Biology subjects

Thompson, Z.

Publications and source records attributed to Thompson, Z..

5 recordsLinked to original sources

bioRxiv2025

A PBD-dimer containing antibody drug conjugate targeting CCRL2 for high-risk MDS/AML

Patients with myelodysplastic syndrome (MDS)/acute myeloid leukemia (AML) with high-risk features including TP53 mutations and deletions have poor outcomes due to lack of effective therapies. The atypical chemokine surface receptor C-C motif chemokine receptor-like 2 (CCRL2) is overexpressed in MDS and secondary AML (sAML) compared to healthy hematopoietic cells and we recently found that TP53-mutated MDS/AML and AML with erythroid features express the highest levels of this receptor across MDS/AML subtypes. To illustrate the therapeutic potential of CCRL2 as a therapeutic target, we developed an anti-CCRL2 antibody-drug conjugate (ADC) by conjugating an anti-CCRL2 antibody with the cytotoxic drug pyrrolobenzodiazepine (PBD), which causes DNA double-strand breaks leading to cancer cell death. The anti-CCRL2 ADC demonstrated strong CCRL2-selective cytotoxicity against cell lines derived from MDS/AML patients with TP53 mutations and erythroid features, surpassing the cytotoxic effects observed with gemtuzumab and PBD-conjugated anti-CD33 and anti-CD123 ADCs. It also induced apoptosis and suppressed the clonogenicity of primary MDS/AML bone marrow samples without affecting the survival, differentiation and clonogenicity of healthy hematopoietic stem and progenitor cells. This agent also suppressed the leukemic growth of TP53-mutated MDS/AML cell line xenografts, improving mice survival and decreasing the leukemic burden in patient-derived TP53-mutated MDS/AML xenografts. In conclusion, our study introduces CCRL2 as a potential new therapeutic target in high-risk MDS/AML. Statement of significancePyrrolobenzodiazepine(PBD)-conjugated anti-CCRL2 ADC shows anti-leukemic effect in MDS/AML models including TP53-mutated disease without affecting healthy hematopoietic cells supporting that it is a promising candidate for single-agent or combination therapies in high-risk MDS/AML.

cancer biology↗

bioRxiv2025

Dietary manipulation of intestinal microbes prolongs survival in a mouse model of Hirschsprung disease

Enterocolitis is a common and potentially deadly manifestation of Hirschsprung disease (HSCR) but disease mechanisms remain poorly defined. Unexpectedly, we discovered that diet can dramatically affect the lifespan of a HSCR mouse model (Piebald lethal, sl/sl) where affected animals die from HAEC complications. In the sl/sl model, diet alters gut microbes and metabolites, leading to changes in colon epithelial gene expression and epithelial oxygen levels known to influence colitis severity. Our findings demonstrate unrecognized similarity between HAEC and other types of colitis and suggest dietary manipulation could be a valuable therapeutic strategy for people with HSCR. AbstractHirschsprung disease (HSCR) is a birth defect where enteric nervous system (ENS) is absent from distal bowel. Bowel lacking ENS fails to relax, causing partial obstruction. Affected children often have "Hirschsprung disease associated enterocolitis" (HAEC), which predisposes to sepsis. We discovered survival of Piebald lethal (sl/sl) mice, a well-established HSCR model with HAEC, is markedly altered by two distinct standard chow diets. A "Protective" diet increased fecal butyrate/isobutyrate and enhanced production of gut epithelial antimicrobial peptides in proximal colon. In contrast, "Detrimental" diet-fed sl/sl had abnormal appearing distal colon epithelium mitochondria, reduced epithelial mRNA involved in oxidative phosphorylation, and elevated epithelial oxygen that fostered growth of inflammation-associated Enterobacteriaceae. Accordingly, selective depletion of Enterobacteriaceae with sodium tungstate prolonged sl/sl survival. Our results provide the first strong evidence that diet modifies survival in a HSCR mouse model, without altering length of distal colon lacking ENS. HighlightsO_LITwo different standard mouse diets alter survival in the Piebald lethal (sl/sl) mouse model of Hirschsprung disease, without impacting extent of distal colon aganglionosis (the region lacking ENS). C_LIO_LIPiebald lethal mice fed the "Detrimental" diet had many changes in colon epithelial transcriptome including decreased mRNA for antimicrobial peptides and genes involved in oxidative phosphorylation. Detrimental diet fed sl/sl also had aberrant-appearing mitochondria in distal colon epithelium, with elevated epithelial oxygen that drives lethal Enterobacteriaceae overgrowth via aerobic respiration. C_LIO_LIElimination of Enterobacteriaceae with antibiotics or sodium tungstate improves survival of Piebald lethal fed the "Detrimental diet". C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=94 SRC="FIGDIR/small/637436v1_ufig1.gif" ALT="Figure 1"> View larger version (15K): org.highwire.dtl.DTLVardef@d95251org.highwire.dtl.DTLVardef@1ab58caorg.highwire.dtl.DTLVardef@5260b0org.highwire.dtl.DTLVardef@49ce42_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2024

