Biology subjects

Singh, P.

Publications and source records attributed to Singh, P..

At least 127 records · Page 7Linked to original sources

bioRxiv2023

Derivation of trophoblast stem cells unveils unrestrained potential of mouse ESCs and epiblast

mESCs and epiblast are considered to follow strict lineage adherence and lack the potential to contribute to trophoectoderm. Here, we report the derivation of trophoblast stem cells (ESTS) from the mESCs. The single-cell transcriptome and molecular characterization of ESTS show similarity with TSCs. They efficiently integrate into the TE compartment of the blastocyst and contribute to the placenta during development. We discovered GSK3{beta} as a critical regulator of the TE fate of ESCs. It plays a vital stage-specific role during ESTS derivation. We further show {beta}-CATENIN and an intron-I regulatory element of Cdx2 are essential for the TE fate of ESCs. We further show that the mouse epiblast can readily differentiate into TE lineage. In contrast to the paradigm of the restricted potential of pluripotent ESCs and epiblast, our data shows that murine ESCs and epiblast have the unrestrained developmental potential for extraembryonic lineages.

developmental biology↗

bioRxiv2023

Efficient self-organization of blastoids solely from mouse ESCs is facilitated by transient reactivation of 2C gene network

Human pluripotent stem cells (hPSCs) can self-organize into a blastocyst-like structure (blastoid) by virtue of their full developmental potential. The pluripotent mouse embryonic stem cells (mESC) are considered to lack this potential and hence can form blastoids only when combined with trophoblast stem cells. We performed a small molecule and cytokine screen to demonstrate that mESC have full potential to efficiently self-organize themselves into E-blastoids (ESC-blastoids). The morphology, cell lineages and the transcriptome of these blastoids resemble the mouse blastocyst. The E-blastoids undergo implantation and in utero development in mice. The transient reactivation of the 2C-gene network by retinoid signaling is essential for E-blastoid generation. GSK3{beta} activity is critical for retinoid signaling and consequent 2C gene network activation. Collectively, the mESC possess full developmental potential to generate blastoids similar to hPSCs and other mammals. The plasticity of PSCs to self-organize into blastoids is not exclusive to humans or larger mammals; rather, it could be a general feature shared by most mammals, including rodents.

developmental biology↗

bioRxiv2023

Genome size, genetic diversity, and phenotypic variability imply the effect of genetic variation instead of ploidy on trait plasticity in the cross-pollinated tree species ofmulberry

Genome size, genetic diversity, and phenotypic vitiation were estimated to develop a model-based population structure and identify ploidy-associated traits of a wide collection of cross-pollinated, highly heterozygous tree species of Morus.Elucidation of genome size (GS), genetic and phenotypic variation is the fundamental aspect of crop improvement programs. Mulberry is a cross-pollinated, highly heterozygous tree eudicot, and comprised of huge ploidy variation with great adaptability across the world. However, because of inadequate information on GS, ploidy-associated traits, as well as the correlation between genetic and phenotypic variation hinder the further improvement of mulberry. In this present research, a core set of 157 germplasm accessions belonging to eight accepted species of Morus including promising functional varieties were chosen to represent the genetic spectrum from the whole germplasm collection. To estimate the GS, accessions were subjected to flow cytometry (FCM) analysis and the result suggested that four different ploidies (2n=2x, 3x, 4x, and 6x) with GS ranging from 0.72{+/-}0.005 (S-30) to 2.89{+/-}0.015 (M. serrata), accounting [~]4.01 fold difference. The predicted polyploidy was further confirmed with metaphase chromosome count. In addition, the genetic variation was estimated by selecting a representative morphologically, diverse population of 82 accessions comprised of all ploidy variations using simple sequence repeats (SSR). The estimated average Polymorphism Information Content (PIC) and expected heterozygosity showed high levels of genetic diversity. Additionally, three populations were identified by the model-based population structure (k=3) with a moderate level of correlation between the populations and different species of mulberry, which imply the effect of genetic variation instead of ploidy on trait plasticity that could be a consequence of the high level of heterozygosity imposed by natural cross-pollination. Further, the correlation between ploidies, especially diploid and triploid with selected phenotypic traits was identified, however, consistency could not be defined with higher ploidy levels (>3x). Moreover, incite gained here can serve as a platform for future omics approaches to the improvement of mulberry traits.

genetics↗

bioRxiv2023

Consolidated Bioprocessing of Lignocellulosic Biomass Poplar to Produce Short-Chain Esters by Clostridium thermocellum

