, Jianjun Tan, Zhixiang Zhou, Yi Zeng
Fusion inhibitors of HIV prevent the virus from entering into the target cell via the interaction with gp41, which stops the process of spatial rearrangement of the viral envelope protein. A series of peptides have been designed and screened to obtain a highly potent novel sequence. Among them, CT105 possesses the most potent anti-viral ability at low nanomolar IC50 values against a panel of HIV-1 pseudoviruses from A, B, C and A1/D subtypes, whereas T20 shows much weaker potency. CT105 also shows excellent inhibitory activity at 260 pico molar IC50 against HIV-1 replication...
January 31, 2018: Bioorganic & Medicinal Chemistry Letters
Yuanmei Zhu, Xiujuan Zhang, Xiaohui Ding, Huihui Chong, Sheng Cui, Jinsheng He, Xinquan Wang, Yuxian He
Enfuvirtide (T20) is the only viral fusion inhibitor approved for clinical use, but it has relatively weak anti-HIV activity and easily induces drug resistance. In succession to T20, T1249 has been designed as a 39-mer peptide composed of amino acid sequences derived from HIV-1, HIV-2, and simian immunodeficiency virus (SIV); however, its development has been suspended due to formulation difficulties. We recently developed a T20-based lipopeptide (LP-40) showing greatly improved pharmaceutical properties. Here, we generated a T1249-based lipopeptide, termed LP-46, by replacing its C-terminal tryptophan-rich sequence with fatty acid...
February 7, 2018: Journal of Biological Chemistry
Saghi Sepehri, Sepehr Soleymani, Rezvan Zabihollahi, Mohammad R Aghasadeghi, Mehdi Sadat, Lotfollah Saghaie, Hamid R Memarian, Afshin Fassihi
A series of tetrahydropyrimidine derivatives (2a-l) were designed, synthesized and screened for anti-HIV-1 properties based on the structures of HIV-1 gp41 binding site inhibitors, NB-2 and NB-64. A computational study was performed to predict the pharmacodynamics, pharmacokinetics and drug-likeness features of the studied molecules. Docking studies revealed that the carboxylic acid group in the molecules forms salt bridges with either Lys574 or Arg579. Physiochemical properties (e.g. molecular weight, number of hydrogen bond donors, number of hydrogen bond acceptors and number of rotatable bonds) of the synthesized compounds confirmed and exhibited that these compounds were within the range set by Lipinski's rule of five...
February 6, 2018: Chemistry & Biodiversity
L Shang, A J Smith, L Duan, K E Perkey, S Wietgrefe, M Zupancic, P J Southern, R P Johnson, J V Carlis, A T Haase
To identify mechanisms by which HIV-1 might penetrate the epithelial barrier during sexual transmission to women and vaccine-associated protection against entry, we characterized early epithelial responses to vaginal inoculation of SIVmac251 in naïve or SIVmac239Δnef-vaccinated rhesus macaques. Vaginal inoculation induced an early stress response in the cervicovaginal epithelium, which was associated with impaired epithelial integrity, damaged barrier function, and virus and bacterial translocation. In vaccinated animals, early stress responses were suppressed, and the maintenance of epithelial barrier integrity correlated with prevention of virus entry...
February 1, 2018: Journal of Infectious Diseases
Edurne Rujas, Daniel P Leaman, Sara Insausti, Lei Ortigosa-Pascual, Lei Zhang, Michael B Zwick, José L Nieva
The 10E8 antibody targets a helical epitope in the membrane-proximal external region (MPER) and transmembrane domain (TMD) of the envelope glycoprotein (Env) subunit gp41, and is among the broadest known neutralizing antibodies against HIV-1. Accordingly, this antibody and its mechanism of action valuably inform the design of effective vaccines and immunotherapies. 10E8 exhibits unusual adaptations to attain specific, high-affinity binding to the MPER at the viral membrane interface. Reversing charge of the basic paratope surface (from net positive to net negative) reportedly lowered its neutralization potency...
January 31, 2018: Journal of Virology
Jinxu Liao, Chen Zhang, Wenjuan Ru, Dan Wang, Wenping Zhang
Previous study showed that exogenously applied recombinant thymosin from Bombyx mori (BmTHY) reduces B. mori nucleopolyhedrovirus (BmNPV) proliferation in silkworm. Which stands to reason that BmTHY in B. mori is crucial for the defense against BmNPV. However, little is known about the effect of endogenously overexpressed or repressed BmTHY on B. mori resistance to virus infection. To study this issue, we constructed an overexpression and inhibited expression systems of BmTHY in BmN cells. The viral titer and the analysis from the quantitative real-time polymerase chain reaction (PCR) revealed that overexpression of BmTHY decreased the copies of BmNPV gene gp41, which goes over to inhibit the proliferation of BmNPV in BmN cells, while the inhibited expression of BmTHY significantly enhanced viral proliferation in infected BmN cells...
January 29, 2018: Archives of Insect Biochemistry and Physiology
J-H Kwon, H-T Kim, S J Sim, Y J Cha, J Lee
The objective of this study is to develop an accurate, rapid, simple, and label-free assay technology that enables point-of-care diagnosis of AIDS. For this, 3-dimensional (3D) probes to sensitively detect anti-HIV antibodies were designed and synthesized by genetically presenting a HIV antigen (gp41) on the surface of engineered human ferritin nanoparticles. The 3D probes also present multi-copies of the hexa-histidine peptide (H6) on their surface to chemisorb gold ions (Au3+), which is essential for the generation and self-enhancement of assay signals...
