bluuebunny/crossref_metadata_2025_split huggingface dataset:
LCMV infection prevents MOG-specific T cell trafficking to the CNS and delays EAE
Authors: Cosby Jennifer M , Evavold Brian D 
Published: January 2023

Abstract
Infections have been implicated in playing a role in autoimmune diseases. Most reports discuss infectious insults as an initiator of autoimmune disease. Despite the idea that microbes act as triggers for autoimmune disease, their direct role in multiple sclerosis for example is still a topic of debate. Instead of assessing the role of infection in initiating disease, we address the converse hypothesis and test whether some infections can have protective effects. We investigated the role of LCMV infection during the well-established C57Bl/6 EAE model of chronic-progressive disease. In our model, mice infected with LCMV had a delay in EAE disease course compared to uninfected controls with significantly fewer myelin tetramer positive CD4 T cells in the CNS. However, roughly equal numbers of myelin-specific T cells were seen in the periphery suggesting that absence in the CNS was not due to lack of antigen-specific expansion. The CNS was instead populated with LCMV specific CD8 T cells. Therefore, EAE disease course is delayed during LCMV infection as a result of a lack of myelin-specific T cell homing into the CNS and the characteristic neuroinflammation mediated by this T cell population.
Dysregulation of intestinal IL17 signaling & the microbiome exacerbate autoimmune neuroinflammation.
Authors: Castillo Patricia , Kumar Pawan , Kolls Jay K 
Published: January 2023

Abstract
Multiple sclerosis (MS) is a chronic autoimmune disorder of the central nervous system (CNS). Studies in experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, strongly indicate that both Th17 cells and the commensal microbiome modulate disease pathogenesis. The commensal, segmented filamentous bacteria (SFB), regulates Th17 responses. Given the relationship between commensals and Th17 cells and the role of each of these factors in EAE, we investigated the significance of enteric IL-17R signaling in EAE using intestinal specific IL-17 receptor knockouts (Il17ra/rcfl/flx villin cre+ mice).
We hypothesized that disruption of the reciprocal regulatory relationship between enteric IL-17 signaling and the gut microbiota leads to dysbiosis, expansion of Th17 cells, and increased predisposition to autoimmune neuroinflammation. Our data suggested that Il17ra/rcfl/fl x villin cre+ mice, which have higher SFB levels, exhibit earlier EAE onset and increased EAE severity and incidence as compared to littermate cre− controls. Treatment with vancomycin ameliorated disease, further supporting our hypothesis. In addition, preliminary data indicated that cre+ mice have increased CCR2 and CCR6 gut expression at baseline. At day 9-post immunization in the same mice, there was increased expression of CCR2 and Nox2 in the spinal cord and Csf2 in the gut. Together, this suggested that there could be increased migration into the CNS of cre+ mice, contributing to exacerbated disease.
These studies will make a significant conceptual advance by elucidating how dysregulation of enteric IL-17R signaling and the commensal microbiota contribute to the pathogenesis of autoimmune conditions such as Multiple Sclerosis.
Intravital imaging of T and B cell migration across high endothelial venules in lymph node
Authors: Choe Kibaek , Song Eunjoo , Lee Soo Yun , Ahn Soyeon , Kim Pilhan , Moon Jieun 
Published: January 2023

Abstract
High endothelial venules (HEVs) in lymph node (LN) facilitate an effective recruitment of circulating lymphocytes from the blood. HEVs have distinctive cuboidal-shaped endothelial cells and prominent perivascular sheaths consisting of fibroblastic reticular cells (FRCs). Yet, detailed dynamic behaviors of lymphocytes during trans-endothelial migration, intra-perivascular channel crawling and trans-FRC migration in HEV are still poorly understood. In this work, we adapted a custom-design confocal microscope to visualize T and B cell migration across HEV in real time in vivo. Actin-DsRed transgenic mice were used to visualize HEV-endothelial cells and T or B cells obtained from actin-GFP mice were adoptively transferred. At the same time, FRCs were labeled in vivo by injecting anti-ER-TR7 antibody conjugated with far-red fluorophore to the footpad. T and B cells squeezed in between endothelial cells (ECs) and then migrated along the perivascular channel, narrow space between ECs and FRCs, for searching a proper site to exit by trans-FRC migration. Interestingly, B cells spent twice longer time in the perivascular channel than T cells although their total moving distances in the perivascular channel were similar. In addition, we observed that there existed preferred exit sites (“exit ramps”) from the perivascular channel for both of T and B cell. To observe whether T and B cell exit through the same exit ramp, we simultaneously transferred DsRed+ T and GFP+ B cells into wild type mouse. Indeed, T and B cells followed each other though the same exit ramp from the perivascular channel. There also existed “entrance ramps” into the perivascular channel; preferred sites for trans-endothelial migration for both of T and B cells.
Chemokine independent T cell migration
Authors: Walling Brandon Lee , Capece Tara , Kim Minsoo 
Published: January 2023

