Biology subjects

Henriksson, J.

Publications and source records attributed to Henriksson, J..

At least 19 recordsLinked to original sources

bioRxiv2026

Assessing chemical toxicity across Eukaryota using multimodal transformers

Biodiversity is globally threatened by chemical pollution, yet toxicity data remain unavailable for millions of species and tens of thousands of chemicals, severely limiting our ability to assess ecological impacts. Here we present TRIDENT-2, a multimodal artificial intelligence model for predicting chemical toxicity across evolutionarily diverse eukaryotic species. Trained on 560,780 toxicity assays spanning 82,775 chemicals, 6,793 species, and multiple exposure scenarios, TRIDENT-2 accurately predicts toxicity across Eukaryota with an average median absolute error ranging from 1.76 to 3.80. By jointly learning from chemical, biological, and experimental information, it remains accurate across broad chemical and taxonomic distances, allowing for toxicity assessment for species and chemicals beyond the current experimental evidence. Our findings demonstrate that artificial intelligence can help overcome longstanding data limitations in ecotoxicology, paving the way for improved decision-making and reducing chemical impacts on biodiversity and ecosystems.

pharmacology and toxicology↗

bioRxiv2025

Large-scale insights into the biosynthetic potential of the Bacillus cereus group

Bacterial secondary metabolites (SMs) are a critical source of natural product-derived drugs. However, SM discovery efforts have focused overwhelmingly on Actinomycetes, potentially overlooking other key producers. Here, we explore the biosynthetic potential of the Bacillus cereus group, an underexplored complex of SM producers. Using a combined rule- and machine learning-based approach, we mine an unprecedented number of B. cereus group genomes (n = 9,744) for SM-producing biosynthetic gene clusters (BGCs; n = 200,196). Notably, 158,678 B. cereus group BGCs (78.2%) did not cluster with previously described BGCs, suggesting new chemical scaffolds to be explored. B. pseudomycoides was particularly prolific in terms of its SM production potential (30.8 BGC families/genome, Kruskal-Wallis p < 0.0001), and we identify a previously uncharacterized, B. pseudomycoides-unique peptide. Overall, our study represents the largest survey of B. cereus group biosynthetic potential to date and posits the complex as an under-queried SM resource.

microbiology↗

bioRxiv2025

Scalable and interpretable secretion system annotation with Sismis

Secretion systems play critical roles in bacterial growth, survival, and pathogenesis. Genes encoding secretion system components often co-occur together as gene clusters in bacterial (meta)genomes. However, existing tools for secretion system annotation are unable to utilize genomic context to make predictions and are unable to detect secretion systems of novel architecture. Here, we present Sismis (secretion system discovery tool; https://github.com/lmc297/Sismis), a scalable, interpretable, machine learning-based tool, which detects and classifies single-locus secretion systems in bacterial (meta)genomes with high accuracy (test set area-under-the-curve [AUC] values of 0.71 and 0.92 for precision-recall [PR] and receiver operating characteristic [ROC] curves, respectively). When applied to {approx}700k prokaryotic (meta)genomes, Sismis identifies 747, 439 total secretion systems comprising 15, 612 major secretion system families, >80% of which contain no previously known/annotated secretion systems. To facilitate further exploration of these data, we present the Sismis Atlas (https://sismis.microbe.dev/), an interactive secretion system database, which we use to identify a largely uncharacterized cluster of secretion systems with tight adherence (Tad) pili-like characteristics. Altogether, Sismis and its companion atlas enable accurate and interpretable secretion system annotation, exploration, and discovery at an unprecedented scale. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=77 SRC="FIGDIR/small/675188v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@89dec2org.highwire.dtl.DTLVardef@17fa652org.highwire.dtl.DTLVardef@18064b9org.highwire.dtl.DTLVardef@54deaa_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2024

