Biology subjects

Homad, L. J.

Publications and source records attributed to Homad, L. J..

5 recordsLinked to original sources

bioRxiv2026

The Synthetic Epitope Atlas: High-Throughput Design and Validation of De Novo Antibody-Antigen Complexes

AO_SCPLOWBSTRACTC_SCPLOWDe novo antibody design models lack sufficient training data to reliably generalize. We demonstrate scalable generation of structural training data for machine learning-driven antibody design by linking in silico designs of antibody-antigen complexes to high-throughput experimental binding validation. Using AlphaSeq, a yeast-based platform for measuring protein binding affinities, we measure the affinity and specificity of thousands of de novo "synthetic epitope proteins" (SEPs) designed to bind to VHHs. The resulting Synthetic Epitope Atlas (SEPIA) pairs over 26 million on- and off-target affinity measurements with computationally designed VHH-SEP "pseudo-structures." We validate strong, specific binding for 1,161 pseudo-structures and >75,000 VHH and SEP mutational variants. We show that these pseudo-structures complement existing structural databases and enable ML models to outperform confidence metrics commonly used to rank de novo antibody designs. Taken together, SEPIA establishes a scalable framework for improving de novo antibody design by augmenting sparse structural data with large-scale experimental binding data.

synthetic biology↗

bioRxiv2025

Humanized mice enable in vivo evaluation of engineered plasma cell biology and therapeutic function

Engineered plasma cells (ePCs) offer a durable strategy for in vivo delivery of therapeutic antibodies, but standard immunodeficient mouse models lack human immune factors critical for plasma cell survival and function. We utilized a humanized mouse model in which NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice were engrafted with human CD34+ stem cells as recipients for infusions with autologous ePCs. In this setting, ePCs localized to plasma cell niches and stably secreted antibodies for over three months. To improve the selection of antibodies for secretion, we developed a B cell receptor surface display screen that identified candidate antibody sequences with high secretion potential. An anti-SARS-CoV-2 antibody (clone 297) selected by this method showed robust secretion both in vitro and vivo, and serum from ePC-engrafted mice potently neutralized SARS-CoV-2 pseudovirus. Together, these findings establish a physiologically relevant model for testing human ePCs, and offer a generalizable strategy for optimizing antibody selection to support long-term therapeutic delivery.

molecular biology↗

bioRxiv2022

Immunization with a self-assembling nanoparticle vaccine displaying EBV gH/gL protects humanized mice against lethal viral challenge

Summary/AbstractEpstein-Barr virus (EBV) is a cancer-associated pathogen responsible for 140,000 deaths per year. EBV is also the etiological agent of infectious mononucleosis and is associated with multiple sclerosis and rheumatoid arthritis. Thus, an EBV vaccine could alleviate significant morbidity and mortality. EBV is orally transmitted and has tropism for both epithelial cells and B cells which are present in the oral cavity. Therefore, a prophylactic vaccine would need to prevent infection of both cell types. Passive transfer neutralizing monoclonal antibodies targeting the viral gH/gL glycoprotein complex prevent experimental EBV infection in humanized mice and rhesus macaques, suggesting that gH/gL is an attractive vaccine candidate. Here, we produced and evaluated the immunogenicity of several nanoparticle immunogens displaying gH/gL with distinct valencies and geometries. After one or two immunizations, all nanoparticles elicited superior binding and neutralizing titers relative to monomeric gH/gL. Antibodies elicited by a computationally designed self-assembling nanoparticle that displays 60 copies of the gH/gL protein conferred protection against a lethal dose of EBV in a humanized mouse challenge model, whereas antibodies elicited by monomeric gH/gL did not. Taken together, these data motivate further development of gH/gL nanoparticle vaccine candidates for EBV.

immunology↗

bioRxiv2020

Designed proteins assemble antibodies into modular nanocages

Antibodies are widely used in biology and medicine, and there has been considerable interest in multivalent antibody formats to increase binding avidity and enhance signaling pathway agonism. However, there are currently no general approaches for forming precisely oriented antibody assemblies with controlled valency. We describe the computational design of two-component nanocages that overcome this limitation by uniting form and function. One structural component is any antibody or Fc fusion and the second is a designed Fc-binding homo-oligomer that drives nanocage assembly. Structures of 8 antibody nanocages determined by electron microscopy spanning dihedral, tetrahedral, octahedral, and icosahedral architectures with 2, 6, 12, and 30 antibodies per nanocage match the corresponding computational models. Antibody nanocages targeting cell-surface receptors enhance signaling compared to free antibodies or Fc-fusions in DR5-mediated apoptosis, Tie2-mediated angiogenesis, CD40 activation, and T cell proliferation; nanocage assembly also increases SARS-CoV-2 pseudovirus neutralization by -SARS-CoV-2 monoclonal antibodies and Fc-ACE2 fusion proteins. We anticipate that the ability to assemble arbitrary antibodies without need for covalent modification into highly ordered assemblies with different geometries and valencies will have broad impact in biology and medicine.

biochemistry↗

bioRxiv2020

Characterization of neutralizing antibodies from a SARS-CoV-2 infected individual

B cells specific for the SARS-CoV-2 S envelope glycoprotein spike were isolated from a COVID-19-infected subject using a stabilized spike-derived ectodomain (S2P) twenty-one days post-infection. Forty-four S2P-specific monoclonal antibodies were generated, three of which bound to the receptor binding domain (RBD). The antibodies were minimally mutated from germline and were derived from different B cell lineages. Only two antibodies displayed neutralizing activity against SARS-CoV-2 pseudo-virus. The most potent antibody bound the RBD in a manner that prevented binding to the ACE2 receptor, while the other bound outside the RBD. Our study indicates that the majority of antibodies against the viral envelope spike that were generated during the first weeks of COVID-19 infection are non-neutralizing and target epitopes outside the RBD. Antibodies that disrupt the SARS-CoV-2 spike-ACE2 interaction can potently neutralize the virus without undergoing extensive maturation. Such antibodies have potential preventive/therapeutic potential and can serve as templates for vaccine-design. IN BRIEFSARS-CoV-2 infection leads to expansion of diverse B cells clones against the viral spike glycoprotein (S). The antibodies bind S with high affinity despite being minimally mutated. Thus, the development of neutralizing antibody responses by vaccination will require the activation of certain naive B cells without requiring extensive somatic mutation. HighlightsO_LIAnalysis of early B cell response to SARS-CoV-2 spike protein C_LIO_LIMost antibodies target non-neutralizing epitopes C_LIO_LIPotent neutralizing mAb blocks the interaction of the S protein with ACE2 C_LIO_LINeutralizing antibodies are minimally mutated C_LI

immunology↗