Biology subjects

Werner, F.

Publications and source records attributed to Werner, F..

10 recordsLinked to original sources

bioRxiv2026

A TFIIB paralog drives cyclic transcription to orchestrate the archaeal cell cycle

Cyclic transcription is a hallmark of the cell cycle. While transcriptional waves in eukaryotes are driven by oscillations in cyclin-dependent kinase (CDK) activity, many archaea have an ordered cell cycle despite lacking CDKs. Here in exploring how cyclic transcription is achieved in Sulfolobus acidocaldarius, we show that TFB2, a paralog of eukaryotic TFIIB, is cyclically expressed, associated with the promoters of division genes (including tfb2 itself), contains a cyclin-box and is degraded as cells exit division. Furthermore, a dominant-negative TFB2 mutant interferes with division gene expression and cytokinesis. These data identify TFB2 as a central player in the circuitry orchestrating the orderly cell cycle in Sulfolobus and, despite the absence of CDKs, reveal parallels between the regulatory logic of archaeal cell division and eukaryotic mitosis.

cell biology↗

bioRxiv2025

Conserved programs and specificities of T cells targeting hematological malignancies

T cell-mediated immune surveillance is critical for cancer control, yet its endogenous effectiveness in hematological malignancies remains limited and poorly understood. Here, we integrate single-cell T cell receptor (TCR) profiling, HLA immunopeptidomics and functional antigen mapping to dissect the specificity landscape of bone marrow lymphocytes (BMLs) in multiple myeloma (MM) and acute myeloid leukemia (AML). We identify a rare subset of tumor-reactive T cells that exhibit a stereotyped transcriptional state distinct from bystander and virus-specific populations. Across both malignancies, immunopeptidomic profiling uncovers a partially conserved antigen repertoire enriched for noncanonical peptides, including products of novel or unannotated open reading frames (nuORFs), pseudogenes, and clonotypic immunoglobulin sequences. Several of these epitopes are recurrently presented and associated with convergent TCR responses across individuals. Based on this immune architecture, we develop a TCR-intrinsic fitness model that infers BML tumor specificity from transcriptional cues and stratifies immunotherapy response across three independent patient cohorts. Together, these findings map the latent potential of endogenous anti-tumor immunity in two biologically distinct diseases and provide a framework for decoding and restoring productive immune surveillance of hematological malignancies. HighlightsO_LISingle-cell resolved TCR profiling maps rare tumor-reactive T cells in the bone marrow of multiple myeloma (MM) and acute myeloid leukemia (AML) reveals conserved transcriptional programs C_LIO_LIA shared immunopeptidome across MM and AML includes noncanonical epitopes from nuORFs and idiotype sequences C_LIO_LIConserved tumor antigens elicit convergent T cell responses across patients C_LI O_LIA TCR fitness model predicts tumor specificity in bone marrow lymphocytes and stratifies immunotherapy response in both hematological malignancies C_LI

immunology↗

bioRxiv2023

CAF variants control the tumor-immune microenvironment and predict skin cancer malignancy

Cancer-associated fibroblasts (CAFs) play a key role in cancer progression and treatment outcome. This study dissects the yet unresolved intra-tumoral variety of CAFs in three skin cancer types -- Basal Cell Carcinoma, Squamous Cell Carcinoma, and Melanoma -- at molecular and spatial single-cell resolution. By integral analysis of the fibroblasts with the tumor microenvironment, including epithelial, mesenchymal, and immune cells, we characterize three distinct CAF subtypes: myofibroblast-like RGS5+ CAFs, matrix CAFs (mCAFs), and immunomodulatory CAFs (iCAFs). Notably, large cohort tissue analysis reveals marked shifts in CAF subtype patterns with increasing malignancy. Two CAF types exhibit immunomodulatory capabilities via distinct mechanisms. mCAFs synthesize extracellular matrix and have the ability to ensheath tumor nests, potentially limiting T cell invasion in low-grade tumors. In contrast, iCAFs are enriched in late-stage tumors, especially infiltrative BCC and high-grade melanoma, and express unexpectedly high mRNA and protein levels of cytokines and chemokines, pointing to their integral role in immune cell recruitment and activation. This finding is further supported by our observation that in vitro exposure of primary healthy fibroblasts to skin cancer cell secretomes induces an iCAF-like phenotype with immunomodulatory functions. Thus, targeting CAF variants, particularly the immunomodulatory iCAF subtype, holds promise for improved efficacy of immunotherapy in skin cancers.

cancer biology↗

bioRxiv2023

Cbp1-Cren7 chromatinization of CRISPR arrays favours transcription from leader- over cryptic promoters