Generative Models Validation via Manifold Recapitulation Analysis

Comparing empirical distributions is central to generative model evaluation, hypothesis testing and data augmentation in high-dimensional biological data. Established methods such as energy distance summarize each point's relationship to the opposing distribution through a single expected distance, providing sensitivity to location shifts. We introduce Signature Distance (SD), a statistical distance that compares empirical distributions through the mean absolute difference of their sorted pointwise distance profiles. SD is a structural generalization of energy distance and matches its quadratic pairwise-distance cost, with an additional sorting step. In controlled experiments and on TCGA pan-cancer transcriptomic data, we show that (1) SD detects density changes with greater sensitivity than energy distance in the tested scale-contraction scenarios; (2) per-point mean-distance and signature-profile landscapes reveal the geometric mechanisms behind their different penalties; (3) linearly interpolated biological samples that receive no increased penalty from energy distance are penalized by SD; (4) SD provides a direct differentiable potential energy for model-free Langevin data expansion, with a bootstrap resampling protocol to assess the stopping epoch; and (5) SD is directly usable as a differentiable generative training loss. Code to reproduce all experiments is available at github.com/lazzaronico/signature-distance.

bioinformatics↗

bioRxiv2024

A scalable CRISPR-Cas9 gene editing system facilitates CRISPR screens in the malaria parasite Plasmodium berghei

Many Plasmodium genes remain uncharacterised due to low genetic tractability. Previous large scale knockout screens have only been able to target about half of the genome in the more genetically tractable rodent malaria parasite Plasmodium berghei. To overcome this limitation, we have developed a scalable CRISPR system called PbHiT, which uses a single cloning step to generate targeting vectors with 100 bp homology arms physically linked to a guide RNA (gRNA) that effectively integrate into the target locus. We show that PbHiT coupled with gRNA sequencing robustly recapitulates known knockout mutant phenotypes in pooled transfections. Furthermore, we provide vector designs and sequences to target the entire P. berghei genome and scale-up vector production using a pooled ligation approach. This work presents for the first time a tool for high-throughput CRISPR screens in Plasmodium for studying the parasites biology at scale.

molecular biology↗

bioRxiv2024

CRISPR-MIP replaces PCR and reveals GC and oversampling bias in pooled CRISPR screens

Pooled CRISPR screening is a powerful tool for finding the most important genes related to a biological process of interest. The quality of the generated gene list is however influenced by a range of technical parameters, such as CRISPR (single guide) sgRNA target efficiency, and further innovations are still called for. One open problem is the precise estimation of sgRNA abundances, as required for the statistical analysis. We do so using molecular inversion probes (MIPs) combined with the use of unique molecular identifiers (UMIs), thus enabling deduplication and absolute counting of cells. We show that this is a viable approach that eliminates sequencing depth bias. Furthermore, we find that GC% bias affects PCR, calling for a reanalysis of published CRISPR screen data and sgRNA efficiency estimates. We propose our method as a new gold standard for sgRNA quantification, especially for genes that are not top ranked but still of broad interest.

molecular biology↗

bioRxiv2024

The CD4 T cell epigenetic JUNB+ state is associated with proliferation and exhaustion

Adoptive cell therapy (ACT) requires the in vitro expansion of T cells, a process where currently several variables are poorly controlled. As the state and quality of the cells affects the treatment outcome, the lack of insight is problematic. To get a better understanding of the production process and its degrees of freedom, we have generated a multiome CD4 T cell single-cell atlas. We find in particular a JUNB+ epigenetic state, orthogonal to traditional CD4 T cell subtype categorization. This new state is present but overlooked in previous transcriptomic CD4 T cell atlases. We characterize it to be highly proliferative, having condensed and actively remodeled chromatin, and correlating with exhaustion. JUNB+ subsets are also linked to memory formation, as well as circadian rhythm, connecting several important processes into one state. To dissect JUNB regulation, we also derived a gene regulatory network (GRN) and developed a new explainable machine learning package, Nando. We propose potential upstream drivers of JUNB, verified by other atlases and orthogonal data. We expect our results to be relevant for optimizing in vitro ACT conditions as well as modulation of gene expression through novel gene editing.

immunology↗

bioRxiv2023

A community-curated, global atlas of Bacillus cereus sensu lato genomes for epidemiological surveillance

