Depletion of B cells in vivo by a chimeric mouse human monoclonal antibody to CD20

Reff, Mitchell E.; Carner, Kristin; Chambers, Karen S.; Chinn, Paul; Leonard, John E.; Raab, Ron; Newman, Roland; Hanna, Nabil; Anderson, Darrell R.

doi:10.1182/blood.v83.2.435.435

Cited by 1,729 publications

(654 citation statements)

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“…Human monoclonal antibodies (MAbs) (in human IgG1s) were produced as described previously (22). In brief, the V H and V L gene fragments of the selected scFvs were separately subcloned into human IgG1 kappa light-chain or lambda light-chain expression vector TCAE5 (44). Human IgG1s were expressed in 293F cells (Invitrogen) or 293T cells by transient transfection and purified by protein A-Sepharose affinity chromatography.…”

Section: Methodsmentioning

confidence: 99%

Effects of Human Anti-Spike Protein Receptor Binding Domain Antibodies on Severe Acute Respiratory Syndrome Coronavirus Neutralization Escape and Fitness

Sui

Deming

Rockx

et al. 2014

J Virol

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The receptor binding domain (RBD) of the spike (S) glycoprotein of severe acute respiratory syndrome coronavirus (SARS-CoV) is a major target of protective immunity in vivo. Although a large number of neutralizing antibodies (nAbs) have been developed, it remains unclear if a single RBD-targeting nAb or two in combination can prevent neutralization escape and, if not, attenuate viral virulence in vivo. In this study, we used a large panel of human nAbs against an epitope that overlaps the interface between the RBD and its receptor, angiotensin-converting enzyme 2 (ACE2), to assess their cross-neutralization activities against a panel of human and zoonotic SARS-CoVs and neutralization escape mutants. We also investigated the neutralization escape profiles of these nAbs and evaluated their effects on receptor binding and virus fitness in vitro and in mice. We found that some nAbs had great potency and breadth in neutralizing multiple viral strains, including neutralization escape viruses derived from other nAbs; however, no single nAb or combination of two blocked neutralization escape. Interestingly, in mice the neutralization escape mutant viruses showed either attenuation (Urbani background) or increased virulence (GD03 background) consistent with the different binding affinities between their RBDs and the mouse ACE2. We conclude that using either single nAbs or dual nAb combinations to target a SARS-CoV RBD epitope that shows plasticity may have limitations for preventing neutralization escape during in vivo immunotherapy. However, RBD-directed nAbs may be useful for providing broad neutralization and prevention of escape variants when combined with other nAbs that target a second conserved epitope with less plasticity and more structural constraint. IMPORTANCEThe emergence of severe acute respiratory syndrome coronavirus (SARS-CoV) in 2002 and Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012 has resulted in severe human respiratory disease with high death rates. Their zoonotic origins highlight the likelihood of reemergence or further evolution into novel human coronavirus pathogens. Broadly neutralizing antibodies (nAbs) that prevent infection of related viruses represent an important immunostrategy for combating coronavirus infections; however, for this strategy to succeed, it is essential to uncover nAb-mediated escape pathways and to pioneer strategies that prevent escape. Here, we used SARS-CoV as a research model and examined the escape pathways of broad nAbs that target the receptor binding domain (RBD) of the virus. We found that neither single nAbs nor two nAbs in combination blocked escape. Our results suggest that targeting conserved regions with less plasticity and more structural constraint rather than the SARS-CoV RBD-like region(s) should have broader utility for antibody-based immunotherapy.

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Section: Methodsmentioning

confidence: 99%

Effects of Human Anti-Spike Protein Receptor Binding Domain Antibodies on Severe Acute Respiratory Syndrome Coronavirus Neutralization Escape and Fitness

Sui

Deming

Rockx

et al. 2014

J Virol

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“…IgG1s were generated by cloning heavy chain variable region (VH) and light chain variable region (VL) into TCAE5.3 vector. 65 Fc-mutated HuG6.3 was constructed in TCAE5.3 with Leu234Ala and Leu235Ala mutations on CH2 domain. Antibodies (scFv-Fc and IgG1) were produced in 293F cells and MuG6 was harvested from the supernatant of MuG6 hybridoma.…”

Section: Expression and Purification Of Antibodiesmentioning

confidence: 99%

Humanized mouse G6 anti-idiotypic monoclonal antibody has therapeutic potential againstIGHV1-69germline gene-based B-CLL

