Biology subjects

Makowski, L.

Publications and source records attributed to Makowski, L..

15 recordsLinked to original sources

bioRxiv2026

Targeting alpha-ketoglutarate starvation within the tumor-immune microenvironment rescues T cell effector function in cancer immunotherapy

Given its status as the leading cause of global cancer mortality, there is a critical need to enhance immunotherapy strategies for lung cancer to overcome widespread resistance to current treatments. Immunotherapy recruits the patient's immune system to attack and destroy cancer cells. While highly effective in a subset of patients, chronic exposure of immune cells to cancer cells leads to a progressive loss of effector T cell function and progression of T cell exhaustion; now considered two well-established hallmarks of immunotherapy resistance. The tumor-immune microenvironment (TIME)-driven differentiation into the exhausted T cell phenotype is marked by a loss of metabolic plasticity and epigenome-wide changes in distribution of repressive histone marks such as histone H3 subunit methylation at lysine 27 (H3K27me3). Here, we studied how these processes are connected to metabolite availability within the TIME. In vitro, chronic antigen stimulation and hypoxia led to rapid loss of effector function, associated with a suppression of alpha-ketoglutarate (aKG) intracellular concentrations in T cells. Supplementation of cell-permeable aKG led to a rescue of effector cytokine production and to improved cytotoxic capacity despite chronic antigen stimulation and hypoxia. Increased intracellular aKG levels restored the activity of H3K27 demethylases UTX and JMJD3, consistent with epigenome-wide decreased H3K27me3. In vivo, dietary supplementation with commercially available calcium-aKG (Ca-aKG) supplements led to an elevation of serum and intratumoral aKG levels associated with a significant increase of immunotherapy effectiveness in mouse models of NSCLC. Clinical samples from patients with NSCLC contained significantly decreased serum aKG levels in older NSCLC patients (>65 years of age). Analysis identified a novel association between serum aKG levels and poor immunotherapy response. Thus, our work demonstrates that intratumoral metabolite starvation can be therapeutically exploited to improve immunotherapy outcomes in non-small cell lung cancer (NSCLC).

cancer biology↗

bioRxiv2025

Rare bioactive tau oligomers from Alzheimer brain support both templated misfolding and fibril formation

In Alzheimers disease, both classical neurofibrillary tangles, and diffusible, aqueous soluble (High Molecular Weight, or HMW) species are able to support templated misfolding. How these tau proteoforms relate is uncertain. Using sequential size exclusion and anion exchange chromatography, we fractionated the HMW tau population and found both seed competent, and seed not competent proteoforms. Super resolution, atomic force, and immunogold electron microscopy confirmed that the size and conformation of both bioactive and non-bioactive tau proteoforms are similar, with dimers, trimers, and tetramers predominating. The presence of surface phosphorylation correlates with seeding capacity. Bioactive tau at fMol concentrations can induce seeding in a reporter cell. The soluble bioactive species support aggregation of a truncated repeat domain tau construct into thioflavin T positive fibrils and retain seeding activity over serial amplification in vitro and in cellulo, whereas non-bioactive oligomeric species do not. Together, these findings indicate that oligomeric assembly is required but not sufficient for seeding; instead, specific biochemical attributes of a rare oligomeric tau subset confer self-propagating, prion-like templated misfolding.

neuroscience↗

bioRxiv2025

Lung Adenocarcinoma Just Desserts: An Expanding Pie of Activating Oncogenes or a Layer Cake of Integrated Alterations

