Biology subjects

Heredia, A.

Publications and source records attributed to Heredia, A..

6 recordsLinked to original sources

bioRxiv2026

STING agonists in combination with epigenetic drugs potentiate ZNFX1-driven inflammatory necroptosis in TP53-mutated AML

TP53-mutated acute myeloid leukemia (AML) has dismal outcomes with current treatments and represents a critical unmet need. TP53-mutated AML is proposed to be susceptible to immunotherapeutic approaches but, to date, there is no established immunotherapy for this sub-group. Expression of stimulator of interferon genes (STING), a key innate immune driver that activates interferon (IFN) signaling, is decreased by epigenetic silencing or mutation in many cancers, including those with TP53 mutations. Here, we report that response to the next-generation synthetic STING agonist C92 is potentiated in AML cell lines and primary cells with TP53-mutated versus wild-type (WT) cells, representing a previously undescribed vulnerability of these leukemia cells to STING small molecule therapies. Moreover, combining treatment with the DNA methyltransferase inhibitor (DNMTi) decitabine (DAC), significantly increases STING activation, with marked transcriptome-wide increase in repetitive elements (REs) and upregulation of a critical set of interferon-related genes. Cell death in TP53 KO versus WT AML is specifically dependent on innate immune zinc finger NFX1-type containing 1 (ZNFX1) and Z-DNA-binding protein 1 (ZBP1) driving increased cleavage and activation of Receptor-Interacting-Serine/Threonine-Protein Kinase 3 (RIPK3) and mixed lineage kinase domain-like protein (MLKL), suggesting mechanisms of necroptosis. Finally, C92 and DAC combination significantly reduces leukemia burden in humanized AML mouse models, accompanied by increased immune responses, including cytokines and cytotoxic T lymphocytes in the leukemia microenvironment. These results support development of clinical trial strategies combining STING agonists with DNMTis for patients with TP53-mutated AML. SummaryO_LITP53-mutated AML potentiates effects of novel next-generation STING agonist C92, with unique allosteric and non-cyclic dinucleotide (non-CD) mechanism of action, inducing increased STING activation and cytokine release C_LIO_LISTING agonists and DNMTis, synergistically increase STING activation with marked transcriptome-wide increase in repetitive elements (REs) and upregulation of a critical set of interferon-related genes in TP53-mutated AML C_LIO_LISTING agonists induce necroptosis via a STING-ZNFX1-ZBP1-necroptosis axis in TP53-mutated AML. C_LIO_LIThis drug combination reduces leukemia burden, activates immune responses in AML models and supports translation for high-risk AML patients. C_LI Statement of Translational RelevanceThis pre-clinical study identifies a novel therapeutic vulnerability in (TP53)-mutated acute myeloid leukemia (AML), a poor prognosis subtype with a critical unmet need. Novel next-generation STING agonist C92, with unique allosteric and non-cyclic dinucleotide (non-CD) mechanism of action, induces increased STING activation and cytokine release, compared with WT TP53 in AML cell lines and primary cells, and has superior STING activity with respect to several STING agonists currently in clinical studies. Combining C92 treatment with the DNA methyltransferase inhibitor (DNMTi) decitabine (DAC) synergistically increases STING activation, with marked transcriptome-wide increase in repetitive elements (REs) and upregulation of a critical set of interferon-related genes, driving ZNFX1-driven inflammatory necroptotic cell death. Utilizing humanized mouse models, C92 in combination with DAC significantly reduces leukemia burden and enhances cytotoxic T-cell responses in the tumor microenvironment, supporting clinical translation for high-risk AML patients.

cancer biology↗

bioRxiv2025

Engineering HIV antibodies with enhanced breadth and potency of neutralization through multistate affinity maturation

Broadly neutralizing antibodies (bnAbs) against HIV hold promise as therapeutic and prophylactic agents, but realizing this potential requires antibodies that function across the antigenic heterogeneity of the HIV envelope glycoprotein (Env). Although numerous bnAbs have been isolated from infected individuals, their breadth and potency may not be sufficient to tackle global viral diversity, motivating efforts to further improve their neutralization capacity. Here, we address this challenge using a multistate antibody engineering approach integrating deep mutational scanning with combinatorial library screening across diverse Env variants. This strategy enables identification of mutation patterns that confer improved binding across antigenically distinct targets. Starting from one of the best-in-class CD4-binding site bnAbs, we performed iterative optimization to increase binding affinity across diverse Env variants. The resulting lead candidate exhibited improved breadth and up to 100-fold higher potency against pseudoviruses from large cross-clade historical and contemporary panels while maintaining biophysical and pharmacokinetic profiles conducive to clinical development. Structural and molecular dynamics analyses revealed a unique tri-tyrosine aromatic triad and reinforced electrostatic contacts that stabilized the bnAb/Env interface. These findings demonstrate that systematic in vitro engineering can generate bnAbs with enhanced breadth and potency, providing a generalizable strategy for developing therapeutic antibodies against highly diverse pathogens.

