Biology subjects

Shulman, Z.

Publications and source records attributed to Shulman, Z..

7 recordsLinked to original sources

bioRxiv2026

IL-13 Induces a Tuft Cell-Intrinsic CD45 Checkpoint to Limit Intestinal Type 2 Immunity

Tuft cells initiate intestinal type 2 immunity, yet the mechanisms that restrain excessive tuft cell activation remain poorly understood. Here, we identify the receptor tyrosine phosphatase CD45 (Ptprc), previously considered a hematopoietic marker, as a regulator of intestinal tuft cell function. CD45 expression is restricted to a subset of tuft cells and is induced by helminth infection and IL-13. Epithelial-specific deletion of Ptprc activated a tuft cell inflammatory program, promoted an epithelial inflammatory state, and increased eosinophil accumulation at homeostasis. During Heligmosomoides polygyrus bakeri infection, CD45 deficiency enhanced ILC2 and Th2 responses and reduced parasite burden, demonstrating that epithelial CD45 limits type 2 immunity in vivo. Accordingly, in intestinal organoids, CD45 was dispensable for IL-13-driven tuft cell differentiation but restrained IL-13-responsive transcriptional programs. Mechanistically, CD45-deficient tuft cells exhibited altered protein abundance of STAT5 and IL17RB, implicated in tuft cell immune regulation. Together, these findings identify CD45 as a tuft cell-intrinsic regulatory checkpoint that restrains intestinal type 2 immunity through an IL-13-induced negative-feedback circuit.

immunology↗

bioRxiv2025

Spatial proteomics reveals mechanisms of cell-intrinsic tryptophan metabolism controlling ovarian cancer survival

Indole-2,3-dioxygenase (IDO1) depletes tryptophan to dampen anti-tumor T cells, yet IDO1 inhibitors (IDO1i) have failed clinically. Using deep visual proteomics, we isolated IDO1 high, medium and low ovarian tumor cells in situ and found IDO1 tightly linked to interferon-{gamma} (IFN-{gamma}) signaling and heterogeneously expressed. Across orthogonal models with tunable IDO1, IFN-{gamma} killed ovarian cancer via a pathway requiring IFN-{gamma} signaling, IDO1-dependent tryptophan depletion, and a biphasic integrated stress response that initially protects from starvation and later drives death. IDO1i or tryptophan supplementation rescued these effects, promoting tumor survival. These data reveal a context-dependent, tumor-suppressive facet of IDO1 and explain how IDO1i can paradoxically favor cancer viability. Our findings call for re-evaluation of IDO1 as a target and suggest exploiting the tryptophan-starvation/GCN2-ISR axis to enhance therapy.

cancer biology↗

bioRxiv2023

TRAF3 Suppression Encourages B Cell Recruitment and Prolongs Survival of Microbiome-Intact Mice with Ovarian Cancer

BackgroundOvarian cancer (OC) has proven to be the most deadly of all gynecologic cancers. Clinical trials involving the use of immunotherapies in OC patients have produced disappointing outcomes, underscoring the necessity of identifying new immunomodulatory targets for the treatment of this cancer. MethodsWe conducted an in-vivo CRISPR screen of immunodeficient (NSG) and immune-intact wild type (WT) C57/BL6 mice to identify tumor-derived immune-escape mechanisms in a BRAC1- and TP53-deficient murine ID8 OC cell line (designated ITB1). To confirm gene expression and signaling pathway activation in ITB1 cells, we employed western blot, qPCR, immunofluorescent staining, and flow cytometry. Flow cytometry was also used to identify immune cell populations in the peritoneum of ITB1-bearing mice. To determine the presence of IgA-coated bacteria in the peritoneum of ITB1 -bearing mice and the ascites of OC patients, we employed 16S sequencing. Testing for differences was done by using Deseq2 test and two-way ANOVA test. Sequence variants (ASVs) were produced in Qiime2 and analyzed by microeco and phyloseq R packages. ResultsWe identified tumor necrosis factor receptor-associated factor 3 (TRAF3) as a tumor-derived immune suppressive mediator in ITB1 cells. Knockout of TRAF3 (TRAF3KO) activated the type-I interferon pathway and increased MHC-I expression. TRAF3KO tumors exhibited a growth delay in WT mice vs. NSG mice, which was correlated with increased B cell infiltration and activation compared to ITB1 tumors. B cells were found to be involved in the progression of TRAF3KO tumors, and B-cell surface-bound and secreted IgA levels were significantly higher in the ascites of TRAF3KO tumors compared to ITB1. The presence of commensal microbiota was necessary for B-cell activation and for delaying the progression of TRAF3KO tumors in WT mice. Lastly, we observed unique profiles of IgA-coated bacteria in the ascites of OC-bearing mice or the ascites of OC patients. ConclusionsTRAF3 is a tumor-derived immune-suppressive modulator that influences B-cell infiltration and activation, making it a potential target for enhancing anti-tumor B-cell responses in OC.

