Cross-species cellular mapping and humanization of Fcγ receptors to advance antibody modeling
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PROVIDER: PRJNA1089941 | ENA |
REPOSITORIES: ENA
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Project description:Fc receptors mediate the effector functions of therapeutic antibodies. Immunoglobulin G (IgG), the predominant antibody in circulation and clinical use, engages diverse Fc gamma (Fcγ) receptors that are expressed by multiple immune and structural cells. Here, we provide a comprehensive overview of Fcγ receptors and FcRn expression at both the transcriptomic and proteomic level in humans, macaques, and mice. We reveal species-specific differences in both Fcγ receptor diversity and cell-specific expression profile that compromise the translation of mouse and macaque preclinical models for antibody research. To overcome this, we generated a new mouse model in which human FcγRI (hCD64), FcγRIIA (hCD32A), FcγRIIB (hCD32B), FcγRIIIA (hCD16A), FcγRIIIB (hCD16B) is expressed under control of the relevant human promotors, replacing the murine counterparts (FcγRI, FcγRIIB, FcγRIII, and FcγRIV). Furthermore, to improve human antibody pharmacokinetics, murine FcRn was replaced by its human analog. We comprehensively mapped the expression of the knock-in receptors, and found that humanization led to much more faithful cell-specific Fcg receptor expression. We validated the functionality of these knock-in human receptors through in vitro and in vivo antibody-dependent cellular cytotoxicity, anaphylaxis and antigen presentation assays. This cross-species Fcγ receptor atlas and humanized mouse model with refined Fcg receptor expression and antibody pharmacokinetics will improve the preclinical assessment of antibody-based therapeutics.
2025-09-01 | GSE261975 | GEO
Project description:SummaryAntibodies are rapidly becoming essential tools in the clinical practice, given their ability to recognize their cognate antigens with high specificity and affinity, and a high yield at reasonable costs in model animals. Unfortunately, when administered to human patients, xenogeneic antibodies can elicit unwanted and dangerous immunogenic responses. Antibody humanization methods are designed to produce molecules with a better safety profile still maintaining their ability to bind the antigen. This can be accomplished by grafting the non-human regions determining the antigen specificity into a suitable human template. Unfortunately, this procedure may results in a partial or complete loss of affinity of the grafted molecule that can be restored by back-mutating some of the residues of human origin to the corresponding murine ones. This trial-and-error procedure is hard and involves expensive and time-consuming experiments. Here we present tools for antibody humanization (Tabhu) a web server for antibody humanization. Tabhu includes tools for human template selection, grafting, back-mutation evaluation, antibody modelling and structural analysis, helping the user in all the critical steps of the humanization experiment protocol.Availabilityhttp://www.biocomputing.it/tabhuContactanna.tramontano@uniroma1.it, pierpaolo.olimpieri@uniroma1.itSupplementary informationSupplementary data are available at Bioinformatics online.
| S-EPMC4308665 | biostudies-literature
Project description:Antibodies derived from non-human sources must be modified for therapeutic use so as to mitigate undesirable immune responses. While complementarity-determining region (CDR) grafting-based humanization techniques have been successfully applied in many cases, it remains challenging to maintain the desired stability and antigen binding affinity upon grafting. We developed an alternative humanization approach called CoDAH ("Computationally-Driven Antibody Humanization") in which computational protein design methods directly select sets of amino acids to incorporate from human germline sequences to increase humanness while maintaining structural stability. Retrospective studies show that CoDAH is able to identify variants deemed beneficial according to both humanness and structural stability criteria, even for targets lacking crystal structures. Prospective application to TZ47, a murine anti-human B7H6 antibody, demonstrates the approach. Four diverse humanized variants were designed, and all possible unique VH/VL combinations were produced as full-length IgG1 antibodies. Soluble and cell surface expressed antigen binding assays showed that 75% (6 of 8) of the computationally designed VH/VL variants were successfully expressed and competed with the murine TZ47 for binding to B7H6 antigen. Furthermore, 4 of the 6 bound with an estimated KD within an order of magnitude of the original TZ47 antibody. In contrast, a traditional CDR-grafted variant could not be expressed. These results suggest that the computational protein design approach described here can be used to efficiently generate functional humanized antibodies and provide humanized templates for further affinity maturation.
| S-EPMC5045135 | biostudies-literature
Project description:Introduction: Mechanisms that contribute to the pathogenesis of liver damage caused by hepatitis C virus (HCV) are not fully understood. Our previous work on liver biopsies from chronic HCV patients has shown modulation of the expression of certain cell cycle proteins indicating HCV-induced modifications of cell cycle events. We therefore hypothesize that HCV infection disrupts normal regulation of cell cycle that contributes to disease progression. Objective: To identify molecular disruptions during the course of HCV-associated disease progression, using liver biopsy specimens of chronic hepatitis C patients. Methods: Liver biopsy samples classified on histological basis as early (fibrosis stage 0-1) or advanced (fibrosis stage 3-4) disease stage were studied using oligonucleotide array ( HG U133 Plus 2.0, Affymetrix GeneChip⢠System). For comparison, liver specimens from patients with non-viral hepatitis were also analyzed by microarray. Expression data was analyzed using Genespring (GX 7.2) and Ingenuity Pathway analysis (3.0). The differential expression of selected cell cycle genes (cyclin D2, KPNA2, HERC5 and Bcl-2) identified after microarray analysis was confirmed by quantitative real-time RT-PCR. Results: Microarray analysis revealed two-fold or greater transcriptional change in 792 genes of the total 38,500 known human genes in HCV-advance disease stage (HCV-A) as compared to HCV-early disease stage (HCV-E). Most of the genes have a defined role in immune response, extracellular matrix and cell cycle and apoptosis. Experiment Overall Design: Liver biopsy samples were collected from patients of (a) HCV-infected early disease stage (HCV-E, control 1) (b) non-HCV advance disease stage (control 2) and (c) HCV-infected advance disease stage (HCV-A) for RNA extraction. Equal amount of RNA was pooled from samples (n=4)within each group and hybridized to HG-U133 Plus 2.0 array.
