bluuebunny/crossref_metadata_2025 huggingface dataset:
Th9-derived Interleukin-9 (IL-9) is a potential therapeutic target for inflammatory cardiovascular disease
Authors: BARAL ISHITA , Baumer Yvonne , Burma Aarohan , Falduto Guido , Sylvester McKella , Schwartz Daniella
Published: November 2024

Psoriasis is a systemic autoimmune disease with a global prevalence of 2-3% and is strongly associated with metabolic dysfunction, vascular inflammation, and atherosclerotic cardiovascular disease (CVD). The IL-23/IL-17 pathway is critical for psoriatic inflammation. However, IL23/IL-17 blockade has no effect on CVD outcomes. Hence, the potential drivers of psoriatic CVD are still to be elucidated. IL-9-producing PU.1+/CD3+/CD4+ Th9 cells are found in the skin and circulation of patients with psoriasis. We found a significant association of Th9 cells with early radiographic atherosclerotic coronary artery disease in a psoriatic patient cohort. We observed an increase in aortic plaque size, and skin/aortic Th9 cells in a psoriatic atherogenesis model (IMQ-treated ApoE KO mice). To understand the involvement of IL-9 as a driver of the disease, we pharmacologically inhibited IL-9 in different modified disease models. IL-9 blockade-treated mice showed decreased skin inflammation compared to isotype-treated mice, accompanied by reduced aortic plaque formation. In vitro, IL-9 induced endothelial cell dysfunction through STAT3. Together, these results suggest that Th9/IL-9 may be a therapeutic target to prevent psoriasis-related atherosclerotic CVD. To further support our finding, we developed IL-9RKO/ApoE KO mice model, as well as conditional deletion of IL9R in various cell types. Further, transcriptomic profiling of endothelial cells will elucidate upon IL-9/STAT3 targets.
A role of DRAK2 in regulatory T cell (Treg) survival and T cell metabolic reprogramming
Authors: Lee Sarah , Walsh Craig , Nguyen Madison , Zangenberg Emma
Published: November 2024

Multiple Sclerosis (MS), one of the prevalent autoimmune disorders causing damage to the brain and spinal cord, requires safer therapeutics since current therapies rely on general immunosuppression, rendering patients susceptible to infection. Prior studies revealed that DAP kinase-related apoptosis-inducing protein kinase 2 (DRAK2) KO mice exhibit resistance to EAE, a mouse model for MS. DRAK2 deficiency also induced an overall reduction in T cell proliferation but an increase in proportion of regulatory T cells (Tregs) upon in vitro stimulation, potentially due to metabolic shift in T cells. To investigate the impact of DRAK2 deficiency on the expansion of different T cell subsets and how it reshapes T cell metabolism, WT and DRAK2-/- mice were used to quantify different T cell subsets and inspect significant alterations in mitochondrial metabolism. Results demonstrated decreased effector T cells and lipid contents in DRAK2-/- mouse T cells upon stimulation. A DRAK2 deficiency displayed an increase in mitochondrial membrane potential using JC-1 and TMRE staining of mouse T cells. RNA sequencing of T cells in WT and DRAK2-/- mice revealed that the absence of DRAK2 promotes the expression of TRIM family proteins which are closely associated with cGAS-STING DNA sensing pathway presumably caused by mtDNA. Altogether, these findings support the hypothesis that DRAK2 serves as a key metabolic regulator in T cells, heightening its potential as a new therapeutic target for MS.
Antigen persistence following mRNA vaccination and the immune consequence of lymph node stromal cell delivery
Authors: Belfon Robert , Tamburini Beth , Hesselberth Jay , Lasda Erika
Published: November 2024

mRNA vaccines have demonstrated their usefulness on a global scale in recent years. They elicit potent humoral and cell mediated responses, but the specific mechanisms by which these responses are produced still require investigation. Our lab described a process termed antigen archiving, in which antigen is retained within lymph node stromal cell (LNSC) subsets following viral infection and subunit vaccination to bolster/prolong memory CD8 T cell responses. Whether mRNA vaccines utilize this mechanism to promote immunity has yet to be determined. Data suggest mRNA-derived antigen persists within LNSC of C57/BL6 mice for at least 3 wks following subcutaneous or intramuscular delivery. We investigate the immune consequence of this prolonged antigen retention using ionizable lipid nanoparticles (LNP) to deliver mRNA constructs encoding the model antigen ovalbumin as well as a fluorescent siinfekl-GFP to monitor antigen-specific T-cell responses and localization of antigen within murine lymph nodes (LNs). We identified LNP formulations facilitating differential uptake/translation within LNSC which also demonstrated robust antigen-specific CD8 T cell responses and persistence of antigen presentation within LNs for at least 3 wks in vivo. We plan to interrogate the immune consequences of enhanced stromal cell targeting and subsequent antigen retention following mRNA vaccination. A better understanding of mRNA and protein delivery and retention will inform future vaccine design.
MicroRNA-29 regulates IgE class-switching in B cells and susceptibility to skin inflammation
Authors: Borbet Timothy , Hines Marcus , Boehringer Thomas , Morrison Tate , Gonzalez Sandra , Koralov Sergei
Published: November 2024

