scholarly journals Structure and Fc-Effector Function of Rhesusized Variants of Human Anti-HIV-1 IgG1s

2022 ◽  
Vol 12 ◽  
Author(s):  
William D. Tolbert ◽  
Dung N. Nguyen ◽  
Marina Tuyishime ◽  
Andrew R. Crowley ◽  
Yaozong Chen ◽  
...  
Keyword(s):  
A Priori ◽  
Conformational Epitope ◽  
Effector Function ◽  
Igg Subclass ◽  
Human Mabs ◽  
Loop Region ◽  
Dependent Cell ◽  
Env Antigens ◽  
Complementarity Determining Regions ◽  
Hiv 1

Passive transfer of monoclonal antibodies (mAbs) of human origin into Non-Human Primates (NHPs), especially those which function predominantly by a Fc-effector mechanism, requires an a priori preparation step, in which the human mAb is reengineered to an equivalent NHP IgG subclass. This can be achieved by changing both the Fc and Fab sequence while simultaneously maintaining the epitope specificity of the parent antibody. This Ab reengineering process, referred to as rhesusization, can be challenging because the simple grafting of the complementarity determining regions (CDRs) into an NHP IgG subclass may impact the functionality of the mAb. Here we describe the successful rhesusization of a set of human mAbs targeting HIV-1 envelope (Env) epitopes involved in potent Fc-effector function against the virus. This set includes a mAb targeting a linear gp120 V1V2 epitope isolated from a RV144 vaccinee, a gp120 conformational epitope within the Cluster A region isolated from a RV305 vaccinated individual, and a linear gp41 epitope within the immunodominant Cys-loop region commonly targeted by most HIV-1 infected individuals. Structural analyses confirm that the rhesusized variants bind their respective Env antigens with almost identical specificity preserving epitope footprints and most antigen-Fab atomic contacts with constant regions folded as in control RM IgG1s. In addition, functional analyses confirm preservation of the Fc effector function of the rhesusized mAbs including the ability to mediate Antibody Dependent Cell-mediated Cytotoxicity (ADCC) and antibody dependent cellular phagocytosis by monocytes (ADCP) and neutrophils (ADNP) with potencies comparable to native macaque antibodies of similar specificity. While the antibodies chosen here are relevant for the examination of the correlates of protection in HIV-1 vaccine trials, the methods used are generally applicable to antibodies for other purposes.

scholarly journals Development of antibody-dependent cell cytotoxicity function in HIV-1 antibodies

2020 ◽  
Author(s):  
Laura E. Doepker ◽  
Sonja Danon ◽  
Elias Harkins ◽  
Duncan Ralph ◽  
Zak Yaffe ◽  
...  
Keyword(s):  
Hiv Vaccine ◽  
Developmental Pathways ◽  
Antigen Binding ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
Adcc Activity ◽  
Sequencing Data ◽  
Protective Antibodies ◽  
Dependent Cell ◽  
Complementarity Determining Regions ◽  
Hiv 1

AbstractA prerequisite for the design of an HIV vaccine that elicits protective antibodies is understanding the developmental pathways that result in desirable antibody features. The development of antibodies that mediate antibody-dependent cellular cytotoxicity (ADCC) is particularly relevant because such antibodies have been associated with HIV protection in humans. We reconstructed the developmental pathways of six human HIV-specific ADCC antibodies using longitudinal antibody sequencing data. Most of the inferred naïve antibodies did not mediate detectable ADCC. Gain of antigen binding and ADCC function typically required mutations in complementarity determining regions of one or both chains. Enhancement of ADCC potency often required additional mutations in framework regions. Antigen binding affinity and ADCC activity were correlated, but affinity alone was not sufficient to predict ADCC potency. Thus, elicitation of human ADCC antibodies may require mutations that first enable high affinity antigen recognition, followed by mutations that optimize factors contributing to functional ADCC activity.

scholarly journals Development of antibody-dependent cell cytotoxicity function in HIV-1 antibodies

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Laura E Doepker ◽  
Sonja Danon ◽  
Elias Harkins ◽  
Duncan K Ralph ◽  
Zak Yaffe ◽  
...  
Keyword(s):  
Hiv Vaccine ◽  
Developmental Pathways ◽  
Antigen Binding ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
Adcc Activity ◽  
Sequencing Data ◽  
Protective Antibodies ◽  
Dependent Cell ◽  
Complementarity Determining Regions ◽  
Hiv 1

