HIV-1-Specific IgA Monoclonal Antibodies from an HIV-1 Vaccinee Mediate Galactosylceramide Blocking and Phagocytosis

ABSTRACTVaccine-elicited humoral immune responses comprise an array of antibody forms and specificities, with only a fraction contributing to protective host immunity. Elucidation of antibody effector functions responsible for protective immunity against human immunodeficiency virus type 1 (HIV-1) acquisition is a major goal for the HIV-1 vaccine field. Immunoglobulin A (IgA) is an important part of the host defense against pathogens; however, little is known about the role of vaccine-elicited IgA and its capacity to mediate antiviral functions. To identify the antiviral functions of HIV-1-specific IgA elicited by vaccination, we cloned HIV-1 envelope-specific IgA monoclonal antibodies (MAbs) by memory B cell cultures from peripheral blood mononuclear cells from an RV144 vaccinee and produced two IgA clonal cell lines (HG129 and HG130) producing native, nonrecombinant IgA MAbs. The HG129 and HG130 MAbs mediated phagocytosis by monocytes, and HG129 blocked HIV-1 Env glycoprotein binding to galactosylceramide, an alternative HIV-1 receptor. These findings elucidate potential antiviral functions of vaccine-elicited HIV-1 envelope-specific IgA that may act to block HIV-1 acquisition at the portal of entry by preventing HIV-1 binding to galactosylceramide and mediating antibody Fc receptor-mediated virion phagocytosis. Furthermore, these findings highlight the complex and diverse interactions of vaccine-elicited IgA with pathogens that depend on IgA fine specificity and form (e.g., multimeric or monomeric) in the systemic circulation and mucosal compartments.IMPORTANCEHost-pathogen interactionsin vivoinvolve numerous immune mechanisms that can lead to pathogen clearance. Understanding the nature of antiviral immune mechanisms can inform the design of efficacious HIV-1 vaccine strategies. Evidence suggests that both neutralizing and nonneutralizing antibodies can mediate some protection against HIV in animal models. Although numerous studies have characterized the functional properties of HIV-1-specific IgG, more studies are needed on the functional attributes of HIV-1-specific IgA, specifically for vaccine-elicited IgA. Characterization of the functional properties of HIV-1 Env-specific IgA monoclonal antibodies from human vaccine clinical trials are critical toward understanding the capacity of the host immune response to block HIV-1 acquisition.

Download Full-text

Anti-phospholipid human monoclonal antibodies inhibit CCR5-tropic HIV-1 and induce β-chemokines

Journal of Experimental Medicine ◽

10.1084/jem.20091281 ◽

2010 ◽

Vol 207 (4) ◽

pp. 763-776 ◽

Cited By ~ 40

Author(s):

M. Anthony Moody ◽

Hua-Xin Liao ◽

S. Munir Alam ◽

Richard M. Scearce ◽

M. Kelly Plonk ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Peripheral Blood Mononuclear Cells ◽

Peripheral Blood ◽

Mononuclear Cells ◽

Virus Entry ◽

Human Monoclonal Antibodies ◽

Peripheral Blood Mononuclear ◽

Blood Mononuclear Cells ◽

Hiv 1

Traditional antibody-mediated neutralization of HIV-1 infection is thought to result from the binding of antibodies to virions, thus preventing virus entry. However, antibodies that broadly neutralize HIV-1 are rare and are not induced by current vaccines. We report that four human anti-phospholipid monoclonal antibodies (mAbs) (PGN632, P1, IS4, and CL1) inhibit HIV-1 CCR5-tropic (R5) primary isolate infection of peripheral blood mononuclear cells (PBMCs) with 80% inhibitory concentrations of <0.02 to ∼10 µg/ml. Anti-phospholipid mAbs inhibited PBMC HIV-1 infection in vitro by mechanisms involving binding to monocytes and triggering the release of MIP-1α and MIP-1β. The release of these β-chemokines explains both the specificity for R5 HIV-1 and the activity of these mAbs in PBMC cultures containing both primary lymphocytes and monocytes.

Download Full-text

Derivation of simian tropic HIV-1 infectious clone reveals virus adaptation to a new host

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1818059116 ◽

2019 ◽

Vol 116 (21) ◽

pp. 10504-10509 ◽

Cited By ~ 4

Author(s):

Fabian Schmidt ◽

Brandon F. Keele ◽

Gregory Q. Del Prete ◽

Dennis Voronin ◽

Christine M. Fennessey ◽

...