The molecular landscape of lung adenocarcinoma (LUAD) is often summarized as a "pie chart" of driver oncogenes, suggesting identification and targeting of oncogenic drivers is the best clinical approach. However, this model oversimplifies LUAD biology. Patients with identical RAS or RAF mutations exhibit heterogeneous signaling influenced by co-mutations, transcriptional programs, and lineage context. We propose a hierarchical framework integrating oncogenes within cellular context by examining canonical EGFR mutations. We defined an EGFR mutation signature (mSig) by identifying differentially expressed genes in EGFR-mutant LUADs. Semi-supervised clustering and machine learning models were used to test performance and reproducibility across independent datasets. We analyzed molecular subtypes, lineage markers, co-occurring mutations, and candidate drug targets in EGFR-mSig positive (+) versus negative (-) tumors. The EGFR mSig showed robust classification performance across datasets (AUROC = 0.83-0.95; mean NPV = 96.3%). Validated unsupervised gene expression subtypes and lung lineage markers were closely aligned with EGFR mSig status. mSig(+) tumors were identified, even in tumors without EGFR mutations. A subset of canonical RAS mutations mirrored the EGFR mutation pattern. EGFR-mutant/mSig(-) tumors were enriched for non-Bronchioid subtypes and had co-mutations in TP53 or RAS. Coordinated mutations were identified including RAS, KEAP1, STK11, TP53, and CDKN2A, supportive of prior reports. In sum, novel EGFR mSig that captures the transcriptional footprint of EGFR activation, revealed a subset of EGFR wildtype LUADs with "mutant-like" features. Lineage-informed classification highlights subtype-dependent oncogene activity and supports new therapeutic strategies. A context-specific association between RAS mutation and expression of the dual-specificity phosphatase gene DUSP4 may have therapeutic potential.

genomics↗

bioRxiv2024

Modulatory Effects of Mdivi-1 on OxLDL-Induced Metabolic Alterations, Inflammatory Responses, and Foam Cell Formation in Human Monocytes

Atherosclerosis, a major contributor to cardiovascular disease, involves lipid accumulation and inflammatory processes in arterial walls, with oxidized low-density lipoprotein (OxLDL) playing a central role. OxLDL is increased during aging and stimulates monocyte transformation into foam cells and induces metabolic reprogramming and pro-inflammatory responses, accelerating atherosclerosis progression and contributing to other age-related diseases. This study investigated the effects of Mdivi-1, a mitochondrial fission inhibitor, and S1QEL, a selective complex I-associated reactive oxygen species (ROS) inhibitor, on OxLDL-induced responses in monocytes. Healthy monocytes isolated from participants were treated with OxLDL, with or without Mdivi-1 or S1QEL, and assessed for metabolic shifts, inflammatory cytokine expression, foam cell formation, and ROS production. OxLDL treatment elevated glycolytic activity (ECAR) and expression of pro-inflammatory cytokines IL1B and CXCL8, promoting foam cell formation and mitochondrial ROS (mtROS) production. Mdivi-1 and S1QEL effectively reduced OxLDL-induced glycolytic reprogramming, inflammatory cytokine levels, and foam cell formation while limiting mtROS. These findings suggest that both Mdivi-1 and S1QEL modulate key monocyte responses to OxLDL, providing insights into potential therapeutic approaches for age-related diseases.

immunology↗

bioRxiv2024

Molecular Polymorphism of tau aggregates in Pick's disease

Tau protein plays a central role in many neuropathies. The trajectory by which tau spreads through neural networks is disease-specific but the events driving progression are unknown. This is due in part to the challenge of characterizing tau aggregates in situ. We address that challenge using in situ micro-x-ray diffraction ({micro}XRD) and micro-X-ray fluorescence (XRF) to examine tau lesions in the brain of a 79-year-old male with dementia. Neuropathological examination revealed classical forms of tau in the hippocampal formation: extensive Pick bodies in the granular layer; modest numbers of neurofibrillary tangles and dystrophic neurites in the CA4 and hilus. {micro}XRD indicated that Pick bodies are low in fibril content, whereas neurofibrillary lesions within adjacent tissue exhibit far greater density of fibrillar tau. XRF demonstrated elevated levels of zinc, calcium and phosphorous in all tau-containing lesions whereas sulfur deposition was greatest in lesions exhibiting high fibrillar content. Correlation of lesion morphology with anatomical localization, tau fibrillation and differential elemental accumulation suggests tau fibrils generate biochemically distinct microenvironments that influence lesion morphology, tau seed formation and spreading.

neuroscience↗

bioRxiv2024

Trem2 deficiency attenuates breast cancer tumor growth in lean, but not obese or weight loss, mice and is associated with alterations of clonal T cell populations