bioengineering↗

bioRxiv2025

Leveraging bioorthogonal conjugation for alpha synuclein fibril surveillance

Alpha synuclein (-syn) amyloid fibrils are associated with various neurodegenerative diseases. To better understand the molecular and cellular basis for -syn fibril persistence and spread, we implemented a fluorophore labeling strategy to surveil pre-formed -syn fibrils in solution and in cells. We leveraged amber codon mediated incorporation of a tetrazine-based artificial amino acid (TetV2.0) to install a cyclooctene-conjugated Janeliaflour, JF549, at four sites on human -syn: residues 4, 60, 96 and 136. Fast coupling occurred under mild buffer conditions and in the presence of the disease-associated cofactor and cytotoxic lipid, psychosine. Labeled fibrils retained their polymorphic features, seeded the growth of new fibrils in vitro, and induced the seeding of positive puncta in -syn FRET biosensor HEK293T cells. This allowed simultaneous tracking of exogenous and endogenous -syn aggregates in biosensor cells, and their localization within the cells. In doing so, our approach facilitates more detailed mechanistic investigation of -syn aggregates.

biochemistry↗

bioRxiv2024

A Comprehensive Engineering Strategy Improves Potency and Manufacturability of a Near Pan-neutralizing Antibody Against HIV

Anti-HIV envelope broadly neutralizing antibodies (bnAbs) are alternatives to conventional antiretrovirals with the potential to prevent and treat infection, reduce latent reservoirs, and/or mediate a functional cure. Clinical trials with "first generation" bnAbs used alone or in combination show promising antiviral effects but also highlight that additional engineering of "enhanced" antibodies will be required for optimal clinical utility, while preserving or enhancing cGMP manufacturing capability. Here we report the engineering of an anti-CD4 binding-site (CD4bs) bnAb, N49P9.3, purified from the plasma of an HIV elite-neutralizer. Through a series of rational modifications we produced a variant that demonstrates: enhanced potency; superior antiviral activity in combination with other bnAbs; low polyreactivity; and longer circulating half-life. Additional engineering for manufacturing produced a final variant, eN49P9, with properties conducive to cGMP production. Overall, these efforts demonstrate the feasibility of developing enhanced anti-CD4bs bnAbs with greatly improved antiviral properties as well as potential translational value.

bioengineering↗

bioRxiv2024

Genetic signatures in the highly virulent subtype B HIV-1 conferring immune escape to V1/V2 and V3 broadly neutralizing antibodies

HIV-1 is considered to become less susceptible to existing neutralizing antibodies over time. Our study on the virulent B (VB) HIV-1 identified genetic signatures responsible for immune escape from broadly neutralizing antibodies (bNAbs) targeting V1/V2 and V3 glycan epitopes. We found that the absence of N295 and N332 glycans in the high mannose patch, which are crucial for neutralization by V3 glycan bNAbs and are typically conserved in subtype B HIV-1, is a notable feature in more than half of the VB variants. Neutralization assays confirmed that the loss of these two glycans in VB HIV-1 leads to escape from V3 glycan bNAbs. Additionally, all VB variants we investigated have an insertion in V2, contributing to immune escape from V1/V2 bNAbs PG9 and PG16. These findings suggest potential co-evolution of HIV-1 virulence and antigenicity, underscoring the need to monitor both the pathogenicity and neutralization susceptibility of newly emerged HIV-1 strains.

microbiology↗

bioRxiv2022

3D (x-y-t) Raman imaging of tomato fruit cuticle: microchemistry during development

The cuticle of tomato fruits was studied in-situ using Confocal Raman Microscopy. Microsections from cuticles isolated at different developmental stages were scanned to reveal the distribution of cuticle components with a spatial resolution of 342 nm by univariate and multivariate data analysis. From the three main components, cutin, polysaccharides and aromatics, the latter one exhibit the strongest Raman scattering intensity. Therefore, Raman imaging opened the view on phenolic acids and flavonoids within the cuticle and resulted in three schematic cuticle models depicting development. At the earliest stage of development, which corresponded to the procuticle layer, phenolic acids were found across the entire cuticle. Based on a mixture analysis with reference component spectra, the phenolic acids were identified as mainly esterified p-coumaric acid together with free p-hydroxybenzoic acid. Later in development, during the cell expansion period of growth, phenolic acids accumulated in an outermost layer of the cuticle and in the middle region of the pegs. In these stages of development cellulose and pectin were appeared towards the epidermal layer, where later during ripening the flavonoid impregnation started. In the first ripening stage chalconaringenin was observed, while methoxylated chalcones were chosen by the algorithm to fit the mature cuticle spectra. The co-location with carbohydrates and esterified p-coumaric acid and methoxylated chalconaringenin suggest that they link polysaccharide and cutin domains. Within the cutin matrix, aromatics confer mechanical and thermal functions, while the outermost phenolic acid layer displays UV-B protection of the plant tissue. One-sentence summaryNew insights into the distribution of cutin, carbohydrates and phenolics along cross sections of green and mature tomato fruit cuticles by Raman mapping and multivariate data analysis.

biophysics↗