Biology subjects

Zarate, L. V.

Publications and source records attributed to Zarate, L. V..

2 recordsLinked to original sources

bioRxiv2026

Multi-compartment immune and tumor cell reprogramming by IFNa2 overcomes colon cancer immunotherapy resistance

Approximately 85-90% of colorectal cancers (CRC) are microsatellite stable and resist immune checkpoint inhibitors (ICI). The recent success of intismeran, a lipid nanoparticle (LNP)-delivered mRNA encoding patient-specific tumor antigens, enhances pembrolizumab responses, showing that LNP-delivered nucleic acids can render ICI-resistant tumors responsive by supplying what the tumor microenvironment lacks. Because an IFN-responsive phenotype predicts CRC response to checkpoint blockade and tumor cell PD-L1 represses IFN-I, we asked whether delivering the missing cytokine, rather than antigen, achieves the same conversion. Here we show that PD-1 blockade failed even when initiated before tumor seeding, yet deleting tumor cell PD-L1 abolished colon cancer lung metastasis, implicating a tumor-intrinsic PD-L1 function that antibody blockade does not neutralize. An LNP-encapsulated IFN2-encoding nanoplasmid (LNP-IFN2) transfected tumor cells within lung metastases, converting them into a self-sustaining and tumor-restricted IFN2 source. LNP-IFN2 suppressed colon cancer lung metastasis in syngeneic and humanized mouse models and sensitized these ICI-resistant tumors to PD-1 blockade. Efficacy improved further with neutralization of co-induced IL6. scRNA-Seq revealed multi-compartment reprogramming: SPP1+ macrophages acquired apoptotic signatures as IFN-responsive monocytes replaced them, progenitor-exhausted T cells exited quiescence and expanded, and tumor cells exited a high-cycling state, gained antigen presentation, and shifted away from cuproptosis resistance. The treated microenvironment transcriptionally recapitulated pembrolizumab-responder signatures, positioning LNP-IFN2 as an off-the-shelf nanomedicine for ICI-resistant CRC.

immunology↗

bioRxiv2025

Vascular endothelial growth factor receptors 1 and 3 mediate placental trophoblast leptin production in preeclampsia, inducing vascular dysfunction

Heightened soluble FMS-like tyrosine kinase-1 (sFlt-1) levels is a hallmark of preeclampsia patients and induces a state of angiogenic imbalance by sequestering free vascular endothelial growth factor (VEGF) and placental growth factor (PlGF). The receptors for VEGF and PlGF, membrane-bound VEGFR, are expressed in placental trophoblast cells, but their functions are largely unknown. Placenta production of leptin significantly increases in preeclampsia, and we recently showed leptin induces placental and vascular endothelial dysfunction in pregnancy. We hypothesized that there is a mechanistic link in which inappropriately high sFlt-1 in preeclampsia leads to an increase in trophoblast leptin production. We treated human placental explants and trophoblast cells with sFlt-1 and show an increase in leptin peptide production, which is ablated by coadministration with either VEGF or placental growth factor (PLGF). We further demonstrate that VEGFR1 and 3, not R2, expressions are predominant in human trophoblasts and that reducing activation of these receptors mediates trophoblast leptin production. In pregnant mice, we show that sFlt-1 infusion induces vascular endothelial dysfunction in association with significantly elevated plasma leptin levels. In pregnant sFlt-1-infused mice treatment with leptin receptor antagonist significantly ablated vascular endothelial dysfunction. Collectively, these data indicate that angiogenic imbalance in preeclampsia impacts placental trophoblast endocrine function by suppressing VEGFR1 and 3 activation, resulting in leptin overproduction. Furthermore, sFlt-1 induces vascular endothelial dysfunction in mice dependent on leptin receptor activation.

physiology↗