scholarly journals Susceptibility to Neutralization by Broadly Neutralizing Antibodies Correlates with Infected Cell Binding for a Panel of Clade B HIV Reactivated from Latent Reservoirs

2018 ◽  
Author(s):  
Yanqin Ren ◽  
Maria Korom ◽  
Ronald Truong ◽  
Dora Chan ◽  
Szu-han Huang ◽  
...  
Keyword(s):  
T Cells ◽  
Infected Cell ◽  
Neutralizing Antibodies ◽  
Individual Variability ◽  
Binding Assays ◽  
Cell Binding ◽  
Specific Antibodies ◽  
Clade B ◽  
Latently Infected ◽  
Selection Of

AbstractEfforts to HIV cure are obstructed by reservoirs of latently infected CD4+T-cells that can re-establish viremia. Broadly neutralizing HIV-specific antibodies (bNAbs), defined by unusually high neutralization breadths against globally diverse viruses, may contribute to the elimination of these reservoirs by binding to reactivated cells, targeting them for immune clearance. However, the relationship between neutralization of reservoir isolates and binding to corresponding infected primary CD4+T-cells has not been determined. Thus, the extent to which neutralization breadths and potencies can be used to infer the corresponding parameters of infected-cell binding is currently unknown. We assessed the breadths and potencies of bNAbs against 36 viruses reactivated from peripheral blood CD4+T-cells of ARV-treated HIV-infected individuals, using paired neutralization and infected-cell binding assays. Single antibody breadths ranged from 0–64% for neutralization (IC80≤10μg/ml) and 0–89% for binding, with two-antibody combinations reaching 0-83% and 50-100%, respectively. Infected-cell binding correlated with virus neutralization for 10 out of 14 antibodies (e.g. 3BNC117, r=0.87, p<0.0001). Heterogeneity was observed, however, with a lack of significant correlations for 2G12, CAP256.VRC26.25, 2F5, and 4E10. Our results provide guidance on the selection of bNAbs for interventional cure studies; both by providing a direct assessment of intra-and inter-individual variability in neutralization and infected cell binding in a novel cohort, and by defining the relationships between these parameters for a panel of bNAbs.ImportanceAlthough anti-retroviral therapies have improved the lives of people who are living with HIV, they do not cure infection. Efforts are being directed towards harnessing the immune system to eliminate the virus that persists, potentially resulting in virus-free remission without medication. HIV-specific antibodies hold promise for such therapies owing to their abilities to both prevent the infection of new cells (neutralization), and also to direct the killing of infected cells. We isolated 36 HIV strains from individuals whose virus was suppressed by medication, and tested 14 different antibodies for neutralization of these viruses and for binding to cells infected with the same viruses (critical for engaging natural killer cells). For both neutralization and infected-cell binding, we observed variation both between individuals, and amongst different viruses within an individual. For most antibodies, neutralization activity correlated with infected cell binding. These data provide guidance on the selection of antibodies for clinical trials.

scholarly journals Susceptibility to Neutralization by Broadly Neutralizing Antibodies Generally Correlates with Infected Cell Binding for a Panel of Clade B HIV Reactivated from Latent Reservoirs

2018 ◽  
Vol 92 (23) ◽  
Author(s):  
Yanqin Ren ◽  
Maria Korom ◽  
Ronald Truong ◽  
Dora Chan ◽  
Szu-Han Huang ◽  
...  
Keyword(s):  
T Cells ◽  
Infected Cell ◽  
Neutralizing Antibodies ◽  
Binding Assays ◽  
Cell Binding ◽  
Broadly Neutralizing Antibodies ◽  
Clade B ◽  
Latently Infected ◽  
Living With Hiv ◽  
Selection Of

