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Decker, T.

Publications and source records attributed to Decker, T..

12 recordsLinked to original sources

Intrathecal antibodies cross-react with EBV BRRF2 and human antigens in multiple sclerosis

Intrathecal antibody synthesis is a hallmark of multiple sclerosis (MS). Although some intrathecally synthesized antibodies in MS are known to target viral antigens, the spectrum of their antigenic specificities remains incompletely defined. We combined proteome-wide antibody profiling by Phage ImmunoPrecipitation Sequencing (PhIP-Seq) with cross-compartment analytics (MICAR) to study intrathecal antibody synthesis at peptide resolution in paired CSF and serum samples from individuals with MS (n = 40) and non-MS controls (n = 83). While intrathecal antibody responses in MS were polyspecific and included reactivities to various viruses, we identified a subset of individuals with a convergent intrathecal antibody reactivity to a previously described motif within the Epstein-Barr virus (EBV) protein BRRF2 (BRRF2408-415). This motif-directed response showed co-reactivity with multiple CNS-expressed human antigens. In an independent cohort of n = 909 individuals with MS and n = 311 controls, including individuals with NMOSD and MOGAD, serum antibodies to BRRF2408-415 were detected in 8.36% of MS individuals and in 0.64% of non-MS controls, corresponding to an odds ratio for MS of 14.1 (95% CI: 4.4-86.04). Within MS individuals, BRRF2408-415 seropositivity was associated with increased intrathecal IgG synthesis. Cross-reactivity of antibodies to BRRF2408-415 with human targets, including TRIM71 and RTN2, was confirmed by competition ELISA and cell-based assays. Together, these data define an intrathecal EBV BRRF2-linked antibody signature with human target cross-reactivity in a subset of MS individuals. This signature identifies a highly specific serological marker in MS and may support future stratification of the heterogeneous MS spectrum.

immunology↗

A Conserved Chromatin-Driven Checkpoint Defines Late Macrophage Maturation Independent of Tissue Specialization

Macrophage identity is widely viewed as a product of ontogeny and tissue-specific imprinting. Here, we identify a conserved, chromatin-driven maturation checkpoint that operates independently of initial lineage commitment and broadly across tissue contexts. Using long-term bone marrow-derived macrophage cultures, we uncover a late-stage transition characterized by coordinated transcriptional and epigenomic remodeling. Integration with in vivo developmental, tissue-resident, and monocyte-repopulation datasets demonstrates that this program is conserved across ontogenies, tissues, species, and experimental systems, revealing a previously unrecognized stage of macrophage maturation. Functionally, late maturation preserves core macrophage activities while promoting lysosomal expansion and fundamentally rewiring innate immune responsiveness. Mature macrophages display enhanced stimulus-specific responses to interferons and microbial danger signals, coupled to increased metabolic and inflammatory competence while restricting interferon-induced transcriptional memory. Together, our findings identify late macrophage maturation as a conserved regulatory checkpoint that reprograms the logic of innate immune responsiveness through chromatin remodeling shaping innate immune function.

immunology↗

Terpenoid balance in Aspergillus nidulans unveiled by heterologous squalene synthase expression

Filamentous fungi produce numerous uncharacterized natural products (NPs) that are often challenging to characterize due to cryptic expression in laboratory conditions. Previously, we have successfully isolated novel NPs by expressing fungal artificial chromosomes (FACs) from a variety of fungal species into Aspergillus nidulans. Here, we demonstrate a new twist to FAC utility wherein heterologous expression of a Pseudogymnoascus destructans FAC in A. nidulans altered endogenous terpene biosynthetic pathways. In contrast to wildtype, the FAC transformant produced increased levels of squalene and aspernidine type compounds, including three new nidulenes (1-2, 5), and lost nearly all ability to synthesize the major A. nidulans characteristic terpene, austinol. Deletion of a squalene synthase gene in the FAC restored wildtype chemical profiles. The altered squalene to farnesyl pyrophosphate ratio leading to synthesis of nidulenes and aspernidines at the expense of farnesyl pyrophosphate derived austinols provides unexpected insight into routes of terpene synthesis in fungi. TeaserReshaping terpenes: Heterologous FAC expression reroutes terpene pathways.

