bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fibroblastic reticular cells sustain innate lymphoid cell niches in the intestinal lamina propria
Authors: Cheng Hung-Wei , Mörbe Urs Michael , Lütge Mechthild , Engetschwiler Celine , Onder Lucas , Novkovic Mario , Gil-Cruz Cristina , Perez-Shibayama Christian , Rülicke Thomas , Hehlgans Thomas , Scandella Elke , Ludewig Burkhard 
Published: February 2023

Abstract
Innate lymphoid cells (ILC) in the small intestine govern immune homeostasis and protect the host against gut pathogens. While distinct cell-intrinsic signals have been identified that determine ILC development and differentiation, it has remained unclear which cell population regulates ILC sustenance. Using unbiased transcriptomic analysis of intestinal fibroblasts, we have identified a specialized Ccl19-expressing fibroblastic reticular cell (FRC) population that underpins solitary intestinal lymphoid tissue (SILT) structures including cryptopatches and isolated lymphoid follicles. Conditional ablation of lymphotoxin-β receptor (LTβR) signalling in SILT FRC impeded the maturation of isolated lymphoid follicles and blocked ILC maintenance resulting in the elevated susceptibility to bacterial infection. Moreover, specific Ltbr ablation in FRC during adulthood revealed that sustained LTβR-dependent FRC-ILC interaction is required to maintain SILT structures and ILC populations. Taken together, our study unveils a critical intestinal FRC niche that secures protective gut immunity.
Regulatory T Cell Transfer Increases Trem2+ Uterine Macrophages and Decreases Fetal Loss
Authors: Lewis Emma L , Porrett Paige M , Elovitz Michal A 
Published: February 2023

Abstract
Intrauterine fetal demise (IUFD) – fetal loss after 20 weeks – affects 6 pregnancies per 1,000 live births in the United States, and the majority of IUFDs are of unknown etiology. We investigated immunological mechanisms of IUFD using the CBA mouse model, which has mid-late gestation fetal loss. Regulatory T cells (Tregs) are critical to establishing maternal-fetal tolerance, thus we hypothesized they may be protective from fetal loss in this model. Adoptive transfer of 2×105 Tregs decreased fetal loss 2.7-fold (p=0.04) and increased pup viability by 69% (p=0.003) (N=7–9/group). To examine how systemic Treg transfer influenced local uterine immune cells, we used single-cell RNA-sequencing of uterine CD11b+ cells from pregnant dams that had received Tregs vs. PBS (N=3/group). Sequencing identified 15 uterine CD11b+ populations, with Trem2+ macrophages increased (p=2.2e–12) and CCL3+ neutrophils decreased (p=3.6e-12) by Treg transfer. Compared to other uterine macrophages, this Trem2+ population was characterized by low expression of MHC-II genes and high expression of Trem2, Apoe, Hexb, cathepsin genes, and C1q genes. The uterine Trem2+ macrophages are enriched for gene sets from Trem2+ macrophages found in other tissues, including those in atherosclerotic plaques and skin. We identified this Trem2+, MHC-II-low macrophage population in the uterus of normal and CBA pregnant mice by flow cytometry (N=6–8/group); and found that CBA mice had 2-fold fewer of this macrophage subtype than normal mice (p=0.0004). These data identify a novel uterine macrophage population that may be critical for healthy pregnancy and demonstrate systemic Treg transfer altering tissue immune populations, which has broad implications for immunotherapy.
Type I interferon enhances γδ intraepithelial lymphocyte migratory behavior via CD47 upregulation
Authors: Fischer Matthew , Jia Luo , Edelblum Karen L 
Published: February 2023