MicroRNA (miRNA) gene regulation is vital for the development of B cells. Our group established that the miR-29 family is a regulator of B cell survival and B cell receptor (BCR) signaling. Specifically, we identified PTEN as a direct target of miR-29. Conditional knockout of miR-29 in B cells diminishes cell viability, which is compensated by normalizing Pten expression. In our latest observations, mice with a B-cell-specific miR-29 deletion exhibited an inflammatory skin phenotype, characterized by cutaneous lesions, continuous itching and a 50% survival rate. Pten ablation fails to improve their lifespan. These findings indicate that miR-29 targets other transcripts in B cells apart from Pten. Notable features such as epidermal proliferation and elevated serum IgE levels. We hypothesize the absence of miR-29 in B cells may lead to to atopic dermatitis. Computational analysis predicts miR-29 likely regulates Il4Ra transcript levels, and qPCR supports this prediction. Our in vitro assays demonstrate that B cells deficient in miR-29 exhibit greater IgE class switching when stimulated with IL-4, compared to wild-type counterparts. Additionally, we observed that mice developing inflammatory skin conditions harbor an increased Staphylococcus burden. Therefore, we propose that miR-29 plays a role in the co-regulation of Pten and Il4ra to influence the survival and function of mature B cells and may alter how these cells respond to environmental/microbial antigens.
The role of HLA-DQ8 and B cells on CD8 IEL activation in celiac disease pathogenesis
Authors: Voisine Jordan , Meyer Celine , Xiao Zhiping , Chun Angela , Davis Amelia , Esubalew Nebiyat , Kauffman Tierney , Jabri Bana , Abadie Valerie
Published: November 2024

Celiac disease (CeD) is an autoimmune-like inflammatory disorder of the small intestine that is triggered by dietary gluten and develops in genetically susceptible individuals expressing HLA-DQ2 or HLA-DQ8 molecules. 1% of the worldwide population is affected by the disease. CeD is characterized by the loss of oral tolerance to gluten manifested by HLA-DQ2 or HLA-DQ8-restricted anti-gluten inflammatory CD4 T cells in the small intestinal mucosa and by a massive expansion of cytotoxic intraepithelial CD8+ lymphocytes (IE-CTLs) that are involved in the killing of intestinal epithelial cells, resulting in villous atrophy (VA). Using the first transgenic CeD mouse model that recapitulates the major clinical features of CeD, including VA, we demonstrated that tissue destruction was dependent on IE-CTLs, HLA-DQ8 and B cells. To uncover the mechanisms enabling VA, we characterized IE-CTL activation during CeD development and identified a particular CD8ɑβ IEL subset that becomes activated and highly cytotoxic in a gluten and HLA-DQ8-dependant manner. Strikingly, HLA-DQ8-expressing B cells acted as antigen-presenting cells for gluten peptides and drove the sustained activation of cytotoxic CD8ɑβ IE-CTLs. Our results support a critical role of B cell-T cell interactions for CeD pathogenesis and suggest that the expression of HLA-DQ8 on B cells is required to promote cytotoxic CD8abintraepithelial lymphocyte activation and the ensuing tissue destruction in CeD.
Identification of T regulatory cell (Treg) proliferation induced by IgM+IgDlo regulatory B cell (BDL) using a multi-color immunofluorescence strategy
Authors: Beltrame Angela , Dittel Bonnie
Published: November 2024

Multiple sclerosis is an autoimmune disease driven by T cell orchestrated demyelination. CD4+Foxp3+ T regulatory cells (Treg) suppress autoimmunity; thus, therapies to increase endogenous Treg numbers are ideal. We identified a novel subset of regulatory IgM+IgDlow/- B cells (BDL) that induce Treg proliferation in a glucocorticoid-induced TNFR-related ligand (GITRL)-dependent manner via cell-cell contact. However, where BDL localize with Treg in the spleen is unknown and imaging is challenging due to numerous required markers. Because Treg are located in the T cell zone, we hypothesize BDL migrate to and interact with Treg at the T-B boundary. A multi-color panel was developed to visualize, localize, and quantitate BDL-Treg conjugates. Fluorescent antibodies were selected via compensation methods using single-stained controls. Serial splenic sections were used to localize BDL-Treg interactions by staining a section with antibodies for splenic architecture: MAdCAM-1 (marginal zone), IgM (B follicle), and CD4 (T cell zone). The consecutive section was stained with antibodies to identify BDL (IgM, IgD), Treg (CD4, Foxp3), and proliferation (Ki-67). This strategy successfully identified Ki-67+ Treg-BDL conjugates in the T-B boundary. Future studies will quantitate the number of Ki-67+ Treg surrounded by BDL. We hope this strategy can be used to aid the development of a BDL-based therapeutic to increase endogenous Treg numbers and reduce autoimmunity.
B-1 cells contribute to plasma cell accumulation in Lyn-/- mice
Authors: Satterthwaite Anne , Ottens Kristina , Schneider Jalyn
Published: November 2024

The autoimmune disease systemic lupus erythematous is characterized by the production of pathogenic autoantibodies that drive inflammation and tissue damage. Defining which B cell subsets give rise to these autoantibodies may reveal therapeutic strategies that target pathogenic B cells while sparing responses to immunization and infection. Mice lacking the tyrosine kinase Lyn develop lupus-like autoimmune disease and accumulate autoreactive plasma cells in the spleen. We hypothesized that preventing plasma cell formation in Lyn-/- mice would result in an accumulation of cells that would have otherwise terminally differentiated. Deleting IRF4, a transcription factor required for plasma cell differentiation, from Lyn-/- mice resulted in a dramatic increase in B-1 cells in the peritoneal cavity and the spleen. B-1 cells are an innate-like subset of B cells that produces natural antibody and has been suggested to play both protective and pathogenic roles in autoimmune and inflammatory disease. A B-1 cell cre-reporter labeled about half of the splenic plasma cells in Lyn-/- mice, suggesting that B-1 cells may contribute to autoantibody production in this lupus model. Ongoing studies are aimed at determining the degree of autoreactivity of these labeled plasma cells in comparison to that of the B-1 cells that accumulate in Lyn-/-IRF4-/- mice.
The Crucial Role of A20 in Human B Cell Function: Implications for Immunoregulation and Autoimmunity
Authors: Sutton Rachel , Gupta Mansi , Scharer Christopher
Published: November 2024

