Structural Basis of the Cross-Reactivity of Genetically Related Human Anti-HIV-1 mAbs: Implications for Design of V3-Based Immunogens

ABSTRACT Staphylococcus aureus and Streptococcus pyogenes secrete exotoxins that act as superantigens, proteins that cause hyperimmune reactions by binding the variable domain of the T-cell receptor beta chain (Vβ), leading to stimulation of a large fraction of the T-cell repertoire. To develop potential neutralizing agents, we engineered Vβ mutants with high affinity for the superantigens staphylococcal enterotoxin B (SEB), SEC3, and streptococcal pyrogenic exotoxin A (SpeA). Unexpectedly, the high-affinity Vβ mutants generated against SEB cross-reacted with SpeA to a greater extent than they did with SEC3, despite greater sequence similarity between SEB and SEC3. Likewise, the Vβ mutants generated against SpeA cross-reacted with SEB to a greater extent than with SEC3. The structural basis of the high affinity and cross-reactivity was examined by single-site mutational analyses. The cross-reactivity seems to involve only one or two toxin residues. Soluble forms of the cross-reactive Vβ regions neutralized both SEB and SpeA in vivo, suggesting structure-based strategies for generating high-affinity neutralizing agents that can cross-react with multiple exotoxins.

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Investigations into the cross-reactivity of rabbit antibodies raised against nonhomologous pairs of synthetic peptides derived from HIV-1 gp120 proteins

Journal of Peptide Research ◽

10.1111/j.1399-3011.1998.tb00665.x ◽

2009 ◽

Vol 52 (5) ◽

pp. 410-420 ◽

Cited By ~ 21

Author(s):

V. Krsmanovic ◽

J.-M. Biquard ◽

M. Sikorska-Walker ◽

I. Cosic ◽

C. Desgranges ◽

...

Keyword(s):

Synthetic Peptides ◽

Cross Reactivity ◽

The Cross ◽

Hiv 1

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Evaluation of Geenius HIV-1/2 Confirmatory Assay for the confirmatory and differential diagnosis of HIV-1/HIV-2 in Japan and reliability of the Geenius Reader in the diagnosis of HIV-2

BMC Infectious Diseases ◽

10.1186/s12879-021-06291-5 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Shigeru Kusagawa ◽

Ai Kawana-Tachikawa ◽

Keiji Matsubayashi ◽

Yuji Hoshi ◽

Ken Ishimaru ◽

...

Keyword(s):

Cross Reactivity ◽

Confirmatory Test ◽

Hiv Positive ◽

Immunodeficiency Virus ◽

Confirmatory Tests ◽

Confirmatory Assay ◽

Combination Test ◽

Visual Reading ◽

Anti Hiv ◽

Hiv 1

Abstract Background NEW LAV BLOT I and II (LAV I and LAV II), they were only option for human immunodeficiency virus (HIV) confirmatory test, following HIV screening test using HIV Ag/Ab combination test in Japan. We evaluated the performance of Geenius HIV-1/2 Confirmatory Assay (Geenius), both as a confirmatory test and for differentiation between HIV-1 and HIV-2, in comparison with LAV I and LAV II. Methods Eighty-nine HIV-1-positive plasma specimens, one anti-HIV-1 low-titer performance panel, 10 seroconversion panels, and two anti-HIV-1/2 combo performance panels were tested. The results were read with the Geenius Reader and by visual reading. Results All 89 HIV-1-positive plasma specimens were identified as HIV-1-positive using Geenius; this 100% success rate was superior to that with LAV I (95.5% using WHO criteria, 98.9% using CDC criteria). The HIV-1-positive specimens showed low cross-reactivity with HIV-2 lines in Geenius. The sensitivity of Geenius for HIV-1 detection was the same as or greater than that of LAV I, but less than that of Genscreen HIV Ag-Ab ULT, in our analysis of the commercial performance and seroconversion panels. In contrast, five of the 13 HIV-2-positive specimens that had been identified as HIV-positive untypable by visual reading because of their cross-reactivity to HIV-1 lines were successfully identified by the Geenius Reader as HIV-2-positive with cross-reactivity. Conclusions Geenius provides strong performance for HIV confirmatory tests and HIV-1 differentiation tests. However, when visual reading is used, its performance in HIV-2 differentiation is less reliable. Because HIV-2 infection has been sporadically reported in Japan, the use of the Geenius Reader is preferable to ensure more reliable HIV-1/HIV-2 differentiation.

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Structural Comparison of Human Anti-HIV-1 gp120 V3 Monoclonal Antibodies of the Same Gene Usage Induced by Vaccination and Chronic Infection

Journal of Virology ◽

10.1128/jvi.00641-18 ◽

2018 ◽

Vol 92 (18) ◽

Cited By ~ 2

Author(s):

Kun-Wei Chan ◽

Ruimin Pan ◽

Matthew Costa ◽

Miroslaw K. Gorny ◽

Shixia Wang ◽

...