Abstract
γδ intraepithelial lymphocytes (IEL) migrate along the basement membrane and into the lateral intracellular space (LIS) between adjacent intestinal epithelial cells (IEC) and is critical to limit microbial translocation across the barrier. Although activated γδ IELs produce interferon (IFN)-α, whether IFNα directly influences γδ IEL migratory behavior remains unknown. To test this, intravital microscopy was performed on GFP γδ T cell reporter mice treated with PBS or IFNα (1 μg, i.v., 3h). We found that γδ IEL track speed was increased 30% and migration into the LIS was enhanced by 75% in IFNα-treated mice compared to controls. To identify candidate genes involved in regulating γδ IEL motility, we performed RNAseq on γδ IELs isolated from control and IFNα-treated mice. As expected, IFNα induced IFN-stimulated gene expression including CD47 (3.5-fold increase), a transmembrane protein involved in neutrophil transepithelial migration. Stimulation of ex vivo cultured γδ IELs with IFNα resulted in a 3-fold increase in CD47 expression compared to unstimulated controls. Next, to investigate whether IFNα enhances γδ IEL motility in vitro, GFP γδ IELs were co-cultured with enteroids expressing membrane tdTomato and treated with 10ng/ml IFNα for 3h. IFNα increased γδ IEL speed (4.5±0.2 vs 3.4±0.2 μm/min; p&lt;0.05) and displacement (47±3.0 μm vs 34±3.1, p&lt;0.05) relative to untreated controls. Addition of anti-CD47 blocking antibody (MIAP301) abrogated the IFNα-mediated increase in γδ IEL migratory behavior. Taken together, these data demonstrate that IFNα enhances γδ IEL motility via a CD47-mediated mechanism, and suggests that CD47 may represent a conserved mechanism of leukocyte migration within the epithelial barrier.
TCDD exposure differentially alters antigen-specific IgA levels when given before or after immunization
Authors: King Aspen E , Ortiz Linda F , Schoenherr Elléanour M , DeKrey Gregory K 
Published: February 2023

Abstract
In mice, activation of the aryl hydrocarbon receptor (AhR) prior to primary antigen challenge can suppress antigen-specific serum IgM and IgG responses. Secondary antibody responses have been reported to be refractory to AhR-mediated suppression. Using ELISAs and female C57Bl/6 mice pretreated with the prototypic AhR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, 40 μg/Kg in peanut oil) one day prior to oral cholera toxin (CT) immunization (10 μg, repeated weekly), we demonstrated significant suppression of CT-specific IgA levels in the feces after two weeks (by 64.4%); however, fecal IgA levels recovered to control levels by week four. Unlike fecal IgA levels, CT-specific serum IgA levels remained significantly suppressed (by 37.1%) through week four. At that time-point, when compared to control mice, the spleens of TCDD-treated mice contained 40.4% fewer leukocytes, and contained 66.4% fewer IgA+ plasma cells (analyzed by ELISpot) (all significantly different). When TCDD exposure was delayed for three weeks after beginning CT immunization, in comparison to control mice, serum CT-specific IgA levels were significantly suppressed by 33.2%, but fecal CT-specific IgA levels were not different, as in TCDD pre-treated mice. Because enhanced migration of some T cells into the gut has been reported after AhR activation, one explanation for the differential effect of TCDD exposure on CT-specific IgA levels when given either before and after immunization could be enhanced migration of plasma cells away from reticuloendothelial tissues and into mucosal tissues.
MicroRNA-146a limits tumorigenic IL-17 signaling in colorectal cancer
Authors: Gopal Murugaiyan , Garo Lucien P. , Ajay Amrendra K. , Fujiwara Mai , Gabriely Galina , Raheja Radhika , Kadowaki-Saga Ryoko 
Published: February 2023