The ability to cause foodborne illness, anthrax, and other infections has been attributed to numerous lineages within Bacillus cereus sensu lato (s.l.). However, existing pathogen surveillance databases facilitate dangerous pathogen misidentifications when applied to B. cereus s.l., potentially hindering outbreak or bioterrorism attack response efforts. To address this, we developed BTyperDB (www.btyper.app), an atlas of B. cereus s.l. genomes with standardized, community-curated metadata. BTyperDB aggregates all publicly available B. cereus s.l. genomes (including >2,600 previously unassembled genomes) with novel genomes donated by laboratories around the world, nearly doubling the number of publicly available B. cereus s.l. genomes. To showcase its utility for pathogen surveillance, we use BTyperDB to identify emerging anthrax toxin- and capsule-harboring lineages. Overall, our study provides insight into the epidemiology of an under-studied group of emerging pathogens and highlights the benefits of inclusive, community-driven metadata FAIRification efforts.

microbiology↗

bioRxiv2023

Acute avoidance of hydrogen sulfide is modulated by external and internal states in C. elegans

Hydrogen sulfide (H2S) acts as an energy source, a toxin, and a gasotransmitter across diverse biological contexts. We use the robust locomotory responses of Caenorhabditis elegans to high levels of H2S to elucidate the molecular mechanisms underlying its acute and adaptive responses. We find that the H2S-evoked behavioral response is shaped by multiple environmental factors including oxygen (O2) levels and nutritional state, and is modulated by various pathways such as insulin, TGF-{beta}, and HIF-1 signaling, as well as by input from O2-sensing neurons. Prolonged exposure to H2S activates HIF-1 signaling, leading to the upregulation of stress-responsive genes, including those involved in H2S detoxification. This promotes an adaptive state in which locomotory speed is reduced in H2S, while responsiveness to other stimuli is preserved. In mutants deficient in HIF-1 signaling, iron storage, and detoxification mechanisms, animals display a robust initial response but rapidly enter a sleep-like behavior characterized by reduced mobility and diminished responsiveness to subsequent sensory stimuli. Furthermore, while acute production of mitochondria-derived reactive O2 species (ROS) appears to initiate the avoidance response to H2S, persistently high ROS promotes an adaptive state, likely by activating various stress-response pathways, without substantially compromising cellular H2S detoxification capacity. Taken together, our study provides comprehensive molecular insights into the mechanisms through which C. elegans modulates and adapts its response to H2S exposure.

animal behavior and cognition↗

bioRxiv2023

Single-cell profiling uncovers regulatory programs of pathogenic Th2 cells in allergic asthma

Lung pathogenic T helper type 2 (pTh2) cells are important drivers of allergic asthma, but fundamental questions remain regarding their regulation and heterogeneity. The differentiation and effector functions of immune cells are tightly regulated by epigenetic processes. Histone deacetylase 1 (HDAC1) is an important epigenetic regulator of T cells, however, its role in pTh2 cells is yet to be determined. Here we investigate immune regulation in allergic asthma by single-cell RNA sequencing (scRNA-seq) in mice challenged with house dust mite, in the presence and absence of HDAC1 function. Our analyses reveal two distinct subsets of lung pTh2 cells: pathogenic effector Th2 (peTh2) and pathogenic Th2 tissue-resident memory (Th2 Trm) cells. Both pTh2 cell subsets are highly proinflammatory and exhibit distinct transcriptional and phenotypic signatures as compared with other lung Th subsets. Based on our scRNA-seq analysis, we identify conditions to generate pTh2 cells in vitro and confirm that these in vitro generated pTh2 cells have a similar transcriptional profile as lung peTh2 cells. Using our new in vitro model, we demonstrate that the p38 mitogen-activated protein kinase pathway is critical for interleukin-5 (IL-5) and IL-13 expression in pTh2 cells. Our data further underline the importance of HDAC1 in limiting the pathogenicity of lung and in vitro pTh2 cells and in the formation of lung Th2 Trm cells. In summary, we have generated novel insights into pTh2 cell biology and established a new in vitro model for investigating pTh2 cells that will be useful for discovering molecular mechanisms involved in pTh2-mediated allergic asthma.

