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Kaminski, M.

Publications and source records attributed to Kaminski, M..

7 recordsLinked to original sources

Deep learning representations of human Immune Health for precision immunology

The human immune system is composed of [~]30-50 distinct cell types, each of which can exist in different states of activation or differentiation. Indeed, the mammalian immune system has evolved to sense and respond to infections, cancers, injuries, and changes in tissue or host homeostasis (1). Moreover, an increasingly large fraction of approved drugs target the immune system directly, and/or cause immune changes (2-4). A key feature of the immune system is to store some of this information, for example as innate or adaptive immune memory (5). In addition, rewiring of immune network architecture induced by disease, environmental exposures, drug treatments, and/or chronological age allows the immune system to store information in the pattern of connections and activity across populations of immune cells. This ensemble information storage, in addition to changes to individual cells, functions as a major way the immune system encodes aspects of immune history and future potential. Genetic information can identify inherited risk alleles, but cannot capture the continual remodeling of the immune system shaped by exposures, infection, inflammation, therapy, and aging (6, 7). To define and use such ensemble immunotypes, we developed a self-supervised deep learning framework that transforms high-dimensional immune profiles into representations of immune health. MAESTRO (MAsked Encoding Set TRansformer with self-distillatiOn) encodes a set of cells from an individual into an embedding that captures immune cell population-level organization. Pretrained on 1,792 peripheral blood samples comprising over 418 million immune cells across 13 clinical diagnoses, MAESTRO learns immune fingerprints that are stable within individuals yet diverse across populations, states of health, disease, and treatment, providing a quantitative basis for comparing immune states across individuals and over time. These fingerprints capture immune architecture beyond coarse cell type proportions, enabling patient-efficient clinical prediction using simple task specific models. MAESTRO model embeddings retain a temporal dimension of immune history and potential, reflecting signatures of past exposures and baseline features that predict future immune responses. Finally, we demonstrate a translational precision immunotherapy application by testing this approach in metastatic Pancreatic Ductal Adenocarcinoma (PDAC), where pretreatment immune landscape circuitry maps enable patient stratification and therapeutic response prediction. Overall, we developed a large, attention-based model that captures deep network architecture of immune states through self- supervised representations of immune cytometry data as a reusable foundation for precision immunology, converting immune complexity into clinically actionable embeddings for diagnosis, monitoring, and therapy selection.

immunology↗

Somatic mtDNA Mutation Burden Shapes Metabolic Plasticity in Leukemogenesis

The role of somatic mitochondrial DNA (mtDNA) mutations in leukemogenesis remains poorly characterized. To determine the impact of somatic mtDNA mutations on the process, we assessed the leukemogenic potential of hematopoietic progenitor cells (HPCs) from mtDNA mutator mice (Polg D257A) with or without NMyc overexpression. We observed a higher incidence of spontaneous leukemogenesis in recipients transplanted with heterozygous Polg HPCs and a lower incidence of NMyc-driven leukemia in those with homozygous Polg HPCs compared to controls. Although mtDNA mutations in heterozygous and homozygous HPCs caused similar baseline impairments in mitochondrial function, only heterozygous HPCs responded to and supported altered metabolic demands associated with NMyc overexpression. Homozygous HPCs showed altered glucose utilization with pyruvate dehydrogenase inhibition due to increased phosphorylation, exacerbated by NMyc overexpression. The impaired growth of NMyc-expressing homozygous HPCs was partially rescued by inhibiting pyruvate dehydrogenase kinase, highlighting a relationship between mtDNA mutation burden and metabolic plasticity in leukemogenesis. TEASERSomatic mtDNA mutations as drivers of metabolic change in the development of leukemia.

cancer biology↗

Single-stranded HDR templates with truncated Cas12a binding sequences improve knock-in efficiencies in primary human T cells