Abstract
Interleukin-17 (IL-17) is a major inflammatory cytokine implicated in colorectal cancer (CRC) development. However, the mechanisms that control tumorigenic IL-17 signaling are poorly understood. Recently, expression changes and polymorphisms in the small non-coding RNA, microRNA-146a (miR-146a), have been associated with clinical outcomes in inflammatory bowel disease and CRC patients. Here, we identified a novel role for miR-146a as a major negative regulator of colonic inflammation and tumorigenesis via modulation of IL-17 responses. MiR-146a-deficient mice are susceptible to both colitis-associated and sporadic CRC, and present with enhanced tumorigenic IL-17 signaling. Within myeloid cells, miR-146a targets RIPK2, an intermediate in NOD2 signaling, to limit myeloid cell-derived IL-17-inducing cytokines and restrict colonic IL-17 levels. Accordingly, myeloid cell-specific deletion of miR-146a leads to CRC susceptibility. Moreover, within intestinal epithelial cells (IECs), miR-146a targets TRAF6, an intermediate in IL-17R signaling, to restrict IEC responsiveness to IL-17. MiR-146a within IECs further suppresses CRC by targeting PTGES2, an enzyme for PGE2 synthesis. IEC-specific deletion of miR-146a confers marked CRC susceptibility. Importantly, preclinical administration of miR-146a mimic or direct inhibition of miR-146a targets, TRAF6/RIPK2 can ameliorate CRC. In conclusion, miR-146a prevents CRC by two interlinked mechanisms: 1) by limiting myeloid cell-mediated IL-17 production; and 2) by inhibiting tumorigenic IL-17R signaling in IECs. Overexpression of miR-146a may be a promising therapeutic approach for CRC to limit multiple pathways converging on tumorigenic IL-17 signaling.
NF-κB signaling in Cx3cr1+ cells is required for neonatal intestinal homeostasis and for NEC-induced monocyte differentiation
Authors: Managlia Elizabeth , Yan Xiaocai , De Plaen Isabelle 
Published: February 2023

Abstract
Necrotizing enterocolitis (NEC) is a life-threatening intestinal disease affecting premature infants. Intestinal macrophages (Mφ) express Cx3cr1 and have been reported to mediate the gut immune response at this age. At birth in mice, embryonic (e) Mφ (Ly6C−CD64+MHCII+Tim4+) are the primary intestinal myeloid cell with few Ly6C+ monocytes. At 3 weeks, differentiated monocyte-derived-Mφ replace intestinal eMφ. In a NEC model, we showed decreased intestinal Ly6C+ cells due to monocyte activation, recruitment, and differentiation. NF-κB inhibition in monocytes decreased their recruitment and differentiation, improved NEC, but did not reduce IL1β. Whether eMφ contribute to inflammation in the neonatal intestine remains unknown. When IKKβ was deleted in Cx3cr1+ cells, we unexpectedly found intestinal IL1β mRNA to be increased in pups exposed to experimental NEC (8.2 ± 0.8; p≤0.05) but also in dam fed (DF) pups (12.6 ± 2.5; p≤0.01). When small intestinal lamina propria Cx3cr1+ cells were traced (using Cre-reporter mice) by flow cytometry, both eMφ (CD11b+Ly6C−CD64+Tim4+) and differentiating monocytes (CD11b+Ly6C+CD64+) expressed Cx3cr1. In mice lacking IKKβ in Cx3cr1+ cells (Cx3cr1cre+/−IKKβf/f but not in Cre- IKKβf/f controls, experimental NEC caused a 2.4 (±0.4)-fold increase in Ly6C+ cells compared to DF, and 30.4% (±8.3) of the Ly6C+ cells expressed CD64 compared to 6.7 (±0.26) in the DF (p≤0.05). CD64+ cells had a 2.4 (± 0.64; p≤0.05) and 8.3 (± 2.9; p≤0.05)-fold decrease in Tim4 and MHCII MFI respectively. Therefore NF-κB signaling in eMφ is required for neonatal intestinal homeostasis and for completing monocyte Ly6C down-regulation and MHCII up-regulation upon gaining CD64 during NEC-induced monocyte differentiation.
Early life stress in mice promotes chronicity of experimental colitis
Authors: Muir Rachel Quinn , Klocke Barbara J. , Foote Jeremy B. , Molina Patrick A. , Pollock Jennifer S. , Maynard Craig L. 
Published: February 2023