AbstractObesity is an established risk factor for breast cancer development and worsened prognosis; however, the mechanisms for this association - and the potential benefits of weight loss - have not been fully explored. The adipose environment surrounding breast tumors, which is inflamed in obesity, has been implicated in tumor progression. An emerging therapeutic target for cancer is TREM2, a transmembrane receptor of the immunoglobulin superfamily that is expressed on macrophages in adipose tissue and tumors. We utilized genetic loss of function (Trem2+/+ and Trem2-/-) models and dietary (lean, obese, and weight loss) intervention approaches to examine impacts on postmenopausal breast cancer. Remarkably, Trem2 deficiency ameliorated tumor growth in lean, but not obese or weight loss mice. Single-cell RNA sequencing, in conjunction with VDJ sequencing of tumor and tumor-adjacent mammary adipose tissue (mATTum-adj) immune cells, revealed that tumors of lean Trem2-/- mice exhibited a shift in clonal CD8+ T cells from an exhausted to an effector memory state, accompanied with increased clonality of CD4+ Th1 cells, that was not observed in any other diet-genotype group. Notably, identical T cell clonotypes were identified in the tumor and mATTum-adj of the same mouse. Finally, an immune checkpoint study demonstrated that PD-1 therapy restricted tumor growth in lean and weight loss, but not obese mice. We conclude that weight history is relevant when considering potential efficacy of TREM2 inhibition in postmenopausal breast cancer. This work reveals immunological interactions between tumors and surrounding adipose tissue, highlighting significant differences under obese and weight loss conditions.

cancer biology↗

bioRxiv2024

Determining susceptibility loci in triple negative breast cancer using a novel pre-clinical model

Breast cancer (BC) is the most common cancer and the second cause of death in US women. Our lack of understanding of how genetic variants affect molecular mechanisms that mediate BC aggression poses a substantial obstacle to advancements in cancer diagnosis and therapy. To examine genetic variants on BC traits, a novel murine model was created with robust phenotypic and genomic variation. The FVB C3(1)-T-antigen ("C3Tag") mouse develops spontaneous tumors in the mammary glands of female mice with a mean latency of 4-5 months of age. This genetically engineered mouse model (GEMM) is well established to resemble human basal-like TNBC. TNBC is an aggressive subtype with few clinical approaches and poor patient outcomes. Thus, to model human heterogeneity in BC outcomes, we systematically crossed the C3Tag GEMM into the BXD recombinant inbred family - the largest and best characterized genetic reference population. The new model is termed "BXD-BC" and F1 hybrids of the cross have isogenic genomes that are reproducible. BXD-BCs are a potent tool to determine the impact of genetic modifiers on BC tumor traits. We hypothesized that examination of BXD-BC GEMMs will enable the identification of susceptibility loci, candidate genes, and molecular networks that underlie variation of multiple BC phenotypes. Using N=29 BXD-BC strains, we demonstrated significant heritable variations in the severity of TNBC characteristics such as tumor latency, multiplicity, and survival. Interestingly, 2 BXD-BC strains never developed tumors out to 1 year of age. Thus, BXD-BC strains demonstrate variance in cancer susceptibility and progression compared to the parent C3Tag GEMM, indicating the presence of genetic modifiers. Through an unbiased systematic quantification of breast cancer severity across BXD-BC hybrids, we identified several significant quantitative trait loci (QTL) and candidate genes for specific tumor traits. In combination with public human GWAS datasets, we defined syntenic regions, candidate genes, and underlying networks through cross-species systems genetics analyses to demonstrate the translational validity of conserved, biologically relevant, and targetable candidates. Our findings suggest conserved candidates predicting TNBC patient survival. In sum, the BXD-BC resource is an innovative, reliable, and robust preclinical model that reflects robust genetic heterogeneity. Using cutting edge systems genetics, we have identified genetic modifiers of BC phenotypic variation that could be targeted to advance therapeutic limitations or as biomarkers of risk or response to therapy.

genetics↗

bioRxiv2022

Binary or non-binary fission? Reproductive mode of a predatory bacterium depends on prey size

