bluuebunny/crossref_metadata_2025_split huggingface dataset:
CONTRIBUTIONS OF FEVER TO THE PROMOTION OF CELLULAR ANTIMICROBIAL DEFENSES
Authors: Barreda Daniel R 
Published: January 2023

Abstract
Thermal changes impact molecular and cellular immune responses. Herein we take advantage of evolutionarily conserved mechanisms for the control of fever to define its contributions to host immune antimicrobial defenses. Our work demonstrates that discrete thermoregulatory programs provide a broader range of immunological benefits than previously anticipated. Complementing prior findings on the modulation of immune gene expression, high resolution quantitative monitoring of cell function showed predictable changes to leukocyte recruitment and pathogen killing capacity. Assessment of kinetics of leukocyte infiltration to a challenge site and changes to the distribution of cellular subsets showed changes in the efficiency of the teleost acute inflammatory response. Ex vivo characterization of cell function as well as in vivo evaluation of host-pathogen interactions pointed to enhancements in immune defenses and pathogen clearance. These have obvious positive implications for health, setting the stage for valuable applications.
Activation-induced cell protrusions and vesicle secretion of human lung macrophages revealed by super-resolution microscopy
Authors: Dechantsreiter Susanne , Ambrose Ashley , Hessel Edith M , Beinke Soren , Tannahill Gillian , Davis Daniel M 
Published: January 2023

Abstract
Recent studies using super-resolution microscopy have established that the organisation of immune cell receptors impacts signal integration and cellular activation. Understanding the nano-scale dynamics of surface receptors on tissue specific macrophages is especially important, as they are phenotypically diverse and possess a large repertoire of receptors. However, tissue macrophages are highly auto-fluorescent, severely limiting the utility of light microscopy. Here, we report a novel correction technique which utilises a moving median filter to remove auto-fluorescent noise from stochastic optical reconstruction microscopy datasets. Using this, we visualised lung macrophages (LMs) activated through Fc receptors by IgG-coated glass slides, representing a 2D model of the phagocytic synapse. This unexpectedly revealed the formation of protrusions, at the surface of LMs but not blood-derived macrophages. Class I MHC protein accumulated at the tips, consistent with a role for macrophage protrusions in antigen presentation. Additionally, staining for the exosome marker CD81 revealed the secretion of extracellular vesicles. Classically, cell-derived vesicles are studied after bulk isolation, which is harsh and comes with many caveats. Imaging them directly upon secretion allows analysis of their properties on a cell-by-cell basis in a near-native state. We discovered that LM vesicles appeared distinct from those secreted from blood-derived macrophages in that their average diameter was much smaller (80 nm ± 19 nm vs. 159 nm ± 78 nm). Thus, our correction method for super-resolution microscopy revealed novel cell biology – protrusion formation and vesicle secretion – triggered upon activation of human LMs.
Temporal transcriptional, metabolic, and functional re-programming of THP-1 macrophages by the Lactobacillus rhamnosus R0011 secretome
Authors: Jeffrey Michael P , MacPherson Chad W , Tompkins Thomas A , Green-Johnson Julia May 
Published: January 2023

Abstract
Macrophage responses to activation are fluid and dynamic and their ability to respond appropriately to subsequent challenge is integral to host defence. Recent evidence suggests that bacteria influence macrophage differentiation and subsequent polarization into pro-inflammatory (M1) and immunoregulatory (M2) phenotypes through direct interactions. However, many questions surround indirect communication mechanisms mediated through secretomes derived from gut bacteria, such as lactobacilli. We examined the effects of secretome-mediated conditioning on macrophage phenotype, focusing on the ability of the Lactobacillus rhamnosus R0011 secretome (LrS) to drive macrophage polarization and to prime responses to subsequent challenge with lipopolysaccharide (LPS). Transcriptional profiling revealed increased M2-associated gene transcription (IL10R, CD36, CD163, TLR1, and TLR8) in response to LrS conditioning. Cytokine and chemokine profiling confirmed these results, indicating increased M2-associated chemokine and cytokine production (IL-10, CCL1, 17, 20, CXCL1 and 2). Metabolite utilization assays indicated diminished reliance on glycolysis for energy generation, coupled with increased phagocytic capacity, characteristics of functional M2 activity. LPS challenge of LrS-conditioned THP-1s revealed heightened responsiveness, indicative of innate immune priming. Overall, the LrS conditions THP-1s into M2 macrophages and primes responses to subsequent LPS challenge. Secretome conditioning of macrophages to respond robustly to inflammatory challenge within an M2 phenotype is an uncharacterized and potentially important route through which lactobacilli can train innate immunity.
Deletion of fetal-specific maternal CD4+ T cells during human pregnancy
Authors: Krupp Katharine , MacDougall Julia , Porrett Paige 
Published: January 2023