immunology↗

bioRxiv2023

Telomemore enables single-cell analysis of cell cycle and chromatin condensation

Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=140 SRC="FIGDIR/small/533267v2_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@eec414org.highwire.dtl.DTLVardef@18b31d7org.highwire.dtl.DTLVardef@1753decorg.highwire.dtl.DTLVardef@346c5f_HPS_FORMAT_FIGEXP M_FIG C_FIG ABSTRACTSingle-cell RNA-seq methods can be used to delineate cell types and states at unprecedented resolution but do little to explain why certain genes are expressed. Single-cell ATAC-seq and multiome (ATAC+RNA) have emerged to give a complementary view of the cell state. It is however unclear what additional information can be extracted from ATAC-seq data besides transcription factor binding sites. Here we show that ATAC-seq telomere-like reads, mostly originating from the subtelomere, cannot be used to infer telomere length, but can be used as a biomarker for chromatin condensation. Using long-read sequencing, we further show that modern hyperactive Tn5 does not duplicate 9bp of its target sequence, contrary to common belief. We provide a new tool, Telomemore, which can quantify non-aligning subtelomeric reads. By analyzing several public datasets, and generating new multiome fibroblast and B cell atlases, we show how this new readout can aid single-cell data interpretation. We show how drivers of condensation processes can be inferred, and how it complements common RNA-seq-based cell cycle inference, which fails for monocytes. Telomemore-based analysis of the condensation state is thus a valuable complement to the single-cell analysis toolbox.

immunology↗

bioRxiv2023

scDual-Seq of Toxoplasma gondii-infected mouse bone marrow-derived dendritic cells reveals host cell heterogeneity and differential infection dynamics

Host-parasite interactions include complex interplays between an invading and a defending organism, each continuously adapting to gain the upper hand. The protozoan parasite, Toxoplasma gondii, can invade every nucleated cell type in a vertebrate host, including immune cells while the host mounts a protective response. Here, we utilize Dual-scSeq to parse out heterogeneous transcription of bone marrow-derived dendritic cells (BMDCs) infected with T. gondii type I, RH (LDM) or type II, ME49 (PTG) parasites, over multiple time points post infection. We find that the two parasite lineages distinctly manipulate two subpopulations of infected BMDCs. Co-expression networks establish host and parasite genes, with implications for modulation of host immunity and host-pathogen interactions. Integration of published data validates immune pathways and suggests novel candidate genes involved in host-pathogen interactions. This study aims to provide a comprehensive resource for future characterization of host-pathogen interplay among other protozoan parasites within their host niches, as well as that of bacterial and viral pathogens.

microbiology↗

bioRxiv2023

IL-17 activation undermines longevity and stress tolerance by inhibiting a protective transcriptional network

Aberrant cytokine secretion contributes to the pathogenesis of autoimmune diseases and age-related disorders, but the molecular mechanism underlying this is not entirely clear. Here, we elucidate how interleukin-17 (IL-17) overactivation shortens lifespan and damages defense mechanisms against stress in C. elegans. Our analysis reveals that NHR-49, the C. elegans ortholog of human PPAR and HNF4, is the central component in the transcriptional network undermined by increased IL-17 signaling. Both NHR-49 and its coactivator MDT-15 physically interact with the downstream components of IL-17 pathway, and their expression is significantly decreased when IL-17 signaling is enhanced. IL-17 overactivation also induces the expression and nucleus entry of the C. elegans ortholog of NF-{kappa}B inhibitor NFKI-1/I{kappa}B{zeta} to repress the activity of transcriptional coactivator MDT-15 and CBP-1. IL-17 signaling acts on neurons to modulate the activity of NFKI-1/I{kappa}B{zeta} and NHR-49. In addition, persistent IL-17 activation decreases the expression of HLH-30/TFEB, leading to the reduced transcription of lysosomal lipase genes in the distal tissues. All these jointly contribute to the increased sensitivity to oxidative stress of animals with enhanced IL-17 signaling. Collectively, our work illustrates a transcription system undermined by IL-17 overactivation in the animals without NF-{kappa}B, and provides mechanistic insight into the pathogenesis of abnormal IL-17 secretion.

cell biology↗

bioRxiv2022

Single-cell transcriptomics to define Plasmodium falciparum stage-transition in the mosquito midgut

Malaria inflicts the highest rate of morbidity and mortality among the vector-borne diseases. The dramatic bottleneck of parasite numbers that occurs in the gut of the obligatory vector mosquito provides a promising target for novel control strategies. Using single-cell transcriptomics, we analyzed Plasmodium falciparum development in the mosquito gut, from unfertilized female gametes through the first 20 hours post blood feeding, including the zygote and ookinete stages. This study revealed the transcriptional trajectories of the ApiAP2 family of transcription factors, and of parasite stress genes in response to the harsh environment of the mosquito midgut. Further, employing structure-based functional predictions we found several upregulated genes predicted to encode intrinsically disordered proteins (IDPs), a category of proteins known for their importance in regulation of transcription, translation and protein-protein interactions. IDPs are known for their antigenic properties and may serve as suitable targets for antibody or peptide-based transmission suppression strategies.

