Advancements in single-cell technologies and deep sequencing have expanded the B cell repertoire available for antibody discovery. However, selecting the highest-affinity antibodies from many sequences remains challenging, reflecting our incomplete understanding of the mechanisms sustaining affinity maturation and associated molecular markers. Here, we generated datasets of antigen-specific B cells after mouse immunization and reanalyzed public data to identify "High Signature" (HS), a transcriptomic signature predictive of high-affinity antibodies. HS was derived through differential expression analyses and machine learning by integrating antibody sequences, gene expression, and affinity measurements of expressed antibodies. HS enabled sub-nanomolar-affinity antibody selection without prior sequence analysis in de novo immunization campaigns. HS-expressing B cells were 3 times more likely to yield high-affinity antibodies than randomly picked cells. HS demonstrated translatability to two human PBMC datasets from COVID patients, resulting in enriched high-affinity antibody selection, highlighting its antibody discovery potential across species. A record of this paper's transparent peer review process is included in the supplemental information.
Interleukin (IL)-33 is released following tissue damage, causing airway inflammation and remodelling via reduced IL-33 (IL-33red)/serum stimulation-2 (ST2) and oxidised IL-33 (IL-33ox)/receptor for advanced glycation end products (RAGE)/epidermal growth factor receptor (EGFR) pathways. This study aimed to identify associations of IL-33 with clinical outcomes and pathological mechanisms during viral lower respiratory tract disease (LRTD). Ultra-sensitive immunoassays were developed to measure IL-33red, IL-33ox and IL-33/sST2 complexes in samples from patients hospitalised with COVID-19. Immunohistochemistry and multiomics were used to characterise lung samples. Elevated IL-33 in the airway and IL-33/sST2 complex in the circulation correlated with poor clinical outcomes (death, need for intensive care or mechanical ventilation). IL-33 was localised to airway epithelial and endothelial barriers, whereas IL1RL1 was expressed on aerocytes, alveolar endothelial cells specialised for gaseous exchange. IL-33 increased expression of mediators of neutrophilic inflammation, immune cell infiltration, interferon signalling and coagulation in endothelial cell cultures. Endothelial IL-33 signatures were strongly related with signatures associated with viral LRTD. Increased IL-33 release following respiratory viral infections is associated with poor clinical outcomes and might contribute to alveolar dysfunction. Although this does not show a causal relationship with disease, these results provide a rationale to evaluate pathological roles for IL-33 in viral LRTD.
Preclinical studies of PD-L1 and CTLA-4 blockade have relied heavily on mouse syngeneic tumor models with intact immune systems, which facilitate dissection of immunosuppressive mechanisms in the tumor microenvironment. Commercially developed monoclonal antibodies (mAbs) targeting human PD-L1, PD-1, and CTLA-4 may not demonstrate cross-reactive binding to their mouse orthologs, and surrogate anti-mouse antibodies are often used in their place to inhibit these immune checkpoints. In each case, multiple choices exist for surrogate antibodies, which differ with respect to species of origin, affinity, and effector function. To develop relevant murine surrogate antibodies for the anti-human PD-L1 mAb durvalumab and the anti-human CTLA-4 mAb tremelimumab, rat/mouse chimeric or fully murine mAbs engineered for reduced effector function were developed and compared with durvalumab and tremelimumab. Characterization included determination of target affinity, in vivo effector function, pharmacokinetic profile, and anti-tumor efficacy in mouse syngeneic tumor models. Results showed that anti-PD-L1 and anti-CTLA-4 murine surrogates with pharmacologic properties similar to those of durvalumab and tremelimumab demonstrated anti-tumor activity in a subset of commonly used mouse syngeneic tumor models. This activity was not entirely dependent on antibody-dependent cellular cytotoxicity, antibody-dependent cellular phagocytosis effector function, or regulatory T-cell depletion, as antibodies engineered to lack these features showed activity in models historically sensitive to checkpoint inhibition, albeit at a significantly lower level than antibodies with intact effector function.