2008-06-15 | E-GEOD-7741 | biostudies-arrayexpress
Project description:Humanization reduces the immunogenicity risk of therapeutic antibodies of non-human origin. Thermostabilization can be critical for clinical development and application of therapeutic antibodies. Here, we show that the computational antibody redesign method Computationally Driven Antibody Humanization (CoDAH) enables these two goals to be accomplished simultaneously and seamlessly. A panel of CoDAH designs for the murine parent of cetuximab, a chimeric anti-EGFR antibody, exhibited both substantially improved thermostabilities and substantially higher levels of humanness, while retaining binding activity near the parental level. The consistently high quality of the turnkey CoDAH designs, over a whole panel of variants, suggests that the computationally directed approach encapsulates key determinants of antibody structure and function.
| S-EPMC5036863 | biostudies-literature
Project description:The cellular prion protein (PrPc) is a cell surface glycoprotein that is highly expressed in a variety of cancer tissues in addition to the nervous system, and its elevated expression is correlated to poor prognosis in many cancer patients. Our team previously found that patients with colorectal cancer (CRC) with high-level PrPc expression had significantly poorer survival than those with no or low-level PrPc expression. Mouse antibodies for PrPc inhibited tumor initiation and liver metastasis of PrPc-positive human CRC cells in mouse model experiments. PrPc is a candidate target for CRC therapy. In this study, we newly cloned a mouse anti-PrPc antibody (Clone 6) and humanized it, then affinity-matured this antibody using a CHO cell display with a peptide antigen and full-length PrPc, respectively. We obtained two humanized antibody clones with affinities toward a full-length PrPc of about 10- and 100-fold of that of the original antibody. The two humanized antibodies bound to the PrPc displayed significantly better on the cell surface than Clone 6. Used for Western blotting and immunohistochemistry, the humanized antibody with the highest affinity is superior to the two most frequently used commercial antibodies (8H4 and 3F4). The two new antibodies have the potential to be developed as useful reagents for PrPc detection and even therapeutic antibodies targeting PrPc-positive cancers.
| S-EPMC10968383 | biostudies-literature
Project description:ChIP-nexus of mineralocorticoid receptors and glucocorticoid receptors in neuroblastoma cells
| PRJNA474922 | ENA
Project description:Murine antibody 10H10 raised against human tissue factor is unique in that it blocks the signaling pathway, and thus inhibits angiogenesis and tumor growth without interfering with coagulation. As a potential therapeutic, the antibody was humanized in a two-step procedure. Antigen-binding loops were grafted onto selected human frameworks and the resulting chimeric antibody was subjected to affinity maturation by using phage display libraries. The results of humanization were analyzed from the structural perspective through comparison of the structure of a humanized variant with the parental mouse antibody. This analysis revealed several hot spots in the framework region that appear to affect antigen binding, and therefore should be considered in human germline selection. In addition, some positions in the Vernier zone, e.g., residue 71 in the heavy chain, that are traditionally thought to be crucial appear to tolerate amino acid substitutions without any effect on binding. Several humanized variants were produced using both short and long forms of complementarity-determining region (CDR) H2 following the difference in the Kabat and Martin definitions. Comparison of such pairs indicated consistently higher thermostability of the variants with short CDR H2. Analysis of the binding data in relation to the structures singled out the ImMunoGeneTics information system® germline IGHV1-2*01 as dubious owing to two potentially destabilizing mutations as compared to the other alleles of the same germline and to other human germlines.
| S-EPMC5825201 | biostudies-literature
Project description:Ricin is regarded as a high terrorist risk for the public due to its high toxicity and ease of production. Currently, there is no therapeutic or vaccine available against ricin. D9, a murine monoclonal antibody developed previously in our laboratory, can strongly neutralize ricin and is therefore a good candidate for humanization. Humanization of D9 variable regions was achieved by a complementarity-determining region grafting approach. The humanized D9 (hD9) variable regions were further grafted onto human heavy and light chain constant regions to assemble the complete antibody gene. A foot-and-mouth-disease virus-derived 2A self-processing sequence was introduced between heavy and light chain DNA sequences to cleave the recombinant protein into a functional full-length antibody molecule from a single open reading frame driven by a single promoter in an adenoviral vector. After expression in mammalian cells and purification, the hD9 was demonstrated to have equimolar expression of the full-length antibody heavy and light chains. More importantly, the hD9 exhibited high affinity to ricin with K(D) of 1.63 nM, comparable to its parental murine D9 (2.55 nM). In a mouse model, intraperitoneal (i.p.) administration of hD9, at a low dose of 5 µg per mouse, 4 hours after the i.p. challenge with 5×LD50 ricin was found to rescue 100% of the mice. In addition, administered 6 hours post-challenge, hD9 could still rescue 50% of the mice. The hD9 has the potential to be used for prophylactic or therapeutic purposes against ricin poisoning.
| S-EPMC3458913 | biostudies-literature