microbiology↗

bioRxiv2021

Activity and stress during a critical period regulate olfactory sensory neuron differentiation

Here, we reveal that the regulation of Drosophila odorant receptor (OR) expression during the pupal stage is permissive and imprecise. We found that olfactory sensory neuron activity directly after hatching both directs and refines OR expression. We demonstrate that, as in mice, dLsd1 and Su(var)3-9 balance heterochromatin formation to direct OR expression. Neuronal activity induces dLsd1 and Su(var)3-9 expression, linking neuronal activity to OR expression. OR expression refinement shows a restricted duration, suggesting a gene regulatory critical period brings olfactory sensory neuron differentiation to an end. Consistent with a change in differentiation, stress during the critical period represses dLsd1 and Su(var)3-9 expression and makes the early permissive OR expression permanent. This induced permissive gene regulatory state makes OR expression resilient to stress later in life. Hence, during a critical period, OR activity feedback similar to in mouse OR selection, defines adult OR expression in Drosophila.

neuroscience↗

bioRxiv2020

Regulation of Decay Accelerating Factor primes human germinal center B cells for phagocytosis

Germinal centers (GC) are sites for extensive B cell proliferation and homeostasis is maintained by programmed cell death. The complement regulatory protein Decay Accelerating Factor (DAF) blocks complement deposition host cells and therefore also phagocytosis of cells. Here, we show that B cells downregulate DAF upon BCR engagement and that T cell-dependent stimuli preferentially led to activation of DAFlo B cells. Consistent with this, a majority of light and dark zone GC B cells were DAFlo and susceptible to complement-dependent phagocytosis, as compared with DAFhi GC B cells. We could also show that the DAFhi GC B cell subset had increased expression of the plasma cell marker Blimp-1. DAF expression was also modulated during B cell hematopoiesis in the human bone marrow. Collectively, our results reveal a novel role of DAF to pre-prime activated human B cells for phagocytosis prior to apoptosis.

immunology↗

bioRxiv2019

Rora regulates activated T helper cells during inflammation

The transcription factor Rora has been shown to be important for the development of ILC2 and the regulation of ILC3, macrophages and Treg cells. Here we investigate the role of Rora across CD4+ T cells, both in vitro as well as in the context of several in vivo type 2 infection models. We dissect the function of Rora using overexpression and a CD4-conditional Rora-knockout mouse, as well as a RORA-reporter mouse. We establish the importance of Rora in CD4+ T cells for controlling lung inflammation induced by Nippostrongylus brasiliensis infection, and have measured the effect on downstream genes using RNA-seq. Using a systematic stimulation screen of CD4+ T cells, coupled with RNA-seq, we identify upstream regulators of Rora, most importantly IL-33 and CCL7. Our data suggest that Rora is a negative regulator of the immune system, possibly through several downstream pathways, and is under control of the local microenvironment.

immunology↗

bioRxiv2018

Reconstructing the human first trimester fetal-maternal interface using single cell transcriptomics

During the early weeks of human pregnancy, the fetal placenta implants into the uterine mucosa (decidua) where placental trophoblast cells intermingle and communicate with maternal cells. Here, we profile transcriptomes of [~]50,000 single cells from this unique microenvironment, sampling matched first trimester maternal blood and decidua, and fetal cells from the placenta itself. We define the cellular composition of human decidua, revealing five distinct subsets of decidual fibroblasts with differing growth factors and hormone production profiles, and show that fibroblast states define two distinct decidual layers. Among decidual NK cells, we resolve three subsets, each with a different immunomodulatory and chemokine profile. We develop a repository of ligand-receptor pairs (www.CellPhoneDB.org) and a statistical tool to predict the probability of cell-cell interactions via these pairs, highlighting specific interactions between decidual NK cells and invading fetal extravillous trophoblast cells, maternal immune and stromal cells. Our single cell atlas of the maternal-fetal interface reveals the cellular organization and interactions critical for placentation and reproductive success.

developmental biology↗