Non-viral gene editing via CRISPR-Cas12a offers an alternative to Cas9-based methods, providing better targeting of AT-rich regions, simplified guide RNA manufacturing, and high specificity. However, the efficacy of editing outcomes is subject to various factors, with template format playing a crucial role. Currently, the predominant non-viral template format for inducing homology-directed repair (HDR) after nuclease-induced DNA breaks is double-stranded DNA (dsDNA), which is toxic when transfected at high doses. Previous studies have demonstrated that using single-stranded DNA (ssDNA) with flanking double-stranded Cas-target-sequences (CTS) as a repair template for Cas9-mediated gene editing can mitigate this toxicity and increase knock-in efficiency. Here, we investigate CTS design for AsCas12a Ultra by exploring PAM orientation and binding requirements of the Cas12a-crRNA complex. Additionally, we rule out in vitro ssDNase activity of AsCas12a Ultra under cell-physiological Mg2+ conditions. Finally, we showcase the advantage of using ssDNA with double-stranded CTS end modifications (ssCTS) at high doses for delivering clinically relevant transgenes of varying sizes into three T-cell receptor-CD3 complex genes (TRAC, CD3{zeta}, CD3{varepsilon}), achieving up to 90% knock-in rates for a 0.8kb insert at the CD3{varepsilon} locus. Overall, AsCas12a Ultra and ssCTS donors represent a platform for highly efficient knock-in in primary human T cells with minimal toxicity.

immunology↗

On the ecology of Acinetobacter baumannii - jet stream rider and opportunist by nature

The natural reservoirs of the nosocomial pathogen Acinetobacter baumannii are not well defined. We previously identified white storks as a model system to study the ecology of A. baumannii. Having screened more than 1,300 white stork nestlings over a period of six years across different regions of Poland and Germany (overall isolation rate of [~]29.5%), including food chain analyses and environmental samplings, we come up with a detailed picture of the dynamics and diversity of A. baumannii in their natural habitats. Adult storks, rather than being stably colonized with strains of A. baumannii which are successively transferred to their offspring, instead initially encounter these bacteria while foraging. Among their common food sources, consisting of earthworms, small mammals, and insects, we identified earthworms as a potential source of A. baumannii, but more so the associated soil as well as plant roots. Through this, hotspot soil and compost habitats were identified which enable population dynamics to be studied over the course of the year. We demonstrate that sterilized plant material is rapidly colonized by airborne A. baumannii suggesting they patrol to search for novel habitats, being opportunist by nature. The prevalence of A. baumannii exhibited a strong seasonality and peaked during summer. The strains we collected in Poland and Germany represent more than 50% of the worldwide known diversity in terms of the intrinsic OXA-51-like {beta}-lactamase. A set of [~]400 genomes was determined and compared to a diverse set of publicly available genomes. Our pan-genome estimate of the species ([~]51,000 unique genes) more than doubles the amount proposed by previous studies. Core-genome based phylogenetic analyses illustrated numerous links between wildlife isolates and hospital strains, including ancient as well as recent intercontinental transfer. Our data further suggest massive radiation within the species early after its emergence, matching with human activity during the Neolithic. Deforestation in particular seemed to set the stage for this bloom as we found that forests do not provide conducive conditions for the proliferation of A. baumannii. In contrast, wet and nutrient-rich soil alongside rivers sampled during the summer can yield an isolation rate of [~]30%. Linking published work on the interaction between A. baumannii and fungi and on aspergillosis as a major cause of mortality in white stork nestlings to our findings, we hypothesized that fungi and A. baumannii share a long history of coevolution. Interaction studies revealed the capability of A. baumannii to adhere to fungal spores and to suppress spore germination. Taken together, the intrinsic resistance endowment and potential to acquire antibiotic resistance can be explained by coevolution with antibiotic-producing fungi and other microorganisms within soil, and resistance to desiccation stress and radiation can be interpreted in the light of intercontinental hitchhiking through fungal spores. Originality - SignificanceThe ecology of the nosocomial pathogen Acinetobacter baumannii remains poorly understood outside the hospital. Here, we present the most comprehensive study on its environmental biology to date, after having collected more than 1,450 independent isolates of which around 400 were whole genome-sequenced. This study more than doubles the size of the pan-genome of the species, illustrating both the diversity of our collection and the bias of previous work, but also the bottleneck for the establishment of lineages within the hospital environment. We reached isolation rates of about 30% both in white stork (Ciconia ciconia) nestlings and in soil samples when considering for sampling all preferences of A. baumannii we uncovered. Thus, it is now possible to study the ecology and evolution of A. baumannii in nature at an unprecedented temporal and spatial resolution. We describe the worldwide spread of A. baumannii lineages in nature as an ancient phenomenon that even surpasses that of human-associated bacteria in magnitude. This is likely due to airborne spread, putatively facilitated by association with fungal spores. We propose that A. baumannii is an opportunist by nature, using airborne patrolling to rapidly enter new suitable habitats consisting of organic matter in early stages of decomposition. Our collective data suggest that A. baumannii, early after its speciation, went through massive radiation during the Neolithic, likely due to deforestation, settlement and farming producing numerous favorable habitats. Their natural lifestyle, which requires rapid adaptability to various habitats as well as tolerance to desiccation, radiation and antibiotic stress, perfectly predispose these opportunistic pathogens to establish within the hospital setting. Comparison of genomes from environmental and clinical isolates will now enable studies of the adaptive evolution of environmental bacteria towards multidrug-resistant opportunistic pathogens.