Abstract
Maternal T cell responses to fetal alloantigens are thought to play a critical role in facilitating successful pregnancy, but mechanisms of maternal-fetal tolerance remain largely unclear. Studies in murine models suggest that deletion of fetus-specific CD4+ T cells may contribute to tolerance; however, the role of deletion in human pregnancy is unknown. Here we use bulk TCR sequencing to assess changes in the maternal CD4+ T cell repertoire over the course of human pregnancy.
Peripheral blood was collected from four primigravid women during the first and third trimesters, and a single peripheral blood sample was taken from their respective partners. Maternal CD4+ T cells were isolated using FACS, and TCR sequencing was performed on genomic DNA using the ImmunoSeqTM assay. The maternal alloreactive repertoire was defined using mixed lymphocyte reactions (MLRs) in which irradiated paternal PBMCs were used to stimulate maternal blood.
An average of 32,077 (SD=9,609) unique CD4+ T cell clones/subject were identified at each timepoint. Within the small cohort examined in this study, we observed a notable increase in repertoire clonality in two of four women (average change in clonality=0.0045 vs. 0.0003). The two subjects that had an increase in CD4 clonality had a significant reduction in the number of alloreactive CD4 clones detected in the third trimester relative to the first whereas this number was effectively unchanged in the other two subjects (first:third=1:0.1±0.02 vs. 1:1.0±0.1). These findings suggest that substantial deletion of CD4+ alloreactive clones occurs in some women over the course of gestation. Deletion of alloreactive T cell clones may thus represent one mechanism of maternal-fetal tolerance in human pregnancy.
Cyclic GMP-AMP synthase Regulates the Development of experimental autoimmune encephalomyelitis
Authors: Mittal Monisha , Tu Sha , Guo Hui , Zhang Jian 
Published: January 2023

Abstract
Cyclic GMP-AMP synthase (cGAS) is a cytosolic DNA sensor that activates type 1 IFN response via cGAS/cGAMP/STING-dependent pathway to defend against viral and bacterial infections. The role of c-GAS in adaptive immunity is completely unknown. In this study, we attempted to determine whether cGAS also regulates T cell responses using mice deficient for cGAS. We found that cGas−/− mice develop ameliorated experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis, which correlates with defective Th1/Th17 responses. This reduced disease activity in cGas−/− mice is unlikely due to the expression cGAS in T cells because Rag1−/− recipients receiving Wild-type and cGas−/− CD4+ T cells develop a comparable degree of EAE. Therefore, our data suggest that cGAS expression in innate immune cells may indirectly regulate pathogenic Th1/Th17 responses during EAE induction.
IRF4 regulates the proliferative capacity of activated B cells during B cell differentiation
Authors: Patterson Dillon , Scharer Christopher D. , Mi Tian , Hicks Sakeenah L. , Zhang Qiang , Boss Jeremy M 
Published: January 2023

Abstract
Cell division is essential for B cell differentiation to a plasma cell (PC). While the cell division coupled changes in the expression of transcription factors that coordinate the PC program have been described, little is known regarding how these factors coordinate the proliferative program. To address this, we exploited an adoptive transfer system and monitored the cell division/differentiation kinetics in response to lipopolysaccharide (LPS). In this system, wildtype (WT) B cells undergo at least 8 cell divisions before differentiating into PC, and the same requirement is also observed following NP-ficoll or influenza immune challenge. Modeling division rates over time identified a proliferative burst between 48 and 60 hours following LPS injection. In contrast, Interferon Regulatory Factor 4-deficient (IRF4−/−) B cells divided but failed to undergo the proliferative burst, stalling at divisions 2–6. To assess the scope of IRF4-dependent reprogramming, WT and IRF4−/− B cells at divisions 0, 1, and 3–6 were sorted for ATAC- and RNA-seq. RNA-seq data revealed hundreds of differentially expressed genes (DEGs) when IRF4 was deleted, a subset of which included MYC target genes. Indeed, IRF4−/− cells failed to upregulate MYC compared to WT cells and consequently, we observed little increase in cell size following immune challenge. Furthermore, IRF4−/− B cells exhibited aberrant cell cycle distribution when compared to WT cells at the same timepoint and division. ATAC-seq data also exposed hundreds of differentially accessible regions, the majority of which contained a known IRF4 binding motif and mapped to a corresponding DEG. Together, these data reveal a critical role for IRF4 in maintaining the proliferative response.
SHARPIN constrains IL-21-induced apoptosis in CD40-activated B cells to mediate the germinal center reaction and T-dependent antibody response
Authors: wang jingwei , Wu Shuai , Kaiser William , Yan Hui , Xu Zhenming 
Published: January 2023