Loss of Ing4 enhances hematopoietic regeneration in multipotent progenitor cells

Despite its critical role in survival, many aspects of hematopoiesis remain unresolved. In the classical model of the hematopoietic program, quiescent hematopoietic stem cells (HSCs) sit at the top of the hematopoietic hierarchy, with the ability to self-renew and differentiate as needed. HSCs give rise to more proliferative progenitor cells, which possess multipotent potential, but have largely or completely lost self-renewal capabilities. Here, we have identified the tumor suppressor, Inhibitor of Growth 4 (Ing4), as a critical regulator of multipotent progenitor (MPP) homeostasis. In the absence of Ing4, we show that MPPs express a transcriptional program of hematopoietic activation, yet they remain quiescent with low levels of reactive oxygen species. Functionally, Ing4-deficient MPPs are capable of robust regeneration following competitive bone marrow transplantation, resulting in substantially higher blood chimerism compared to wild-type MPPs. These data suggest Ing4 deficiency promotes a poised state in MPPs, quiescent, but transcriptionally primed for activation, and capable of converting the poised state into robust repopulation upon stress. Our model provides key tools for further identification and characterization of pathways that control quiescence and regeneration in MPPs.

molecular biology↗

bioRxiv2023

Chromatin conformation dynamics during CD4+ T cell activation implicates autoimmune disease-associated genes and regulatory elements

Genome-wide association studies (GWAS) have identified hundreds of genetic signals associated with autoimmune disease. The majority of these signals are located in non-coding regions and likely impact cis-regulatory elements (cRE). Because cRE function is dynamic across cell types and states, profiling the epigenetic status of cRE across physiological processes is necessary to characterize the molecular mechanisms by which autoimmune variants contribute to disease risk. We localized risk variants from 15 autoimmune GWAS to cRE active during TCR-CD28 costimulation of naive human CD4+ T cells. To characterize how dynamic changes in gene expression correlate with cRE activity, we measured transcript levels, chromatin accessibility, and promoter-cRE contacts across three phases of naive CD4+ T cell activation using RNA-seq, ATAC-seq, and HiC. We identified [~]1,200 protein-coding genes physically connected to accessible disease-associated variants at 423 GWAS signals, at least one-third of which are dynamically regulated by activation. From these maps, we functionally validated a novel stretch of evolutionarily conserved intergenic enhancers whose activity is required for activation-induced IL2 gene expression in human and mouse, and is influenced by autoimmune-associated genetic variation. The set of genes implicated by this approach are enriched for genes controlling CD4+ T cell function and genes involved in human inborn errors of immunity, and we pharmacologically validated eight implicated genes as novel regulators of T cell activation. These studies directly show how autoimmune variants and the genes they regulate influence processes involved in CD4+ T cell proliferation and activation.

immunology↗

bioRxiv2021

Ing4-deficiency enhances HSC quiescence and confers resistance to inflammatory stress

Hematopoiesis is tightly regulated by a network of transcription factors and complexes that are required for the development and maintenance of hematopoietic stem cells (HSCs). We recently identified the tumor suppressor, Ing4, as a critical regulator of HSC homeostasis. Though the Ing4 mechanism of action remains poorly characterized, it has been shown to promote stem-like cell characteristics in malignant cells. This activity is, in part, due to Ing4 mediated regulation of several major signaling pathways, including NF-{kappa}B and c-Myc. In murine hematopoiesis, Ing4 deficiency induces G0 arrest in HSCs, while simultaneously promoting gene expression signatures associated with differentiation. This results in a poised state for Ing4-deficient HSCs. Long term HSCs are unable to overcome this block, but short-term HSCs convert the poised state into regenerative capacity during hematopoietic challenges, including irradiation and transplantation. Overall, our findings suggest that Ing4 plays a crucial role in the regulation of hematopoiesis. Our model provides key tools for further identification and characterization of pathways that control quiescence and differentiation in HSCs.

cell biology↗