Abstract
Our current understanding of T cell migration is focused on chemokine-mediated integrin activation, which dictates that chemokines provide critical directional signals to guide T cell migration to target tissues within the body. Emerging evidence, however, supports that activated T cells can migrate to certain vascularized tissues, despite chemokine receptor deficiency or with the inhibition of chemokine receptors. This suggests the presence of a chemokine-independent mechanism through which T cells can activate integrins, induce adhesion and subsequent cell migration. We found with OT-I T cell receptor transgenic mice that integrin LFA-1 mediated migration of naïve T cells was strictly dependent on chemokine stimulation. In contrast, activated CD8+ T cells migrated in the absence of chemokines both in vitro and in vivo. Additionally, activated CD8+ T cells migrate in the presence of the chemokine inhibitors pertussis toxin and Gallein (a Gβγ inhibitor), further supporting chemokine-independent T cell migration. Using mass spectrometry, we discovered three cytoskeletal molecules, non-muscle myosin heavy chain IIA (MyH9), αII-spectrin, and βII-spectrin, associate with LFA-1 in T cells. Western blot analysis of mouse T cells revealed expression levels of MyH9 and αII-spectrin remained stable after T cell activation, but surprisingly, βII-spectrin expression was dramatically down-regulated during CD8+ T cell activation. Over-expression of βII-spectrin in activated CD8+ T cells abolished chemokine-independent migration on integrin ligand ICAM-1. Therefore, we hypothesize that βII-spectrin provides a mechanical link between LFA-1 and the cytoskeleton to regulate T cell migration without chemokine stimulation.
Differential regulation of human and mouse IL33 expression in the lungs of human IL33 BAC transgenic mice.
Authors: Pivniouk Vadim I , Rosenbaum David , Herrell Amanda , Pivniouk Oksana , Rafaels Nicholas , Mathias Rasika , Barnes Kathleen , Vercelli Donata 
Published: January 2023

Abstract
Interleukin-33 (IL33) is a member of the IL-1 cytokine family. IL33 polymorphisms are strongly associated with asthma susceptibility and IL33 deletion attenuates asthma in mice. However, the use of mouse models to elucidate the role of IL-33 in asthma is hampered by notably different tissue-specific patterns of IL33 expression in humans and mice.
To bypass this limitation, we generated mice carrying a 157 kB human BAC transgene (TG) that includes IL33 and its flanking sequences on chromosome 9. This TG contains protective alleles for a number of asthma-associated polymorphisms. Five founders with 1, 2, or 6 BAC copies were obtained. All were healthy, fertile, and transmitted the transgene at the expected Mendelian ratio.
To compare expression of transgenic human (h) and endogenous mouse (m)IL33, mice were challenged intranasally with Alternaria, which induces rapid release of mIL-33 in the lungs. Bronchoalveolar lavage fluid analysis showed that hIL-33 was also induced by Alternaria. Analysis of lung RNA by real-time PCR showed that Alternaria-induced hIL33 transcription was TG copy number-dependent and comparable with that of mIL33.
IL33 is known to be expressed by human but not mouse endothelial cells. Indeed, we found high levels of hIL33 RNA in endothelial cell-enriched mouse CD31+ lung cells while mIL33 was barely detectable.
These results suggest that tissue-specific hIL33 expression is controlled by cis-acting element(s) within the IL33 locus. More generally, our BAC TG appears to include all cis-regulatory elements necessary for faithful tissue-specific and copy number-dependent regulation of hIL33 expression, suggesting our mice are an ideal tool to study IL33 and its role in asthma.
HEB plays a critical role in the generation of IL-17 producing Vγ2+ γδ T cells
Authors: In Tracy , Trotman-Grant Ashton , Anderson Michele K 
Published: January 2023