Most eukaryotic and bacterial cells divide by binary fission, where one mother cell produces two progeny cells, or, rarely, by non-binary fission. All bacteria studied to date use only one of these two reproduction modes. Here, we demonstrate for the first time that the predatory bacterium Bdellovibrio bacteriovorus reproduces through both binary and non-binary fission. Switching between the two modes correlates with the prey size. In relatively small host cells, B. bacteriovorus undergoes binary fission; the FtsZ ring assembles in the midcell and the mother cell splits into two daughter cells. In larger host cells, B. bacteriovorus switches to non-binary fission and creates multiple FtsZ rings to produce three or more daughter cells. Completion of bacterial cell cycle critically depends on precise spatiotemporal coordination of chromosome replication and segregation with other cell-cycle events, including cell division. Our studies reveal that B. bacteriovorus always initiates chromosome replication at the invasive pole of the cell, but the spatiotemporal choreography of subsequent steps depends on the fission mode and/or the number of progeny cells. In non-binary dividing filaments producing five or more progeny cells, the last round(s) of replication may also be initiated at the noninvasive pole. Finally, we show that binary-dividing B. bacteriovorus needs to extensively rebuild the flagellated pole of the mother cell to turn it into the invasive pole of a daughter cell. Altogether, we find that B. bacteriovorus reproduces through bimodal fission and that extracellular factors, such as the host size, can shape replication choreography, providing new insights about bacterial life cycles.

molecular biology↗

bioRxiv2022

Small-angle x-ray microdiffraction from fibrils embedded in tissue thin sections

Small-angle x-ray scattering (SAXS) from fibrils embedded in a fixed, thin section of tissue includes contributions from the fibrils; the polymeric matrix surrounding the fibrils; other constituents of the tissue; and cross-terms due to the spatial correlation between fibrils and neighbouring molecules. This complex mixture severely limits the amount of information that can be extracted from scattering studies. However, availability of micro- and nano-beams has made possible measurement of scattering from very small volumes which, in some cases, may be dominated by a single fibrillar constituent. In those cases, information about the predominant species may be accessible. Nevertheless, even in these cases, the correlations between the positions of fibrils and other constituents have significant impact on the observed scattering. Here, we propose strategies to extract partial information about fibril structure and tissue organization on the basis of SAXS from samples of this type. We show that the spatial correlation function of the fibril in the direction perpendicular to the fibril axis can be computed and contains information about the predominant fibril structure and the organization of the surrounding tissue matrix. It has significant advantages over approaches based on techniques developed for x-ray solution scattering. We present examples of the calculation of correlation in different types of samples to demonstrate the kinds of information that can be obtained from these measurements. SynopsisThe availability of micro- and nano- x-ray beams is making possible measurement of scattering from very small volumes, opening possibilities for deriving in situ structural information on fibrillar constituents in complex materials and tissues. This work outlines a set of strategies for confronting the formidable technical obstacles to extracting useful structural information from scattering derived from these materials.

biophysics↗

bioRxiv2022

Response to immune checkpoint blockade improved in pre-clinical model of breast cancer after bariatric surgery

Bariatric surgery is becoming more prevalent as a sustainable weight loss approach, with vertical sleeve gastrectomy (VSG) being the first line of surgical intervention. We and others have shown that obesity exacerbates tumor growth while diet-induced weight loss impairs obesity-driven progression. It remains unknown how bariatric surgery-induced weight loss impacts cancer progression or alters responses to therapy. Using a pre-clinical model of diet induced obesity followed by VSG or diet-induced weight loss, breast cancer progression and immune checkpoint blockade therapy was investigated. Weight loss by bariatric surgery or weight matched dietary intervention before tumor engraftment protected against obesity-exacerbated tumor progression. However, VSG was not as effective as dietary intervention in reducing tumor burden despite achieving a similar extent of weight and adiposity loss. Circulating leptin did not associate with changes in tumor burden. Uniquely, tumors in mice that received VSG displayed elevated inflammation and immune checkpoint ligand, PD-L1. Further, mice that received VSG had reduced tumor infiltrating T lymphocytes and cytolysis suggesting an ineffective anti-tumor microenvironment. VSG-associated elevation of PD-L1 prompted us to next investigate the efficacy of immune checkpoint blockade in lean, obese, and formerly obese mice that lost weight by VSG or weight matched controls. While obese mice were resistant to immune checkpoint blockade, anti-PD-L1 potently impaired tumor progression after VSG through improved anti-tumor immunity. Thus, in formerly obese mice, surgical weight loss followed by immunotherapy reduced breast cancer burden.