A prerequisite for the design of an HIV vaccine that elicits protective antibodies is understanding the developmental pathways that result in desirable antibody features. The development of antibodies that mediate antibody-dependent cellular cytotoxicity (ADCC) is particularly relevant because such antibodies have been associated with HIV protection in humans. We reconstructed the developmental pathways of six human HIV-specific ADCC antibodies using longitudinal antibody sequencing data. Most of the inferred naïve antibodies did not mediate detectable ADCC. Gain of antigen binding and ADCC function typically required mutations in complementarity determining regions of one or both chains. Enhancement of ADCC potency often required additional mutations in framework regions. Antigen binding affinity and ADCC activity were correlated, but affinity alone was not sufficient to predict ADCC potency. Thus, elicitation of broadly active ADCC antibodies may require mutations that enable high affinity antigen recognition along with mutations that optimize factors contributing to functional ADCC activity.

A novel EGFP-CEM-NKr flow cytometric method for measuring antibody dependent cell mediated-cytotoxicity (ADCC) activity in HIV-1 infected individuals

2006 ◽  
Vol 315 (1-2) ◽  
pp. 1-10 ◽  
Author(s):  
Wannee Kantakamalakul ◽  
Kovit Pattanapanyasat ◽  
Surat Jongrakthaitae ◽  
Vatcharain Assawadarachai ◽  
Silawun Ampol ◽  
...  
Keyword(s):  
Adcc Activity ◽  
Flow Cytometric Method ◽  
Flow Cytometric ◽  
Dependent Cell ◽  
Hiv 1

scholarly journals Novel compound inhibitors of HIV-1NL4-3 Vpu

2021 ◽  
Author(s):  
Carolyn A Robinson ◽  
Terri D Lyddon ◽  
Hwi Min Gil ◽  
David T. Evans ◽  
Yury V Kuzmichev ◽  
...  
Keyword(s):  
Host Cell ◽  
Particle Production ◽  
Viral Glycoprotein ◽  
New Class ◽  
Host Cell Proteins ◽  
Viral Particles ◽  
Dependent Cell ◽  
A Cell ◽  
Hiv 1

HIV-1 Vpu targets the host cell proteins CD4 and BST-2/Tetherin for degradation, ultimately resulting in enhanced virus spread and host immune evasion. The discovery and characterization of small molecules that antagonize Vpu would further elucidate the contribution of Vpu to pathogenesis and lay the foundation for the study of a new class of novel HIV-1 therapeutics. To identify novel compounds that block Vpu activity, we developed a cell-based 'gain of function' assay that produces a positive signal in response to Vpu inhibition. To develop this assay, we took advantage of the viral glycoprotein, GaLV Env. In the presence of Vpu, GaLV Env is not incorporated into viral particles, resulting in non-infectious virions. Vpu inhibition restores infectious particle production. Using this assay, a high throughput screen of >650,000 compounds was performed to identify inhibitors that block the biological activity of Vpu. From this screen, we identified several positive hits but focused on two compounds from one structural family, SRI-41897 and SRI-42371. It was conceivable that the compounds inhibited the formation of infectious virions by targeting host cell proteins instead of Vpu directly, so we developed independent counter-screens for off target interactions of the compounds and found no off target interactions. Additionally, these compounds block Vpu-mediated modulation of CD4, BST-2/Tetherin and antibody dependent cell-mediated toxicity (ADCC). Unfortunately, both SRI-41897 and SRI-42371 were shown to be specific to the N-terminal region of NL4-3 Vpu and did not function against other, more clinically relevant, strains of Vpu.

scholarly journals Knowns and Unknowns of Assaying Antibody-Dependent Cell-Mediated Cytotoxicity Against HIV-1

2019 ◽  
Vol 10 ◽  
Author(s):  
George K. Lewis ◽  
Margaret E. Ackerman ◽  
Gabriella Scarlatti ◽  
Christiane Moog ◽  
Marjorie Robert-Guroff ◽  
...  
Keyword(s):  
Dependent Cell ◽  
Hiv 1

scholarly journals Broad neutralization by a combination of antibodies recognizing the CD4 binding site and a new conformational epitope on the HIV-1 envelope protein

2012 ◽  
Vol 209 (8) ◽  
pp. 1469-1479 ◽  
Author(s):  
Florian Klein ◽  
Christian Gaebler ◽  
Hugo Mouquet ◽  
D. Noah Sather ◽  
Clara Lehmann ◽  
...  
Keyword(s):  
Binding Site ◽  
Envelope Protein ◽  
Neutralizing Antibodies ◽  
Conformational Epitope ◽  
Broadly Neutralizing Antibodies ◽  
Cd4 Binding Site ◽  
Capture Method ◽  
Anti Hiv ◽  
Hiv 1 ◽  
Viral Isolates