ABSTRACTEfforts to cure human immunodeficiency virus (HIV) infection are obstructed by reservoirs of latently infected CD4+T cells that can reestablish viremia. HIV-specific broadly neutralizing antibodies (bNAbs), defined by unusually wide neutralization breadths against globally diverse viruses, may contribute to the elimination of these reservoirs by binding to reactivated cells, thus targeting them for immune clearance. However, the relationship between neutralization of reservoir isolates and binding to corresponding infected primary CD4+T cells has not been determined. Thus, the extent to which neutralization breadths and potencies can be used to infer the corresponding parameters of infected cell binding is currently unknown. We assessed the breadths and potencies of bNAbs against 36 viruses reactivated from peripheral blood CD4+T cells from antiretroviral (ARV)-treated HIV-infected individuals by using paired neutralization and infected cell binding assays. Single-antibody breadths ranged from 0 to 64% for neutralization (80% inhibitory concentration [IC80] of ≤10 μg/ml) and from 0 to 89% for binding, with two-antibody combinations (results for antibody combinations are theoretical/predicted) reaching levels of 0 to 83% and 50 to 100%, respectively. Infected cell binding correlated with virus neutralization for 10 of 14 antibodies (e.g., for 3BNC117,r = 0.82 andP < 0.0001). Heterogeneity was observed, however, with a lack of significant correlation for 2G12, CAP256.VRC26.25, 2F5, and 4E10. Our results provide guidance on the selection of bNAbs for interventional cure studies, both by providing a direct assessment of intra- and interindividual variabilities in neutralization and infected cell binding in a novel cohort and by defining the relationships between these parameters for a panel of bNAbs.IMPORTANCEAlthough antiretroviral therapies have improved the lives of people who are living with HIV, they do not cure infection. Efforts are being directed towards harnessing the immune system to eliminate the virus that persists, potentially resulting in virus-free remission without medication. HIV-specific antibodies hold promise for such therapies owing to their ability to both prevent the infection of new cells (neutralization) and direct the killing of infected cells. We isolated 36 HIV strains from individuals whose virus was suppressed by medication and tested 14 different antibodies for neutralization of these viruses and for binding to cells infected with the same viruses (critical for engaging natural killer cells). For both neutralization and infected cell binding, we observed variation both between individuals and amongst different viruses within an individual. For most antibodies, neutralization activity correlated with infected cell binding. These data provide guidance on the selection of antibodies for clinical trials.

scholarly journals Anti-HIV designer T cells progressively eradicate a latently infected cell line by sequentially inducing HIV reactivation then killing the newly gp120-positive cells

Virology ◽  
2013 ◽  
Vol 446 (1-2) ◽  
pp. 268-275 ◽  
Author(s):  
Gautam K. Sahu ◽  
Kaori Sango ◽  
Nithianandan Selliah ◽  
Qiangzhong Ma ◽  
Gail Skowron ◽  
...  
Keyword(s):  
T Cells ◽  
Infected Cell ◽  
Cell Line ◽  
Infected Cell Line ◽  
Latently Infected ◽  
Anti Hiv

scholarly journals Susceptibility to neutralization by bnAbs orrelates with infected cell binding for a panel of clade B HIV reactivated from latent reservoirs

2017 ◽  
Vol 3 ◽  
pp. 32-33
Author(s):  
Y. Ren ◽  
M. Korom ◽  
R. Truong ◽  
Szu-Han Huang ◽  
D. Chan ◽  
...  
Keyword(s):  
Infected Cell ◽  
Cell Binding ◽  
Clade B

scholarly journals Involvement of the "I" domain of LFA-1 in selective binding to ligands ICAM-1 and ICAM-3.

