bluuebunny/crossref_metadata_2025_split huggingface dataset:
The nonreceptor tyrosine kinase SYK induces autoinflammatory osteomyelitis in a mouse model of chronic recurrent multifocal osteomyelitis
Authors: Banoth Balaji , Kanneganti Thirumala-Devi 
Published: January 2023

Abstract
Chronic recurrent multifocal osteomyelitis (CRMO) in humans can be modeled in Pstpip2cmo mice, which carry a missense mutation in the proline-serine-threonine phosphatase-interacting protein 2(Pstpip2) gene. As cmo disease is mediated specifically by IL-1β, not IL-1α, delineating the molecular pathways contributing to the pathogenic IL-1β production is crucial to develop targeted therapies. In particular, our earlier findings support redundant roles for NLRP3 and caspase-1 with caspase-8 in instigating the disease. However, the signaling components upstream of caspase-8 and pro-IL-1β cleavage in Pstpip2cmo mice are not well understood. Therefore, we investigated the signaling pathways in these mice and characterized the central role of the nonreceptor tyrosine kinase SYK in mediating osteomyelitis. We demonstrate that while absent in melanoma 2 (AIM2), receptor-interacting serine/threonine protein kinase 3 (RIPK3), and caspase recruitment domain-containing protein 9 (CARD9) are dispensable for osteomyelitis induction in Pstpip2cmo mice, genetic deletion of Syk completely rescues disease. We further show that SYK centrally mediates signaling upstream of caspase-1 and caspase-8 activation and principally regulates NF-κB and IL-1β signaling in Pstpip2cmo mice to instigate disease. These data provide a rationale for directly targeting SYK and its downstream signaling components in CRMO.
Neutrophil Effector Responses to Cystic Fibrosis Clinical Isolates of Staphylococcus aureus and Pseudomonas aeruginosa
Authors: Fantone Kayla M , Miller Arthur , Fricker Rachel , Yadav Ruchi , Stecenko Arlene , Goldberg Joanna , Rada Balazs 
Published: January 2023

Abstract
Cystic fibrosis (CF) airway disease is characterized by chronic microbial infections and infiltration of polymorphonuclear neutrophil granulocytes (PMNs). In CF, PMNs are unable to clear lung pathogens resulting in lung damage. Neutrophil extracellular traps (NETs) and superoxide production represent defense mechanisms of PMNs to kill extracellular pathogens. NETs and superoxide in the CF lung, however, seem unable to clear Pseudomonas aeruginosa and Staphylococcus aureus, the two main lung pathogens in CF. Our goal of this study was to determine antimicrobial functions of PMNs to S. aureus and P. aeruginosa CF isolates and to observe how the CF airway environment influences them. Human PMNs were isolated from healthy donors. Isolates of S. aureus were obtained from adult CF patients: four strains were methicillin-resistant (MRSA), four were methicillin-sensitive S. aureus (MSSA), and ten CF isolates of P. aeruginosa. PMN effector functions were measured: killing was assessed by bacterial growth assay, NET formation was measured by Sytox fluorescence and superoxide was monitored by Diogenes chemiluminescence. Results were subjected to paired t-test, significant if p&lt;0.05. PMNs from healthy volunteers were able to kill all CF isolates. The extent of killing varied among strains, however, P. aeruginosa was killed more efficiently by blood PMNs than S. aureus clinical isolates. The enhanced killing of P. aeruginosa is correlated with enhanced NET release and superoxide production compared to S. aureus. Killing of all isolates was inhibited by CF sputum pretreatment. Overall, the results show that CF bacterial clinical isolates stimulate PMN effector responses that are impaired by the CF airway environment.
The CF airway environment affects neutrophil antibacterial effector mechanisms: phagocytosis and NET formation
Authors: Tucker Samantha L , Yadav Ruchi , Stecenko Arlene , Rada Balazs 
Published: January 2023