microbiology↗

Dynamic control of gene expression by ISGF3 and IRF1 duringIFNbeta and IFNgamma signaling

Type I interferons (IFN-I, including IFN{beta}) and IFN{gamma} produce overlapping, yet clearly distinct immunological activities. Recent data show that distinctness of global transcriptional responses to the two IFN types is not apparent when comparing their immediate effects. By analyzing nascent transcripts induced by IFN-I or IFN{gamma} over a period of 48hrs we now show that the distinctiveness of the transcriptomes emerges over time and is based on a different employment of the ISGF3 complex as well as the second-tier transcription factor IRF1. The distinct transcriptional properties of ISGF3 and IRF1 correspond with a largely diverse nuclear protein interactome. Mechanistically, we describe specific input of ISGF3 and IRF1 into enhancer activation and the regulation of chromatin accessibility at interferon-induced genes (ISG). We further report differences between the IFN types in altering RNA polymerase II pausing at ISG 5 ends. Our data provide insight how transcriptional regulators create immunological identities of IFN-I and IFN{gamma}.

immunology↗

Vgamma9+Vdelta2+Tcell-mediated purging of Listeria monocytogenes-infected epithelial cells requires butyrophilin 3A genes

Intracellular bacteria produce antigens, which serve as potent activators of {gamma}{delta} T cells. Phosphoantigens are presented via a complex of Butyrophilins (BTN) to signal infection to human V{gamma}9+V{delta}2+ T cells. Here, we established an in vitro system allowing for studies of V{gamma}9+V{delta}2+ T cell activity in coculture with epithelial cells infected with the intracellular bacterial pathogen Listeria monocytogenes. We report that the V{gamma}9+V{delta}2+ T cells efficiently purge such cultures from infected cells. This effector function requires the expression of members of the BTN3A family on epithelial cells. Specifically, the BTN3A1 and BTN3A3 are redundant in their ability to present antigen to V{gamma}9+V{delta}2+ T cells. Since BTN3A1 is the only BTN3A associated with phosphoantigen presentation our study suggests that BTN3A3 may present different classes of antigens to mediate V{gamma}9+V{delta}2+ T cell effector function against L. monocytogenes-infected epithelia.

immunology↗

Pseudorabies virus hijacks DDX3X, initiating an addictive 'mad itch' and immune suppression, to facilitate viral spread.

Infections with defined Herpesviruses, such as Pseudorabies virus (PRV) and Varicella zoster virus (VZV) can cause neuropathic itch, referred to as "mad itch" in multiple species. The underlying mechanisms involved in neuropathic "mad itch" are poorly understood. Here, we show that PRV infections hijack the RNA helicase DDX3X in sensory neurons to facilitate anterograde transport of the virus along axons. PRV induces re-localization of DDX3X from the cell body to the axons which ultimately leads to death of the infected sensory neurons. Inducible genetic ablation of Ddx3x in sensory neurons results in neuronal death and "mad itch" in mice. This neuropathic "mad itch" is propagated through activation of the opioid system making the animals "addicted to itch". Moreover, we show that PRV co-opts and diverts T cell development in the thymus via a sensory neuron-IL-6-hypothalamus-corticosterone stress pathway. Our data reveal how PRV, through regulation of DDX3X in sensory neurons, travels along axons and triggers neuropathic itch and immune deviations to initiate pathophysiological programs which facilitate its spread to enhance infectivity.

neuroscience↗

SPOP targets the immune transcription factor IRF1 for proteasomal degradation

Adaptation of the functional proteome is essential to counter pathogens during infection, yet precisely timed degradation of these response proteins after pathogen clearance is likewise key to preventing autoimmunity. Interferon Regulatory Factor 1 (IRF1) plays an essential role as a transcription factor in driving the expression of immune response genes during infection. The striking difference in functional output with other IRFs, is that IRF1 also drives the expression of various cell cycle inhibiting factors, making it an important tumor suppressor. Thus, it is critical to regulate the abundance of IRF1 to achieve a "Goldilocks" zone in which there is sufficient IRF1 to prevent tumorigenesis, yet not too much which could drive excessive immune activation. Using genetic screening, we identified the E3 ligase receptor Speckle Type BTB/POZ Protein (SPOP) to mediate IRF1 proteasomal turnover. We identified four S/T-rich degrons in IRF1 required for its SPOP MATH domain-dependent turnover. In the absence of SPOP, increased IRF1 protein levels functionally drive increased transcription of IRF1-response-genes, underpinning the biological significance of SPOP in curtailing IRF1 protein abundance.

