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Sorouri, M.

Publications and source records attributed to Sorouri, M..

3 recordsLinked to original sources

BAP1 loss and PRAME expression converge to remodel the tumor-immune ecosystem during uveal melanoma progression

Uveal melanoma (UM) is characterized by a small number of recurrent genetic alterations that determine metastatic propensity. BAP1 loss and PRAME expression define the dominant prognostic axes in UM, yet how they promote malignant progression remains unclear. We profiled 190,535 cells from normal uvea, uveal nevus, primary and metastatic UM using single-cell transcriptomics, T cell receptor sequencing, spatial transcriptomics and isogenic perturbation models. Normal melanocytes, nevus cells and UM cells formed a transcriptional continuum marked by loss of differentiation and emergence of neural crest-like, stress-responsive, hypoxic-glycolytic and immune-interacting states. BAP1 loss and PRAME expression imposed distinct but convergent immunoregulatory programs, inducing interferon and TNF-NFkB signaling and MHC-I expression, with HLA-E showing the strongest response. These alterations were accompanied by macrophage and CD8+ T cell remodeling. PRAME-enriched tumor regions formed spatially organized niches enriched for macrophages and plasma cells. These findings define BAP1 loss and PRAME expression as distinct but convergent axes of tumor-immune coevolution and nominate HLA-E as a candidate mediator of immune resistance.

cancer biology↗

Metabolic reprogramming tips vaccinia virus infection outcomes by stabilizing interferon-g induced IRF1

Interferon (IFN) induced activities are critical, early determinants of immune responses and infection outcomes. A key facet of IFN responses is the upregulation of hundreds of mRNAs termed interferon-stimulated genes (ISGs) that activate intrinsic and cell-mediated defenses. While primary interferon signaling is well-delineated, other layers of regulation are less explored but implied by aberrant ISG expression signatures in many diseases in the absence of infection. Consistently, our examination of tonic ISG levels across uninfected human tissues and individuals revealed three ISG subclasses. As tissue identity and many comorbidities with increased virus susceptibility are characterized by differences in metabolism, we characterized ISG responses in cells grown in media known to favor either aerobic glycolysis (glucose) or oxidative phosphorylation (galactose supplementation). While these conditions over time had a varying impact on the expression of ISG RNAs, the differences were typically greater between treatments than between glucose/galactose. Interestingly, extended interferon-priming led to divergent expression of two ISG proteins: upregulation of IRF1 in IFN-{gamma}/glucose and increased IFITM3 in galactose by IFN- and IFN-{gamma}. In agreement with a hardwired response, glucose/galactose regulation of interferon-{gamma} induced IRF1 is conserved in unrelated mouse and cat cell types. In galactose conditions, proteasome inhibition restored interferon-{gamma} induced IRF1 levels to that of glucose/interferon-{gamma}. Glucose/interferon-{gamma} decreased replication of the model poxvirus vaccinia at low MOI and high MOIs. Vaccinia replication was restored by IRF1 KO. In contrast, but consistent with differential regulation of IRF1 protein by glucose/galactose, WT and IRF1 KO cells in galactose media supported similar levels of vaccinia replication regardless of IFN-{gamma} priming. Also associated with glucose/galactose is a seemingly second block at a very late stage in viral replication which results in reductions in herpes- and poxvirus titers but not viral protein expression. Collectively, these data illustrate a novel layer of regulation for the key ISG protein, IRF1, mediated by glucose/galactose and imply unappreciated subprograms embedded in the interferon response. In principle, such cellular circuitry could rapidly adapt immune responses by sensing changing metabolite levels consumed during viral replication and cell proliferation.

microbiology↗

MISTR: A conserved MItochondrial STress Response network revealed by signatures of evolutionary conflict

Host-pathogen conflicts leave genetic signatures of variation in homologous host genes. Using these "molecular scars" as a guide, we discovered a vertebrate-specific MItochondrial STress Response circuit (MISTR). MISTR proteins are associated with electron transport chain factors and activated by stress signals such as interferon-gamma and hypoxia. Upon stress, ultraconserved miRNAs downregulate MISTR1 followed by replacement with paralogs MISTR AntiViral (MISTRAV) or MISTR Hypoxia (MISTRH), depending on the insult. While cells lacking MISTR1 are more sensitive to apoptotic triggers, cells lacking MISTRAV or expressing the poxvirus-encoded vMISTRAV exhibit resistance to the same insults. Rapid evolution signatures across primate genomes for MISTR1 and MISTRAV indicate ancient and ongoing conflicts with pathogens. MISTR proteins are also found in plants, yeasts, and an algal virus indicating ancient origins and suggesting diverse means of altering mitochondrial function under stress. The discovery of MISTR circuitry highlights the use of evolution-guided studies to reveal fundamental biological processes.

genetics↗