Abstract
Cystic Fibrosis (CF) is an autosomal recessive disease caused by mutations in the epithelial chloride channel CFTR. Lung disease is the main cause of mortality and morbidity in CF. CF airways are characterized by chronic, mainly neutrophil-mediated inflammation and persistent bacterial infections. Despite their increased presence in the CF lung, airway neutrophils are unable to clear respiratory pathogens like Pseudomonas aeruginosa and Staphylococcus aureus. We hypothesized that the CF airway environment affects two antibacterial effector mechanisms of neutrophils: phagocytosis and neutrophil extracellular trap (NETs) formation. While neutrophils are known to kill P. aeruginosa and S. aureus mainly by phagocytosis-mediated intracellular killing, NET-mediated extracellular killing remains relatively inefficient against these pathogens. To examine this in CF, blood PMNs from healthy donors were incubated in sputum supernatants from CF patients to mimic the CF airway environment. Using this in vitro model, different markers and functions of neutrophils were measured by flow cytometry. Phagocytosis of fluorescently-labelled P. aeruginosa was significantly inhibited by CF sputum treatment. Surface expression of CD33, a myeloid-derived suppressor cell marker known to inhibit phagocytosis, was increased following CF sputum treatment. CF sputum exposure slightly increased both of the NET-specific markers studied: intracellular levels of citrullinated histone H3 and surface expression of gasdermin-D. These results suggest that the CF airway environment contributes to the inability of neutrophils to eliminate bacteria while promoting the release of dangerous, tissue-damaging neutrophil cargo via NET formation.
Mucosal correlates associated with natural regression of HPV-associated dysplasia
Authors: Choi Yoojin , Salit Irving , Grech Sarah , Sano Marie , Weiss Edward , Coburn Bryan , Kaul Rupert 
Published: January 2023

Abstract

Background
Anal HPV infection and associated pre-cancerous changes, known as anal intraepithelial neoplasia (AIN), are common among men who have sex with men (MSM). While natural regression of AIN is often observed, there are currently no predictors for disease outcomes. Therefore, we assessed mucosal immune and microbiological correlates of natural AIN regression.

Methods
Fifty-five HIV-infected, ART-treated MSM were recruited, of whom 26 had confirmed AIN. The microbiome was defined via qPCR and 16s sequencing of anal swabs; biopsies were collected from both healthy and AIN-confirmed sites by high-resolution anoscopy, and lymphocyte populations were defined by flow cytometric analysis including CD38 and HLA-DR as activation markers. AIN regressors vs non-regressors were compared by Mann-Whitney (SPSS).

Results
AIN regression was observed in 15/26 (58%) participants. Regression was associated with a higher proportion of CD8+ T cells (p= 0.006), and AIN regressors had significantly higher levels of both activated CD8+ (p= 0.023; 44.5% vs 27.9%) and activated CD4+ T cells (p=0.023; 20.4% vs 9.81%) compared to non-regressors. Interestingly, AIN regressors had reduced microbiome diversity (p=0.026; 241 vs 284 OTUs) and a trend towards a lower bacterial load (p=0.059). While age was similar between groups, AIN regressors had been living with HIV for a shorter time (p=0.023). No differences were observed between groups in T cells derived from AIN-free anal mucosa.

Conclusions
AIN-specific immune activation was associated with subsequent regression of AIN. Given that AIN non-regressors had greater anal microbiome diversity, defining key bacterial species and their role in HPV pathogenesis may merit further investigation.
Single-cell RNA-sequencing of leprosy skin lesions reveals a titin (TTN) expressing T cell subset associated with the progressive disease
Authors: de Andrade Silva Bruno Jorge , Hughes Travis K , Andrade Priscila R , Ma Feiyang , Teles Rosane MB , Shalek Alex K , Bloom Barry , Pellegrini Matteo , Modlin Robert L 
Published: January 2023

Abstract
The immune response to intracellular bacteria is critical for host defense against the invading pathogen. This interaction can be studied in the human disease leprosy caused by the intracellular bacterium Mycobacterium leprae affecting primarily the skin compartments. Patients with tuberculoid leprosy (T-lep) express a Th1 cytokine pattern in skin lesions and develop a protective immunity that eliminates the infection, whereas those with lepromatous leprosy (L-lep) express Th2 cytokines in lesions and sustain a progressive infection. In the reversal reaction (RR) state, patients upgrade, either spontaneously or during chemotherapy, from the L-lep to the T-lep pole. Herein, we used unbiased single-cell RNA-sequencing to explore the breadth of potential immune cell states in leprosy. Unexpectedly, we identified a lymphocyte cluster marked by expression of titin (TTN), which is commonly found in the sarcomere of muscle cells. TTN+ T cells were predominantly enriched in L-lep lesions and RNA-FISH showed a higher number of TTN mRNA dots on CD3+ T cells from L-lep in comparison with RR patients. TTN gene expression decreased in the skin lesion cells of L-lep patients undergoing RR episodes associated with the onset of therapy. Protein expression was confirmed by analysis of T cell clones isolated from leprosy lesions and blood-derived CD3+ T cells from healthy donors. Indeed, immunohistochemical staining of lesions and healthy tonsil showed that TTN was present in the CD3+ T cell zones. Canonical pathways analysis revealed that TTN might be involved with T cell inhibitory RhoA signaling pathway. The role of TTN on T cells remains unknown, however, it could represent a novel mechanism in the skin immune response against cutaneous pathogens.
MISTR: A conserved

