Biology subjects

Hazuda, D.

Publications and source records attributed to Hazuda, D..

3 recordsLinked to original sources

bioRxiv2026

Refactored intracellular domains enhance CAR expression and function

Chimeric antigen receptor (CAR) intracellular domains (ICDs) couple antigen recognition to T-cell activation. Here we worked with AI agents to refactor CAR ICDs, proposing designs and refining them as measurements accumulated over three rounds. This approach yielded KRGR-{zeta}1-40, a 45-amino-acid ICD less than a third the length of the clinical 4-1BB-CD3{zeta} (BB{zeta}) ICD. Compared with BB{zeta}, KRGR-{zeta}1-40 increased CAR surface expression and antigen-driven IFN-{gamma} release, without detectable antigen-independent IFN-{gamma} release. KRGR-{zeta}1-40 extended CAR expression and target-cell killing after transient mRNA delivery, supported the expression of four CARs from a shared mRNA dose, and enhanced B-cell depletion after lentiviral and lipid-nanoparticle delivery. These results show that iterative agent-guided design with experimental feedback can yield compact ICDs that enhance CAR expression and sustain CAR T-cell function.

bioengineering↗

bioRxiv2025

Functional and structural characterization of a combination of pan-sarbecovirus antibodies with potent antiviral activity

Sarbecoviruses, a subgenus of coronaviruses, include strains with zoonotic spillover risk as exemplified by recent outbreaks (SARS-CoV-1, SARS-CoV-2). Monoclonal antibodies targeting conserved spike protein regions (RBD class 4, S2 fusion machinery) exhibit broad sarbecovirus neutralization, but their utility has been impacted by immune selection leading to escape and suboptimal neutralization. Using structure-conditioned machine-learning protein design we optimized two broadly neutralizing sarbecovirus antibodies to rescue the activity of a class 4 anti-RBD antibody against Omicron variants and improve the neutralization profile of an anti-S2 stem antibody, resulting in the identification of the lead candidates PRO-37587 and GB-0669. Both antibodies displayed remarkable resilience to SARS-CoV-2 evolution. Structural analyses elucidated the mechanistic basis of their broad neutralization profiles. In combination, these antibodies exhibited improved SARS-CoV-2 neutralization in vitro and in vivo and a higher barrier to resistance. These findings support further evaluation of such antibody combination as countermeasure against current and emerging sarbecoviruses.

microbiology↗

bioRxiv2020

Microbiome and Metabolome driven differentiation of TGF-β producing Tregs leads to Senescence and HIV latency

Current therapeutic interventions to eradicate latent HIV ("reservoir") and restore immune function in ART-treated HIV infection have yet to show efficacy. To explore mechanisms of HIV persistence, we apply an integrated systems biology approach and identify a distinct group of individuals with poor CD4 T-cell reconstitution (Immunologic non-responders, "INRs") and high frequencies of cells with inducible HIV. Contrary to the prevailing notion that immune activation drives HIV persistence and immune dysfunction, peripheral blood leukocytes from these subjects have enhanced expression of a network of genes regulated by cellular senescence driving transcription factors (TFs) FOXO3, SMAD2 and IRF3. In these subjects, increased frequencies of regulatory T cells and expression of the TGF-{beta} signaling cascade are complimented by the downregulation of cell cycle, metabolic and pro-inflammatory pathways. Lactobacillaceae family and metabolites (members of the butyrate family - i.e. -ketobutyrate) were correlated with Treg frequencies in "Senescent-INRs" ex vivo, triggered the differentiation of TGF-{beta} producing Tregs and promoted HIV latency establishment in vitro. These cascades, downstream of PD-1/TGF-{beta}, prevent memory T cell differentiation and are associated with an increase in frequencies of cells with inducible HIV ex vivo. Our findings identify cellular senescence responses that can be targeted by PD-1 or TGF-{beta} specific interventions that have shown safety and efficacy in cancer, and may prove to be crucial for HIV eradication.

immunology↗