Reprogramming the antigen specificity of B cells using genome-editing technologies
- The Scripps Research Institute, United States
- Universidad Autónoma de Madrid (UAM), Spain
- Karolinska Institutet, Sweden
- University College London, United Kingdom
- University of Southern California, United States
Abstract
We have developed a method to introduce novel paratopes into the human antibody repertoire by modifying the immunoglobulin (Ig) genes of mature B cells directly using genome editing technologies. We used CRISPR-Cas9 in a homology directed repair strategy, to replace the heavy chain (HC) variable region in B cell lines with that from an HIV broadly neutralizing antibody, PG9. Our strategy is designed to function in cells that have undergone VDJ recombination using any combination of variable (V), diversity (D) and joining (J) genes. The modified locus expresses PG9 HC which pairs with native light chains resulting in the cell surface expression of HIV specific B cell receptors (BCRs). Endogenous activation-induced cytidine deaminase (AID) in engineered cells allowed for Ig class switching and generated BCR variants with improved anti-HIV neutralizing activity. Thus, BCRs engineered in this way retain the genetic flexibility normally required for affinity maturation during adaptive immune responses. Peripheral blood derived primary B cells from three different donors were edited using this strategy. Engineered cells could bind the PG9 epitope by FACS and sequenced mRNA from these cells showed PG9 HC expressed as several different isotypes after culture with CD40 ligand and IL-4.
Data availability
Next generation sequencing data from RT-PCR amplicons have been deposited at Dryad:DOI: https://doi.org/10.5061/dryad.45j0r70.Amplification free whole genome sequencing reads mapped to the human reference genome have been deposited to NCBI with BioSample accession numbers SAMN09404498 and SAMN09404497
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PG9HC(V434)Ramos-WGSNCBI SRA, SAMN09404498.
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PG9HC(V781)Ramos-WGSNCBI SRA, SAMN09404497.
Article and author information
Author details
Funding
National Institutes of Health (5R01DE025167-05)
- Dennis Burton
Bill and Melinda Gates Foundation (OPP1183956)
- James E Voss
Ramón y Cajal Merit Award, Ministerio de Ciencia, Innovacion y Universidades (RYC-2016-21155)
- Alicia Gonzalez-Martin
Marie-Curie Fellowship (FP7-PEOPLE-2013-IOF)
- Laura E McCoy
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Tomohiro Kurosaki, Osaka University, Japan
Version history
- Received: October 19, 2018
- Accepted: December 31, 2018
- Accepted Manuscript published: January 16, 2019 (version 1)
- Accepted Manuscript updated: January 17, 2019 (version 2)
- Version of Record published: January 31, 2019 (version 3)
Copyright
© 2019, Voss et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Reprogramming the antigen specificity of B cells using genome-editing technologies
eLife 8:e42995.
https://doi.org/10.7554/eLife.42995
Further reading
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- Immunology and Inflammation
- Medicine
Background:
Prinflammatory extracellular chromatin from neutrophil extracellular traps (NETs) and other cellular sources is found in COVID-19 patients and may promote pathology. We determined whether pulmonary administration of the endonuclease dornase alfa reduced systemic inflammation by clearing extracellular chromatin.
Methods:
Eligible patients were randomized (3:1) to the best available care including dexamethasone (R-BAC) or to BAC with twice-daily nebulized dornase alfa (R-BAC + DA) for seven days or until discharge. A 2:1 ratio of matched contemporary controls (CC-BAC) provided additional comparators. The primary endpoint was the improvement in C-reactive protein (CRP) over time, analyzed using a repeated-measures mixed model, adjusted for baseline factors.
Results:
We recruited 39 evaluable participants: 30 randomized to dornase alfa (R-BAC +DA), 9 randomized to BAC (R-BAC), and included 60 CC-BAC participants. Dornase alfa was well tolerated and reduced CRP by 33% compared to the combined BAC groups (T-BAC). Least squares (LS) mean post-dexamethasone CRP fell from 101.9 mg/L to 23.23 mg/L in R-BAC +DA participants versus a 99.5 mg/L to 34.82 mg/L reduction in the T-BAC group at 7 days; p=0.01. The anti-inflammatory effect of dornase alfa was further confirmed with subgroup and sensitivity analyses on randomised participants only, mitigating potential biases associated with the use of CC-BAC participants. Dornase alfa increased live discharge rates by 63% (HR 1.63, 95% CI 1.01–2.61, p=0.03), increased lymphocyte counts (LS mean: 1.08 vs 0.87, p=0.02) and reduced circulating cf-DNA and the coagulopathy marker D-dimer (LS mean: 570.78 vs 1656.96 μg/mL, p=0.004).
Conclusions:
Dornase alfa reduces pathogenic inflammation in COVID-19 pneumonia, demonstrating the benefit of cost-effective therapies that target extracellular chromatin.
Funding:
LifeArc, Breathing Matters, The Francis Crick Institute (CRUK, Medical Research Council, Wellcome Trust).
Clinical trial number:
-
- Immunology and Inflammation
Trained immunity is the long-term functional reprogramming of innate immune cells, which results in altered responses toward a secondary challenge. Despite indoxyl sulfate (IS) being a potent stimulus associated with chronic kidney disease (CKD)-related inflammation, its impact on trained immunity has not been explored. Here, we demonstrate that IS induces trained immunity in monocytes via epigenetic and metabolic reprogramming, resulting in augmented cytokine production. Mechanistically, the aryl hydrocarbon receptor (AhR) contributes to IS-trained immunity by enhancing the expression of arachidonic acid (AA) metabolism-related genes such as arachidonate 5-lipoxygenase (ALOX5) and ALOX5 activating protein (ALOX5AP). Inhibition of AhR during IS training suppresses the induction of IS-trained immunity. Monocytes from end-stage renal disease (ESRD) patients have increased ALOX5 expression and after 6 days training, they exhibit enhanced TNF-α and IL-6 production to lipopolysaccharide (LPS). Furthermore, healthy control-derived monocytes trained with uremic sera from ESRD patients exhibit increased production of TNF-α and IL-6. Consistently, IS-trained mice and their splenic myeloid cells had increased production of TNF-α after in vivo and ex vivo LPS stimulation compared to that of control mice. These results provide insight into the role of IS in the induction of trained immunity, which is critical during inflammatory immune responses in CKD patients.