Consolidated bioprocessing (CBP) of lignocellulosic biomass using cellulolytic microorganisms presents a promising sustainable and economical biomanufacturing platform where enzyme production, biomass hydrolysis, and fermentation to produce biofuels, biochemicals, and biomaterials occur in a single step. However, understanding and redirecting metabolism of microorganisms to be compatible with CBP to produce non-native metabolites are limited. In this study, we metabolically engineered a cellulolytic thermophile Clostridium thermocellum and demonstrated its compatibility with CBP integrated with a mild Co-solvent Enhanced Lignocellulosic Fractionation (CELF) pretreatment for conversion of hardwood poplar into short-chain esters (i.e., ethyl acetate, ethyl isobutyrate, isobutyl acetate, isobutyl isobutyrate) with broad use as solvents, flavors, fragrances, and biofuels. A recombinant C. thermocellum engineered with deletion of carbohydrate esterases and stable overexpression of a thermostable alcohol acetyltransferase improved the target esters production without compromised deacetylation activities. We discovered these esterases exhibited promiscuous thioesterase activities and their deletion improved ester production by increasing isobutanol flux and rerouting the native electron and carbon fermentative metabolism besides their known major function of ester degradation. The total ester production could be further enhanced up to 80-fold and the composition of short-chain esters could be modified by deleting lactate biosynthesis and/or CELF-pretreated poplar under different pretreatment conditions.

bioengineering↗

bioRxiv2023

Representations of carbon dioxide in the mosquito antennal lobe

Carbon dioxide (CO2) is one of the prominent sensory cues used by mosquitoes to find hosts for blood-feeding. CO2 is detected on the maxillary palps by capitate peg sensory neurons, whose axons project to the antennal lobe in the brain. Behavioral studies have shown that mosquitoes prefer non-homogenous plumes of CO2 over homogenous plumes and CO2 greatly enhances the attractiveness of lactic acid, a skin volatile. However, the neural mechanisms underlying these behavioral preferences are not known. Using in vivo intracellular recordings from projection neurons and local neurons in the antennal lobe, along with single sensillum recordings from the maxillary palps, we checked the representations of CO2 in the first two layers of the Aedes aegypti olfactory system. We found that the preference to non-homogeneous plumes of CO2 and its synergistic attraction with lactic acid are encoded in the PN population responses. Our results provide a foundation for understanding CO2-mediated host-attraction in mosquitoes.

neuroscience↗

bioRxiv2023

Rapid systemic responses of Arabidopsis to waterlogging stress

Waterlogging stress (WLS) negatively impacts the growth and yield of crops resulting in heavy losses to agricultural production. Previous studies revealed that WLS induces a systemic response in shoots that is partially dependent on the plant hormones ethylene and abscisic acid. However, the role of rapid cell-to-cell signaling pathways, such as the reactive oxygen species (ROS) and calcium waves, in systemic responses of plants to WLS is unknown at present. Here we reveal that an abrupt WLS treatment of Arabidopsis thaliana plants growing in peat moss triggers systemic ROS and calcium wave responses, and that the WLS-triggered ROS wave response of Arabidopsis is dependent on the ROS generating RESPIRATORY BURST OXIDASE HOMOLOG D (RBOHD), calcium-permeable channels GLUTAMATE-LIKE RECEPTOR 3.3 and 3.6 (GLR3.3 and GLR3.6), and aquaporin PLASMA MEMBRANE INTRINSIC PROTEIN 2;1 (PIP2;1) proteins. We further show that WLS is accompanied by a rapid systemic transcriptomic response that is evident as early as 10 min following waterlogging initiation, includes many hypoxia-response transcripts, and is partially dependent on RBOHD. Interestingly, the abrupt WLS of Arabidopsis resulted in the triggering of a rapid hydraulic wave response and the transient opening of stomata on leaves. Taken together, our findings reveal that the initiation of WLS in plants is accompanied by rapid systemic physiological and transcriptomic responses that involve the ROS, calcium, and hydraulic waves. These findings reveal that systemic plant responses to WLS are rapid and at least partially dependent on cell-to-cell signaling mechanisms.

plant biology↗

bioRxiv2023

Genetic screening identifies integrated stress response kinase HRI (EIF2AK1) as a negative regulator of PINK1 and mitophagy signalling