Keyword(s):

Mononuclear Cells ◽

Infectious Clone ◽

Host Protein ◽

Peripheral Blood Mononuclear ◽

New Host ◽

Species Specific ◽

Hiv 1 ◽

Pigtail Macaques

To replicate in a new host, lentiviruses must adapt to exploit required host factors and evade species-specific antiviral proteins. Understanding how host protein variation drives lentivirus adaptation allowed us to expand the host range of HIV-1 to pigtail macaques. We have previously derived a viral swarm (in the blood of infected animals) that can cause AIDS in this new host. To further exploit this reagent, we generated infectious molecular clones (IMCs) from the viral swarm. We identified clones with high replicative capacity in pigtail peripheral blood mononuclear cells (PBMC) in vitro and used in vivo replication to select an individual IMC, named stHIV-A19 (for simian tropic HIV-1 clone A19), which recapitulated the phenotype obtained with the viral swarm. Adaptation of HIV-1 in macaques led to the acquisition of amino acid changes in viral proteins, such as capsid (CA), that are rarely seen in HIV-1–infected humans. Using stHIV-A19, we show that these CA changes confer a partial resistance to the host cell inhibitor Mx2 from pigtail macaques, but that complete resistance is associated with a fitness defect. Adaptation of HIV-1 to a new host will lead to a more accurate animal model and a better understanding of virus–host interactions.

Download Full-text

Ebselen, a Small-Molecule Capsid Inhibitor of HIV-1 Replication

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02574-15 ◽

2016 ◽

Vol 60 (4) ◽

pp. 2195-2208 ◽

Cited By ~ 45

Author(s):

Suzie Thenin-Houssier ◽

Ian Mitchelle S. de Vera ◽

Laura Pedro-Rosa ◽

Angela Brady ◽

Audrey Richard ◽

...

Keyword(s):

High Throughput Screening ◽

Mononuclear Cells ◽

Screening Method ◽

Influenza Viruses ◽

Ionization Mass ◽

Peripheral Blood Mononuclear ◽

Immunodeficiency Virus ◽

Pharmacologically Active ◽

Hiv 1

ABSTRACTThe human immunodeficiency virus type 1 (HIV-1) capsid plays crucial roles in HIV-1 replication and thus represents an excellent drug target. We developed a high-throughput screening method based on a time-resolved fluorescence resonance energy transfer (HTS-TR-FRET) assay, using the C-terminal domain (CTD) of HIV-1 capsid to identify inhibitors of capsid dimerization. This assay was used to screen a library of pharmacologically active compounds, composed of 1,280in vivo-active drugs, and identified ebselen [2-phenyl-1,2-benzisoselenazol-3(2H)-one], an organoselenium compound, as an inhibitor of HIV-1 capsid CTD dimerization. Nuclear magnetic resonance (NMR) spectroscopic analysis confirmed the direct interaction of ebselen with the HIV-1 capsid CTD and dimer dissociation when ebselen is in 2-fold molar excess. Electrospray ionization mass spectrometry revealed that ebselen covalently binds the HIV-1 capsid CTD, likely via a selenylsulfide linkage with Cys198 and Cys218. This compound presents anti-HIV activity in single and multiple rounds of infection in permissive cell lines as well as in primary peripheral blood mononuclear cells. Ebselen inhibits early viral postentry events of the HIV-1 life cycle by impairing the incoming capsid uncoating process. This compound also blocks infection of other retroviruses, such as Moloney murine leukemia virus and simian immunodeficiency virus, but displays no inhibitory activity against hepatitis C and influenza viruses. This study reports the use of TR-FRET screening to successfully identify a novel capsid inhibitor, ebselen, validating HIV-1 capsid as a promising target for drug development.

Download Full-text

Drug Combination of AZT and ddl: Synergism of Action and Prevention of Appearance of AZT-Resistance

Antiviral Chemistry and Chemotherapy ◽

10.1177/095632029400500108 ◽

1994 ◽

Vol 5 (1) ◽

pp. 51-55 ◽

Cited By ~ 6

Author(s):

G. Antonelli ◽

F. Dianzani ◽

D. Bellarosa ◽

O. Turriziani ◽

E. Riva ◽

...