MI

tochondrial

ST

ress

R

esponse network revealed by signatures of evolutionary conflict
Authors: Hancks Dustin , Sorouri Mahsa , Chang Tyron , Pinkham Chelsea , Jesudhasan Palmy 
Published: January 2023

Abstract
While the identities of many interferon-stimulated genes (ISGs) are established, the functions of the majority of these gene products as well as their relationship with other cellular factors are unknown. To drive functional characterization, we sought to identify ISGs with genetic hallmarks indicative of conflicts with pathogens and common to key host defense factors: 1) rapid evolution and 2) viral homolog. Using these “molecular scars” as a guide, we discovered a vertebrate-specific MItochondrial STress Response circuit (MISTR). MISTR proteins are associated with electron transport chain factors and activated by stress signals such as interferon-gamma and hypoxia. Upon stress, ultraconserved miRNAs downregulate MISTR1 followed by replacement with paralogs MISTR AntiViral (MISTRAV) or MISTR Hypoxia (MISTRH), depending on the insult. While cells lacking MISTR1 are more sensitive to apoptotic triggers, cells lacking MISTRAV or expressing the poxvirus-encoded vMISTRAV exhibit resistance to the same insults. Rapid evolution signatures across primate genomes for MISTR1 and MISTRAV indicate ancient and ongoing conflicts with pathogens. MISTR proteins are also found in plants, yeasts, and an algal virus indicating ancient origins and suggesting diverse means of altering mitochondrial function under stress. The discovery of MISTR circuitry highlights the use of evolution-guided studies to reveal not only new dimensions of innate defenses but also fundamental biological processes.
VAMP8 mediates TLR4-dependent TNF secretion in RBL-2H3 pro-inflammatory cells
Authors: Segura Deisy Lizbeth , Ibarra-Sánchez Alfredo , Blank Ulrich , González-Espinosa Claudia 
Published: January 2023

Abstract
Mast cells (MCs) participate in allergic diseases by producing pro-inflammatory mediators and regulatory cytokines. After high affinity IgE (FceRI) receptor activation, they release tryptase, b-hexosaminidase and other preformed pro-inflammatory substances by anaphylactic degranulation. Also, upon stimulation through Toll-like receptor 4 (TLR4), they release pro-inflammatory mediators (such as Tumor Necrosis Factor, TNF), by piecemeal degranulation, orchestrating protective reactions against pathogens. Reactions involved in anaphylactic degranulation require specific vesicular-associated membrane proteins (VAMPs) involved in the latest step of exocytosis. However, the particular roles of VAMP proteins on piecemeal secretion observed after TLR4 receptor activation are not known. Utilizing RBL-2H3 cells differentiated to a pro-inflammatory phenotype, we investigated the role of VAMP8 and VAMP3 on lipopolysaccharide (LPS)-induced mediator secretion in MCs. Confocal microscopy images showed that, in non-stimulated cells, TNF localizes in VAMP3 and VAMP8-positive vesicles. After TLR4 stimulation, we observed an increase in TNF and VAMP8 co-localization, without any change on TNF and VAMP3 co-localization. Remarkably, VAMP8 blockade with specific siRNA impaired TNF secretion after LPS-challenge, while VAMP3 siRNA-mediated down regulation did not. Our data indicate that, although TNF is maintained in VAMP3-containing vesicles, TLR4 triggering leads to the secretion of TNF in VAMP8-containing carriers. Our results contribute to the description of the molecular events involved in late steps of TNF secretion induced by innate immune stimuli in that important immune cell type.
Extensive sex-dimorphism in age-related transcriptional remodeling in mouse peritoneal macrophages
Authors: Lu Ryan , Brown Shelby B , Sampathkumar Nirmal Kumar , Shen Courtney , Chae Jisoo , Benayoun Bérénice A 
Published: January 2023