Abstract
SHARPIN is an obligatory component of the fully functional LUBAC complex, which is implicated in the antibody response. Here, we have addressed the B cell-intrinsic function of SHARPIN by generating mice in which only B cells expressed non-functional SHARPIN, as encoded by the missense Cpdm mutation. These mice were normal in B cell development and homeostatic survival, but severely impaired in mounting specific IgM and IgG responses to the T-dependent antigen NP-CGG, concomitant with reduced generation of class-switched B cells and plasma cells, likely resulting from the virtual absence of germinal centers. Consistent with their failure in the germinal center development in vivo, as dependent on CD154 and IL-21 produced by T follicular helper cells, Sharpin mutant B cells activated by CD40 engagement in vitro displayed normal proliferation, but significantly elevated apoptosis upon stimulation with IL-21. This cytokine, while critical for CD40-induced plasma cell differentiation, up-regulated expression of pro-apoptotic Bim and downregulated anti-apoptotic Bcl-2 and Bcl2l1, thereby activating the mitochondria-dependent intrinsic apoptosis pathway. Indeed, Sharpin mutant B cells, upon stimulation by CD154 and IL-21, expressed the apoptosis gene signature at a high level and showed increased Caspase 3 activation. These, together the rescue of the survival of Sharpin mutant B cells and their production of class-switched IgG by apoptosis inhibitor Z-VAD, show that SHARPIN plays an important role in protecting germinal center B cells from apoptosis, thereby mediating the antibody response.
Therapeutic hypothermia rescues severe acute lung injury (ALI) by IL-1β-induced neutrophil extracellular traps (NETs) formation through down-regulation of Gasdermin D
Authors: Shimada Kenichi , Nosaka Nobuyuki , Martinon Daisy , Crother Timothy R , Arditi Moshe 
Published: January 2023

Abstract
ARDS is a serious ALI defined by the acute onset of non-cardiogenic pulmonary edema and hypoxemia. We have previously published that NLRP3 inflammasome is required to develop hypoxemia in LPS plus mechanical ventilator (MV) two-hit-induced ALI. We initially observed that, despite equal neutrophil infiltration, severe alveolar leakage and hypoxemia were not observed in Il1r1KO mice, confirming that NLRP3 inflammasome is critical in this two-hit induced hypoxemia. However, this hypoxemia was significantly attenuated in neutrophil-depleted mice. Furthermore, we found that NETs formations were significantly attenuated in Il1r1KO mice. These data demonstrated that IL-1R signaling plays a regulating role in neutrophil functionality in the alveoli, and not their infiltration. We next examined whether NETs formation contributed to develop hypoxemia in two-hit ALI. by Pad4 inhibitor and DNase I. Both treatments improved the development of hypoxemia. In the course of experiments, we serendipitously found that body temperature is a critical factor regulating severe hypoxemia. Therapeutic hypothermia at 32°C during MV rescued development of hypoxemia with significantly attenuated alveolar leakage, reduced IL-1β secretion, and less NETs formation. 32°C condition inhibited IL-1β secretion by Mϕ as well as NETs induction. Unexpectedly, we observed similar Caspase-1 activities in LPS-primed Mϕ stimulated with ATP or nigericin at 32°C while IL-1βsecretion was significantly reduced. We found decreased GSDMD expression and unsecreted mature IL-1β at 32 °C treatment. Overall our data suggests that hypothermia suppresses ALI development by inhibiting IL-1β secretion and NETs formation through down-regulation of GSDMD.
Negative elongation factor complex enables macrophage inflammatory responses by controlling anti-inflammatory gene expression
Authors: Yu Li , Zhang Bin , Deochand Dinesh , Sacta Maria A. , Coppo Maddalena , Shang Yingli , Guo Ziyi , Rollins David A. , Tharmalingam Bowranigan , Li Rong , Chinenov Yurii , Rogatsky Inez , Hu Xiaoyu 
Published: January 2023