Autoimmune diseases, such as systemic lupus erythematosus (SLE), are underscored by dysregulated B cell function including the production of autoantibodies, skewed population ratios, and aberrant signaling. Given that the family of nuclear factor kappa B (NF-kB) transcription factors govern responses to stimuli, survival, differentiation, and so forth understanding the intricate regulatory network of NF-kB in B cell biology is paramount for unraveling treatments for B cell-linked autoimmune diseases. Here, we focus on a negative regulator of NF-kB signaling, A20 (TNFAIP3), that deactivates NF-kB transcription factor translocation through the ubiquitination and deubiquitination of target proteins. Haploinsufficiency in A20 results in an autoimmune phenotype and mutations to A20 have been associated with SLE, suggesting implications to B cell function. To investigate the role of A20 in B cell signaling, we generated a TNFAIP3 knockout (KO) human B cell line. We then stimulated KO and WT cells with agonists such as B-cell activating factor (BAFF), CD40L, anti-IgM, TNFa, and R848 that activated distinct modes of NF-kB signaling. Using a combination of qRT-PCR, western blotting, and flow cytometry, the differences in gene expression patterns, protein production, and activation of NF-kB transcription factors were evaluated. Together, these findings provide a framework to understand how A20 controls B cell signaling and contributes to B cell-regulated autoimmune diseases.
Identification of environmental factors that promote intestinal inflammation
Authors: Kenison-White Jessica , Sanmarco Liliana , Chao Chun-Cheih , Wang Yu-Chao , Li Zhaorong , Rone Joseph , Quintana Francisco
Published: November 2024

Genome-wide association studies have identified risk loci linked to inflammatory bowel disease (IBD)—a complex chronic inflammatory disorder of the gastrointestinal tract. The increasing prevalence of IBD in industrialized countries and the augmented disease risk observed in migrants who move into areas of higher disease prevalence suggest that environmental factors are also important determinants of IBD susceptibility and severity. However, the identification of environmental factors relevant to IBD and the mechanisms by which they influence disease has been hampered by the lack of platforms for their systematic investigation. To overcome this limitation, we developed an integrated systems approach which combines publicly available databases, zebrafish chemical screens, machine learning, and mouse preclinical models to identify environmental factors that control intestinal inflammation. Using this approach we established that the herbicide propyzamide increases inflammation in the small and large intestine. Moreover, we found that an AHR–NF-κB–C/EBPβ signalling axis operates in T cells and dendritic cells to promote intestinal inflammation, and is targeted by propyzamide. In conclusion, we developed a pipeline for the identification of environmental factors and mechanisms of pathogenesis in IBD and, potentially, other inflammatory diseases.
Comparative transcriptomic analyses of in vivo-differentiated alveolar macrophages reveals unique as well as differential gene signatures and biological pathways
Authors: Vo Thao , Singamsetty Dhruthi , Lamichhance Richa , Saini Yogesh
Published: November 2024

Alveolar macrophages (AMs) originate from fetal liver and self-renew under homeostasis. However, exposure to environmental agents is known to alter alveolar macrophage populations by promoting self-renewal and/or by inducing recruitment and differentiation of bone marrow-derived circulating monocytes. However, the transcriptomic profiling of fetal- versus bone marrow-derived AMs populations remains awaited. Therefore, we conducted transcriptomic analysis on two in vitro-differentiated (bone marrow-derived macrophages (BMDMs) and fetal liver-derived macrophages (FLDMs)) and three alveolar macrophage (BM-chimera, FL-chimera and naive C57BL6/J mice) populations. We hypothesized that, due to their fetal-liver origin, FLDMs, FL-chimera and naïve alveolar macrophages exhibit comparable gene expression patterns. Interestingly, the Principal Component Analysis revealed separation of these three macrophage populations, suggesting that lung microenvironment as well as precursor origin are critical in shaping AM gene expression profile. This finding was further supported by differential gene expression analysis. Custom gene sets relevant to selective macrophage functions revealed distinct expression patterns in in vitro, naïve, and chimeric AMs. This study is likely to provide critical insights on how lung microenvironment and precursor origin define gene expression and associated biological pathways.
Exploring the Immunomodulatory Potential of Natures Immuno: A Study on Mushroom Formulations in Alleviating LPS-Induced Inflammation.
Authors: Nascimento Amanda , Pandher Upkar , Thompson Brooke , Schneberger David , Singh Baljit , Kirychuk Shelley
Published: November 2024

Introduction: Inflammatory diseases, such as pulmonary inflammation, lung cancer, and asthma, pose a significant global economic impact, affecting health and quality of life. Proinflammatory cytokines released by the immune system can be activated by Lipopolysaccharides (LPS), an endotoxin mimicking infection by Gram-negative bacteria. Literature suggests an increased risk of inflammatory diseases in females compared to males. Natures Immuno, a formulation extracted from five commonly used mushrooms (Turkey Tail, Cordyceps, Reishi, Shiitake, and Agaricus), aims to address this issue. However, the combined influence of these mushrooms on the immune system is poorly understood. To explore this, we conducted a series of studies evaluating the effect of the treating with this formulation on LPS-induced inflammation. Methods: C57Bl/6 male and female mice (n = 7 per group) were challenged with or without LPS. After the challenge, they were divided into eight groups. Four groups received 1 drop of Natures Immuno twice daily for 5 days, while four groups acted as a control. Inflammatory differences were compared in blood, bronchoalveolar lavage fluid, and lung tissue samples at the end of the treatment periods. Results: Lung inflammatory markers in Natures Immuno-treated mice were significantly lower than in LPS-treated mice. Conclusions: These findings suggest that treatment with these five mushrooms may assist in supporting the immune system against LPS-induced inflammation.
IL-10 differentially promotes mast cell responsiveness to IL-33 resulting in induction of anaphylaxis and suppression of neutrophilia
Authors: Ranjitkar Saurav , Krajewski Dylan , Garcia Chelsea , Polukort Stephanie , Rovatti Jeffrey , Mire Mohamed , Tedeschi Caitlin , Blesso Christopher , Jellison Evan , Schneider Sallie , Ryan John , Mathias Clinton
Published: November 2024