Cell surface membrane proteins comprise a wide array of structurally and functionally diverse proteins involved in a variety of important physiological and homeostatic processes. Complex integral membrane proteins, which are embedded in the lipid bilayer by multiple transmembrane-spanning helices, are represented by families of proteins that are important target classes for drug discovery. Such protein families include G-protein-coupled receptors, ion channels and transporters. Although these targets have typically been the domain of small-molecule drugs, the exquisite specificity of monoclonal antibodies offers a significant opportunity to selectively modulate these target proteins. Nevertheless, the isolation of antibodies with desired pharmacological functions has proved difficult because of technical challenges in preparing membrane protein antigens for antibody drug discovery. In this review, we describe recent progress in defining strategies for the generation of membrane protein antigens. We also describe antibody-isolation strategies that identify antibodies that bind the membrane protein and modulate protein function.
The success of immune checkpoint inhibitors CTLA4 and PD-1 monoclonal antibody, both FDA approved cancer therapies, specifically counteracts inhibitory pathways to activate antigen-specific T cells. However, their success is limited by the fact that not all patients respond to immunotherapy and a variety of adverse events due to non specific and systemic T cell activation limits their administration. A newly identified B7 family receptor, CD28H/TMIGD2, is constitutively expressed on T, pDCs and innate lymphoid cells including NK and ILCs. CD28H is also detected in TILs including the CD8+ tissue resident memory T cells (TRM), a T cell subset that correlates with better prognosis and response to immune checkpoint inhibitor therapy. Functionally, CD28H provides costimulatory function to T cells in the context of TCR signaling events during activation. We engineered a bispecific antibody (Bis mAb) targeting CD28H and PDL1 aimed to augment T cell costimulation and NK activation. The CD28H-PDL1 Bis mAb potentiates T cell proliferative and cytokine responses in antigen-specific human T cell assays and induces human NK -mediated redirected killing of PDL1+ tumor cells. In T cells, the mechanism of action of the Bis mAb requires intracellular signaling domain of the CD28H which downmodulates SHP phosphorylation upon CD3 activation. Intriguingly, we found that the Bis mAb increases induction of CD8 TRM cells in vitro. In human TILs, where CD28H is mostly expressed on CD8 TRM in tumors, the Bis mAb enables higher cytokine responses over PDL1 mAb alone. Given the recent relevance of TRM cells as an important pool of anti-tumor T cell immunity, the rationale for targeting this population via CD28H in the context of blocking PDL1 may prove to be a therapeutic tool for enhancing responses to checkpoint inhibitor therapy. Citation Format: Madhu Ramaswamy, Taeil Kim, Desmond Jones, Hormas Ghadially, Tamer Mahmoud, Andrew Garcia, Susan Wilson, Jeffrey Riggs, Darren Schofield, GIanluca Carlesso. A bispecific antibody targeting CD28H and PDL-1 is a novel and potent immunomodulator of T cell responses [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4438.
This thesis sheds new light upon a socially significant, complex and multi-dimensional occupation largely hidden from public view. UK food and grocery retail buyers influence our consumer choices, what we eat, our finances, and the wider environment from which the products they select and buy on behalf of UK food and grocery retailers originate. Little has been written about their occupation and the vocational education and training (VET) which educates these key employees in a sector of the UK economy estimated to be worth £190.3 billion (IGD, 2018). This thesis analyses factors of on and off the job learning that might inform occupational knowledge, standards, and competencies for the education and training needs of UK food and grocery retail buyers. It draws from the perceptions and lived experiences of a unique sample of thirteen practising and former buyers from top 10 UK retailers. Documentary analysis further supports a research design including an original conceptual framework combining human capital theory with conceptualisations of on and off the job learning (Sfard, 1998), performance (Appelbaum, 2000), and pedagogy (Nind, et al., 2016) used to thematically analyse data from semi-structured interviews. Key findings reveal the differing relevance of on and off the job learning to buyer performance which evolves over the working lives and changing career statuses of buyers. The findings extend from participant perceptions that depict contradictory notions to conventions of post-16 education and qualifications yet paradoxically suggest, post-16 qualifications may become a necessity for future entry to the buying occupation. The common ground of a two-year period of, “learning to survive” initial buyer training is defined by participants and linked to notions of self-interest, achievement (McClelland, 1961) and expectancy (Vroom, 1964) that may underpin early-career buyers’ motivation not to choose off the job learning activities, and which may shape enduring on the job learning mindsets. Further key findings expose a highly competitive occupation fuelled by perceptions of the relative economic status of different product ranges buyers buy and which may be viewed as a proxy for buyer competency. Contrasting ideas of the buyer as an enthusiast and the buyer as caretaker of the product ranges they buy are also advanced as indicative notions of what makes a good buyer. Additionally, the use of social learning methods by retail organisations to offset mid-career buyer learning motivations, largely dismissive of off the job learning is advanced alongside evidence of why attaining managerial status as a buyer is marked by greater levels of buyer engagement with off the job learning opportunities. This thesis identifies extensive opportunities to better understand, accelerate and enhance buyer learning, especially in the areas of corporate social responsibility and pre-entry occupational knowledge and curriculum development. It introduces a conceptual framework that may offer a useful method for investigating VET in comparable competitive, fast-moving occupational environments. This thesis also makes the case for greater cooperation between competing individual, organisational and state actors to further develop and support occupational knowledge and learning across the working lives of UK food and grocery retail buyers.
