Project description:Transcriptomic and proteomic insights into innate immunity and adaptations to a symbiotic lifestyle in the gutless marine worm Olavius algarvensis
Project description:<p>Healthy behavioral patterns could modulate organ functions to enhance the body’s immunity. However, whether exercise regulates antiviral innate immunity remains elusive. Here, we found that exercise promotes type-I IFN (IFN-I) production in the liver and enhances IFN-I immune activity of the body. Despite the possibility that many exercise-induced factors could regulate IFN-I production, we identified Gpld1 as a crucial molecule and the liver as the major organ to promote IFN-I production after exercise. Exercise largely loses the efficiency to induce IFN-I in Gpld1-/- mice. Further studies demonstrated that exercise-produced 3-hydroxybutanoic acid (3-HB) critically induces Gpld1 expression in the liver. Gpld1 blocks the PP2A-IRF3 interaction and therefore enhances IRF3 activation and IFN-I production, and improves the body’s antiviral ability. This study reveals that the exercise behavior improves antiviral innate immunity by linking the liver metabolism to systemic IFN-I activity, and uncovers an unknown function of liver cells in innate immunity.</p>
Project description:Monocyte differentiation into macrophages represents one of the cornerstone processes in innate host defense. In addition, immunological imprinting of either tolerance or trained immunity after an initial infection determines the functional fate of innate immune cells and the susceptibility of the host to secondary infections. Here we comprehensively characterize the epigenetic profiles of these functional states relative to healthy adult naM-CM-/ve monocytes. Inflammatory and metabolic pathways are strongly modulated in the derived macrophages, including decreased activation of inflammasome components. The cAMP-dependent signaling pathway is remodeled and adrenergic signaling was functionally implicated in trained innate immunity induction in vivo. Interestingly, M-oM-^AM-"-Glucan trains innate immune cells through extensive remodeling of distal regulatory region-bound histone acetylation, resulting in a sizeable exclusive epigenomic signature. Accordingly, genome-wide transcription factor footprint analysis reveals a specific transcription factor repertoire at trained cell-specific enhancers when recouped with epigenetic data, forming a rich hypothesis generator to manipulate innate immunity. Monocytes were pre-incubated either with cell culture medium (RPMI), M-NM-2-glucan (5M-BM-5g/mL) or with LPS (100ng/mL), for 24 hours in a total volume of 10 mL. After a wash-out, cells were cultured in RPMI supplemented with 10% human pool serum. Monocytes were collected at different time points (0 h and 6 d after treatment) and counted before further treatment for chromatin immunoprecipitation, RNA or DNaseI treatment. Different donor Buffycoats (BC) were used as independent replicates. Replicates were generated for all the profiles including ChIPseq,RNAseq and DNaseIseq.
Project description:Innate immunity serves as the primary defense against viral and microbial infections in humans. Among its components, retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) are well-characterized intracellular pattern-recognition proteins that trigger innate immune responses upon viral infection. However, the precise influence of cellular metabolites, especially fatty acids, on the regulation of RLR-mediated antiviral innate immunity remains largely elusive. Here, through screening a metabolite library, palmitic acid (PA) has been identified as a crucial metabolite responsible for modulating antiviral infections. Mechanistically, PA induces the palmitoylation of MAVS, leading to MAVS aggregation and subsequent activation, thereby enhancing the innate immune response against viral infections. Functionally, the enzyme palmitoyl-transferase ZDHHC24 plays a key role in catalyzing the palmitoylation of MAVS at both C46 and C79 residues, thereby facilitating the transduction of RLR-mediated TBK1-IRF3-IFN signaling pathway, particularly under conditions of PA stimulation or high-fat diet feeding. Conversely, the absence of ZDHHC24 significantly attenuates virus-induced innate immune responses in both cells and mice. Moreover, APT2 counteracts with ZDHHC24 to de-palmitoylate MAVS, thus inhibiting the antiviral response. Consequently, inhibition of APT2 using compounds like ML349 effectively reverses MAVS palmitoylation and activation in response to antiviral infections. These findings underscore the critical role of PA and ZDHHC24 in regulating antiviral innate immunity through MAVS palmitoylation, and suggest potential therapeutic strategies for combating viral infections, such as enhancing PA intake or specifically targeting APT2.
Project description:Circular RNAs (circRNAs) are widely expressed in eukaryotes. However, only a subset have been functionally characterized. We identify and validate a collection of circRNAs in Drosophila, and show that depletion of the brain-enriched circRNA Edis causes hyperactivation of antibacterial innate immunity both in cultured cells and in vivo. Notably, Edis depleted flies display heightened resistance to bacterial infection and enhanced pathogen clearance. Conversely, ectopic Edis expression blocks innate immunity signaling. In addition, inactivation of Edis in vivo leads to impaired locomotive activity and shortened lifespan. Remarkably, these phenotypes can be recapitulated with neuron-specific depletion of Edis, accompanied by defective neurodevelopment. Importantly, restoration of Edis expression suppresses both innate immunity and neurodevelopment phenotypes elicited by Edis depletion. We provide evidence that Edis encodes a functional protein that associates with and compromises the processing of the immune transcription factor Relish. Consistent with these observations, inactivation of Relish suppresses the innate immunity hyperactivation phenotype in the fly brain and rescues the neurodevelopment defects in Edis knockdown neurons. Thus, our study establishes the circRNA Edis as a key regulator of neurodevelopment and innate immunity.
Project description:Innate immunity is fundamental to recognition and clearance of bacterial infection. The relevant cells and molecules that orchestrate an effective response, however, remain incompletely understood. Here we describe a previously unknown population of B cells, which we have named innate response activator (IRA) B cells that recognize bacteria directly through TLR-4-MyD88 and protect against polymicrobial sepsis. IRA-B cells have a unique IgM high CD23 low CD43 + CD93+ GM-CSF+ signature, develop and diverge from B1a B cells, require BAFFR, and adhere to tissue via VLA-4 and LFA-1. B cell subsets are sorted from the spleen and peritoneum of C57BL/6 mice that were given intraperitoneal injections of LPS once daily for four days.