CRISPR arrays form the physical memory of CRISPR adaptive immune systems by incorporating foreign DNA as spacers that are often AT-rich and derived from viruses. As promoter elements such as the TATA-box are AT-rich, CRISPR arrays are prone to harbouring cryptic promoters. Sulfolobales harbor extremely long CRISPR arrays spanning several kilobases, a feature that is accompanied by the CRISPR-specific transcription factor Cbp1. Aberrant Cbp1 expression modulates CRISPR array transcription, but the molecular mechanisms underlying this regulation are unknown. Here, we characterise the genome-wide Cbp1 binding at nucleotide resolution and characterise the binding motifs on distinct CRISPR arrays, as well as on unexpected non-canonical binding sites associated with transposasons. Cbp1 recruits Cren7 forming together chimeric chromatin-like structures at CRISPR arrays. We dissect Cbp1 function in vitro and in vivo and show that the third HTH domain is responsible for Cren7 recruitment, and that Cbp1-Cren7 chromatinization plays a dual role in the transcription of CRISPR arrays. It suppresses spurious transcription from cryptic promoters within CRISPR arrays but enhances CRISPR RNA transcription directed from their cognate promoters in their leader region. Our results show that Cbp1-Cren7 chromatinization drives the productive expression of long CRISPR arrays.

microbiology↗

bioRxiv2021

A prebiotic basis for ATP as the universal energy currency

ATP is universally conserved as the principal energy currency in cells, driving metabolism through phosphorylation and condensation reactions. Such deep conservation suggests that ATP arose at an early stage of biochemical evolution. Yet purine synthesis requires six phosphorylation steps linked to ATP hydrolysis. This autocatalytic requirement for ATP to synthesize ATP implies the need for an earlier prebiotic ATP-equivalent, which could drive protometabolism before purine synthesis. Why this early phosphorylating agent was replaced, and specifically with ATP rather than other nucleotide triphosphates, remains a mystery. Here we show that the deep conservation of ATP reflects its prebiotic chemistry in relation to another universally conserved intermediate, acetyl phosphate, which bridges between thioester and phosphate metabolism by linking acetyl CoA to the substrate-level phosphorylation of ADP. We confirm earlier results showing that acetyl phosphate can phosphorylate ADP to ATP at nearly 20 % yield in water in the presence of Fe3+ ions. We then show that Fe3+ and acetyl phosphate are surprisingly favoured: a panel of other prebiotically relevant ions and minerals did not catalyze ADP phosphorylation; nor did a number of other potentially prebiotic phosphorylating agents. Only carbamoyl phosphate showed some modest phosphorylating activity. Critically, we show that acetyl phosphate does not phosphorylate other nucleotide diphosphates or free pyrophosphate in water. The phosphorylation of ADP monomers seems to be favoured by the interaction between the N6 amino group on the adenine ring with Fe3+ coupled to acetyl phosphate. Our findings suggest that the reason ATP is universally conserved across life is that its formation is chemically favoured in aqueous solution under mild prebiotic conditions.

biochemistry↗

bioRxiv2021

The determinants of African Swine Fever Virus Virulence - the Georgia 2007/1 strain and the host macrophage response

African swine fever virus (ASFV) has a major global economic impact. With a case fatality in domestic pigs approaching 100%, it currently presents the largest threat to animal farming. Although genomic differences between attenuated and highly virulent ASFV strains have been identified, the molecular determinants for virulence at the level of gene expression have remained opaque. Here we characterise the transcriptome of ASFV genotype II Georgia 2007/1 (GRG) during infection of the physiologically relevant host cells, porcine macrophages. In this study we applied Cap Analysis Gene Expression sequencing (CAGE-seq) to map the 5 ends of viral mRNAs at 5 and 16 hours post-infection. A bioinformatics analysis of the sequence context surrounding the transcription start sites (TSSs) enabled us to characterise the global early and late promoter landscape of GRG. We compared transcriptome maps of the GRG isolate and the lab-attenuated BA71V strain that highlighted GRG virulent-specific transcripts belonging to multigene families, including two predicted MGF 100 genes I7L and I8L. In parallel, we monitored transcriptome changes in the infected host macrophage cells. Of the 9,384 macrophage genes studied, transcripts for 652 host genes were differentially regulated between 5 and 16 hours-post-infection compared with only 25 between uninfected cells and 5 hours post-infection. NF-kB activated genes and lysosome components like S100 were upregulated, and chemokines such as CCL24, CXCL2, CXCL5 and CXCL8 downregulated. ImportanceAfrican swine fever virus (ASFV) causes haemorrhagic fever in domestic pigs with case fatality rates approaching 100%, and no approved vaccines or antivirals. The highly-virulent ASFV Georgia 2007/1 strain (GRG) was the first isolated when ASFV spread from Africa to the Caucasus region in 2007. Then spreading through Eastern Europe, and more recently across Asia. We used an RNA-based next generation sequencing technique called CAGE-seq to map the starts of viral genes across the GRG DNA genome. This has allowed us to investigate which viral genes are expressed during early or late stages of infection and how this is controlled, comparing their expression to the non-virulent ASFV-BA71V strain to identify key genes that play a role in virulence. In parallel we investigated how host cells respond to infection, which revealed how the ASFV suppresses components of the host immune response to ultimately win the arms race against its porcine host.