1994 ◽  
Vol 126 (2) ◽  
pp. 529-537 ◽  
Author(s):  
R C Landis ◽  
A McDowall ◽  
C L Holness ◽  
A J Littler ◽  
D L Simmons ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Binding Site ◽  
Alpha Subunit ◽  
Adhesion Assay ◽  
Binding Assays ◽  
Cell Binding ◽  
Cos Cells ◽  
First Time ◽  
Inside Out

To analyze the binding requirements of LFA-1 for its two most homologous ligands, ICAM-1 and ICAM-3, we compared the effects of various LFA-1 activation regimes and a panel of anti-LFA-1 mAbs in T cell binding assays to ICAM-1 or ICAM-3 coated on plastic. These studies demonstrated that T cell binding to ICAM-3 was inducible both from the exterior of the cell by Mn2+ and from the interior by an agonist of the "inside-out" signaling pathway. T cells bound both ICAM ligands with comparable avidity. A screen of 29 anti-LFA-1 mAbs led to the identification of two mAbs specific for the alpha subunit of LFA-1 which selectively blocked adhesion of T cells to ICAM-3 but not ICAM-1. These two mAbs, YTH81.5 and 122.2A5, exhibited identical blocking properties in a more defined adhesion assay using LFA-1 transfected COS cells binding to immobilized ligand. Blocking was not due to a steric interference between anti-LFA-1 mAbs and N-linked carbohydrate residues present on ICAM-3 but not ICAM-1. The epitopes of mAbs YTH81.5 and 122.2A5 were shown to map to the I domain of the LFA-1 alpha subunit. A third I domain mAb, MEM-83, has been previously reported to uniquely activate LFA-1 to bind ICAM-1 (Landis, R. C., R. I. Bennett, and N. Hogg. 1993. J. Cell Biol. 120:1519-1527). We now show that mAb MEM-83 is not able to stimulate binding of T cells to ICAM-3 over a wide concentration range. Failure to induce ICAM-3 binding by mAb MEM-83 was not due to a blockade of the ICAM-3 binding site on LFA-1. This study has demonstrated that two sets of functionally distinct mAbs recognizing epitopes in the I domain of LFA-1 are able to exert differential effects on the binding of LFA-1 to its ligands ICAM-1, and ICAM-3. These results suggest for the first time that LFA-1 is capable of binding these two highly homologous ligands in a selective manner and that the I domain plays a role in this process.

scholarly journals Longitudinal Antibody Signatures Following FVIII Replacement Therapy in Previously Untreated Patients with Severe Hemophilia Α- New Insights from the Hemophilia Inhibitor PUP Study (HIPS)

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 88-88
Author(s):  
Bagirath Gangadharan ◽  
Birgit Reipert ◽  
Fritz Scheiflinger ◽  
Joel Bowen ◽  
Elizabeth Donnachie ◽  
...  
Keyword(s):  
T Cells ◽  
Board Of Directors ◽  
Th17 Cells ◽  
Neutralizing Antibodies ◽  
Research Funding ◽  
Advisory Committees ◽  
Inhibitor Development ◽  
Specific Antibodies ◽  
High Affinity ◽  
Fviii Inhibitor