Loss-of-function mutations of the PINK1 kinase cause familial early-onset Parkinsons disease (PD). PINK1 is activated upon mitochondrial damage to phosphorylate Ubiquitin and Parkin to trigger removal of damaged mitochondria by autophagy (mitophagy). PINK1 also indirectly phosphorylates a subset of Rab GTPases including Rab8A. We have performed an siRNA screen targeting all human Ser/Thr kinases in HeLa cells and discovered that knockdown of the eukaryotic translation initiation factor 2-alpha kinase 1 (EIF2AK1), also known as heme-regulated inhibitor (HRI) kinase, a branch of the integrated stress response (ISR), selectively enhances mitochondrial depolarization-induced stabilization of PINK1 and increased phosphorylation of ubiquitin and Rab8A. We confirm our findings in multiple human cell lines, including SK-OV-3, U2OS and ARPE-19 cells. Knockdown of the upstream mitochondrial-cytosol relay component, DELE1, enhanced PINK1 stabilisation and activation similar to EIF2AK1 knockdown. Strikingly, we demonstrate that the small molecule ISR inhibitor, ISRIB, also enhances PINK1 activation and signaling under conditions of mitochondrial damage. Using the mito-QC mitophagy reporter in human cells, we observe that EIF2AK1 knockdown or ISRIB treatment significantly enhances PINK1-dependent mitophagy but does not alter deferiprone-induced mitophagy. Our findings indicate that the DELE1-EIF2AK1 ISR signaling relay is a negative regulator of PINK1-dependent mitophagy and suggest that inhibitors of DELE1-EIF2AK1 and/or ISRIB analogues could have therapeutic benefits in PD and related disorders.

biochemistry↗

bioRxiv2023

A rapid method to quantify vein density in C4 plants using starch staining

C4 photosynthesis has evolved multiple times in the angiosperms and typically involves alterations to the biochemistry, cell biology and development of leaves. One common modification found in C4 plants compared with the ancestral C3 state is an increase in vein density such that the leaf contains a larger proportion of bundle sheath cells. Recent findings indicate that there may be significant intra-specific variation in traits such as vein density in C4 plants but to use such natural variation for trait-mapping, rapid phenotyping would be required. Here we report a high-throughput method to quantify vein density that leverages the bundle sheath specific accumulation of starch found in C4 species. Starch staining allowed high-contrast images to be acquired that permitted image analysis using a MATLAB-based program. The method works for the dicotyledon Gynandropsis gynandra where significant variation in vein density was detected between natural accessions, and the monocotyledon Zea mays where no variation was apparent in the genotypically diverse lines assessed. We anticipate this approach will be useful to map genes controlling vein density in C4 species demonstrating natural variation for this trait. One sentence summaryPreferential accumulation of starch in bundle sheath cells of C4 plants allows high-throughput phenotyping of vein density.

plant biology↗

bioRxiv2023

O-GlcNAc modification forces the formation of an α-Synuclein amyloid-strain with notably diminished seeding activity and pathology

The process of amyloid fibril formation remains one of the primary targets for developing diagnostics and treatments for several neurodegenerative diseases (NDDs). Amyloid-forming proteins such -Synuclein and Tau, which are implicated in the pathogenesis of Alzheimers and Parkinsons disease, can form different types of fibril structure, or strains, that exhibit distinct structures, toxic properties, seeding activities, and pathology spreading patterns in the brain. Therefore, understanding the molecular and structural determinants contributing to the formation of different amyloid strains or their distinct features could open new avenues for developing disease-specific diagnostics and therapies. In this work, we report that O-GlcNAc modification of -Synuclein monomers results in the formation of amyloid fibril with distinct core structure, as revealed by Cryo-EM, and diminished seeding activity in seeding-based neuronal and rodent models of Parkinsons disease. Although the mechanisms underpinning the seeding neutralization activity of the O-GlcNAc modified fibrils remain unclear, our in vitro mechanistic studies indicate that heat shock proteins interactions with O-GlcNAc fibril inhibit their seeding activity, suggesting that the O-GlcNAc modification may alter the interactome of the -Synuclein fibrils in ways that lead to reduce seeding activity in vivo. Our results show that post-translational modifications, such as O-GlcNAc modification, of -Synuclein are key determinants of -Synuclein amyloid strains and pathogenicity. These findings have significant implications for how we investigate and target amyloids in the brain and could possibly explain the lack of correlation between amyloid burden and neurodegeneration or cognitive decline in some subtypes of NDDs.