microbiology↗

bioRxiv2021

Successful IL-12 cancer immunotherapy requires NK cell-derived CCL5 for anti-tumor DC-T cell crosstalk

T cell-directed cancer immunotherapy often fails to generate lasting tumor control. Harnessing additional effectors of the immune response against tumors may strengthen the clinical benefit of immunotherapies. Here, we demonstrate that therapeutic targeting of the IFN{gamma}-IL-12 pathway relies on the ability of a population of tissue-resident NK (trNK) cells to orchestrate an anti-tumor microenvironment. Particularly, utilizing an engineered adenoviral platform, we show that paracrine IL-12 enhances functional DC-CD8 T cell interactions to generate adaptive anti-tumor immunity. This effect depends on the abundance of trNK cells and specifically their capacity to produce the cDC1-chemoattractant CCL5. Failure to respond to IL-12 and other IFN{gamma}-inducing therapies such as immune checkpoint blockade in tumors with low trNK cell infiltration could be overcome by intra-tumoral delivery of CCL5. Our findings reveal a novel barrier for T cell-focused therapies and offer mechanistic insights into how T cell-NK cell-DC crosstalk can be enhanced to promote anti-tumor immunity and overcome resistance. SignificanceWe identified the lack of CCL5-producing, tissue-resident NK (trNK) cells as a barrier to T cell-focused therapies. While IL-12 induces anti-tumoral DC-T cell crosstalk in trNK cellrich tumors, resistance to IL-12 or anti-PD-1 in trNK cellpoor tumors can be overcome by the additional delivery of CCL5.

immunology↗

bioRxiv2021

Imaging protein conformational space in liquid water

Withdrawal StatementThe authors have withdrawn their manuscript owing to a mistake in one of the proteins used for the data used to generate Fig.1, where we believed we used the apoferritin but instead used the ferritin proteins. Therefore, the authors do not wish this work to be cited as a reference for the project. If you have any questions, please get in touch with the corresponding author.

biophysics↗

bioRxiv2020

Promoter-proximal elongation regulates transcription in archaea

Recruitment of RNA polymerase and initiation factors to the promoter is the only known mechanisms for transcription activation and repression in archaea. Whether any of the subsequent steps towards productive transcription elongation is involved in regulation is not known. We characterised how the basal transcription machinery is distributed along genes in the archaeon Sulfolobus solfataricus. We discovered a distinct early elongation phase where RNA polymerases sequentially recruit the elongation factors Spt4/5 and Elf1 to form the transcription elongation complex (TEC) before the TEC escapes into productive transcription. TEC escape is rate-limiting for transcription output during exponential growth. Oxidative stress causes changes in TEC escape that correlate with changes in the transcriptome. Our results thus establish that TEC escape contributes to the basal promoter strength and facilitates transcription regulation. Impaired TEC escape coincides with the accumulation of initiation factors at the promoter and recruitment of termination factor aCPSF1 to the early TEC. This suggests two possible mechanisms for how TEC escape limits transcription, physically blocking upstream RNA polymerases during transcription initiation and premature termination of early TECs.

molecular biology↗

bioRxiv2019

Temporal Transcriptome and Promoter Architecture ofthe African Swine Fever Virus

The African Swine Fever Virus causes haemorrhagic fever in domestic pigs and presents the biggest global threat to animal farming in recorded history. Despite its importance, very little is known the mechanisms and temporal regulation of transcription in ASFV. Here we report the first detailed viral transcriptome analysis of ASFV during early and late infection of Vero cells. In addition to total RNA sequencing, we have characterised the transcription start sites and transcription termination sites at nucleotide-resolution, revealing the distinct DNA consensus motifs of early and late promoters, as well as the sequence determinants for transcription termination. ASFV can utilise alternative promoters to generate distinct proteins from the same transcription unit that differ with respect to the polypeptide N-terminus. Finally, our results reveal that the ASFV-RNAP undergoes transcript slippage at the 5 end of transcription units that in a promoter sequence-specific manner results in the addition of 5-AT and 5-ATAT tails to mRNAs.

genomics↗