Chang

Kurella

Biswas

et al. 2016

mAbs

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A Marasco (2016) Humanized mouse G6 anti-idiotypic monoclonal antibody has therapeutic potential against IGHV1-69 germline gene-based B-CLL, mAbs, 8:4, 787-798, DOI: 10.1080/19420862.2016 To link to this article: https://doi.org/10. 1080/19420862.2016 ABSTRACTIn 10-20% of the cases of chronic lymphocytic leukemia of B-cell phenotype (B-CLL), the IGHV1-69 germline is utilized as VH gene of the B cell receptor (BCR). Mouse G6 (MuG6) is an anti-idiotypic monoclonal antibody discovered in a screen against rheumatoid factors (RFs) that binds with high affinity to an idiotope expressed on the 51p1 alleles of IGHV1-69 germline gene encoded antibodies (G6-id C ). The finding that unmutated IGHV1-69 encoded BCRs are frequently expressed on B-CLL cells provides an opportunity for anti-idiotype monoclonal antibody immunotherapy. In this study, we first showed that MuG6 can deplete B cells encoding IGHV1-69 BCRs using a novel humanized GTL mouse model. Next, we humanized MuG6 and demonstrated that the humanized antibodies (HuG6s), especially HuG6.3, displayed »2-fold higher binding affinity for G6-id C antibody compared to the parental MuG6. Additional studies showed that HuG6.3 was able to kill G6-id C BCR expressing cells and patient B-CLL cells through antibodydependent cell-mediated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC). Finally, both MuG6 and HuG6.3 mediate in vivo depletion of B-CLL cells in NSG mice. These data suggest that HuG6.3 may provide a new precision medicine to selectively kill IGHV1-69-encoding G6-id C B-CLL cells.

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“…Briefly, scFv-Fcs were constructed by cloning the single-chain variable region (scFv) into pcDNA3.1-Hinge vector in frame with human IgG1 Fc region. IgG1 was generated by cloning heavy-chain variable region (VH) and light-chain variable region (VL) into TCAE5.3 vector (22). Antibodies were produced in 293T or 293F cells and purified by proteinA-Sepharose (Amersham) affinity chromatography.…”

Section: Cellsmentioning

confidence: 99%

Humanization of an Anti-CCR4 Antibody That Kills Cutaneous T-Cell Lymphoma Cells and Abrogates Suppression by T-Regulatory Cells

Chang

Sui

Geng

et al. 2012

Molecular Cancer Therapeutics

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Cutaneous T-cell lymphoma (CTCL) is a heterogeneous group of neoplastic disorders characterized by clonally derived and skin-homing malignant T-cells that express high level of chemokine receptor CCR4, which is associated with their skin-homing capacity. CCR4 is also highly expressed on T-regulatory cells (Tregs) that can migrate to several different types of chemotactic ligand CCL17 and CCL22 secreting tumors to facilitate tumor cell evasion from immune surveillance. Thus, its high level expression on CTCL cells and Tregs makes CCR4 a potential ideal target for antibody-based immunotherapy for CTCL and other types of solid tumors. Here we performed humanization and affinity optimization of a murine anti-CCR4 monoclonal antibody (mAb), mAb1567, that recognizes both the N-terminal and extracellular domains of CCR4 with high affinity and inhibits chemotaxis of CCR4+ CTCL cells. In a mouse CTCL tumor model, mAb1567 exhibited a potent anti-tumor effect and in vitro mechanistic studies showed that both complement-dependent cytotoxicity (CDC) and neutrophil-mediated antibody-dependent cellular cytotoxicity (ADCC) likely mediated this effect. MAb1567 also exerts human NK cell-mediated ADCC activity in vitro. Moreover, mAb1567 also effectively inhibits chemotaxis of CD4+CD25high Tregs via CCL22 and abrogates Treg suppression activity in vitro. An affinity optimized variant of humanized mAb1567, mAb2-3, was selected for further preclinical development based on its higher binding affinity and more potent ADCC and CDC activities. Taken together, this high affinity humanized mAb2-3 with potent anti-tumor effect and a broad range of mechanisms of action may provide a novel immunotherapy for CTCL and other solid tumors.

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Depletion of B cells in vivo by a chimeric mouse human monoclonal antibody to CD20

Cited by 1,729 publications

References 23 publications

Effects of Human Anti-Spike Protein Receptor Binding Domain Antibodies on Severe Acute Respiratory Syndrome Coronavirus Neutralization Escape and Fitness

Effects of Human Anti-Spike Protein Receptor Binding Domain Antibodies on Severe Acute Respiratory Syndrome Coronavirus Neutralization Escape and Fitness

Humanized mouse G6 anti-idiotypic monoclonal antibody has therapeutic potential againstIGHV1-69germline gene-based B-CLL

Humanization of an Anti-CCR4 Antibody That Kills Cutaneous T-Cell Lymphoma Cells and Abrogates Suppression by T-Regulatory Cells

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