MPER-specific antibodies induce gp120 shedding and irreversibly neutralize HIV-1

Interference with virus entry is known to be the principle mechanism of HIV neutralization by antibodies, including 2F5 and 4E10, which bind to the membrane-proximal external region (MPER) of the gp41 envelope protein. However, to date, the precise molecular events underlying neutralization by MPER-specific antibodies remain incompletely understood. In this study, we investigated the capacity of these antibodies to irrevocably sterilize HIV virions. Long-term effects of antibodies on virions can differ, rendering neutralization either reversible or irreversible. MPER-specific antibodies irreversibly neutralize virions, and this capacity is associated with induction of gp120 shedding. Both processes have similar thermodynamic properties and slow kinetics requiring several hours. Antibodies directed to the CD4 binding site, V3 loop, and the MPER can induce gp120 shedding, and shedding activity is detected with high frequency in plasma from patients infected with divergent genetic HIV-1 subtypes. Importantly, as we show in this study, induction of gp120 shedding is closely associated with MPER antibody inhibition, constituting either a primary event leading to virion neutralization or representing an immediate consequence thereof, and thus needs to be factored into the mechanistic processes underlying their activity.

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Neutralization of genetically diverse HIV-1 strains by IgA antibodies to the gp120–CD4-binding site from long-term survivors of HIV infection

AIDS ◽

10.1097/qad.0b013e3283376e88 ◽

2010 ◽

Vol 24 (6) ◽

pp. 875-884 ◽

Cited By ~ 21

Author(s):

Stephanie Planque ◽

Maria Salas ◽

Yukie Mitsuda ◽

Marcin Sienczyk ◽

Miguel A Escobar ◽

...

Keyword(s):

Hiv Infection ◽

Binding Site ◽

Iga Antibodies ◽

Cd4 Binding Site ◽

Long Term Survivors ◽

Hiv 1

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Long-term effects of HIV-1 protease inhibitors on insulin secretion and insulin signaling in INS-1 beta cells

Journal of Endocrinology ◽

10.1677/joe.1.05620 ◽

2004 ◽

Vol 183 (3) ◽

pp. 445-454 ◽

Cited By ~ 36

Author(s):

M Schütt ◽

J Zhou ◽

M Meier ◽

H H Klein

Keyword(s):

Insulin Secretion ◽

Protease Inhibitors ◽

Beta Cells ◽

Insulin Signaling ◽

Cell Function ◽

Long Term Effects ◽

Akt Phosphorylation ◽

Glucose Stimulated Insulin Secretion ◽

Hiv 1

The mechanism by which chronic treatment with HIV (human immunodeficiency virus)-1 protease inhibitors leads to a deterioration of glucose metabolism appears to involve insulin resistance, and may also involve impaired insulin secretion. Here we investigated the long-term effects of HIV-1 protease inhibitors on glucose-stimulated insulin secretion from beta cells and explored whether altered insulin secretion might be related to altered insulin signaling. INS-1 cells were incubated for 48 h with different concentrations of amprenavir, indinavir, nelfinavir, ritonavir or saquinavir, stimulated with 20 mM d-glucose, and insulin determined in the supernatant. To evaluate insulin signaling, cells were stimulated with 100 nM insulin for 2 min, and insulin-receptor substrate (IRS)-1, -2 and Akt phosphorylation determined. Incubation for 48 h with ritonavir, nelfinavir and saquinavir resulted in impaired glucose-induced insulin secretion at 2.5, 5 and 5 μM respectively, whereas amprenavir or indinavir had no effects even at 20 and 100 μM respectively. The impaired insulin secretion by ritonavir, nelfinavir and saquinavir was associated with decreased insulin-stimulated IRS-2 phosphorylation, and, for nelfinavir and saquinavir, with decreased insulin-stimulated IRS-1 and Thr308-Akt phosphorylation. No such effects on signaling were observed with amprenavir or indinavir. In conclusion, certain HIV-1 protease inhibitors, such as ritonavir, nelfinavir and saquinavir, not only induce peripheral insulin resistance, but also impair glucose-stimulated insulin secretion from beta cells. With respect to the long-term effect on beta-cell function there appear to be differences between the protease inhibitors that may be clinically relevant. Finally, these effects on insulin secretion after a 48 h incubation with protease inhibitor were associated with a reduction of the insulin-stimulated phosphorylation of insulin signaling parameters, particularly IRS-2, suggesting that protease inhibitor-induced alterations in the insulin signaling pathway may contribute to the impaired beta-cell function.