Abstract Background and objectives The Hemophilia Inhibitor PUP Study (HIPS, clinicaltrials.gov NCT01652027) is a prospective multicenter observational study of PUPs with severe hemophilia A during their first 50 exposure days (EDs) to recombinant Factor VIII (FVIII, Advate TM). The objective is to elucidate immune system changes and identify potential early biomarkers of inhibitor development in PUPs. Previously we reported that the appearance of high-affinity anti-FVIII antibodies preceded clinical diagnosis of FVIII inhibitors in patients (Reipert 2016). Here we present longitudinal antibody data including titers of FVIII-specific IgM, IgG1-4, IgA, apparent affinities of antibodies and titers of FVIII inhibitors for the first 15 patients who completed the antibody analysis of the HIPS study. Moreover, we present longitudinal monitoring data for key circulating immune cells such as FoxP3+ T cells (Tregs), pro-inflammatory Th17 cells, total T cells and granulysin+ NK cells. Methods FVIII inhibitor testing (Nijmegen methodology, performed in the central laboratory Medical College of Vienna) and antibody analytics were done prior to first exposure, 7-9 days after ED 1 and 5-7 days after EDs 5, 10, 20, 30, 40, and 50. FVIII-specific antibody analytics, including specifications of isotypes, IgG subclasses and apparent affinities were done using methodology described by Whelan 2013 and Hofbauer 2015. Circulating immune cells including FoxP3+ T cells (Tregs), pro-inflammatory Th17 cells, total T cells and granulysin+ NK cells were monitored by epigenetic cell counting in whole blood using quantitative PCR-based methylation assays (www.epiontis.com) Results 25 subjects have been enrolled among 15 study sites. Data for 15 subjects who had completed 50 exposure days were available for analysis. Among these 15 subjects, 4 developed FVIII inhibitors by study criteria (&gt; 0.6 B.U. x 2 measurements in central laboratory) at exposure days 6, 10 and 20. All inhibitors were associated with the development of high affinity FVIII-specific antibodies. High-affinity IgG1 antibodies were detected first and subsequently switched to IgG3 and IgG4, switching to IgG2 was observed only in one of the 4 patients. Two of the 4 inhibitor patients initially developed low affinity IgG1 antibodies which were subsequently accompanied by high affinity IgG1 before switching to high-affinity IgG3 and IgG4. One of the 4 inhibitor patients expressed non-neutralizing FVIII-specific IgG1 antibodies prior to first FVIII infusion already and developed a high-titer inhibitor as early as ED6 Six of the 15 patients who had completed 50 exposure days developed non-neutralizing antibodies (detected on at least 2 time points). Five of them expressed low affinity IgG1 which was never accompanied by high affinity IgG1 or by any other IgG subclass. One of the 6 patients initially expressed low affinity IgG1 which was later accompanied by non-neutralizing high affinity IgG1. Switching to other IgG subclasses was not observed. Three patients had no antibodies detected and 2 had non-neutralizing antibodies detected at a single time point only. Levels of circulating FoxP3+ Tregs in the infant patients were in the same range as in healthy adults with some variation between individuals. In contrast, circulating TH17 cells were barely detectable. The levels of granulysin+ NK cells showed substantial variations between patients as well as during longitudinal monitoring in the same patient. Conclusion Antibody data obtained from the first 15 patients who completed 50 exposure days in the HIPS study confirms that FVIII inhibitor development is preceded by the detection of high-affinity FVIII-specific antibodies. High affinity IgG1 antibodies appeared first and subsequently switched to IgG3 and IgG4 which indicates a T-cell dependent pathway in FVIII inhibitor development. Switching to IgG2 was only seen in 1 of the 4 inhibitor patients. In contrast, patients with non-neutralizing antibodies only expressed IgG1 antibodies and never switched to another IgG subclass. 5 of the 6 patients with non-neutralizing antibodies only expressed low affinity IgG1 which might reflect a T-cell independent pathway of antibody development. In summary, our data indicate that comprehensive analysis of FVIII-specific antibodies might provide early biomarkers which indicate evolving FVIII inhibitors. Disclosures Gangadharan: Shire: Employment. Reipert: Shire: Employment. Scheiflinger: Shire: Employment. Bowen: Shire: Research Funding. Fijn van Draat: ZonMW,CSL Behring: Research Funding; Baxalta: Membership on an entity's Board of Directors or advisory committees; Pfizer, Novo Nordisk: Other: Lectures. Gruppo: Shire: Other: Honorarium for participation on physician advisory board. Male: Bayer, Baxalta, Biotest, CSL Behring, Novo Nordisk, Pfizer: Other: Speaker Honoraria and/Travel support. McGuinn: Shire/Baxalta: Consultancy; Shire / Baxalta, Spark, Biogen, Roche/Genetehc: Research Funding. Recht: Baxalta, Novo Nordisk, Biogen, Pfizer: Research Funding; Biogen , Kediron: Consultancy. Ragni: A Anylam,Biomarin,Tecere, Benitec: Honoraria; Alnylam, CSL Behring, Dimensions, Genetech/Roche,Pfizer, Shire, SPARK: Research Funding. Yaish: Baxalta, Bayer and Octapharma, CSL behring: Consultancy, Membership on an entity's Board of Directors or advisory committees; Baxalta: Honoraria, Membership on an entity's Board of Directors or advisory committees. Santagostino: : Bayer, Shire, Pfizer, Novo Nordisk, Kedrion, Roche, Sobi, Bioverativ, CSL Behring, Grifols, Octapharma: Speakers Bureau; Bayer, Shire, Pfizer, Novo Nordisk, Kedrion, Roche, Sobi, Bioverativ: Other: Advisory board. Brown: Shire: Research Funding.