cancer biology↗

bioRxiv2022

Protein Kinase C Delta Regulates Mononuclear Phagocytes and Hinders Response to Immunotherapy in Cancer

Checkpoint immunotherapy unleashes T cell antitumor potential which has revolutionized cancer treatment showing unprecedented long-term responses. However, most patients do not respond to immunotherapy which often correlates with a dysfunctional or immunosuppressive myeloid compartment. The mononuclear phagocyte system (MPS) is a sub-class of myeloid cells comprising monocytes, macrophages and dendritic cells which plays a crucial role in tissue homeostasis. However, accumulating evidence suggests that mononuclear phagocytes contribute to all phases of tumorigenesis including orchestrating inflammatory events during de novo carcinogenesis, contribution to the progression of established tumors and promotion of resistance to checkpoint blockade. Thus, targeting the MPS could be an effective strategy to enhance checkpoint blockade efficacy and promote control of tumors. Here, we found that protein kinase C delta (PKC{delta}), a serine/threonine kinase, is abundantly expressed by mononuclear phagocytes in several human and mouse tumors. PKC{delta}-/- mice were more resistant to growth of various cancers compared to wild-type mice and were more responsive to anti-PD-1 immunotherapy. Furthermore, we found that tumors from PKC{delta}-/- mice harbor a Th-1-skewed immune landscape including increased antigen cross-presentation and T cell activation. Depletion of mononuclear phagocytes in vivo altered tumor growth in wild-type mice, but not in PKC{delta}-/- mice. In addition, coinjection of PKC{delta}-/--deficient M2-like macrophages with cancer cells into wild-type mice markedly delayed tumor growth and significantly increased intratumoral T cell activation compared to wild-type M2-like macrophages coinjected with cancer cells. Finally, intrinsic loss of PKC{delta}-/- functionally reprogrammed macrophages and dendritic cells by promoting their antigen presenting and cross-presenting capacity and triggered type I and type II interferon signaling. Thus, PKC{delta} might be targeted to reprogram mononuclear phagocytes and augment checkpoint blockade efficacy.

immunology↗

bioRxiv2021

Protein crosslinking as a therapeutic strategy for SOD1-related ALS

Mutations in the gene encoding Cu-Zn superoxide dismutase 1 (SOD1) cause a subset of familial amyotrophic lateral sclerosis (fALS). One effect of these mutations is that SOD1, which is normally a stable dimer, dissociates into toxic monomers. Considerable research efforts have been devoted to developing compounds that stabilize the dimer of fALS SOD1 variants, but these have not yet resulted in an approved drug. We demonstrate that a cyclic thiosulfinate cross-linker can stabilize prevalent disease-causing SOD1 variants. The degree of stabilization afforded by cyclic thiosulfinates (up to 24 {degrees}C) is unprecedented. We show this compound works rapidly in vivo with a half-life of ~3 days. The efficacy, low toxicity, and pharmacodynamics of cross-linker mediated stabilization make it a promising therapeutic approach for SOD1-related fALS. Significance statementCyclic thiosulfinate S-XL6 enables the kinetic stabilization of ALS-associated SOD1 variants, in vivo.

neuroscience↗

bioRxiv2020

Raf promotes dimerization of the Ras G-domain with increased allosteric connections

Ras dimerization is critical for Raf activation, yet Ras alone does not dimerize. Here we show that the Ras binding domain of Raf (Raf-RBD) induces robust Ras dimerization at low surface densities on supported lipid bilayers and, to a lesser extent, in solution as observed by size exclusion chromatography and confirmed by SAXS. Community network analysis based on molecular dynamics (MD) simulations show robust allosteric connections linking the two Raf-RBD D113 residues, located in the Galectin scaffold protein binding site of each Raf-RBD molecule and 85 [A] apart on opposite ends of the dimer complex. Our results suggest that Raf-RBD binding and Ras dimerization are concerted events that lead to a high-affinity signaling complex at the membrane that we propose is an essential unit in the macromolecular assembly of higher order Ras/Raf/Galectin complexes important for signaling through the Ras/Raf/MEK/ERK pathway.