Keyword(s):

In Vitro Selection ◽

Mononuclear Cells ◽

Peripheral Blood Mononuclear ◽

Immunodeficiency Virus ◽

Resistant Strains ◽

Azt Resistance ◽

Hiv 1

Both 3′-azido-3′-deoxythymidine (AZT) and 2′,3′-dideoxynosine (ddl) strongly inhibit the replication of human immunodeficiency virus type 1 (HIV-1). Here, it is shown that combination of AZT and ddl at concentrations that are readily achievable in vivo synergistically inhibit HIV-1 replication in C8166 cells and peripheral blood mononuclear cells. The synergism is significant even when the effect of AZT and ddl alone was negligible. Our findings show that AZT-resistance is less likely to occur when a combination of AZT and ddl is used. Particularly, generation of AZT-resistant strains by in vitro selection is prevented, or delayed, by the combination of AZT plus ddl. Taken together these observations provide a rationale for combination of AZT and ddl in the therapy of AIDS patients.

Download Full-text

Genotypic Correlates of Phenotypic Resistance to Efavirenz in Virus Isolates from Patients Failing Nonnucleoside Reverse Transcriptase Inhibitor Therapy

Journal of Virology ◽

10.1128/jvi.75.11.4999-5008.2001 ◽

2001 ◽

Vol 75 (11) ◽

pp. 4999-5008 ◽

Cited By ~ 162

Author(s):

Lee Bacheler ◽

Susan Jeffrey ◽

George Hanna ◽

Richard D'Aquila ◽

Lany Wallace ◽

...

Keyword(s):

Reverse Transcriptase ◽

Mononuclear Cells ◽

Site Directed Mutagenesis ◽

Cross Resistance ◽

Peripheral Blood Mononuclear ◽

In Vitro Susceptibility ◽

Virus Isolates ◽

Hiv 1

ABSTRACT Efavirenz (also known as DMP 266 or SUSTIVA) is a potent nonnucleoside inhibitor of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) activity and of HIV-1 replication in vitro and in vivo. Most patients on efavirenz-containing regimens have sustained antiviral responses; however, rebounds in plasma viral load have been observed in some patients in association with the emergence of mutant strains of HIV-1. Virus isolates from the peripheral blood mononuclear cells (PBMCs) of patients with such treatment failures, as well as recombinant viruses incorporating viral sequences derived from patient plasma, show reduced in vitro susceptibility to efavirenz in association with mutations in the RT gene encoding K103N, Y188L, or G190S/E substitutions. Patterns of RT gene mutations and in vitro susceptibility were similar in plasma virus and in viruses isolated from PBMCs. Variant strains of HIV-1 constructed by site-directed mutagenesis confirmed the role of K103N, G190S, and Y188L substitutions in reduced susceptibility to efavirenz. Further, certain secondary mutations (V106I, V108I, Y181C, Y188H, P225H, and F227L) conferred little resistance to efavirenz as single mutations but enhanced the level of resistance of viruses carrying these mutations in combination with K103N or Y188L. Viruses with K103N or Y188L mutations, regardless of the initial selecting nonnucleoside RT inhibitor (NNRTI), exhibited cross-resistance to all of the presently available NNRTIs (efavirenz, nevirapine, and delavirdine). Some virus isolates from nevirapine or delavirdine treatment failures that lacked K103N or Y188L mutations remained susceptible to efavirenz in vitro, although the clinical significance of this finding is presently unclear.

Download Full-text

Antibody-targeted MHC complex–directed expansion of HIV-1– and KSHV-specific CD8+ lymphocytes: a new approach to therapeutic vaccination

Blood ◽

10.1182/blood-2003-09-3023 ◽

2004 ◽

Vol 103 (5) ◽

pp. 1791-1795 ◽

Cited By ~ 11

Author(s):

Justin Stebbing ◽

Brian Gazzard ◽

Steve Patterson ◽

Mark Bower ◽

Dhayaneethie Perumal ◽

...