Keyword(s):

Hiv Infection ◽

Chronic Infection ◽

Germ Line ◽

Affinity Maturation ◽

Hiv Vaccine ◽

Structural Basis ◽

Antigen Binding ◽

Gene Usage ◽

Anti Hiv ◽

Hiv 1

ABSTRACTElucidating the structural basis of antibody (Ab) gene usage and affinity maturation of vaccine-induced Abs can inform the design of immunogens for inducing desired Ab responses in HIV vaccine development. Analyses of monoclonal Abs (MAbs) encoded by the same immunoglobulin genes at different stages of maturation can help to elucidate the maturation process. We have analyzed four human anti-V3 MAbs with the same VH1-3*01 and VL3-10*01 gene usage. Two MAbs, TA6 and TA7, were developed from a vaccinee in the HIV vaccine phase I trial DP6-001 with a polyvalent DNA prime/protein boost regimen, and two others, 311-11D and 1334, were developed from HIV-infected patients. The somatic hypermutation (SHM) rates in VH of vaccine-induced MAbs are lower than in chronic HIV infection-induced MAbs, while those in VL are comparable. Crystal structures of the antigen-binding fragments (Fabs) in complex with V3 peptides show that these MAbs bind the V3 epitope with a new cradle-binding mode and that the V3 β-hairpin lies along the antigen-binding groove, which consists of residues from both heavy and light chains. Residues conserved from the germ line sequences form specific binding pockets accommodating conserved structural elements of the V3 crown hairpin, predetermining the Ab gene selection, while somatically mutated residues create additional hydrogen bonds, electrostatic interactions, and van der Waals contacts, correlating with an increased binding affinity. Our data provide a unique example of germ line sequences determining the primordial antigen-binding sites and SHMs correlating with affinity maturation of Abs induced by vaccine and natural HIV infection.IMPORTANCEUnderstanding the structural basis of gene usage and affinity maturation for anti-HIV-1 antibodies may help vaccine design and development. Antibodies targeting the highly immunogenic third variable loop (V3) of HIV-1 gp120 provide a unique opportunity for detailed structural investigations. By comparing the sequences and structures of four anti-V3 MAbs at different stages of affinity maturation but of the same V gene usage, two induced by vaccination and another two by chronic infection, we provide a fine example of how germ line sequence determines the essential elements for epitope recognition and how affinity maturation improves the antibody's recognition of its epitope.

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Cross-Reactivity of Anti-HIV-1-p17-Derivative Peptide (P30–52) Antibody to Env V3 Peptide

Hybridoma ◽

10.1089/hyb.1999.18.149 ◽

1999 ◽

Vol 18 (2) ◽

pp. 149-157 ◽

Cited By ~ 5

Author(s):

AKEMI OTA ◽

KEIKO TANAKA-TAYA ◽

SHIGEHARU UEDA

Keyword(s):

Cross Reactivity ◽

Anti Hiv ◽

Hiv 1

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Structural Basis of Antibody Conformation and Stability Modulation by Framework Somatic Hypermutation

Frontiers in Immunology ◽

10.3389/fimmu.2021.811632 ◽

2022 ◽

Vol 12 ◽

Author(s):

Zizhang Sheng ◽

Jude S. Bimela ◽

Phinikoula S. Katsamba ◽

Saurabh D. Patel ◽

Yicheng Guo ◽

...

Keyword(s):

Binding Affinity ◽

Somatic Hypermutation ◽

Affinity Maturation ◽

Structural Basis ◽

Common Mechanism ◽

Bioinformatics Pipeline ◽

Constant Domains ◽

Anti Hiv ◽

Hiv 1

Accumulation of somatic hypermutation (SHM) is the primary mechanism to enhance the binding affinity of antibodies to antigens in vivo. However, the structural basis of the effects of many SHMs remains elusive. Here, we integrated atomistic molecular dynamics (MD) simulation and data mining to build a high-throughput structural bioinformatics pipeline to study the effects of individual and combination SHMs on antibody conformation, flexibility, stability, and affinity. By applying this pipeline, we characterized a common mechanism of modulation of heavy-light pairing orientation by frequent SHMs at framework positions 39H, 91H, 38L, and 87L through disruption of a conserved hydrogen-bond network. Q39LH alone and in combination with light chain framework 4 (FWR4L) insertions further modulated the elbow angle between variable and constant domains of many antibodies, resulting in improved binding affinity for a subset of anti-HIV-1 antibodies. Q39LH also alleviated aggregation induced by FWR4L insertion, suggesting remote epistasis between these SHMs. Altogether, this study provides tools and insights for understanding antibody affinity maturation and for engineering functionally improved antibodies.

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Glycan reactive anti-HIV-1 antibodies bind the SARS-CoV-2 spike protein but do not block viral entry

Scientific Reports ◽

10.1038/s41598-021-91746-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Dhiraj Mannar ◽

Karoline Leopold ◽

Sriram Subramaniam

Keyword(s):

Viral Entry ◽

Focal Point ◽

Cross Reactivity ◽

Dependent Manner ◽

Antibody Titers ◽

Antibody Design ◽

Anti Hiv ◽

Virus Neutralization Antibody ◽

Hiv 1 ◽

Spike Proteins

AbstractThe SARS-CoV-2 spike glycoprotein is a focal point for vaccine immunogen and therapeutic antibody design, and also serves as a critical antigen in the evaluation of immune responses to COVID-19. A common feature amongst enveloped viruses such as SARS-CoV-2 and HIV-1 is the propensity for displaying host-derived glycans on entry spike proteins. Similarly displayed glycosylation motifs can serve as the basis for glyco-epitope mediated cross-reactivity by antibodies, which can have important implications on virus neutralization, antibody-dependent enhancement (ADE) of infection, and the interpretation of antibody titers in serological assays. From a panel of nine anti-HIV-1 gp120 reactive antibodies, we selected two (PGT126 and PGT128) that displayed high levels of cross-reactivity with the SARS-CoV-2 spike. We report that these antibodies are incapable of neutralizing pseudoviruses expressing SARS-CoV-2 spike proteins and are unlikely to mediate ADE via FcγRII receptor engagement. Nevertheless, ELISA and other immunoreactivity experiments demonstrate these antibodies are capable of binding the SARS-CoV-2 spike in a glycan-dependent manner. These results contribute to the growing literature surrounding SARS-CoV-2 S cross-reactivity, as we demonstrate the ability for cross-reactive antibodies to interfere in immunoassays.

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