biochemistry↗

bioRxiv2023

Control of telomere length in yeast by SUMOylated PCNA and the Elg1 PCNA unloader

Telomeres cap and protect the linear eukaryotic chromosomes. Telomere length is determined by an equilibrium between positive and negative regulators of telomerase activity. A systematic screen for yeast mutants that affect telomere length maintenance in the yeast Saccharomyces cerevisiae revealed that mutations in any of [~]500 genes affects telomere length. One of the genes that, when mutated, causes telomere elongation is ELG1, which encodes an unloader of PCNA, the processivity factor for replicative DNA polymerases. PCNA can undergo SUMOylation on two conserved residues, K164 and K127, or ubiquitination at lysine 164. These modifications have already been implicated in genome stability processes. We report that SUMOylated PCNA acts as a signal that positively regulates telomerase activity. We also uncovered physical interactions between Elg1 and the CST (Cdc13-Stn1-Ten) complex, and dissected the mechanism by which Elg1 and Stn1 negatively regulates telomere elongation, coordinated by SUMO. We present a model that provides mechanistic insights on how chromosomal replication and telomere elongation are coordinated.

molecular biology↗

bioRxiv2023

System analysis of differentially expressed miRNAs in hexaploid wheat display tissue-specific regulatory role during Fe deficiency response

BackgroundIron (Fe) is an essential mineral element, and its deficiency in soil largely affects crop productivity. In plants, the molecular mechanisms underlying the genetic regulation of Fe deficiency responses have yet to be well understood. Specifically, microRNA (miRNA) mediated regulation of Fe deficiency response and its regulatory network is largely elusive. In the current work, we utilized a whole genome transcriptomic approach to identify the Fe deficiency-responsive miRNAs to understand the molecular mechanisms of Fe deficiency response in wheat seedlings. The study also identifies nine novel miRNAs putatively involved in Fe deficiency response. Further, the identified miRNAs showed tissue preferences relating them to differential mechanisms against Fe deficiency. ResultsIn the present study, we performed small RNA-targeted whole genome transcriptome analysis to identify the involvement of sRNAs in Fe deficiency response. The analysis identified 105 differentially expressed miRNAs corresponding to Fe deficiency response, among them, 9 miRNAs were found to be novel in this study. Interestingly, tissue-specific regulation of Fe deficiency response also participates through miRNA-mediated regulation. We identified 17 shoot specific miRNAs and 18 root-specific miRNAs with altered expression. We validated the tissue specificity of these miRNAs by stem-loop quantitative RT-PCR. Further, an attempt was made to predict their targets to speculate their participation in Fe deficiency response. This miRNA target prediction analysis suggested a few major targets of the identified miRNAs, such as multicopper oxidases, E3 ubiquitin ligases, GRAS family, and WRKY transcription factors previously known to play key roles in Fe homeostasis. Our analysis of selected miRNAs also confirmed a temporal regulation of the response. ConclusionThe first information generated here will classify the repository of wheat miRNAs (with few novel miRNAs) for their role in Fe deficiency response. Our work provides insights into miRNA-mediated regulatory pathways during Fe deficiency.

plant biology↗

bioRxiv2023

How useful is genomic data for predicting maladaptation to future climate?

Methods using genomic information to forecast potential population maladaptation to climate change are becoming increasingly common, yet the lack of model validation poses serious hurdles toward their incorporation into management and policy. Here, we compare the validation of maladaptation estimates derived from two methods - Gradient Forests (GFoffset) and the Risk Of Non-Adaptedness (RONA) - using exome capture pool-seq data from 35 to 39 populations across three conifer taxa: two Douglas-fir varieties and jack pine. We evaluate sensitivity of these algorithms to the source of input loci (markers selected from genotype-environment associations [GEA] or those selected at random). We validate these methods against two-year and 52-year growth and mortality measured in independent transplant experiments. Overall, we find that both methods often better predict transplant performance than climatic or geographic distances. We also find that GFoffset and RONA models are surprisingly not improved using GEA candidates. Even with promising validation results, variation in model projections to future climates makes it difficult to identify the most maladapted populations using either method. Our work advances understanding of the sensitivity and applicability of these approaches, and we discuss recommendations for their future use.

evolutionary biology↗

bioRxiv2023

Separation of function mutations in microcephaly protein CPAP/CENPJ, reveal its role in regulating centriole number and length.