cancer biology↗

bioRxiv2022

The cellular states and fates of shed intestinal cells

The intestinal epithelium is replaced every few days1. Enterocytes are shed into the gut lumen predominantly from the tips of villi3,4, and are believed to rapidly die upon their dissociation from the tissue. However, technical limitations prohibited studying the cellular states and fates of shed intestinal cells. Here, we used bulk and single cell RNA sequencing of mouse intestinal fecal washes to demonstrate that shed epithelial cells remain viable and up-regulate distinct anti-microbial programs upon shedding. We further identify abundant shedding of immune cells, a process that is elevated in DSS-induced colitis. We find that fecal host transcriptomics mirrors changes in the intestinal tissue following perturbations. Our study suggests potential functions of shed cells in the intestinal lumen and demonstrates that host cell transcriptomes in intestinal washes can be used to probe tissue states.

cell biology↗

bioRxiv2022

Identification of a multipotent lung progenitor for lung regeneration

We recently showed that intravenous infusion of mouse or human, fetal or adult lung cells following conditioning of recipient mice leads to lung chimerism within alveolar and bronchiolar lineages, in distinct patches containing both epithelial and endothelial cells. We show here, using R26R-Confetti mice as donors, that these multi-lineage patches are derived from a single lung progenitor. FACS of adult mouse lung cells revealed that the putative patch-forming progenitors co-express the endothelial marker CD31 (PECAM-1) and the epithelial marker CD326 (EPCAM). Transplantation of lung cells from transgenic Cre/lox mice expressing nuclear GFP under the VEcad promoter (VEcad-Cre-nTnG), led to GFP+ patches comprising both GFP+ endothelial and epithelial cells in vivo, and in ex-vivo culture of CD326+CD31+ progenitors. Single cell RNA sequencing of CD326+CD31+ lung cells revealed a subpopulation expressing canonical epithelial and endothelial genes. Such double positive GFP+NKX2.1+SOX17+ cells were also detected by immunohistological staining in lungs of VEcad-Cre-nTnG (expressing nuclear GFP) mice in proximity to blood vessels. These findings provide new insights on lung progenitors and lung development and suggest a potential novel approach for lung regeneration. SummaryWe show in the present study, that multi-lineage regenerative patches in our transplantation model are derived from a single lung progenitor, co-expressing the endothelial marker CD31 and the epithelial marker CD326. These findings provide new insights on lung progenitors and lung development.

cell biology↗

bioRxiv2020

B Cell Division Capacity in Germinal Centers Depends on Myc Transcript Stabilization Through m6A mRNA Methylation and IGF2BP3 Functions

Long-lasting immunity from pathogens depends on the generation of protective antibodies through the germinal center (GC) reaction. The Myc gene produces highly short-lived transcripts which are essential for generation of high-affinity antibodies. mRNA lifetime is regulated by N6-methyladenosine (m6A)-modification of mRNAs through METTL3 activity; however, the role of this machinery in the GC remains unclear. Here, we find that m6A-modification of mRNAs is required for GC maintenance through Myc mRNA stabilization by the atypical m6A-interactor, IGF2BP3. MYC expression, activation of MYC transcriptional programs and cell-cycle progression were diminished in METTL3-deficient GC B cells. METTL3 attenuated Myc-transcript decay and overexpression of MYC in METTL3-deficient GC B cells restored the GC reaction. IGF2BP3 which was induced by CD40-signaling, reinforced MYC expression and MYC-related gene programs in GC B cells. Our findings explain how GC responses are maintained through regulation of Myc-transcript lifetime and expose new targets for manipulation in MYC-driven lymphoma. One Sentence SummaryGerminal centers depend on the m6A-machinery

immunology↗

bioRxiv2020

Sulfopin, a selective covalent inhibitor of Pin1, blocks Myc-driven tumor initiation and growth in vivo

The peptidyl-prolyl cis-trans isomerase, Pin1, acts as a unified signaling hub that is exploited in cancer to activate oncogenes and inactivate tumor suppressors, in particular through up-regulation of c-Myc target genes. However, despite considerable efforts, Pin1 has remained an elusive drug target. Here, we screened an electrophilic fragment library to discover covalent inhibitors targeting Pin1s active site nucleophile - Cys113, leading to the development of Sulfopin, a double-digit nanomolar Pin1 inhibitor. Sulfopin is highly selective for Pin1, as validated by two independent chemoproteomics methods, achieves potent cellular and in vivo target engagement, and phenocopies genetic knockout of Pin1. Although Pin1 inhibition had a modest effect on viability in cancer cell cultures, Sulfopin induced downregulation of c-Myc target genes and reduced tumor initiation and tumor progression in murine and zebrafish models of MYCN-driven neuroblastoma. Our results suggest that Sulfopin is a suitable chemical probe for assessing Pin1-dependent pharmacology in cells and in vivo. Moreover, these studies indicate that Pin1 should be further investigated as a potential cancer target.

cancer biology↗