Abstract
Studies on macrophage gene expression have historically focused on events leading to RNA polymerase II recruitment and transcription initiation whereas the contribution of post-initiation steps to macrophage activation remains poorly understood. Here, we report widespread promoter-proximal RNA polymerase II pausing in resting macrophages, marked by broad co-localization of the negative elongation factor (NELF) complex and facilitated by PU.1. Upon inflammatory stimulation, over 60% of activated transcriptome is regulated by polymerase pause-release and a transient genome-wide NELF dissociation from chromatin, unexpectedly, independent of CDK9, a presumed NELF kinase. Genetic disruption of NELF in macrophages enhanced transcription of AP-1-encoding Fos and Jun and, consequently, AP-1 targets including Il10. Augmented expression of IL-10, a critical anti-inflammatory cytokine, in turn, attenuated production of pro-inflammatory mediators and, ultimately, macrophage-mediated inflammation in vivo. Together, these findings establish a previously unappreciated role of NELF in constraining transcription of inflammation inhibitors thereby enabling inflammatory macrophage activation.
The BCMA:Tomato Mouse – a new reporter to characterize long-lived plasma cells
Authors: Schulz Sebastian R , Wittner Jens , Kueh Andrew J. , Pal Martin , Herold Marko J , Schuh Wolfgang , Jäck Hans-Martin 
Published: January 2023

Abstract
Plasma cells provide humoral protection by secreting large amounts of antibodies. The heterogeneity of the plasma cell compartment has recently been demonstrated by functional studies and subpopulation markers, but the distinct properties of long-lived plasma cells (LLPC) are still unresolved.
B Cell Maturation Antigen (BCMA) has been described as an essential receptor for LLPC survival. To elucidate the mechanisms of BCMA-mediated survival we established a reporter mouse line that expresses a tdTomato fluorescent protein together with BCMA under the control of the promoter of Tnfrsf17, the gene that encodes BCMA. In this reporter model, we could demonstrate the restricted expression of Tomato and BCMA in plasma cells making this an ideal system for the identification and tracking of plasma cells. Importantly, we observed an increase in the abundance of BCMA:Tomato along with a gradual loss of CD19 expression, delineating a developmental progression from plasmablasts to mature plasma cell subsets. In contrast, plasmablasts generated in vitro display only minimal BCMA induction, confirming the independence of BCMA expression from the Blimp1 master regulator of PC differentiation.
In summary, we have developed a new plasma cell-specific reporter model that, together with an inducible BCMA-KO mouse, will allow us to investigate the BCMA-dependent signals of the generation and maintenance of LLPC.
This work was supported, in part, by the Deutsche Forschungsgemeinschaft (DFG) through research grants TRR130 to H.-M.J. and W.S. and GRK1660 to H.-M.J.
Malt1 Protease Is Critical in Maintaining Function of Regulatory T Cells and May Be a Therapeutic Target for Antitumor Immunity
Authors: Cheng Liqing , Lin Xin 
Published: January 2023

Abstract
The paracaspase Malt1 is a key molecule in mediating Ag receptor–induced NF-kB activation in lymphocytes, but the role of Malt1 in the function of regulatory T (Treg) cells is still unclear. Here, we reported that specific deletion of Malt1 in Treg cells would lead to Scurfy-like lethal autoimmune disease, which was caused by Treg cell dysfunction but not number loss. Interestingly, Foxp3Cre-Malt1fl/C472A mice, in which Malt1 protease was specifically inactivated in Treg cells, also displayed spontaneous inflammatory disorders, with severe hair loss and skin hyperplasia. Consistently, Foxp3Cre-Malt1fl/C472A mice showed enhanced antitumor response because of their decreased function and infiltration of Treg cells, as well as reduced CD8+ T cell exhaustion. Gene expression profiling analysis revealed dysregulated expression pattern of Treg effector genes upon Malt1 deletion or its protease inactivation. Together, our data unraveled a critical role of Malt1, especially its protease activity, in maintaining homeostasis and function of Treg cells.
Defining heterogeneity and biological signature in human effector memory CD8+ T cells expressing different levels of IL-7 receptor alpha by high-dimensional analysis
Authors: Shin Min Sun , Kim Dongjoo , Park Hong-Jai , Dong Xuemei , Koumpouras Fotios , Kang Insoo 
Published: January 2023