Abstract
Inflammatory bowel diseases (IBD) are chronic disorders of the gastrointestinal tract with peak onset during adolescence. The etiology of IBD remains poorly understood, but is believed to involve genetic susceptibility, improper immune regulation, and environmental factors. Psychological stress is one environmental trigger that has been associated with an increased risk of inflammatory diseases. Specifically, previous studies have linked early life stress (ELS) with hypothalamic–pituitary–adrenal (HPA) axis dysfunction leading to adverse health outcomes later in life. Our goal was to determine whether ELS in mice affects susceptibility to, and severity of, colitis – induced subsequent to stress exposure. We used an established mouse model of ELS, maternal separation with early weaning (MSEW), in which newborn mice are separated from their mothers for 4–8 hours daily from day of life (DOL) 2 until early weaning on DOL 17. Then, starting on DOL 28, colitis was induced in MSEW mice and their normally-reared (NR) counterparts by transient blockade of the interleukin-10 receptor (IL-10R). Prior to induction of colitis, MSEW mice showed systemic and colon-specific depletion of corticosterone relative to NR mice. In addition, MSEW mice with active colitis harbored significantly reduced numbers of colonic Foxp3+ T cells compared to colitic NR mice. Finally, whereas NR mice were mostly in remission by 15 days following cessation of IL-10R blockade, MSEW mice showed consistently elevated Tnf in the proximal colon and sustained epithelial damage. Our results suggest that ELS-mediated HPA-axis dysfunction causes hypo-corticosteronism, which may subsequently promote prolonged colonic inflammation in susceptible hosts.
Induction with MHC variant peptide MOG 45D generates MOG-reactive T cells but no clinical disease
Authors: Faust Michael A , Kolawole Elizabeth Motunrayo , Evavold Brian D 
Published: February 2023

Abstract
Demyelinating disease can be driven by CD4+ T cells specific for myelin oligodendrocyte glycoprotein (MOG). We have previously decreased the affinity of MOG for Class II MHC by mutating the P6 anchor residue from an S to a D amino acid, creating the 45D MHC variant peptide. 45D is incapable of inducing experimental autoimmune encephalomyelitis (EAE) despite its CD4 epitope bearing the same T cell receptor contact residues as the wildtype MOG epitope (wtMOG). Although the wtMOG and 45D peptides generate CD4 T cells specific for MOG in the periphery and CNS, there is an overall decrease in the number of high-affinity CD4 T cells in response to 45D priming. Analysis of the responding T cell populations to 45D also found increases in MOG-reactive Tregs and decreases in MOG-specific CD8 T cells. Thus, the variant peptide 45D alters the MOG-specific T cell response in favor of peripheral tolerance mechanisms that ultimately result in the absence of clinical disease.
Innate immunity contributes to pathogenesis following Mannheimia haemolytica infections.
Authors: Slate Jamison Ray , Briggs Robert , McGill Jodi L 
Published: February 2023

Abstract
Mannheimia haemolytica (MH) is a common commensal bacteria found in the nasopharynx of healthy cattle, and its colonization is generally well controlled by innate and adaptive immune defenses. Following immunological stressors, MH can migrate into the lungs and develop into lower respiratory tract infections or pneumonia. These infections are often exacerbated by infiltrating cytotoxic leukocytes and excessive inflammation. IL-17A is thought to play an integral part in MH pathogenesis by driving inflammatory pathways, invoking neutrophilia, and modulating innate immune defenses. Therefore, to better understand the immune-induced tissue damage that follows MH infection, this study employed the use of an IL-17A inhibitor, ursolic acid (UA), and determined its impact on immune responses and disease severity. Two independent experiments were performed using 4 week old Holstein calves; each of these studies challenged a non-treated group (UA−/MH+; n = 8) and a prophylactic UA treated group (UA+/MH+; n=8). Serum samples, whole blood, and nasal swabs were collected throughout the course of both studies, with bronchoalveolar lavage fluid and lung tissue sections collected at necropsy. UA treated calves had reduced lung pathology and bacterial loads in the lungs compared to control calves. Subsequent analysis of lung tissue confirmed UA treatment modulated host immune responses, including decreased expression of the inflammatory mediators IL-6, IL-17, and STAT3; furthermore, expression of innate defense molecules, such as antimicrobial peptides, mucins, and metalloproteases, was altered. Taken together, these results outline a mechanistic role for IL-17A-mediated immunity to contribute to the pathogenesis of MH infection.
Identification of porcine ileal innate lymphoid cells using single-cell RNA sequencing
Authors: Wiarda Jayne E , Sivasankaran Sathesh K , Loving Crystal L 
Published: February 2023