Abstract
Chronic low-level inflammation is one of the hallmarks of aging. In addition, age-related diseases share common inflammatory mechanisms, a phenomenon named “inflamm-aging”. To date, the effect of age and sex on the genomic landscape of macrophages is largely unexplored, especially regarding sex-dimorphic trajectories in aging macrophages. Based on accumulating evidence indicating aging is highly sex-dimorphic, we hypothesize that aging will affect the phenotype of immune cells, such as macrophages, in a sex-dimorphic manner. To test our hypothesis, we used female and male C57BL/6N mice aged 4 and 20 months to investigate resident peritoneal macrophages. We generated RNA-seq data from purified peritoneal macrophages and identified genes modulated with aging as a function of sex. Complementing this ‘omic’ dataset, we performed an array of functional assays for these cells in several cohorts of aging mice, including immunophenotyping, metabolic profiling, lysosomal acidification tracking, phagocytic efficiency, etc. We observed sex-dependent functional decline, such as a male-specific decrease in macrophage ability to acidify lysosomes upon exposure to Zymosan. Interestingly, aspects of age-related functional changes may be mediated by age-related changes in circulating sex hormones. We are currently analyzing our single cell RNA-seq datasets from peritoneal lavages of naïve aging female and male mice, and generating complementary datasets that are profiling chromatin-level changes to identify putative drivers of age-related transcriptional and functional remodeling in macrophages. Ultimately, this project will help delineate sex dimorphic mechanisms modulating “inflamm-aging”.
The G9a methyltransferase inhibitor BIX01294 inhibits IFN-α production and regulates DNMT1 in virus-activated pDC
Authors: Codrington Alicia L , Yin Zhiwei , Singh Sukhwinder , Fitzgerald-Bocarsly Patricia 
Published: January 2023

Abstract
Plasmacytoid dendritic cells (pDC) are innate immune cells that represent 0.2–0.5% of human PBMC and produce IFN-α upon TLR7 or -9 activation by virus to stimulate innate and adaptive responses. Because of its potency and propensity to induce autoimmunity, IFN-α production must be tightly controlled. We investigated the role of histone 3 lysine 9 di-methylation (H3K9me2) and DNA Methyltransferase 1 (DNMT1) in IFN-α gene silencing in virus-activated pDC. DNMT1 recruits histone deacetylases, which are known to regulate cytokines. H3K9me2 is methylated by G9a methyltransferase, which suppresses IFN-α in fibroblasts. However, in virus-activated pDC, H3K9me2 may induce IFN-α. PBMCs were isolated from healthy donors and stimulated with IAV, HIV, or HSV for 24-hrs. We surface stained for pDC markers CD123 and HLA-DR, and CD11c, then intracellular stained for DNMT1. We also treated pDC with G9a methyltransferase inhibitor, BIX01294, and measured IFN-α and DNMT1 6-hr post stimulation with HSV and IAV. qRT-PCR was performed to measure DNMT1, demethylases, and G9a mRNA in purified pDC. In IAV and HSV stimulated pDC, DNMT1 was significantly upregulated at 24-hrs compared to 8-hr stimulated and unstimulated controls. IFN-α production and DNMT1 expression in IAV-activated pDC, but not in HSV, was significantly inhibited by BIX01294. Furthermore, G9a methyltransferase mRNA was elevated in IAV and HIV-1 purified pDC, but absent in HSV-stimulated cells. The elevation of DNMT1 may assist with limiting IFN-α production in pDC at 24-hrs to prevent excessive immune activation. Further, the reduction of DNMT1 in IAV, but not HSV-activated pDC upon treatment with BIX01294 implies a virus or TLR pathway (TLR7 vs -9) specific role of DNMT1.
STING-dependent type-1 interferon restrains schistosome immunopathology via down-regulation of the CD209a lectin receptor
Authors: Kalantari Parisa , Shecter Ilana , Gois Andrea Pilotta , Hopkins Jacob , Morales Yoelkys , Sharma Shruti , Stadecker Miguel 
Published: January 2023

Abstract
Infection with the helminth parasite Schistosoma mansoni causes morbidity and mortality via a pathogenic host CD4 T cell-mediated immune response directed against parasite egg antigens. We now demonstrate that stimulation of dendritic cells (DCs) with schistosome eggs induces robust IFNβ production in a manner dependent on the cyclic GMP-AMP synthase (cGAS)/Stimulator of Interferon genes (STING) cytosolic DNA sensing pathway, resulting in the suppression of proinflammatory IL-1β and IL-23 production and in Th17 cell activation. Consistent with these results, low-pathology BL/6 mice lacking STING exhibited markedly enhanced hepatic granulomatous inflammation associated with significantly increased Th17 and diminished Th2 cytokine responses. Mechanistically, IFNβ acts by suppressing DC expression and function of CD209a, a C-type lectin receptor associated with severe schistosome immunopathology. Importantly, there was an increased baseline CD209a expression in unstimulated DCs from STING−/− mice, suggesting a role for constitutive IFN signaling. Our findings demonstrate that innate, cGAS/STING-dependent sensing of parasite DNA represents a novel pathway inducing type I IFN production, which protects the host from excessive inflammation and immunopathology in schistosomiasis. This work is supported by NIAID grant R01 AI018919 to MJS.
Activation of the cGAS-STING pathway during Trypanosoma cruzi infection induces a type I interferon response that promotes parasite growth at the infection site
Authors: Iyam-Perumal Amanda-Natasha , Tarleton Rick L. 
Published: January 2023