Mast cells (MCs) play critical roles in the establishment of allergic diseases. We recently demonstrated an unexpected, proinflammatory role for IL-10 in regulating MC responses. IL-10 enhanced MC activation and promoted IgE-dependent responses during food allergy. However, whether the effects of IL-10 on MCs extend to IgE-independent stimuli is not clear. Herein, we demonstrate that IL-10 plays a critical role in driving IL-33-mediated MC responses. IL-10 stimulation significantly enhanced MC expansion, ST2 expression, IL-6 and IL-13 production, and MC degranulation in IL-33-treated BMMCs. In contrast, it suppressed TNF-a in IL-33-responding cells. These differential effects also extended in vivo. In a model of IL-33-induced neutrophilia, IL-10 enhanced IL-33 responsiveness leading to increased MC activation and suppression of neutrophils via decreased TNF-a. In contrast, during IL-33-induced type 2 inflammation, IL-10 priming exacerbated MC activity, resulting in MC recruitment to various tissues, enhanced ST2 expression and induction of anaphylaxis. Our data elucidate a novel role for IL-10 as an augmenter of IL-33-mediated MC responses, with implications during both allergic diseases and other MC-dependent disorders.
NLRP12 negatively regulates alcohol-induced fatty liver disease
Authors: Alam Manzar , Zaki Hasan
Published: November 2024

Alcoholic liver disease (ALD) characterized by hepatic steatosis, fibrosis, and inflammation is a global health problem caused by chronic consumption of alcohol. NOD-like receptor family member NLRP12 has emerged as a negative regulator of inflammation in diverse pathophysiological conditions. We previously showed that Nlrp12 deficiency promotes hepatocellular carcinoma (HCC) in mice and increased HCC was associated with higher hepatic steatosis and inflammation. However, the role of NLRP12 in alcohol-induced liver disorder was unknown. Here we investigated the role of NLRP12 in ALD using mouse models and in vitro studies. WT and Nlrp12-/- mice were fed with an alcohol diet for 4 weeks. Histopathological analysis showed increased steatosis in Nlrp12-/- mouse livers. Consistently, there was higher expression of proinflammatory cytokines and chemokines, and activation of JNK and AKT pathways as measured by real-time PCR and Western blotting, respectively. To understand the role of NLRP12 in alcohol-induced steatosis and inflammation, we stimulated primary hepatocytes from wild-type and Nlrp12-/- mice with ethanol. Interestingly, inflammatory responses as well as activation of JNK and AKT were higher in alcohol-treated Nlrp12-/- hepatocytes compared to those of wild-type. Similar responses were also seen in Nlrp12-/- macrophages stimulated with alcohol. Together these data suggest that NLRP12 is a critical negative regulator of alcohol induced liver disorders.
Peripherally activated brain CD8+ T cells promote AD in 5xFAD mice
Authors: Biragyn Arya , Campbell Britney , Bodogai Monica , Wang Xin , McDevitt Ross , Konda Kumaraswami
Published: November 2024

The role of the adaptive immunity in Alzheimer’s Disease (AD) remains poorly understood. Recent findings from our group, which link B cells to manifestation AD 1, and others, which show increase of CD8+ T cells in the AD brain 2, suggest that the adaptive immunity is an important but overlooked player in this progressive neurodegenerative disease. Here, our aim was to determine the role of CD8+ T cells in the brain in transgenic 5xFAD mice, which develop human AD-like symptoms. We manipulated brain CD8+ T cells in AD mice by depleting circulating CD8+ T cells with anti-CD8 mAb or expanding antigen-specific CD8+ T cells with Aβ-CoreS (encodes Ab1-11) RNA immunization. We found that while the CD8+ T cell depletion decreases Aβ plaques and disease-associated microglia in the hippocampus, and improves cognition, Aβ-CoreS exacerbates AD symptoms via increasing brain CD8+ T cells with cytotoxic and exhausted phenotype. Overall, our results indicate the AD manifestation requires brain antigen-specific CD8+ T cells, which upon peripheral induction/expansion infiltrate the brain and exacerbate AD symptoms. We propose that CD8+ T cells may similarly exacerbate AD in humans, as we detected their significant increase in the brain of deceased people with AD.

1. Kim et al. Nat Commun. 2021;12(1):2185.

2. Gate et al. (2020). Nature 577, 399-404.

This research was supported by the Intramural Research Program of the National Institute on Aging, NIH
Plasmablast Ig repertoire dynamics through repeat Plasmodium falciparum challenges reveal signatures of negative selection
Authors: Ferrer Patricia , Frank Andrew , Berry Andrea , Lyke Kirsten , Williamson Kim
Published: November 2024

To understand the development of immunity against malaria, a controlled human malaria challenge (CHMI) model was used to expose malaria-naïve individuals to the same P. falciparum (Pf) strain (NF54) four times over two years. Consistent with the gradual immunity observed naturally, the time to parasite detection increased significantly (delayed patency (DP)) by the 3rd CHMI. Plasmablast Ig repertoire maturation was tracked 7 days after peak parasitemia at each CHMI. Clone copy numbers and CDR3 counts for the major clones (CDR3 >200 or clone copy >20 000) increased significantly after exposure to Pf in all participants with DP and peaked at CHMI-2 in most DP. In contrast, the participants without DP had no significant increase in clone copy number or CDR3 count until CHMI-4. In these major clones, the ratio of replacement to silent mutations (R/S) declined from baseline through the 4 CHMIs and there was a significant decrease in R/S for the 12 Ig heavy chain variable genes associated with anti-Pf immunity in DP only. Phylogenetic analysis indicated that clones with longer tree lengths (more divergence) correlated with increasing negative selection (omega). These patterns suggest that a certain level of B cell activation is needed to reduce parasite replication and DP. However, there is a limit to the maturation of specific clones, possibly because most additional replacement mutations do not improve affinity and are selected against.
Proximal immune-epithelial progenitor interactions drive chronic tissue sequelae post-COVID-19
Authors: Narasimhan Harish , Cheon In Su , Qian Wei , Hu Sheng'en , Parimon Tanyalak , Li Chaofan , Goplen Nick , Wu Yue , Wei Xiaoqin , Son Youngmin , Fink Elizabeth , Santos Gislane , Tang Jinyi , Muehling Lyndsey , Canderan Glenda , Kadl Alexandra , Cannon Abigail
Published: November 2024