Two to three years after infection, a fraction of HIV-1–infected individuals develop serologic activity that neutralizes most viral isolates. Broadly neutralizing antibodies that recognize the HIV-1 envelope protein have been isolated from these patients by single-cell sorting and by neutralization screens. Here, we report a new method for anti–HIV-1 antibody isolation based on capturing single B cells that recognize the HIV-1 envelope protein expressed on the surface of transfected cells. Although far less efficient than soluble protein baits, the cell-based capture method identified antibodies that bind to a new broadly neutralizing epitope in the vicinity of the V3 loop and the CD4-induced site (CD4i). The new epitope is expressed on the cell surface form of the HIV-1 spike, but not on soluble forms of the same envelope protein. Moreover, the new antibodies complement the neutralization spectrum of potent broadly neutralizing anti-CD4 binding site (CD4bs) antibodies obtained from the same individual. Thus, combinations of potent broadly neutralizing antibodies with complementary activity can account for the breadth and potency of naturally arising anti–HIV-1 serologic activity. Therefore, vaccines aimed at eliciting anti–HIV-1 serologic breadth and potency should not be limited to single epitopes.

scholarly journals Small CD4 Mimetics Prevent HIV-1 Uninfected Bystander CD4 + T Cell Killing Mediated by Antibody-dependent Cell-mediated Cytotoxicity

EBioMedicine ◽  
2016 ◽  
Vol 3 ◽  
pp. 122-134 ◽  
Author(s):  
Jonathan Richard ◽  
Maxime Veillette ◽  
Shilei Ding ◽  
Daria Zoubchenok ◽  
Nirmin Alsahafi ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Killing ◽  
Cd4 T Cell ◽  
Dependent Cell ◽  
Hiv 1

scholarly journals Comparison of Antibody-Dependent Cell-Mediated Cytotoxicity and Virus Neutralization by HIV-1 Env-Specific Monoclonal Antibodies

2016 ◽  
Vol 90 (13) ◽  
pp. 6127-6139 ◽  
Author(s):  
Benjamin von Bredow ◽  
Juan F. Arias ◽  
Lisa N. Heyer ◽  
Brian Moldt ◽  
Khoa Le ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Rhesus Macaques ◽  
Virus Neutralization ◽  
Viral Neutralization ◽  
Immunodeficiency Virus ◽  
Dependent Cell ◽  
Antiviral Activities ◽  
Infected Cells ◽  
The Relationship ◽  
Hiv 1

ABSTRACTAlthough antibodies to the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein have been studied extensively for their ability to block viral infectivity, little data are currently available on nonneutralizing functions of these antibodies, such as their ability to eliminate virus-infected cells by antibody-dependent cell-mediated cytotoxicity (ADCC). HIV-1 Env-specific antibodies of diverse specificities, including potent broadly neutralizing and nonneutralizing antibodies, were therefore tested for ADCC against cells infected with a lab-adapted HIV-1 isolate (HIV-1NL4-3), a primary HIV-1 isolate (HIV-1JR-FL), and a simian-human immunodeficiency virus (SHIV) adapted for pathogenic infection of rhesus macaques (SHIVAD8-EO). In accordance with the sensitivity of these viruses to neutralization, HIV-1NL4-3-infected cells were considerably more sensitive to ADCC, both in terms of the number of antibodies and magnitude of responses, than cells infected with HIV-1JR-FLor SHIVAD8-EO. ADCC activity generally correlated with antibody binding to Env on the surfaces of virus-infected cells and with viral neutralization; however, neutralization was not always predictive of ADCC, as instances of ADCC in the absence of detectable neutralization, and vice versa, were observed. These results reveal incomplete overlap in the specificities of antibodies that mediate these antiviral activities and provide insights into the relationship between ADCC and neutralization important for the development of antibody-based vaccines and therapies for combating HIV-1 infection.IMPORTANCEThis study provides fundamental insights into the relationship between antibody-dependent cell-mediated cytotoxicity (ADCC) and virus neutralization that may help to guide the development of antibody-based vaccines and immunotherapies for the prevention and treatment of HIV-1 infection.

Sign in / Sign up

Export Citation Format

Share Document