Centriole are microtubule-based cylindrical structures characterized by their definite size, and stable, slow growing microtubules. The centriole core protein CPAP/CENPJ is known to act as a molecular cap regulating centriole length by interacting with microtubule/tubulin via the conserved microtubule destabilizing, PN2-3, and microtubule stabilizing, A5N, domains. The C-terminus of CPAP has a conserved glycine-rich G-box/TCP domain (1050-1338 amino acids). This region is involved in centriole cartwheel assembly by interacting with the cartwheel protein STIL. However, previously reported primary microcephaly mutation mapped in the G-box of CPAP, i.e., E1235V (MCPH6) affects centriole length via an unknown mechanism. Recently, another primary microcephaly mutation has been mapped to this region of CPAP, i.e., D1196N. However, the effect of D1196N on CPAP functioning is not known. We simultaneously characterized these two MCPH mutations in the G-box of CPAP. We identified that despite affecting the same domain of CPAP, they affect distinct CPAP functions at the centriole. The E1235V mutation caused an overly long centriole, and the D1196N mutation increased the centriole number. Interestingly, both these mutations affect CPAP direct interaction with the cartwheel protein STIL, which is involved in CPAP recruitment to the centriole. Accordingly, the CPAP E1235V centriole localization is significantly affected at the centriole. However, CPAP D1196N can still localize to centriole at levels comparable to the wild-type CPAP. We show that CPAP utilizes an alternate CEP152-dependent route for centriole recruitment. Importantly, our work highlights the importance of the CPAP region outside direct microtubule/tubulin interacting domains in influencing CPAP activity in cartwheel assembly and centriole length. Perhaps, this is why deleterious naturally occurring missense mutations are frequently occurring in this particular region of CPAP in primary microcephaly.

cell biology↗

bioRxiv2023

Spermidine Is The Main Polyamine Required By Intracellular Parasites For Survival Within Host Erythrocytes

Intracellular eukaryotic pathogens such as Babesia and Plasmodium, the agents of human babesiosis and malaria, require salvage or de novo synthesis of several nutrients for survival in human erythrocytes. One such nutrient is putrescine, which is either transported from the host or synthesized from ornithine and serves as a precursor for the biosynthesis of two other polyamines: spermidine and spermine. However, the specific polyamines required by these parasites for survival and the molecular process they control remain unknown. We show in both B. duncani and P. falciparum that spermidine is the main product of the polyamine biosynthesis machinery required for parasite survival. Simultaneous inhibition of spermidine synthesis from putrescine and catabolism from spermine results in cell death and parasite survival can only be rescued by spermidine. Finally, we demonstrate that spermidines essential function in these parasites is through regulation of protein translation via hypusination of the translation initiation factor eIF5A.

microbiology↗

bioRxiv2022

Accuracy of functional gene community detection in Saccharomyces cerevisiae by maximizing Generalized Modularity Density

Identifying functionally-cohesive gene communities from large data sets of expression data for individual genes is a key approach to understanding the molecular components of biological processes. Here, we compare the accuracy of twelve different approaches to infer gene co-expression networks and then find gene communities within the networks. Among the approaches used are ones involving a recently developed clustering method that identifies communities by maximizing Generalized Modularity Density (Qg). RNA-Seq data from 691 samples of S. cerevisiae (yeast) are analyzed. These data have been obtained from organisms grown under diverse environmental and developmental conditions and encompass varied mutant lines. To assess the accuracy of different approaches, we introduce a statistical measure, the Average Adjusted Rand Index (AARI) score, which compares their results to Gene Ontology (GO) term associations. Inferring gene networks using the Context Likelihood of Relatedness (CLR) and subsequently clustering by maximizing Generalized Modularity Density is found to identify the most significant functional communities. Also, to quantify the extent to which the identified communities are biologically relevant, a GO term enrichment analysis is performed. The results indicate that many of the communities found by maximizing Generalized Modularity Density are enriched in genes with known biological functions. Furthermore, some of the communities contain genes of unknown function, enabling inference of potentially novel functional interactions involving these genes. Furthermore, some genes are species-specific orphan genes; assignment of these orphan genes to communities enriched in a particular biological process provides a method to infer the biological process in which they are involved. We focus on a few communities that are highly significantly enriched in a particular biological process, and develop experimentally-testable predictions about the orphan genes in these communities. Author summaryFinding gene communities that are of biological relevance from expression profiles of individual genes is a critical approach to understanding biological processes and their molecular components. Various computational methods have been developed to infer underlying metabolic and regulatory networks and to identify functional communities of genes. Which network inference and clustering methods works best to achieve this goal has largely remained an open question. Here, using genome-wide transcriptomic data for S. cerevisiae, we systematically compare the effectiveness of several commonly used network inference and clustering methods. We rank these methods by comparing the clusters obtained by different methods to Gene Ontology (GO) terms. We find that inferring gene networks using a method known as the Context Likelihood of Relatedness (CLR) and subsequently clustering by maximizing Generalized Modularity Density identifies the most significant functional communities.