Keyword(s):

T Lymphocytes ◽

Mononuclear Cells ◽

Ex Vivo ◽

Kaposi Sarcoma ◽

Human Leukocyte ◽

Clinical Value ◽

Peripheral Blood Mononuclear ◽

Cd8 T Lymphocytes ◽

Hiv 1

AbstractThe ability of therapeutic vaccines to generate large numbers of CD8+ T lymphocytes that have specificity for HIV-1 or other virally infected cells has enormous potential clinical value. However, approaches to produce cytotoxic T lymphocytes (CTLs) in vivo via vaccine technology have thus far been disappointing and the ex vivo production of cells for adoptive transfer is labor intensive and expensive. We describe the results of a 2-step antibody-targeting system for the production of CD8+ T lymphocytes specific for HIV-1 and Kaposi sarcoma–associated herpesvirus (KSHV), suitable for use in vivo. In 8 consecutive human leukocyte antigen–A2 (HLA-A2)–positive HIV-1–infected individuals with Kaposi sarcoma, 2 cycles of this system resulted in more than 1 Log increases of specific anti-HIV and anti-KSHV CD8+ lymphocytes. These expanded cells have an effector phenotype that includes the ability to produce interferon-γ and CD45Ra+/CD69+ staining. We have shown that antibody-targeted B cells can function as effective antigen-presenting molecules and lead to sustained specific T-lymphocyte expansion from peripheral blood mononuclear cells (PBMCs) of immunosuppressed individuals. This approach, which offers an easy and effective protocol for the amplification of specific antiviral and antitumor CTLs, may offer significant advances for in vivo T-cell immunotherapeutic protocols.

Download Full-text

Coreceptor Usage of Human Immunodeficiency Virus Type 2 Primary Isolates and Biological Clones Is Broad and Does Not Correlate with Their Syncytium-Inducing Capacities

Journal of Virology ◽

10.1128/jvi.72.7.6260-6263.1998 ◽

1998 ◽

Vol 72 (7) ◽

pp. 6260-6263 ◽

Cited By ~ 34

Author(s):

Christophe Guillon ◽

Marchina E. van der Ende ◽

Patrick H. M. Boers ◽

Rob A. Gruters ◽

Martin Schutten ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Mononuclear Cells ◽

Target Cells ◽

Coreceptor Usage ◽

Peripheral Blood Mononuclear ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT Entry of human immunodeficiency virus type 1 (HIV-1) into target cells is mediated by binding of the surface envelope glycoprotein to the CD4 molecule. Interaction of the resulting CD4-glycoprotein complex with α- or β-chemokine receptors, depending on the biological phenotype of the virus, then initiates the fusion process. Here, we show that primary HIV-2 isolates and biological clones, in contrast to those of HIV-1, may use a broad range of coreceptors, including CCR-1, CCR-3, CCR-5, and CXCR-4. The syncytium-inducing capacity of these viruses did not correlate with the ability to infect via CXCR-4 or any other coreceptor. One cell-free passage of the intermediate isolates in mitogen-stimulated, CD8+ cell-depleted peripheral blood mononuclear cells resulted in the outgrowth of variants with CCR-5 only, whereas the coreceptor usage of late and early isolates did not change. Since HIV-2 is less pathogenic in vivo than HIV-1, these data suggest that HIV pathogenicity in vivo is not directly related to the spectrum of coreceptors used in in vitro systems.

Download Full-text

Enhanced Cellular Immunity in Macaques following a Novel Peptide Immunotherapy

Journal of Virology ◽

10.1128/jvi.79.6.3748-3757.2005 ◽

2005 ◽

Vol 79 (6) ◽

pp. 3748-3757 ◽

Cited By ~ 23

Author(s):

S. Chea ◽

C. J. Dale ◽

R. De Rose ◽

I. A. Ramshaw ◽

S. J. Kent

Keyword(s):

T Cell ◽

Mononuclear Cells ◽

De Novo ◽

T Cell Responses ◽

Peripheral Blood Mononuclear ◽

Cell Responses ◽

Cell Immunity ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT Advances in treating and preventing AIDS depend on understanding how human immunodeficiency virus (HIV) is eliminated in vivo and on the manipulation of effective immune responses to HIV. During the development of assays quantifying the elimination of fluorescent autologous cells coated with overlapping 15-mer simian immunodeficiency virus (SIV) or HIV-1 peptides, we made a remarkable observation: the reinfusion of macaque peripheral blood mononuclear cells, or even whole blood, pulsed with SIV and/or HIV peptides generated sharply enhanced SIV- and HIV-1-specific T-cell immunity. Strong, broad CD4+- and CD8+-T-cell responses could be enhanced simultaneously against peptide pools spanning 87% of all SIV- and HIV-1-expressed proteins—highly desirable characteristics of HIV-specific immunity. De novo hepatitis C virus-specific CD4+- and CD8+-T-cell responses were generated in macaques by the same method. This simple technique holds promise for the immunotherapy of HIV and other chronic viral infections.