Abstract
Innate lymphoid cells (ILCs) are integral in maintaining intestinal defense and homeostasis, but intestinal ILCs have not been identified in pigs. Pigs are an important global food source and human biomedical model, thus identifying and characterizing porcine intestinal ILCs can have broad implications. Single-cell RNA sequencing of porcine ileal lymphocytes yielded 31,983 cells distributed across 54 clusters. Five clusters were closely related to T cell clusters yet lacked expression of the pan-T cell marker, CD3E. One cluster had high expression of genes related to type 3 immunity, including IL22, RORC, and CXCL8, indicating identification of putative ILC3s. The other four clusters expressed genes encoding for NK receptors (KLRK1, KLRC1, KLRD1) and effector molecules (CCL5, PRF1), yet they lacked expression of genes traditionally expressed by porcine NK cells (CD8A, KLRB1, HCST). Thus, we putatively identified the four clusters as ILC1s. Profiles of putative porcine ILC clusters were further compared to transcriptomic signatures of murine intestinal ILC subsets. Results indicated a relative enrichment of murine ILC3 gene signatures in the porcine ILC3 cluster, while relative enrichment of murine ILC1 gene signatures was observed for the other four clusters of porcine ILC1s. We further utilized single-cell gene expression profiles to develop a gating strategy to identify porcine intestinal ILCs as CD45+CD2+CD3ɛ−CD79α− lymphocytes at the protein level by flow cytometry. Altogether, the data allowed us to create the first transcriptomic descriptions of porcine intestinal ILCs and develop approaches to identify ILCs at the protein level, which will be applicable for future research.
The pandemic matrix gene is associated with increased pro-inflammatory immune responses during influenza virus infection
Authors: Griffin Emily Fate , Curran Shelly , Tompkins Mark 
Published: February 2023

Abstract
The 2009 H1N1 influenza pandemic (pdmH1N1) arose from multiple genetic reassortment events between three swine influenza A virus (swIAV) lineages and became established as a seasonal H1N1 human influenza virus. Through reverse-zoonotic events, the pdmH1N1 strain contributed gene segments to endemic swIAVs and the pandemic matrix gene (pdmM) completely replaced the classical swine matrix gene (swM), suggesting a fitness benefit. We assessed a panel of swIAVs in the BALB/c mouse model and demonstrated that swIAVs containing the pdmM gene caused increased morbidity, lung pathology, and mortality compared to swIAVs containing the swM gene. We hypothesized that swIAVs containing the pdmM gene induce dysregulation of the innate response, causing increased disease. To test this, mice were infected with swIAVs containing either the pdmM or the swM gene segment, and immune cell infiltrates, cytokine production, and histopathology were assessed. We found that pdmM viruses elicited increased cellular infiltration, NK cell activation and increased IFNγ production in bronchial alveolar lavage (BAL) fluid compared to mice infected with swM viruses. We also detected increased numbers of infiltrating macrophages, neutrophils, DCs, and eosinophils, as well as increased proinflammatory cytokine production. Additionally, elevated myeloperoxidase content was detected in BAL fluid, suggesting increased neutrophil activation. Finally, infection with pdmM viruses resulted in greater histologic lesion scores compared to swM viruses. We conclude the pdmM gene elicits increased innate immune responses, causing greater disease in a mouse model of infection. Future studies will identify determinants of increased disease severity.
Unique immune signatures predict potential cardiometabolic risk in severe COVID-19 patients and COVID-19 recovered individuals
Authors: Liyanage Namal , Gunasena Manuja , Wijewantha Yasasvi , Bowman Emily , Gabriel Janelle , Kumar Amrendra , Kettelhut Aaren , Ruwanpathirana Anushka , Weragalaarachchi Krishanthi , Kasturiratna Dhanuja , Vilgelm Anna , Pannu Sonal , Bednash Joseph , Demberg Thorsten , Funderburg Nicholas 
Published: February 2023