cell biology↗

Genomes of novel Myxococcota reveal severely curtailed machineries for predation and cellular differentiation

Cultured Myxococcota are predominantly aerobic soil inhabitants, characterized by their highly coordinated predation and cellular differentiation capacities. Little is currently known regarding yet-uncultured Myxococcota from anaerobic, non-soil habitats. We analyzed genomes representing one novel order (o__JAFGXQ01) and one novel family (f__JAFGIB01) in the Myxococcota from an anoxic freshwater spring in Oklahoma, USA. Compared to their soil counterparts, anaerobic Myxococcota possess smaller genomes, and a smaller number of genes encoding biosynthetic gene clusters (BGCs), peptidases, one- and two-component signal transduction systems, and transcriptional regulators. Detailed analysis of thirteen distinct pathways/processes crucial to predation and cellular differentiation revealed severely curtailed machineries, with the notable absence of homologs for key transcription factors (e.g. FruA and MrpC), outer membrane exchange receptor (TraA), and the majority of sporulation-specific and A-motility-specific genes. Further, machine-learning approaches based on a set of 634 genes informative of social lifestyle predicted a non-social behavior for Zodletone Myxococcota. Metabolically, Zodletone Myxococcota genomes lacked aerobic respiratory capacities, but encoded genes suggestive of fermentation, dissimilatory nitrite reduction, and dissimilatory sulfate-reduction (in f_JAFGIB01) for energy acquisition. We propose that predation and cellular differentiation represent a niche adaptation strategy that evolved circa 500 Mya in response to the rise of soil as a distinct habitat on earth. ImportanceThe Myxococcota is a phylogenetically coherent bacterial lineage that exhibits unique social traits. Cultured Myxococcoat are predominantly aerobic soil-dwelling microorganisms that are capable of predation and fruiting body formation. However, multiple yet-uncultured lineages within the Myxococcota has been encountered in a wide range of non-soil, predominantly anaerobic habitats; and the metabolic capabilities, physiological preferences, and capacity of social behavior of such lineages remains unclear. Here, we analyzed genomes recovered from a metagenomic analysis of an anoxic freshwater spring in Oklahoma, USA that represent novel, yet-uncultured, orders and families in the Myxococcota. The genomes appear to lack the characteristic hallmarks for social behavior encountered in Myxococcota genomes, and displayed a significantly smaller genome size and a smaller number of genes encoding biosynthetic gene clusters, peptidases, signal transduction systems, and transcriptional regulators. Such perceived lack of social capacity we confirmed through detailed comparative genomic analysis of thirteen pathways associated with Myxococcota social behavior, as well as the implementation of machine learning approaches to predict social behavior based on genome composition. Metabolically, these novel Myxococcota are predicted to be strict anaerobes, utilizing fermentation, nitrate rductio, and dissimilarity sulfate reduction for energy acquisition. Our result highlight the broad patterns of metabolic diversity within the yet-uncultured Myxococcota and suggest that the evolution of predation and fruiting body formation in the Myxococcoat has occurred in response to soil formation as a distinct habitat on earth.

microbiology↗

Interferons Reshape the 3D Conformation and Accessibility of Macrophage Chromatin

