scholarly journals A recombinant gp145 Env glycoprotein from HIV-1 expressed in two different cell lines: Effects on glycosylation and antigenicity

PLoS ONE ◽  
2020 ◽  
Vol 15 (6) ◽  
pp. e0231679
Author(s):  
José A. González-Feliciano ◽  
Pearl Akamine ◽  
Coral M. Capó-Vélez ◽  
Manuel Delgado-Vélez ◽  
Vincent Dussupt ◽  
...  
Keyword(s):  
Hiv 1 ◽  
2020 ◽  
Vol 94 (7) ◽  
Author(s):  
Shixia Wang ◽  
Yegor Voronin ◽  
Peng Zhao ◽  
Mayumi Ishihara ◽  
Nickita Mehta ◽  
...  

ABSTRACT Envelope (Env) glycoprotein of human immunodeficiency virus type 1 (HIV-1) is an important target for the development of an HIV vaccine. Extensive glycosylation of Env is an important feature that both protects the virus from antibody responses and serves as a target for some highly potent broadly neutralizing antibodies. Therefore, analysis of glycans on recombinant Env proteins is highly significant. Here, we present glycosylation profiles of recombinant gp120 proteins from four major clades of HIV-1 (A, B, C, and AE), produced either as research-grade material in 293 and CHO cells or as two independent lots of clinical material under good manufacturing practice (GMP) conditions. Almost all potential N-linked glycosylation sites were at least partially occupied in all proteins. The occupancy rates were largely consistent among proteins produced under different conditions, although a few sites showed substantial variability even between the two GMP lots. Our data confirmed previous studies in the field, showing an abundance of oligomannose on Env protein, with 40 to 50% of glycans being Man5 to Man9 on all four proteins under all production conditions. Overall, the differences in occupancy and glycan forms among different Env subtypes produced under different conditions were less dramatic than anticipated, and antigenicity analysis with a panel of six monoclonal antibodies, including antibodies that recognize glycan forms, showed that all four gp120s maintained their antibody-binding profiles. Such findings have major implications for the final production of a clinical HIV vaccine with Env glycoprotein components. IMPORTANCE HIV-1 Env protein is a major target for the development of an HIV-1 vaccine. Env is covered with a large number of sugar-based glycan forms; about 50% of the Env molecular weight is composed of glycans. Glycan analysis of recombinant Env is important for understanding its roles in viral pathogenesis and immune responses. The current report presents the first extensive comparison of glycosylation patterns of recombinant gp120 proteins from four major clades of HIV-1 produced in two different cell lines, grown either under laboratory conditions or at 50-liter GMP scale in different lots. Information learned in this study is valuable for the further design and production of HIV-1 Env proteins as the critical components of HIV-1 vaccine formulations.


2001 ◽  
Vol 75 (17) ◽  
pp. 7944-7955 ◽  
Author(s):  
Noriko Nakajima ◽  
Richard Lu ◽  
Alan Engelman

ABSTRACT Functional retroviral integrase protein is thought to be essential for productive viral replication. Yet, previous studies differed on the extent to which integrase mutant viruses expressed human immunodeficiency virus type 1 (HIV-1) genes from unintegrated DNA. Although one reason for this difference was that class II integrase mutations pleiotropically affected the viral life cycle, another reason apparently depended on the identity of the infected cell. Here, we analyzed integrase mutant viral infectivities in a variety of cell types. Single-round infectivity of class I integration-specific mutant HIV-1 ranged from <0.03 to 0.3% of that of the wild type (WT) across four different T-cell lines. Based on this approximately 10-fold influence of cell type on mutant gene expression, we examined class I and class II mutant replication kinetics in seven different cell lines and two primary cell types. Unexpectedly, some cell lines supported productive class I mutant viral replication under conditions that restricted class II mutant growth. Cells were defined as permissive, semipermissive, or nonpermissive based on their ability to support the continual passage of class I integration-defective HIV-1. Mutant infectivity in semipermissive and permissive cells as quantified by 50% tissue culture infectious doses, however, was only 0.0006 to 0.005% of that of WT. Since the frequencies of mutant DNA recombination in these lines ranged from 0.023 to <0.093% of the WT, we conclude that productive replication in the absence of integrase function most likely required the illegitimate integration of HIV-1 into host chromosomes by cellular DNA recombination enzymes.