microbiology↗

A molecular mechanism for membrane chaperoning by a late embryogenesis abundant protein

Environmental stress can result in substantial damage to proteins, membranes, and genetic material, impacting organismal survival1-3. Stress tolerance can be conferred by intrinsically disordered proteins (IDPs)4 that lack stable tertiary structure. IDPs from the large family of late embryogenesis abundant (LEA) proteins confer a fitness advantage when heterologously expressed5,6. Such protection suggests a general molecular function leading to stress tolerance, although the mechanisms remain unclear. Here, we report that a tardigrade LEA protein that confers stress tolerance in yeast acts as a molecular chaperone for the mitochondrial membrane. This protein, named HeLEA1, localizes to the mitochondrial matrix, and harbors conserved LEA sequence motifs that undergo dynamic disorder-to-helical transition upon binding to negatively charged membranes. Yeast expressing HeLEA1 show increased mitochondrial membrane fluidity, increased membrane potential, and enhanced tolerance to hyperosmotic stress under non-fermentative growth without significantly altering mitochondrial lipid composition or triggering a generic stress response. We demonstrate that membrane binding ameliorates excess surface tension, possibly by stabilizing lipid packing defects. Evolutionary analysis suggests that HeLEA1 homologs localize to different membrane-bound organelles and share similar sequence and biophysical features. We suggest that membrane chaperoning by LEA proteins represents a general biophysical solution that can operate across the domains of life.

biophysics↗

Specific induction of double negative B cells during protective and pathogenic immune responses

1Double negative (DN) (CD19+CD20lowCD27-IgD-) B cells are expanded in patients with autoimmune and infectious diseases; however their role in the humoral immune response remains unclear. Using systematic flow cytometric analyses of peripheral blood B cell subsets, we observed an inflated DN B cell population in patients with variety of active inflammatory conditions: myasthenia gravis, Guillain-Barre syndrome, neuromyelitis optica spectrum disorder, meningitis/encephalitis, and rheumatic disorders. Furthermore, we were able to induce DN B cells in healthy subjects following vaccination against influenza and tick borne encephalitis virus. Transcriptome analysis revealed a gene expression profile in DN B cells that clustered with naive B cells, memory B cells, and plasmablasts. Immunoglobulin VH transcriptome sequencing and analysis of recombinant antibodies revealed clonal expansion of DN B cells, that were targeted against the vaccine antigen. Our study suggests that DN B cells are expanded in multiple inflammatory neurologic diseases and represent an inducible B cell population that responds to antigenic stimulation, possibly through an extra-follicular maturation pathway.

immunology↗

MYCN Amplification and ATRX Mutations are Incompatible in Neuroblastoma

Aggressive cancers often have activating mutations in growth-controlling oncogenes and inactivating mutations in tumor-suppressor genes. In neuroblastoma, amplification of the MYCN oncogene and inactivation of the ATRX tumor-suppressor gene correlate with high-risk disease and poor prognosis. Here we show that ATRX mutations and MYCN amplification are mutually exclusive across all ages and stages in neuroblastoma. Using human cell lines and mouse models, we found that elevated MYCN expression and ATRX mutations are incompatible. Elevated MYCN levels promote metabolic reprogramming, mitochondrial dysfunction, reactive-oxygen species generation, and DNA-replicative stress. The combination of replicative stress caused by defects in the ATRX-histone chaperone complex and that induced by MYCN-mediated metabolic reprogramming leads to synthetic lethality. Therefore, ATRX and MYCN represent an unusual example, where inactivation of a tumor-suppressor gene and activation of an oncogene are incompatible. This synthetic lethality may eventually be exploited to improve outcomes for patients with high-risk neuroblastoma.

cancer biology↗