The long-term physiological consequences of SARS-CoV-2 – post-acute sequelae of COVID-19 (PASC), are rapidly evolving into a major public health concern. Increasing evidence links PASC to abnormal immune responses and organ recovery post infection but the underlying cellular and molecular etiology remains poorly defined. With insights from 3 independent PASC patient cohorts, we established a clinically relevant mouse model to study post-viral lung disease. Using spatial transcriptomics and imaging, we identified dysregulated proximal interactions between immune cells and epithelial progenitors unique to the fibroproliferation in respiratory PASC but not acute COVID-19 or idiopathic pulmonary fibrosis. Specifically, we found a central role for lung-resident CD8+ T cell-macrophage interactions in maintaining dysplastic epithelial progenitors, thus impairing alveolar regeneration post injury. Mechanistically, CD8+ T cell-derived IFN-γ and TNF stimulated local macrophages to chronically release IL-1β, resulting in the abnormal accumulation of immature epithelial progenitors and lung fibrosis. Notably, therapeutic neutralization of IFN-γ and TNF, or IL-1β after acute infection resulted in markedly improved repair and pulmonary function. In contrast to other approaches requiring early intervention, we highlight therapeutic strategies to rescue fibrotic disease in the aftermath of respiratory viral infections, addressing the current unmet need in the clinical management of PASC.
Longitudinal characterization of CD8+ T cells recognizing a dominant epitope of SARS-CoV-2 spike protein in COVID-19 vaccinated and infected individuals
Authors: Zou Ainslee , Li Jiangyuan , Chen Joseph , Elbahnasawy Mostafa , Choy Cecily , Lu Jian , Reed Quinton , Baptiste Beverly , McKelvey Julia , Melvin Denise , Ruffolo Jeannie , Zukley Linda , Wallace Tonya , Dunn Christopher , Nguyen Cuong , An Yang , Fan Jinshui
Published: November 2024

COVID-19, caused by SARS-CoV-2 infection, sparked an ongoing global pandemic. While cell-mediated immunity is crucial in mitigating the severity and eradicating viral infections, a comprehensive characterization of CD8+ T cell antigen-specificity, frequency, proliferative capacity, and TCR sequences against SARS-CoV-2 in both COVID-19 vaccinated and recovered adults remains incomplete. In this study, we embark on a longitudinal analysis of circulating CD8+ T cells targeting 10 epitopes from the SARS-CoV-2 spike (S) protein across multiple visits from donors spanning three and a half years. Utilizing multi-color flow cytometry with antigen-specific tetramers, we observed frequencies of circulating CD8+ T cells ranging from undetectable to 1% in HLA-A2+ vaccinated and infected individuals. Notably, we did not observe significant differences in spike-specific CD8+ T cell frequencies between vaccinated and infected donors. However, among vaccinated donors, we noted a decline over time in central memory T cells specific to a dominant S protein epitope, S-YLQ (S-269-277, YLQPRTFLL). Our in vitro stimulation assays revealed robust expansion of CD8+ T cells, both in percentage and magnitude, against the S-YLQ epitope compared to other epitopes in infected and vaccinated individuals. Analysis of longitudinal follow-up data spanning three years is ongoing.
Glucocorticoid-mediated immunosuppression prolongs SARS-CoV-2 replication in the lower airways of rhesus macaques
Authors: Nelson Christine , Kauffman Keith , Sakai Shunsuke , Gomez Felipe , Via Laura , Barber Daniel
Published: November 2024

The mechanisms that regulate the balance between pathogenic inflammation and viral control in the respiratory tract during SARS-CoV-2 are not well-understood. Glucocorticoids have improved clinical outcomes in severe cases of COVID-19, but are not recommended in non-hospitalized patients due to limited efficacy. Here, we used rhesus macaques to examine the effects of glucocorticoids (GC) during acute SARS-CoV-2 infection. Rhesus macaques were pre-treated with intravenous methylprednisolone or saline daily for 5 days and then infected with SARS-CoV-2 delta (B.1.617.2) and animals receiving glucocorticoids were maintained on oral prednisolone. GC treated animals had decreased focal lung inflammation, as detected with 18FDG-PET/CT imaging, but prolonged viral replication in the lower airways and the pulmonary lymph node. A kinetics of single cell RNA sequencing from the airways revealed prolonged type I IFN responses during GC treatment. GC treated animals had a reduced influx of plasmacytoid dendritic cells (pDC) and eosinophils. Most of the IFNb1 produced in the lung after infection was not made by pDCs but by inflammatory myeloid cells. SARS-CoV-2 specific CD8 T cell responses in the airways were also reduced with GC treatment, as were B cells and TFH responses in secondary lymphoid organs. Overall, glucocorticoid treatment during SARS-CoV-2 infection reduced lung inflammation, impaired host immune responses, and delayed viral clearance from the lower respiratory tract.
The Autoimmunity-Associated Minor Allele of PTPN22 Enhances Antiviral Immunity During Coronavirus Infection
Authors: Bevis Alec , Shaikh Anam , Kerr Catherine , Barnes Jenna , Rosa Kate , Cockerham Tammy , Schwarting Nancy , Fehr Anthony , Orozco Robin
Published: November 2024