Abstract
Human effector memory (EM) CD8+ T cells have been divided into a small number of subsets based on the expression of a single or a few cell surface molecules. Previously, we showed the presence of human EM CD8+ T cell subsets expressing IL-7 receptor alpha chain (IL-7Rα) high and low that have different characteristics like the expression of cytotoxic molecules, cytokines, co-stimulatory molecules, and DNA methylation. However, it is unknown whether IL-7Rα can serve as a key molecule in defining a comprehensive landscape of heterogeneity in human EM CD8+ T cells as determined by high-dimensional single cell analysis. Here we addressed this question by performing Cytometry by Time-Of-Flight (CyTOF) and single-cell RNA-seq (scRNA-seq) analysis on human EM CD8+ T cells and analyzing such data using computational algorithms. IL-7Rα had diverse, but organized, expressional relationship in EM CD8+ T cells with molecules related to gene regulation, effector function, survival, and migration, which rendered an immune landscape defining heterogeneous cell subsets. The differential expression of these molecules likely has biological implications as we found in vivo signatures of transcription factors and homeostasis cytokine receptors, including T-bet and IL-7Rα, as well as the possible alterations of EM CD8+ T cell heterogeneity defined by these molecules in lupus patients. Our findings indicate the existence of heterogeneity in human EM CD8+ T cells as defined by distinct but organized expression patterns of multiple molecules in relationship to IL-7Rα and possible biological significance of differential expression of such molecules in modulating downstream events and pathologic conditions.
Nonencapsulated Streptococcus pneumoniae causes Bacteremia in C1q-Deficient Mice
Authors: McDaniel Larry S , Bradshaw Jessica L 
Published: January 2023

Abstract
Since the introduction of the pneumococcal conjugate vaccines, the frequency of infections by nonencapsulated Streptococcus pneumoniae (NESp) has steadily increased. We previously demonstrated that NESp expressing AliC and AliD instead of the canonical capsule synthesis genes in the cps locus are able to survive killing in a whole blood bactericidal assay. Also, NESp expressing AliC and AliD are associated with invasive pneumococcal disease (IPD). The purpose of this study was to determine if NESp expressing AliC and AliD evade complement-mediated killing. Flow cytometry was used to examine binding of C3b and factor H (FH) to NESp in vitro. We used a chinchilla model of otitis media (OM) and mouse models of infection to examine complement interaction with NESp in vivo. Deletion of aliC and aliD resulted in reduced expression of choline binding protein AC (CbpAC), a variant of pneumococcal surface protein C (PspC). There was a four-fold increase in C3b deposition on a CbpAC mutant compared to the wild-type. Deletion of cbpA significantly reduced virulence in OM in which complement is known to play a role. When C1q-deficient mice were intravenously challenged with the wild-type strain, 60% of the mice failed to survive compared to 100% survival of mice challenged with the CbpA deficient mutant. Further, the wild-type NESp burden in the blood of C1q-deficient mice reached 1×107CFU/ml, and bacteremia persisted for at least five days. In contrast, the CbpAC mutant was not detectable in the blood by 48 hours post-infection. Overall, the ratio of CbpA and deposited C3b on the NESp surface appears to be crucial for NESp to counteract complement deposition and evade host response. Thus, NESp are able to initiate bacteremia and persist within the host.
Identification of a phagosomal F-actin structure that evades dendritic cell immunity to Cryptococcus gattii
Authors: Jamil Khusraw , Polyak Maria J , Feehan David D , Surmanowicz Philip , Li Shushun , Ogbomo Henry , Stack Danuta , Olszewski Michal A , Ganguly Anutosh , Mody Christopher H 
Published: January 2023

Abstract
Hypervirulent Cryptococcus gattii is a major cause of life-threatening cryptococcosis in immunocompetent individuals and responsible for the ongoing outbreak in the Pacific Northwest. This deadly fungus is known to subvert dendritic cell (DC) maturation and concomitant T cell immunity via immune evasion mechanisms that are poorly understood. Here, we show that primary human DC can phagocytose endemic yeasts but trafficking to the late phagolysosome is blocked by retention of a filamentous actin (F-actin) cage surrounding the phagosomes. Structural studies by super resolution microscopy revealed a novel highly branched F-actin cage that physically interfered with lysosomal fusion. Mechanistically, we demonstrate that C. gattii F-actin cage promotes immune evasion by silencing the canonical RelA signaling of the NF-κB pathway required for DC costimulation and T cell activation. Disruption of the F-actin cage through targeted inhibition or by TNF-α signaling reprogrammed quiescent DC to immunocompetent antigen-presenting cells (APCs) and revealed the existence of a negative feedback loop between periphagosomal F-actin aggregation and pro-inflammatory NF-κB signaling. Collectively, our results have uncovered a unique mechanism of DC immune subversion by organisms such as hypervirulent C. gattii and revealed the potential clinical significance of the immunomodulatory function of phagosomal F-actin in host-pathogen interaction.