Abstract
Host cell invasion by Trypanosoma cruzi is a markedly silent process that induces a modest, yet reproducible type I interferon (IFN-I) response. In this study, we report that T. cruzi -induced IFNβ production occurs through the cGAS-STING pathway. The induction of IFNβ transcription in primary murine macrophages at 24 hours post-infection was nearly abolished in cGAS−/− or STING−/− macrophages. Infected cGAS−/−, STING−/− and IFNAR−/− macrophages had significantly higher amastigotes compared to WT macrophages, indicating that activation of the STING pathway constrains intracellular parasite growth. To further assess the impact of the STING pathway in vivo, mice were infected in the footpads with tdTomato-expressing T. cruzi and the fluorescence intensity at the infection site was quantified as a measure of parasite growth. Despite an initial increase in parasite growth, we unexpectedly found that STING−/− and IFNAR−/− mice ultimately accumulated fewer parasites in the footpads as compared to WT mice. Surprisingly, contrary to STING−/− mice, we observed increased parasite growth in the footpads in cGAS−/− mice but not in cGAS−/−IFNAR−/− mice. Together, these results indicate that IFN-I response favors parasite growth at the site of infection. T. cruzi -induced IFN-I production results in increased monocyte and decreased neutrophil recruitment to the infection site, but depletion of these cells in mice had a minimal role in affecting parasite growth. Future studies will investigate the mechanism of IFN-I mediated enhancement of parasite growth and the overall impact of cGAS-STING activation in parasite control.
Phagocyte-derived SOCS1 disrupts Staphylococcus aureus skin host defense
Authors: Klopfenstein Nathan , Brandt Stephanie , Serezani C. Henrique 
Published: January 2023

Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) skin infection is controlled by the actions of skin resident macrophages and the formation of a neutrophilic abscess that prevents bacterial spread and tissue damage. We and others have shown that myeloid differentiation factor 88 (MyD88) is required for the clearance of MRSA skin infection in mice. MyD88 expression is controlled by the balance between STAT1 and the suppressor of cytokine signaling 1 (SOCS1). Here, we hypothesized that SOCS1 inhibits antimicrobial effector functions and the inflammatory response, leading to poor abscess formation and tissue injury during MRSA skin infection. Our data show that MRSA skin infection enhances SOCS1 expression. Infection in myeloid-specific SOCS1 deficient mice displays decreased lesion size, lower bacterial loads, and increased abscess thickness when compared to WT mice. When we treated infected mice with a peptide that specifically inhibits the kinase inhibitory region (KIR) of SOCS1, it also improved infection outcome. Examining the mechanisms by which SOCS1 enhanced skin host defense, we observed increased phagocytosis and bacterial killing in SOCS1 deficient macrophages and KIR peptide-treated cells. Increased antimicrobial effector function correlated with enhanced STAT1 activation and increased production of IFNγ in vivo and in vitro. Next we tested whether IFNγ is crucial to improved host defense in KIR-treated mice. Our data show that the beneficial effect of SOCS1 KIR peptide in skin host defense was abrogated in mice treated with an IFNR blocking antibody and in the IFNR deficient mice. Overall, these data show that preventing SOCS1 actions enhances microbial clearance and host defense during MRSA skin infection.
Regulation of the immune response by ST8Sia6
Authors: Crotts Sydney B , Friedman David J , Wang Zheng , Shapiro Michael J , Rajcula Matthew , McCue Shaylene , Sun Jie , Shapiro Virginia Smith 
Published: January 2023

Abstract
Sialic acids are the terminal modification on glycoproteins and glycolipids. The sialic acid transferase ST8Sia6 generates a2,8-linked disialic acids on O-linked glycoproteins, which bind to the inhibitory receptor Siglec-E on innate immune cells and suppress immune activation. Recently, our lab has shown that ST8Sia6 expression on tumor cells inhibits the immune response through Siglec-E, leading to increased tumor growth and decreased survival. Therefore, the products of ST8Sia6 can modulate the immune response to tumors. Our lab has generated ST8Sia6 knockout (KO) mice, and we seek to understand the role of ST8Sia6 in regulating the immune response to pathogens. We find that ST8Sia6 KO mice, when challenged with influenza virus, clear the infection significantly faster than wildtype controls, suggesting that absence of ST8Sia6 reduces inhibition of the innate compartment, thereby increasing immune recruitment to infection. This data suggests an important role for interactions between Siglec-E and ST8Sia6-generated disialic acids in immune regulation and recruitment to infection sites.