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Erratum: Corrigendum: The differential short- and long-term effects of HIV-1 latency-reversing agents on T cell function

Scientific Reports ◽

10.1038/srep34430 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 2

Author(s):

G. Clutton ◽

Y. Xu ◽

P. L. Baldoni ◽

K. R. Mollan ◽

J. Kirchherr ◽

...

Keyword(s):

T Cell ◽

Cell Function ◽

Long Term Effects ◽

T Cell Function ◽

Short And Long Term ◽

Hiv 1 ◽

Reversing Agents

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Long-term effects of protease-inhibitor-based combination therapy on CD4 T-cell recovery in HIV-1-infected children and adolescents

The Lancet ◽

10.1016/s0140-6736(03)15098-2 ◽

2003 ◽

Vol 362 (9401) ◽

pp. 2045-2051 ◽

Cited By ~ 48

Author(s):

Chang-Heok Soh ◽

James M Oleske ◽

Michael T Brady ◽

Stephen A Spector ◽

William Borkowsky ◽

...

Keyword(s):

T Cell ◽

Combination Therapy ◽

Protease Inhibitor ◽

Children And Adolescents ◽

Cd4 T Cell ◽

Long Term Effects ◽

Cell Recovery ◽

Hiv 1

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SOSIP trimer-specific antibodies isolated from a SHIV-infected monkey with versus without a pre-blocking step with gp41

Journal of Virology ◽

10.1128/jvi.01582-21 ◽

2021 ◽

Author(s):

Natasha N. Duggan ◽

Kim L. Weisgrau ◽

Diogo M. Magnani ◽

Eva G. Rakasz ◽

Ronald C. Desrosiers ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Mononuclear Cells ◽

Broadly Neutralizing Antibodies ◽

Peripheral Blood Mononuclear ◽

Specific Antibodies ◽

Neutralizing Activity ◽

Infected Monkey ◽

External Domain ◽

Hiv 1

BG505 SOSIP.664 (hereafter referred to as SOSIP), a stabilized trimeric mimic of the HIV-1 envelope spike resembling the native viral spike, is a useful tool for isolating anti-HIV-1 neutralizing antibodies. We screened long-term SHIV-AD8 infected rhesus monkeys for potency and breadth of serum neutralizing activity against autologous and heterologous viruses: SHIV-AD8, HIV-1 YU2, HIV-1 JR-CSF, and HIV-1 NL4-3. Monkey rh2436 neutralized all viruses tested and showed strong reactivity to the SOSIP trimer, suggesting this was a promising candidate for attempts at monoclonal antibody (mAb) isolation. Monoclonal antibodies were isolated by performing single B-cell sorts from peripheral blood mononuclear cells (PBMC) by FACS using the SOSIP trimer as a probe. An initial round of sorted cells revealed the majority of isolated mAbs were directed to the gp41 external domain portion of the SOSIP trimer and were mostly non-neutralizing against tested isolates. A second sort was performed, introducing a gp41 blocking step prior to PBMC staining and FACS sorting. These isolated mAbs bound SOSIP trimer but were no longer directed to the gp41 external domain portion. A significantly higher proportion of mAbs with neutralizing activity were obtained with this strategy. Our data show this pre-blocking step with gp41 greatly increases the yield of non-gp41 reactive, SOSIP- specific mAbs and increases the likelihood of isolating mAbs with neutralizing activity. Importance Recent advancements in the field have focused on the isolation and use of broadly neutralizing antibodies for both prophylaxis and therapy. Finding a useful probe to isolate broad potent neutralizing antibodies while avoiding non-neutralizing antibodies is important. The SOSIP trimer has been shown to be a great tool for this purpose because it binds known broadly neutralizing antibodies. However, the SOSIP trimer can isolate non-neutralizing antibodies as well, including gp41-specific mAbs. Introducing a pre-blocking step with gp41 recombinant protein decreased the percent of gp41-specific antibodies isolated with SOSIP probe, as well as increased the number of neutralizing antibodies isolated. This method could be used as a tool to increase the chances of isolating neutralizing antibodies.