Abstract
Covid-19, the disease caused by SARS-CoV-2 infection, has resulted in millions of deaths and led to a global public health emergency. SARS-CoV-2 infected patients exhibit a wide variety of phasic clinical manifestations ranging from asymptomatic to severe complications and death. SARS-CoV-2 infection can lead to excessive immune activation, inflammation and multi-organ damage. Clinical data showed that COVID-19 may promote the development of cardiovascular disorders (CVDs). Immune activation, thrombosis, cytokine storm, and altered adhesion molecule expression on leukocyte populations have been proposed as possible mechanisms that trigger COVID-19 associated CVDs. A lack of systematic studies on how SARS-CoV-2 infection triggered immune responses that may lead to CVDs, hinder early risk identification and therapeutic interventions. In this study, by using deep immune profiling and extensive cytokine and chemokine profiling, we explore potential mechanisms of developing CVDs in severe COVID-19 patients (ICU) (n=20) as well as patients recovered from COVID-19 (RD) (n=30). We identify core immune signatures in ICU patients and RD compared to healthy controls (n=17) that may predict potential cardiovascular risk. We found that significantly elevated eosinophils and neutrophils and increased circulating levels of tissue factor, fatty acid binding protein 4 and, LPS binding protein in ICU patients suggested increased immune activation and thrombotic risk. Interestingly, we found significant elevation of several immune parameters (TIMP-1, TIMP-2, Monocytes) that were associated with cardiometabolic risk, in RD group. Thus, our data suggest a possible mechanistic link between severe COVID-19 and cardiometabolic risk.
Using single cell spatial and transcriptional analysis to understand early host response to RNA viral infections.
Authors: Arakkal Leanne , Sturdevant Gail , Robertson Shelly , Best Sonja M , Germain Ronald N , Speranza Emily 
Published: February 2023

Abstract
The innate immune system serves as the first line of defense against pathogens. One innate defense mechanism is the RIG-I like receptor pathway (RLR) which signals through the mitochondrial anti-viral signaling protein (MAVS) which plays a role in initiating the interferon (IFN) response to RNA viruses such as vesicular stomatitis virus (VSV). To investigate the mechanisms the MAVS-dependent pathway has on early viral control following VSV infection in vivo, we used a combination of two approaches: single cell RNA sequencing and multiplex imaging. These two techniques allow us to assess the individual cellular response to VSV in whole lymph node tissue. After intradermal inoculation, skin draining lymph nodes were assessed using single cell sequencing. Macrophages and plasmacytoid dendritic cells (pDCs) showed significantly elevated IFN stimulated gene (ISG) detection in C57Bl/6J (B6) mice compared to the MAVS−/− animals at 8 hours post infection (hpi), yet there was no detectable viral reads. This early initiation of ISG expression played a role in detection of viral RNA at 24 hpi which saw significantly elevated viral RNA in the MAVS−/− animals compared to the B6 animals. Interestingly, the virus replication in both conditions was contained to the macrophage populations suggesting that without the MAVS pathway active, the virus was still contained. Combining this information along with the observed spatial organization through multiplex tissue imaging, we aim to develop a model illustrating the role of the MAVS-dependent pathway in controlling early virus replication.
Animal experiments were done in accordance with the guidelines of the NIAID/NIH Institutional ACUC. This research was supported by the IRP of NIH/NIAID.