biophysics↗

bioRxiv2019

In situ SAXS of protein deposits in Alzheimer's disease

Deposits of A{beta} peptides (plaques) and tau protein (neurofibrillary tangles (NFTs)) are ubiquitous features of brain tissue in Alzheimers disease. Their contribution to disease etiology remains controversial. The molecular-to-nano-scale organization of fibrillar species in these protein aggregates remains uncertain, but may contain clues as to the contributions of these structures to disease. Whether or not all plaques are the same structure, and all tangles are the same, has implications for current hypotheses about polymorphic templated misfolding of their constituent proteins, A{beta} and tau. Here we use x-ray microdiffraction in the small-angle regime (SAXS) to probe the molecular organization of these deposits. Using unstained histological sections of human brain tissue, we demonstrate that SAXS can characterize A{beta} fibrils and tau filaments in situ. A{beta} fibrils have a cross-sectional radius of gyration (Rxc) of ~45 [A], and larger (Rxc >150 [A]) aggregates appear to represent A{beta} fibrils that have coalesced side-to-side with one another to create fibrillar bundles or macrofibrillar aggregates. Tau fibrils exhibit an Rxc of ~55 [A] with little sign of coalescence into larger structure. The in situ mapping of these structures revealed subtle variation in A{beta} structure across different brain areas and different cases.

neuroscience↗

bioRxiv2019

Dynamics of chromosome replication and its relationship to predatory attack lifestyles in Bdellovibrio bacteriovorus

Bdellovibrio bacteriovorus is a small Gram-negative, an obligate predatory bacterium that is largely found in wet, aerobic environments (i.e. soil). This bacterium attacks and invades other Gram-negative bacteria, including animal and plant pathogens. The intriguing life cycle of B. bacteriovorus consists of two phases: a free-living non-replicative attack phase wherein the predatory bacterium searches for its prey, and a reproductive phase, in which B. bacteriovorus degrades a hosts macromolecules and reuses them for its own growth and chromosome replication. Although the cell biology of this predatory bacterium has gained considerable interest in recent years, we know almost nothing about the dynamics of chromosome replication in B. bacteriovorus. Here, we performed a real-time investigation into the subcellular localization of the replisome(s) in single cells of B. bacteriovorus. Our results confirm that in B. bacteriovorus chromosome replication fires only during the reproductive phase, and show for the first time that this predatory bacterium exhibits a novel spatiotemporal arrangement of chromosome replication. The replication process starts at the invasive pole of the predatory bacterium inside the prey cell and proceeds until several copies of the chromosome have been completely synthesized. This chromosome replication is not coincident with the predator-cell division, and it terminates shortly before synchronous predator-filament septation occurs. In addition, we demonstrate that if this lifecycle fails in some cells of B. bacteriovorus, they can instead use two prey cells sequentially to complete their life cycle.\n\nImportanceNew strategies are needed to combat multidrug-resistant bacterial infections. Application of the predatory bacterium, Bdellovibrio bacteriovorus, which kills other bacteria including pathogens, is considered promising for bacterial infections. The B. bacteriovorus life cycle consists of two phases, a free-living, invasive attack phase and an intracellular reproductive phase, in which this predatory bacterium degrades the hosts macromolecules and reuses them for its own growth. To understand the use of B. bacteriovorus as a living antibiotic, it is first necessary to dissect its life cycle including chromosome replication. Here, we present for the first time a real-time investigation into subcellular localization of chromosome replication in a single cells of B. bacteriovorus. This process initiates at the invasion pole of B. bacteriovorus and proceeds until several copies of the chromosome have been completely synthesized. Interestingly, we demonstrate that some cells of B. bacteriovorus require two prey cells sequentially to complete their life cycle.

microbiology↗