Engagement of macrophages in innate immune responses is directed and enhanced by type I and type II interferons. An essential component of IFN activity is the use of JAK-STAT signal transduction for the transcriptional control of interferon-stimulated genes (ISG). Here, we study the immediate early nuclear response to type I IFN and IFN-{gamma} in murine macrophages. Despite their distinct immunological activities, both IFN types triggered highly overlapping epigenomic and transcriptional changes. These changes included a rapid rearrangement of the 3D chromatin organization and an increase of DNA accessibility at ISG loci. ISGF3, the major transcriptional regulator of ISG, controlled homeostatic as well as induced-state DNA accessibility at a subset of ISG. Increases in DNA accessibility correlated with the appearance of activating histone marks at surrounding nucleosomes. Collectively our data emphasize changes in the three-dimensional nuclear space and epigenome as an important facet of transcriptional control by the IFN-induced JAK-STAT pathway.

immunology↗

DCA promotes a novel tolerogenic program in CD4+ T cells by inhibiting CDK8

Immune health requires innate and adaptive immune cells to engage precisely balanced pro- and anti-inflammatory forces. We employ the concept of chemical immunophenotypes to classify small molecules functionally or mechanistically according to their patterns of effects on primary innate and adaptive immune cells. The high-specificity, low-toxicity cyclin dependent kinase 8 (CDK8) inhibitor DCA exerts a distinct tolerogenic profile in both innate and adaptive immune cells. DCA promotes Treg and Th2 differentiation, while inhibiting Th1 and Th17 differentiation, in both murine and human cells. This unique chemical immunophenotype led to mechanistic studies showing that DCA promotes Treg differentiation in part by regulating a previously undescribed CDK8-GATA3-FOXP3 pathway that regulates early pathways of Foxp3 expression. These results highlight previously unappreciated links between Treg and Th2 differentiation and extend our understanding of the transcription factors that regulate Treg differentiation and their temporal sequencing. These findings have significant implications for future mechanistic and translational studies of CDK8 and CDK8 inhibitors.

immunology↗

Evolution of protective human antibodies against Plasmodium falciparum circumsporozoite protein repeat motifs

Circumsporozoite protein of the human malaria parasite Plasmodium falciparum (PfCSP) is the main target of antibodies that prevent the infection and disease. Protective antibodies recognize the central PfCSP domain, but our understanding of how parasite inhibition is associated with recognition of this domain and with the evolution of potent antibodies remains scattered. Here, we characterized the epitope specificity of 200 human monoclonal PfCSP antibodies. We show that the majority of PfCSP antibodies bind to NANP and NANP-like motifs with different preferences and define the molecular basis for recognition. Epitope cross-reactivity evolved with increasing antibody affinity around a conserved (N/D)P-NANP-N(V/A) core. High affinity to this motif, but not binding to NANP-like motifs, was associated with parasite inhibition and protection. Thus, NANP drives the development of potent PfCSP antibodies independently of their cross-reactivity profile, a finding with direct implications for the design of a second-generation PfCSP-based malaria vaccine.\n\nHIGHLIGHTSO_LIThe majority of human PfCSP antibodies recognize multiple epitopes\nC_LIO_LINANP affinity maturation drives the evolution of cross-reactive PfCSP antibodies\nC_LIO_LIPreferential PfCSP antibody binding to a conserved core motif\nC_LIO_LIHigh affinity not epitope specificity is associated with PfCSP antibody potency\nC_LI

immunology↗

Homeostatic and Interferon-induced gene expression represent different states of promoter-associated transcription factor ISGF3

Cells maintain the balance between homeostasis and inflammation by adapting and integrating the activity of intracellular signalling cascades, including the JAK-STAT pathway. Our understanding how a tailored switch from homeostasis to a strong receptor-dependent response is coordinated remains limited. We used an integrated transcriptomic and proteomic approach to analyze transcription-factor binding, gene expression and in vivo proximity-dependent labelling of proteins in living cells under homeostatic and interferon (IFN)-induced conditions. We show that interferons (IFN) switch murine macrophages from resting-state to induced gene expression by alternating subunits of transcription factor ISGF3. Whereas preformed STAT2-IRF9 complexes control basal expression of IFN-induced genes (ISG), both type I IFN and, unexpectedly, IFN{gamma} cause promoter binding of a complete ISGF3 complex containing STAT1, STAT2 and IRF9. In contrast to the dogmatic view of ISGF3 formation in the cytoplasm, our results suggest a model wherein the assembly of the ISGF3 complex occurs on DNA.

immunology↗