Download Full-text

High Levels of TRIM5a Are Associated with Xenophagy in HIV-1-Infected Long-Term Nonprogressors

Cells ◽

10.3390/cells10051207 ◽

2021 ◽

Vol 10 (5) ◽

pp. 1207

Author(s):

Fabiola Ciccosanti ◽

Marco Corazzari ◽

Rita Casetti ◽

Alessandra Amendola ◽

Diletta Collalto ◽

...

Keyword(s):

Mononuclear Cells ◽

Protective Role ◽

Antiretroviral Drugs ◽

Peripheral Blood Mononuclear ◽

Successful Control ◽

Special Subset ◽

Hiv 1

Autophagy is a lysosomal-dependent degradative mechanism essential in maintaining cellular homeostasis, but it is also considered an ancient form of innate eukaryotic fighting against invading microorganisms. Mounting evidence has shown that HIV-1 is a critical target of autophagy that plays a role in HIV-1 replication and disease progression. In a special subset of HIV-1-infected patients that spontaneously and durably maintain extremely low viral replication, namely, long-term nonprogressors (LTNP), the resistance to HIV-1-induced pathogenesis is accompanied, in vivo, by a significant increase in the autophagic activity in peripheral blood mononuclear cells. Recently, a new player in the battle of autophagy against HIV-1 has been identified, namely, tripartite motif protein 5α (TRIM5α). In vitro data demonstrated that TRIM5α directly recognizes HIV-1 and targets it for autophagic destruction, thus protecting cells against HIV-1 infection. In this paper, we analyzed the involvement of this factor in the control of HIV-1 infection through autophagy, in vivo, in LTNP. The results obtained showed significantly higher levels of TRIM5α expression in cells from LTNP with respect to HIV-1-infected normal progressor patients. Interestingly, the colocalization of TRIM5α and HIV-1 proteins in autophagic vacuoles in LTNP cells suggested the participation of TRIM5α in the autophagy containment of HIV-1 in LTNP. Altogether, our results point to a protective role of TRIM5α in the successful control of the chronic viral infection in HIV-1-controllers through the autophagy mechanism. In our opinion, these findings could be relevant in fighting against HIV-1 disease, because autophagy inducers might be employed in combination with antiretroviral drugs.

Download Full-text

Human Immunodeficiency Virus Type 1 Derivative with 7% Simian Immunodeficiency Virus Genetic Content Is Able To Establish Infections in Pig-Tailed Macaques

Journal of Virology ◽

10.1128/jvi.00960-07 ◽

2007 ◽

Vol 81 (20) ◽

pp. 11549-11552 ◽

Cited By ~ 43

Author(s):

Tatsuhiko Igarashi ◽

Ranjini Iyengar ◽

Russel A. Byrum ◽

Alicia Buckler-White ◽

Robin L. Dewar ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Simian Immunodeficiency Virus ◽

Human Immunodeficiency Virus Type ◽

Virus Type ◽

Mononuclear Cells ◽

Peripheral Blood Mononuclear ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT A human immunodeficiency virus type 1 (HIV-1) derivative (HIVNL-DT5R) containing sequences encoding a 7-amino-acid segment of CA and the entire vif gene from simian immunodeficiency virus (SIV) was previously shown to establish spreading infections in cultured macaque peripheral blood mononuclear cells. To assess its replicative and disease-inducing properties in vivo, HIVNL-DT5R was inoculated into pig-tailed macaques. HIVNL-DT5R generated plasma viremia in all five of the monkeys and elicited humoral responses against all of the HIV-1 structural proteins but did not cause CD4+ T-lymphocyte depletion or clinical disease. Additional adaptation will be required to optimize infectivity in vivo.

Download Full-text