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Neutralization of genetically diverse HIV-1 strains by IgA antibodies to the gp-120-CD4-binding site from long-term survivors of HIV infection

AIDS ◽

10.1097/qad.0b013e328346bef5 ◽

2011 ◽

Vol 25 (10) ◽

pp. 1345-1346

Author(s):

&NA;

Keyword(s):

Hiv Infection ◽

Binding Site ◽

Gp 120 ◽

Iga Antibodies ◽

Cd4 Binding Site ◽

Long Term Survivors ◽

Hiv 1

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Structure of an N276-Dependent HIV-1 Neutralizing Antibody Targeting a Rare V5 Glycan Hole Adjacent to the CD4 Binding Site

Journal of Virology ◽

10.1128/jvi.01357-16 ◽

2016 ◽

Vol 90 (22) ◽

pp. 10220-10235 ◽

Cited By ~ 16

Author(s):

Constantinos Kurt Wibmer ◽

Jason Gorman ◽

Colin S. Anthony ◽

Nonhlanhla N. Mkhize ◽

Aliaksandr Druz ◽

...

Keyword(s):

B Cell ◽

Binding Site ◽

Deep Sequencing ◽

Neutralizing Antibodies ◽

Broadly Neutralizing Antibodies ◽

Specific Antibodies ◽

Founder Virus ◽

Cd4 Binding Site ◽

Hiv 1 ◽

Transmitted Founder Virus

ABSTRACT All HIV-1-infected individuals develop strain-specific neutralizing antibodies to their infecting virus, which in some cases mature into broadly neutralizing antibodies. Defining the epitopes of strain-specific antibodies that overlap conserved sites of vulnerability might provide mechanistic insights into how broadly neutralizing antibodies arise. We previously described an HIV-1 clade C-infected donor, CAP257, who developed broadly neutralizing plasma antibodies targeting an N276 glycan-dependent epitope in the CD4 binding site. The initial CD4 binding site response potently neutralized the heterologous tier 2 clade B viral strain RHPA, which was used to design resurfaced gp120 antigens for single-B-cell sorting. Here we report the isolation and structural characterization of CAP257-RH1, an N276 glycan-dependent CD4 binding site antibody representative of the early CD4 binding site plasma response in donor CAP257. The cocrystal structure of CAP257-RH1 bound to RHPA gp120 revealed critical interactions with the N276 glycan, loop D, and V5, but not with aspartic acid 368, similarly to HJ16 and 179NC75. The CAP257-RH1 monoclonal antibody was derived from the immunoglobulin-variable IGHV3-33 and IGLV3-10 genes and neutralized RHPA but not the transmitted/founder virus from donor CAP257. Its narrow neutralization breadth was attributed to a binding angle that was incompatible with glycosylated V5 loops present in almost all HIV-1 strains, including the CAP257 transmitted/founder virus. Deep sequencing of autologous CAP257 viruses, however, revealed minority variants early in infection that lacked V5 glycans. These glycan-free V5 loops are unusual holes in the glycan shield that may have been necessary for initiating this N276 glycan-dependent CD4 binding site B-cell lineage. IMPORTANCE The conserved CD4 binding site on gp120 is a major target for HIV-1 vaccine design, but key events in the elicitation and maturation of different antibody lineages to this site remain elusive. Studies have shown that strain-specific antibodies can evolve into broadly neutralizing antibodies or in some cases act as helper lineages. Therefore, characterizing the epitopes of strain-specific antibodies may help to inform the design of HIV-1 immunogens to elicit broadly neutralizing antibodies. In this study, we isolate a narrowly neutralizing N276 glycan-dependent antibody and use X-ray crystallography and viral deep sequencing to describe how gp120 lacking glycans in V5 might have elicited these early glycan-dependent CD4 binding site antibodies. These data highlight how glycan holes can play a role in the elicitation of B-cell lineages targeting the CD4 binding site.

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