The deadly consequences of viral infection were clearly demonstrated by the COVID-19 pandemic. Therefore, identifying new therapeutic targets to enhance our antiviral immunity and combat virus infection is essential, such as the immune-regulatory gene PTPN22. 5-15% of North Americans express a PTPN22 alternative allele which is linked with multiple autoimmune diseases. However, there is a significant research gap regarding the role of PTPN22 and its common allele during viral infection. To address this, we used CRISPR/Cas9 generated Ptpn22 knockout (PEP-null) and Ptpn22 minor allele expressing (PEP-619WW) mice and infected them with the common murine model of coronavirus, Mouse Hepatitis Virus (MHV) A59. We hypothesize that PEP-null and PEP-619WW mice have enhanced antiviral immunity during coronavirus infection. Following MHV A59 infection, PEP-null and PEP-619WW mice have reduced weight loss and increased survival over WT mice. Additionally, PEP-null and PEP-619WW mice have enhanced innate immunity, such as increased Natural Killer (NK) cell numbers. Furthermore, we show that PEP-null and PEP-619WW innate immune cells offer enhanced protection during MHV A59 infection, but lymphocytes are necessary for survival. These results demonstrate that PEP-null and PEP-619WW are beneficial during coronavirus infection. This research sets the precedent to interrogate the role of Ptpn22 in other RNA virus infections and as a novel therapeutic target to enhance antiviral immunity.
Navigating the Cellular Labyrinth: Unveiling the Molecular Interplay and Expansion Patterns of Intraepithelial T Lymphocytes
Authors: Ran Ran , Brubaker Douglas , Trapecar Martin , Uslu Merve
Published: November 2024

Intraepithelial T lymphocytes (T-IELs) are essential for protecting the intestinal barrier and facilitating a rapid immune response to local antigens. In this study, αβ T cell receptor sequencing and single-cell RNA sequencing were employed to elucidate the complex dynamics of T cells isolated from the colon epithelium and the lamina propria (LP) in three healthy human. The results reveal a significant enrichment of CD8 and γδT cells in the T-IEL population, in contrast to a predominance of CD4 cells in the LP, underscoring the presence of semi-activated antigen-experienced resident memory populations in both tissues. Differential gene expression analysis highlights an upregulation of activator protein-1 (AP-1) components, Jun and Fos, coupled with a downregulation of NF-κB subunits in both αβ CD4 and CD8 TRM cells within T-IELs, without a corresponding increase in cytokine gene transcription, as compared to LP-T cells. Gene set enrichment analysis and pseudotime analysis of LP-T and IEL-T cells from the same clones suggest the activation of an NF-κB-independent TNF pathway, concurrent with the translocation of αβT cells to the epithelium. Additionally, the LP and IEL repertoires share multiple clones, with some of the most abundant cdr3b sequences in both pools showing remarkable similarity to TCRs known to bind influenza A and CMV antigens. TCR clustering using GLIPH2 reveals common motifs across donors, yet most expanded clones in both locations possess distinct TCRs.
Rosiglitazone, a PPAR-γ agonist inhibits extracellular matrix production in TGFβ1 induced intestinal fibrosis.
Authors: Gaowa Arong
Published: November 2024

Intestinal fibrosis, a common complication of intestinal bowel disease and is defined as an excessive deposition of extracellular matrix protein in the intestinal wall. Rosiglitazone, a PPAR-γ agonist, exerts anti-fibrotic effect in several organ fibrosis; however, its inhibitory effect on intestinal fibrosis is still not completely understood. Here, we investigated the inhibitory effects of rosiglitazone on fibrotic gene expression using TGFβ1 induced intestinal fibrosis model. Intestinal organoids were treated with TGFβ1 alone (2 ng/mL) or TGFβ1 plus rosiglitazone (50 uM) for 24 hours. Markers of fibrogenesis, including collagens and fibronectin were evaluated by measuring mRNA level using RT-PCR, and protein level by immunofluorescence or Western blotting. Signaling pathways involved in fibrosis were characterized by Western blotting analysis of cell lysates using indicated antibodies. We found that rosiglitazone significantly suppressed TGFβ1-induced expression of profibrogenic genes (collagen and fibronectin), epithelial to mesenchymal transition and cytokines production in intestinal fibrosis model. Furthermore, it was found that rosiglitazone inhibited the phosphorylation of Smad2/3 and Erk1/2. Taken together, these findings indicate that rosiglitazone exerts potent anti-fibrotic effect in TGFβ1 induced intestinal fibrosis via Smad- and non-Smad pathway.
A distinct autoimmune signature in Post-treatment Lyme Disease Syndrome (PTLD)
Authors: Chen Xin , Zhou Xin , Wang Haozhen , Ji Xuhuai , Rebman Alison , Soloski Mark , Wagner Christine , Snyder Michael , Robinson William , Aucott John , Davis Mark
Published: November 2024

Post-Treatment Lyme Disease (PTLD) is characterized as a persistent inflammatory condition in a large fraction of patients following antibiotic treatment for Borreliella infection, but what leads to PTLD is not known. Here, we analyzed 56 peripheral blood mononuclear cell (PBMC) samples from 23 individuals at risk for PTLD in a multi-year longitudinal study via single-cell RNA sequencing. We found a significant association between an expanded subset of pro-inflammatory monocytes and Lyme disease, a phenomenon notably more prevalent in PTLD patients compared to individuals who have returned to health (RTH). Furthermore, PTLD patients exhibited a range of autoimmune-related phenotypes, absent in healthy and RTH individuals, including a positive correlation between disease severity and CD8+ KIR+ Tregs, functional impairment of CD4+ FOXP3+ Tregs, and heightened lymphocyte cytotoxicity. Interestingly, these phenotypes are associated with the stimulation by a specific peptidoglycan produced by Borreliella and this may be a key driver of PTLD. These findings hold significant potential for the development of targeted therapeutic strategies for PTLD, potentially transforming patient prognosis.
Essential Role of the Pentose Phosphate Pathway Activation in Macrophages for Granuloma Formation in Sarcoidosis
Authors: Nakamizo Satoshi , Sugiura Yuki , Ishida Yoshihiro , Egawa Gyohei , Kabashima Kenji
Published: November 2024