P2X4 is a ligand-gated ion channel implicated in neuropathic pain. Drug discovery efforts targeting P2X4 have been unsuccessful largely because of the difficulty in engineering specificity and selectivity. Here, we describe for the first time the generation of a panel of diverse monoclonal antibodies (mAbs) to human and mouse P2X4, capable of both positive and negative modulation of channel function. The affinity-optimised anti-P2X4 mAb IgG#151-LO showed exquisite selectivity for human P2X4 and induced potent and complete block of P2X4 currents. Site-directed mutagenesis of P2X4 revealed the head domain as a key interaction site for inhibitory mAbs. Inhibition of spinal P2X4 either by intrathecal delivery of an anti-P2X4 mAb or by systemic delivery of an anti-P2X4 bispecific mAb with enhanced blood spinal cord barrier permeability produced long-lasting (>7 days) analgesia in a mouse model of neuropathic pain. We therefore propose that inhibitory mAbs binding the head domain of P2X4 have therapeutic potential for the treatment of neuropathic pain.
There are no approved drug therapies that can prevent or slow the progression of Parkinson's disease (PD). Accumulation and aggregation of α-synuclein protein is observed throughout the nervous system in PD. α-Synuclein is a core component of Lewy bodies and neurites that neuropathologically define PD, suggesting that α-synuclein may be a key causative agent in PD. Recent experimental data suggest that PD progression may arise due to spreading of pathological forms of extracellular α-synuclein throughout the brain via a cellular release, uptake and seeding mechanism. We have developed a high affinity α-synuclein antibody, MEDI1341, that can enter the brain, sequester extracellular α-synuclein and attenuate α-synuclein spreading in vivo. MEDI1341 binds both monomeric and aggregated forms of α-synuclein. In vitro, MEDI1341 blocks cell-to-cell transmission of pathologically relevant α-synuclein preformed fibrils (pffs). After intravenous injection into rats and cynomolgus monkeys, MEDI1341 rapidly enters the central nervous system and lowers free extracellular α-synuclein levels in the interstitial fluid (ISF) and cerebrospinal fluid (CSF) compartments. Using a novel lentiviral-based in vivo mouse model of α-synuclein spreading in the brain, we show that treatment with MEDI1341 significantly reduces α-synuclein accumulation and propagation along axons. In this same model, we demonstrate that an effector-null version of the antibody was equally as effective as one with effector function. MEDI1341 is now in Phase 1 human clinical trial testing as a novel treatment for α-synucleinopathies including PD with the aim to slow or halt disease progression.
The use of large genetically encoded binder libraries in co-operation with display technologies has matured over the past 25 years, and is now one of the primary methods used for selection of protein binders. Display technology has proven to be a robust and versatile method for generating binders to almost any antigen of interest. The evolution of this technology beyond antibody phage display has opened up new aspects for the concept of designer biologics. The ability to construct large populations of eukaryotic cells, including mammalian cells, where each cell expresses an individual antibody, peptide or engineered protein has added great value in identifying binders with desired properties. Here we review the evolution of display technology and highlight how it is being used today to generate binders with exquisite specificity, selectivity, affinity and developability characteristics.