scholarly journals Comprehensive Cross-Clade Characterization of Antibody-Mediated Recognition, Complement-Mediated Lysis, and Cell-Mediated Cytotoxicity of HIV-1 Envelope-Specific Antibodies toward Eradication of the HIV-1 Reservoir

2017 ◽  
Vol 91 (16) ◽  
Author(s):  
Shariq Mujib ◽  
Jun Liu ◽  
A. K. M. Nur-ur Rahman ◽  
Jordan A. Schwartz ◽  
Phil Bonner ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Neutralizing Antibodies ◽  
Specific Antibodies ◽  
Global Epidemic ◽  
Infected Cells ◽  
Hiv 1 ◽  
Hiv Aids

ABSTRACT Immunotherapy with passive administration of broadly neutralizing HIV-1 envelope-specific antibodies (bnAbs) in the setting of established infection in vivo has yielded mixed results. The contribution of different antibodies toward the direct elimination of infected cells is poorly understood. In this study, we determined the ability of 12 well-characterized anti-HIV-1 neutralizing antibodies to recognize and eliminate primary CD4 T cells infected with HIV-1 belonging to clades A, B, C, and D, via antibody-dependent complement-mediated lysis (ADCML) and antibody-dependent cell-mediated cytotoxicity (ADCC), in vitro. We further tested unique combinations of these antibodies to determine the optimal antibody cocktails to be tested in future clinical trials. We report that antibody binding to infected CD4 T cells is highly variable and correlates with ADCML and ADCC processes. Particularly, antibodies targeting the envelope glycan shield (2G12) and V1/V2 site (PG9, PG16, and PGT145) are best at recognizing HIV-1-infected CD4 T cells. However, only PG9 and PG16 and their combinations with other bnAbs sufficiently induced the elimination of HIV-1-infected CD4 T cells by ADCML, ADCC, or both. Notably, CD4 binding site antibodies VRC01, 3BNC117, and NIH45-46 G54W did not exhibit recognition of infected cells and were unable to induce their killing. Future trials geared toward the development of a cure for HIV/AIDS should incorporate V1/V2 antibodies for maximal clearance of infected cells. With the use of only primary immune cells, we conducted a comprehensive cross-clade physiological analysis to aid the direction of antibodies as therapeutics toward the development of a cure for HIV/AIDS. IMPORTANCE Several antibodies capable of neutralizing the majority of circulating HIV-1 strains have been identified to date and have been shown to prevent infection in animal models. However, the use of combinations of such broadly neutralizing antibodies (bnAbs) for the treatment and eradication of HIV-1 in infected humans remains uncertain. In this study, we tested the ability of bnAbs to directly recognize and eliminate primary human CD4 T cells infected with diverse HIV-1 strains representative of the global epidemic by antibody-dependent pathways. We also tested several combinations of bnAbs in our assays in order to maximize the clearance of infected cells. We show that the ability of bnAbs to identify and kill infected cells is highly variable and that only a few of them are able to exert this function. Our data will help guide the formulation of bnAbs to test in future human trials aimed at the development of a cure.

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