Sarcoidosis is a disease of unknown cause that forms granulomas in various organs, has no specific treatment established. Here, we investigated the mechanism of granuloma formation by applying single-cell RNA sequencing to skin biopsy specimens from human patients with sarcoidosis. In cutaneous sarcoidosis granuloma lesions, there was an increase in macrophages expressing angiotensin-converting enzyme (ACE) and lysozyme, which are known to be elevated in the serum of sarcoidosis patients. These macrophages were hypermetabolic, especially in the pentose phosphate pathway (PPP). Immunostaining of organs from patients with sarcoidosis revealed elevated expression of PPP-related enzymes in granuloma lesions beyond the skin, including those in the lung, lymph nodes, and heart. When human peripheral blood monocytes were cultured with interferon gamma and CD40L, along with concanavalin A (a C-type lectin), there was an elevation in PPP-related enzymes in macrophages, and granulomas with giant cells were formed. Inhibitors of the PPP pathway inhibited granuloma formation. Similarly, PPP inhibitors also suppressed granuloma formation in a mouse model. Until this study, the details and metabolic pathways of granuloma constituent cells were completely unknown. However, our findings have elucidated that macrophages with elevated PPP-related enzymes contribute to granuloma formation and that targeting PPP-related enzymes could be a therapeutic approach in granulomatous diseases.
IL10 signal of lung interstitial macrophages prevents progressive lung fibrosis by suppressing commensal dysbiosis
Authors: Kim Seung Hyeon , White Zachary , Gainulina Anastasiia , Kang Soeun , Kim Jiseon , Dominguez Joseph , Cabrera Ivan , Gunzer Matthias , Hay Nissim , Jung Steffen , Chevrier Nicholas , Sano Teruyuki , Kim Ki-Wook
Published: November 2024

Our understanding of lung microbial ecology underscores the impact of diseases on microbe-host interactions, influencing lung disease pathogenesis. However, the intricate mechanisms governing host immune responses and the lung microbiome remain incompletely elucidated. IL-10, an anti-inflammatory cytokine, crucially modulates immune responses, yet the significance of the IL-10/IL-10 receptor (IL-10R) axis in maintaining lung homeostasis is unknown. We found that IL-10R signaling in lung interstitial macrophages (IMs) preserves balanced lung microbiota, contributing to homeostasis. The lack of IL-10 surprisingly triggered spontaneous lung inflammation, progressing to pulmonary fibrosis without external factors. IL-10R deficiency in CX3CR1-expressing MHC IIhi IMs led to inflammatory phenotypes similar to IL-10-deficient mice. 16S bacterial rRNA sequencing identified dominant colonization of Proteobacteria (e.g., D. acidovorans) and Actinobacteria (e.g., R. erythropolis) in IL-10R-deficient CX3CR1-expressing MHC IIhi IMs mice lungs. Lung inflammation occurred in germ-free (GF) IL10-/- mice after commensal colonization, while GF IL10+/+ mice remained unaffected. Using human fecal microbiota transplantation, we observed that human gut commensals induce lung inflammation in GF IL-10-/- mice. These results highlight the roles of IL-10R-expressing MHC IIhi IMs in lung homeostasis, regulating the interaction between host immune responses and commensal microbiota.
Murine chorioamnionitis alters the neonatal and infant immune response to respiratory syncytial virus.
Authors: Knobbe Jessica , Bermick Jennifer
Published: November 2024

Chorioamnionitis is infection and/or inflammation of the fetal membranes and placenta during pregnancy and is a risk factor for neonatal bronchopulmonary dysplasia (BPD) and childhood asthma and wheezing. BPD and childhood asthma are associated with more severe infection with respiratory syncytial virus (RSV). Despite this, it is unknown whether chorioamnionitis alters the neonatal or infant immune response to RSV. To investigate this, we used a murine model of chorioamnionitis and infected pups with RSV on postnatal days 3-5 (neonate) or postnatal days 14-16 (infant). 5-days post-infection, mRNA was isolated from lungs and analyzed via qPCR for expression of MUC5AC, GOB5, IL1B, IL5, IL6, IL13, IL17A, IFNB, IFNG, RSV-N, RSV-F, RSV-G, and GAPDH. We hypothesized that murine chorioamnionitis-exposed neonatal and infant offspring would display increased severity of RSV infection with increased lung mRNA expression of pro-inflammatory cytokines and a higher viral burden. Our neonatal results displayed significantly lower relative mRNA expression of IL1B in chorioamnionitis-exposed pups (p=0.0035, Mann-Whitney test). Our infancy results displayed increased expression of RSV-N (p=0.0288), MUC5AC (p=0.0594), and GOB5 (p=0.0510), and decreased expression of IFNB (p=0.0101) in chorioamnionitis-exposed pups. In conclusion, murine chorioamnionitis alters both the neonatal and infant immune response to RSV.
B7H3 (CD276) regulation of myeloid cell differentiation in pulmonary fibrosis
Authors: LIU TIANJU
Published: November 2024