Genetic methods of antibody generation offer a highly tuneable tool for the production of target specific reagents suitable for a wide range of applications, including immunohistochemistry. The direct linkage between binder phenotype and genotype enables the rapid identification and manipulation of specific binders into formats suitable for highly specific and sensitive detection of targets from soluble proteins to individual components of multi-protein structures within the context of living tissues. Here we review the types of genetic methods employed and binder formats available and demonstrate how mining huge combinatorial repertoires of binders can deliver diverse and exquisitely sensitive tools for the use in immunohistochemistry. Finally, we offer a perspective on how this approach might be further refined to routinely deliver binders for specific use in immunohistochemical studies.
Rituximab, which binds CD20 on B cells, is one of the best-characterized antibodies used in the treatment of B-cell malignancies and autoimmune diseases. Rituximab triggers natural killer (NK)-cell-mediated antibody-dependent cellular cytotoxicity (ADCC), but little is known about the spatial and temporal dynamics of cell-cell interactions during ADCC or what makes rituximab potent at triggering ADCC. Here, using laser scanning confocal microscopy, we found that rituximab caused CD20 to cap at the B-cell surface independent of antibody crosslinking or intercellular contact. Unexpectedly, other proteins, including intercellular adhesion molecule 1 and moesin, were selectively recruited to the cap of CD20 and the microtubule organizing center became polarized toward the cap. Importantly, the frequency at which NK cells would kill target cells via ADCC increased by 60% when target cells were polarized compared with when they were unpolarized. Polarized B cells were lysed more frequently still when initial contact with NK cells occurred at the place where CD20 was capped. This demonstrates that the site of contact between immune cells and target cells influences immune responses. Together, these data establish that rituximab causes a polarization of B cells and this augments its therapeutic function in triggering NK-cell-mediated ADCC.
ABSTRACT Hepatitis E virus (HEV) is a human pathogen that causes acute hepatitis. When an HEV capsid protein containing a 52-amino-acid deletion at the C terminus and a 111-amino-acid deletion at the N terminus is expressed in insect cells, the recombinant HEV capsid protein can self-assemble into a T=1 virus-like particle (VLP) that retains the antigenicity of the native HEV virion. In this study, we used cryoelectron microscopy and image reconstruction to show that anti-HEV monoclonal antibodies bind to the protruding domain of the capsid protein at the lateral side of the spikes. Molecular docking of the HEV VLP crystal structure revealed that Fab224 covered three surface loops of the recombinant truncated second open reading frame (ORF2) protein (PORF2) at the top part of the spike. We also determined the structure of a chimeric HEV VLP and located the inserted B-cell tag, an epitope of 11 amino acids coupled to the C-terminal end of the recombinant ORF2 protein. The binding site of Fab224 appeared to be distinct from the location of the inserted B-cell tag, suggesting that the chimeric VLP could elicit immunity against both HEV and an inserted foreign epitope. Therefore, the T=1 HEV VLP is a novel delivery system for displaying foreign epitopes at the VLP surface in order to induce antibodies against both HEV and the inserted epitope.
Abstract Objective To identify ageing and retirement patterns of the pharmacy workforce since 1986 and the implications of those changes for future workforce planning. Method Australian Bureau of Statistics census data from 1986 to 2001 were used to examine ageing of the pharmacy workforce and attrition of pharmacists aged 50 years and over. The number of pharmacists to retire was projected over the next 20 years. Key findings The Australian pharmacy workforce has aged significantly since 1986 (P < 0.01). Forty-one per cent of pharmacists practising in 2001 are predicted to retire by 2026. Baby boomer pharmacists were more likely to work long hours (49+ per week) in 2001 than in 1986, and than generation X pharmacists in 2001. The proportion of women in pharmacy has increased from 39% in 1986 to over 50% in 2001. Women are still more likely to work part-time than males, although they are less likely to do so than they were in 1986. Conversely, the proportion of male pharmacists working part-time is rising. Conclusions With baby boomer and older cohorts currently making up 65% of the pharmacy workforce, their retirement will place increased pressure on a profession already facing severe shortages. The growing proportion of female pharmacists and their generally lower workforce participation mean the potential for continued pharmacy shortages.