systems biology↗

bioRxiv2022

Identification of Disease Modules Using Higher-Order Network Structure

MotivationHigher-order interaction patterns among proteins have the potential to reveal mechanisms behind molecular processes and diseases. While clustering methods are used to identify functional groups within molecular interaction networks, these methods largely focus on edge density and do not explicitly take into consideration higher-order interactions. Disease genes in these networks have been shown to exhibit rich higher-order structure in their vicinity, and considering these higher-order interaction patterns in network clustering have the potential to reveal new disease-associated modules. ResultsWe propose a higher-order community detection method which identifies community structure in networks with respect to specific higher-order connectivity patterns beyond edges. Higher-order community detection on four different protein-protein interaction networks identifies biologically significant modules and disease modules that conventional edge-based clustering methods fail to discover. Higher-order clusters also identify disease modules from GWAS data, including new modules that were not discovered by top-performing approaches in a Disease Module DREAM Challenge. Our approach provides a more comprehensive view of community structure that enables us to predict new disease-gene associations. Availabilityhttps://github.com/Reed-CompBio/graphlet-clustering

systems biology↗

bioRxiv2022

Transcriptome and biochemical analysis pinpoint multi-layered molecular processes associated with iron deficiency tolerance in hexaploid wheat

Iron (Fe) is an essential nutrient for plants that is indispensable for many physiological activities. Although few genotypes were identified with contrasting tolerance to Fe deficiency, the molecular insight into the distinct biochemical and transcriptional responses determining the trait is poorly known. This study aimed to identify the molecular and biochemical basis for the contrasting Fe deficiency tolerance in wheat genotype showing tolerance to Fe deficiency (cv. Kanchan-KAN) compared to susceptible (cv. PBW343-PBW) cultivar. Under Fe deficiency, the KAN show delayed chlorosis, high SPAD values and low malondialdehyde activity compared to PBW. The shoot transcriptomics studies show that a large set of genes for photosynthetic pathways were highly induced in PBW, suggesting its sensitivity to Fe deficiency. Although, under Fe deficiency, both the cultivars show distinct molecular re-arrangements, including high expression of genes involved in Fe uptake (including membrane transporters) and mobilization, the gene expression level was higher in KAN. Furthermore, the KAN cultivar also shows high ubiquitination activity in the shoot tissue suggesting a high turnover of proteins in the tolerant cultivar. These observations were also co-related with the high root phytosiderophores biosynthesis and its release that contributes to the enhanced Fe translocation index in KAN. Overall, our work provides the key link to understanding the mechanistic insight for the Fe deficiency tolerance in hexaploid wheat. This will enable wheat breeders to select genotypes for better Fe use efficiency for agriculture.

plant biology↗

bioRxiv2022

Myeloid-specific KDM6B inhibition sensitizes Glioblastoma to PD1 blockade

Glioblastoma (GBM) tumors are enriched in immune-suppressive myeloid cells and are refractory to immune checkpoint therapy (ICT). Targeting epigenetic pathways to reprogram the functional phenotype of immune-suppressive myeloid cells to overcome resistance to ICT remains unexplored. Single-cell and spatial transcriptomic analyses of human GBM tumors demonstrated high expression of an epigenetic enzyme - histone 3 lysine 27 demethylase (KDM6B) in intra- tumoral immune-suppressive myeloid cell subsets. Importantly, myeloid-cell specific Kdm6b deletion enhanced pro-inflammatory pathways and improved survival in GBM tumor-bearing mice. Mechanistic studies elucidated that the absence of Kdm6b enhances antigen-presentation, interferon response and phagocytosis in myeloid cells by inhibiting mediators of immune suppression including Mafb, Socs3 and Sirpa. Further, pharmacological inhibition of KDM6B mirrored the functional phenotype of Kdm6b deleted myeloid cells and enhanced anti-PD1 efficacy. Thus, this study identified KDM6B as an epigenetic regulator of the functional phenotype of myeloid cell subsets and a potential therapeutic target to improve response to ICT.

immunology↗