Myeloid-derived suppressor cells (MDSCs) are induced in cancer and fibrosis, while absent in healthy tissues. The expansions of MDSC are correlated with disease severity and lung function deterioration in the latter. B7H3 induced in lung fibrosis causes the recruitment of MDSCs. However, the mechanism underlying the biogenesis of MDSCs is unclear. To study if B7H3-induced expansion of MDSCs is due to inhibition of the differentiation of myeloid progenitors, the role of B7H3 in the regulation of BM-derived myeloid cells was studied. The results showed that B7H3 deficiency in BM LysM+ myeloid cells significantly increased differentiation to mature myeloid cells. In contrast, treatment with B7H3 inhibited such differentiation. In mice, LysM+ cells-specific B7H3 deficiency induced mature myeloid cell differentiation, but significantly decreased immature MDSCs, which was associated with less immunosuppressive capability. Lack of B7H3 caused a significant reduction of MDSC marker genes characteristic. Furthermore, the delayed B7H3 antibody treatment or by ablating of its secretion from collagen-expressing cells reduced BM-derived MDSCs and PD1-expressing progenitors but increased mature myeloid cell number, which was accompanied by attenuated lung fibrosis. These findings suggested that activated fibroblasts in lung fibrosis may be a key source of soluble B7H3 essential for the signal to BM skewing myeloid lineage fate and induced biogenesis of MDSC
Effects of Exercise Therapy on Circadian Rhythm Regulation of Neutrophils
Authors: Huang Xingping , Hu Jiannan , Huang Xingping , Liu Shuchang , Guo Xiaorong , Wu Grace , Jayakumar Preethi , Yao Yonghong , Deng Meihong , Huang Hai , Jiang Yi
Published: November 2024

Background: Physical inactivity is recognized as a risk factor for numerous common illnesses, while exercise has been shown to be beneficial. Neutrophils are the first line of cell-mediated defense, with characterized by circadian rhythms. The liver is metabolically active organ that is strongly influenced by circadian regulation. The effects of exercise-induced circadian changes may modify the neutrophils phenotype and function.

Methods: Male mice undergoing a four-week treadmill regimen for 1h at ZT3(3h after lights on). Bone marrow, blood and liver tissue were analyzed at different time points. Circadian genes and neutrophil subpopulations were assessed.

Results: The circulating neutrophil numbers were fluctuated according to a circadian pattern with a peak at ZT3 and a nadir at ZT15. Rhythmicity analysis revealed that the circadian amplitude was increased, but the period and phase were unaltered. Mice subjected to exercise had fewer immature and higher mature neutrophils in bone marrow at ZT3. The expression of clock-related genes in liver, including Arntl and Clock, increased at ZT3, while others, like Per1 were decreased. The number of aged neutrophil follows diurnal patterns with a peak at ZT3, and exhibited a greater percentage and number of neutrophils with an aging phenotype in blood at Exercise group.

Summary: Exercise modulates circadian-dependent neutrophils quiescence, promotes maturation of myeloid neutrophils and driven circulating neutrophil aging phenotype.
Forebrain organoids reveal neuronal capacity to elicit protective antiviral responses.
Authors: Negatu Seble , Vazquez Christine , Bannerman Carl , Ming Guo-li , Jurado Kellie
Published: November 2024

Mosquito-borne arboviruses with potential to cause neurotropic disease are a global health threat. These neurotropic viruses are the most common cause of infectious encephalitis (inflammation of the brain), yet our knowledge of antiviral immune regulation at this site remains limited. Neurons are the highly targeted by these viruses and thus must be important mediators of viral replication and spread. Our studies sought to use La Crosse Virus, an emerging arbovirus, to define intrinsic neuronal orchestration of antiviral responses between infected cells and neighboring uninfected bystanders. We observed widespread infection and viral growth in both murine cortical neurons and cerebral organoids. Transcriptomics approaches revealed infection of cortical neurons induced expression of interferon-stimulated genes (ISGs) in both infected and bystander neurons. In forebrain organoids, we found that uninfected bystander neurons have high ISG expression as compared with neighboring infected neurons. Intriguingly, this bystander activation was capable of restricting viral spread. This finding demonstrates that intraneuronal communication mediates protective antiviral response in the CNS. Future directions aim to define the mediators of communication and the protective antiviral signatures using spatial transcriptomics of infected organoid sections.
Earliest Lymphoid Precursors in the Fetal Liver Contribute Constructing Mucosal Immunity in a HSC-Independent Manner
Authors: Kobayashi Michihiro , Cornelius Samuel , Cheng Haizi , Hughe David , Syed Alina , Lattore Augsto , Variente Noemi , Nishida Chika , Yoshimoto Momoko
Published: November 2024

We've been clarifing the role of hematopoietic stem cell (HSC) -indepenbdent progenitors for the consisting the post-natal immune-layers. Recent our repors, combining fate-mapping (FM) study and transplantation of E11.5 AGM cells, displayed nearly half of lympoid cells are maintained by HSC-independent progenitors even in old mice. Here, we characterized eariest lymoid progenitors in the E12.5 fetal liver (FL) by using IL-7RCre:flox-dTom mice and FM study. Unlike protein expression, dTom % in the E12 FL lin-Sca1-Kit+ (LSK) cells were more than 30% (34.8 ± 7.2%, n=7). Tom+ or Tom- LSK cells were further divided into HSC (CD48loEPCRhi) and MPP (CD+EPCRlo~dim) and sorted 4-populatios were transplanted into NSG mice. Recipients with Tom-HSCs showed multi-lineage reconstitution wile MPPs (Tom- or Tom+) repopulated B-1 and T-cells. Interestingly Tom+CD48loEPCRhi, phenotypically equivalent to HSCs, exibited unique properties that reconstituted only B-1 cells in PerC and IgA+ cells and type 2 innate lymphoid cells in the small intestine. These data suggest HSC-independent PerC B-1a cells and IgA+ cells share the common progenitor.

As for FM study, we labeled neonatal HSC with dTom by injecting p2 Tamoxifen into Fgd5-based FM model, resulted in very lower contribution to the IgA+ B-cells in the lamina proplia. Relative Tom percentage showed 0.382 ± 0.12, indicating IgA+ cells are maintained by largely HSC-indepent mannar than previously thought.