January 24, 2018: Analyst
Shuang Liang, Punsisi Ratnayake, Craig Keinath, Lihui Jia, Robert Wolfe, Ahinsa Ranaweera, David P Weliky
Human immunodeficiency virus (HIV) is membrane-enveloped and an initial infection step is joining/fusion of viral and cell membranes. This step is catalyzed by gp41 which is a single-pass integral viral membrane protein. The protein contains a ~170-residue ectodomain located outside the virus that is important for fusion, and includes the fusion peptide (FP), N-helix, loop, C-helix, and viral membrane-proximal external region (MPER). The virion initially has non-covalent complexes between three gp41 ectodomains and three gp120 proteins...
January 18, 2018: Biochemistry
Bibek Parajuli, Kriti Acharya, Harry C Bach, Bijay Parajuli, Shiyu Zhang, Amos B Smith, Cameron F Abrams, Irwin Chaiken
We previously reported first generation recombinant DAVEI construct, a dual action virus entry inhibitor composed of cyanovirin-N (CVN) fused to a membrane proximal external region (MPER) or its derivative peptide Trp3. DAVEI exhibits potent and irreversible inactivation of HIV-1 viruses by dual engagement of gp120 and gp41. However, the promiscuity of CVN to associate with multiple glycosylation sites in gp120 and its multivalency limit current understanding of the molecular arrangement of the DAVEI molecules on trimeric spike...
January 17, 2018: Biochemical Journal
Sergio Ita, Alison K Hill, Evan C Lam, Fay J Dufort, Xiao Yang, Ruchi Newman, Sivan Leviyang, Ismael B Fofana, Welkin E Johnson
Primate lentiviruses, including the human and simian immunodeficiency viruses (HIV and SIV), produce infections marked by persistent, ongoing viral replication. This occurs despite the presence of virus-specific adaptive immune responses, including antibodies targeting the viral envelope glycoprotein (Env), and evolution of antibody-escape variants is a well-documented feature of lentiviral infection. Here, we examined the evolutionary dynamics of the SIV env gene during early infection (≤ 29 weeks post-infection) in a cohort of four SIVmac251-infected rhesus macaques...
January 17, 2018: Journal of Virology
Xiyuan Wu, Zixuan Liu, Xiaohui Ding, Danwei Yu, Huamian Wei, Bo Qin, Yuanmei Zhu, Huihui Chong, Sheng Cui, Yuxian He
SC29EK is an electronically constrained α-helical peptide HIV-1 fusion inhibitor highly effective against both wild-type and enfuvirtide (T20)-resistant viruses. In this study, we focused on investigating the mechanism of HIV-1 resistance to SC29EK by two approaches. First, SC29EK-escaping HIV-1 variants were selected and characterized. Three mutant viruses, which possessed two (E43K/E49A) or three (Q39R/N43K/N126K, N43K/E49A/N126K) amino acid substitutions in the N- and C-terminal repeat regions of gp41 were identified as conferring high resistance to SC29EK and cross-resistance to the first-generation (T20, C34) and newly-designed (sifuvirtide, MT-SC29EK, 2P23) fusion inhibitors...
January 10, 2018: Journal of Virology
Alexis Kafando, Eric Fournier, Bouchra Serhir, Christine Martineau, Florence Doualla-Bell, Mohamed Ndongo Sangaré, Mohamed Sylla, Annie Chamberland, Mohamed El-Far, Hugues Charest, Cécile L Tremblay
Identifying recent HIV-1 infections is crucial for monitoring HIV-1 incidence and optimizing public health prevention efforts. To identify recent HIV-1 infections, we evaluated and compared the performance of 4 sequence-based diversity measures including percent diversity, percent complexity, Shannon entropy and number of haplotypes targeting 13 genetic segments within the env gene of HIV-1. A total of 597 diagnostic samples obtained in 2013 and 2015 from recently and chronically HIV-1 infected individuals were selected...
2017: PloS One
Johannes S Gach, Margaux Bouzin, Marcus P Wong, Veronika Chromikova, Andrea Gorlani, Kuan-Ting Yu, Brijesh Sharma, Enrico Gratton, Donald N Forthal
Fc gamma receptor (FcyR)-mediated antibody functions play a crucial role in preventing HIV infection. One such function, antibody-dependent phagocytosis (ADP), is thought to be involved in controlling other viral infections, but its role in HIV infection is unknown. We measured the ability of HIV-specific polyclonal and monoclonal antibodies (mAbs) to mediate the internalization of HIV-1 virions and HIV-1-decorated cells by phagocytes. To measure ADP of virions, we primarily used a green-fluorescent protein-expressing molecular clone of HIV-1JRFL, an R5, clinical isolate, in combination with polyclonal HIVIG or mAbs known to capture and/or neutralize HIV-1...
December 27, 2017: PLoS Pathogens
Sai Chaitanya Chiliveri, John M Louis, Rodolfo Ghirlando, James L Baber, Ad Bax
Cryo-electron microscopy and X-ray crystallography have shown that the pre- and post-fusion states of the HIV-1 gp41 viral coat protein, although very different from one another, each adopt C3 symmetric structures. A stable homotrimeric structure for the transmembrane domain (TM) also was modeled and supported by experimental data. For a C3 symmetric structure, alignment in an anisotropic medium must be axially symmetric, with the unique axis of the alignment tensor coinciding with the C3 axis. However, NMR residual dipolar couplings (RDCs) measured under three different alignment conditions were found to be incompatible with C3 symmetry...
December 26, 2017: Journal of the American Chemical Society
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"