Oncogene ◽  
2002 ◽  
Vol 21 (30) ◽  
pp. 4613-4625 ◽  
Author(s):  
Karuppiah Muthumani ◽  
Donghui Zhang ◽  
Daniel S Hwang ◽  
Sagar Kudchodkar ◽  
Nathanael S Dayes ◽  
...  

2008 ◽  
Vol 89 (3) ◽  
pp. 356-361 ◽  
Author(s):  
C. GRYLLIS ◽  
M. A. WAINBERG ◽  
Z. BENTWICH ◽  
M. GORNITSKY ◽  
B. G. BRENNER
Keyword(s):  
Hiv 1 ◽  

2017 ◽  
Author(s):  
◽  
Obiaara Ukah

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The Human Immunodeficiency Virus Type-1 (HIV-1) is the etiological agent of Acquired Immunodeficiency Syndrome, a disease that causes the host to succumb to secondary infections. There is currently no cure for HIV-1 infection, but Highly Active Anti-Retroviral Therapy (HAART) can bring the viral load in patients down to undetectable levels in the blood (less than 50 copies/mL). Furthermore, when the minimal limit of detection has been reached and the patient stops HAART, the viral load in the blood increases at an exponential rate due to the reactivation of latent HIV-1 infected cells that evaded HAART. Ongoing efforts focus on the eradication of HIV-1 by the development of potent latency reversing agents (LRAs) that can successfully reactivate latently infected cells, and of antivirals that can effectively inhibit re-establishment of infection post reactivation. This dissertation focuses on the evaluations of 2 classes of HIV-1 drugs, Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs), and LRAs, to better understand the mechanisms by which each drug class inhibits and reactivates HIV-1 replication respectively, to aid in the effort towards the development of antivirals that will lead to HIV-1 eradication. Chapter II describes the inhibitory mechanisms of NNRTIs using biochemical methods, which may further explain the differences in potency among drugs of this class. In addition, we explain how changes in the position of HIV-1 RT in the DNA substrate sequence, and the nucleotide terminating the primer 3'-end have a significant effect on the polymerase properties of the enzyme. We demonstrate that there are NNRTI- and site-dependent differences in the potency of NNRTIs, which is demonstrated by the repositioning, or lack there of, of the primer 3'-end of DNA/DNA substrates from the polymerase active site. This is further supported by the efficiency of dNTP or NRTI incorporation in the presence of NNRTI with multiple DNA/DNA substrates, which are representative of different sites in the template sequence. We also show that there are site-dependent differences in the polymerase properties of RT, which is demonstrated by rate of dNTP incorporation and incorporation efficiency at different sites in the template sequence. Chapter III describes the various effects of different types of LRAs, such as histone deacetylase inhibitors and histone methyltransferase inhibitors, on the dynamics of HIV-1 latency reversal in latent cell lines. Here, we demonstrate the use of branched DNA in situ hybridization in combination with immunocytochemistry to study the kinetics and dynamics of latency reversal in various latent cell lines. This technique is augmented with the use of automated screening using microscopy and flow cytometry to quickly detect different populations of latent and reactivated proviruses in thousands of cells in a short amount of time. Understanding the mechanisms by which a drug affects a biological process is important for establishing drug efficacy. Such information can influence what modifications are added to, or removed from drugs, which can cause a change in drug potency. This dissertation outlines assays used to evaluate the mechanisms of various drugs, and the influence of these drugs on the dynamics of HIV-1 replication. It is our hope that the work presented here will help progress efforts to eradicate HIV-1 infection.


1993 ◽  
Vol 9 (2) ◽  
pp. 167-174 ◽  
Author(s):  
MAHESH PATEL ◽  
MASAKI YANAGISHITA ◽  
GREGORY RODERIQUEZ ◽  
DUMITH CHEQUER BOU-HABIB ◽  
TAMAS ORAVECZ ◽  
...  

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