Abstract
IL-17 producing Vγ2+ γδ T cells (Vγ2 T cells) form an integral part of the immune system of various lymphoid and mucosal tissues in mice. The γδ T cells acquire the ability to produce IL-17 during their thymic development but the molecular basis of this programming is not well understood. Here, we aim to characterized the role of HEB in the development of IL-17 producing Vγ2 T cells by utilizing HEB conditional knockout mice on a vav-Cre background (HEB conKO). First, we observed that there was a block in the development of Vγ2 T cells in the fetal thymic organ culture (FTOC) from HEB conKO embryos at E14. However, in contrast to the near absence of fetal thymic Vγ2 T cells in FTOC, neonatal thymus of HEB conKO mice supported the development of Vγ2 T cells, albeit at a significantly lower frequency than the wildtype thymus. Further, the frequency of Vγ2 T cells in the thymus of adult mice was the equivalent to that in the wildtype thymus, showing a gradual increase in the development of Vγ2 T cells in the HEB conKO thymus with age. As IL-17 producing γδ T cells have been shown to be generated preferentially during fetal development, we characterized the functional subsets of Vγ2 T cells found in adult HEB conKO mice. In fact, there was a significant reduction in the frequency of RORγt+ Vγ2+ T cells in the thymus of adult HEB conKO mice, as well as in the lungs, spleen and lymph nodes. Furthermore, the HEB-deficient Vγ2 T cells in the lungs, spleen and lymph nodes exhibited a profound deficiency in their ability to produce IL-17 in response to stimulation with IL-1β, IL-23 and IL-21 or PMA/Ionomycin. Collectively, our work shows for the first time that HEB is required for the generation of IL-17 producing Vγ2 T cells for various lymphoid and mucosal tissues.
Hematopoietic stem cell niches control multipotent progenitor differentiation
Authors: Pereira Joao P , Lim Vivian , Gomes Ana , Hara Takahiro , Herndler-Brandstetter Dietmar , Flavell Richard A , Nagasawa Takashi , Ikuta Koichi 
Published: January 2023

Abstract
Hematopoietic stem cells (HSC) self-renew in bone marrow niches formed by CXCL12+ mesenchymal progenitor and endothelial cells. Here, we show that hematopoietic multipotent progenitors (MPPs) encounter lineage-instructive differentiation signals in HSC niches. Conditional deletion of CXCR4 in MPPs profoundly reduced differentiation into common lymphoid progenitors (CLPs), which significantly decreased lymphopoiesis. CXCR4 was required for CLP positioning near IL-7+ cells and, consequently, for optimal IL-7R signaling. IL-7+ cells form a large subset of CXCL12-abundant reticular mesenchymal progenitor cells capable of differentiation into osteoblasts and adipocytes, and a minor subset of BM sinusoidal endothelial cells. Conditional Il7 deletion in Lepr+ mesenchymal progenitor cells dramatically reduced B-lineage committed CLPs, developing B cell subsets, and peripheral mature B cells. Importantly, more than 50% of HSCs and MPPs were found in direct contact with IL-7+ cells, and more than 75% of HSCs and MPPs resided at &lt;15 micrometers away from IL-7+ cells. Our studies demonstrate that MPPs and CLPs rely on positional cues to encounter short-range lymphopoietic signals provided by CXCL12+ mesenchymal progenitors. We conclude that HSC maintenance and multilineage differentiation are distinct cell lineage decisions controlled by HSC niches.
Embryonic stem cell-derived B-1 cells engraft in immunodeficient mice, recapitulating YS B lymphopoiesis.
Authors: Yoshimoto Momoko , Lin Yang , Yoder Mervin C. 
Published: January 2023

Abstract
It has been reported that B cells are produced from embryonic stem cells (ESCs) when co-cultured with OP9 stromal cells. However, these ESC-derived B cells have not been well characterized; it is unknown whether they belong to the B-1 or B-2 lineage and whether they are transplantable into immunodeficient mice.
We previously reported that the first wave of B lymphopoiesis occurs in the extra-embryonic yolk sac (YS) at the time prior to hematopoietic stem cell (HSC) emergence and these cells belong to the B-1 cell lineage. YS-derived B progenitor cells display a AA4.1+CD19+B220dim B-1 specific progenitor phenotype, are transplantable into immunodeficient mice, and secrete natural antibodies; all key features of B-1 cells. Since differentiation of ESC into blood cells recapitulates YS hematopoiesis, we hypothesized that B progenitor cells produced from mouse ESCs in vitro belong to the B-1 cell lineage. We co-cultured ESCs with OP9 stromal cells and generated Flk1+ cells. Isolated Flk1+ cells were replated onto OP9 stromal cells, and after 9–12 days of co-culture, AA4.1+CD19+B220+ cells were detected. We transplanted these cells into sublethally irradiated immunodeficient neonates. Donor-derived B-1 cells were detected in the recipient peritoneal cavity up to 6 months after transplantation. Furthermore, ESC-derived B-1 cells produced anti-phosphorylcholine antibodies detected by Elispot assay, showing the ability of these innate B-1 cells to produce natural antibodies.
Thus, we have demonstrated that ESC-derived B cells engraft in vivo as functional B -1 cells secreting natural antibodies. These B cell developmental processes recapitulate B lymphopoiesis in the YS and might be utilized for innate immune cell therapy in the future.
Bone marrow basophils enhance immature B cell survival by recruitment and contact dependent signals
Authors: Moreau Joshua Michael , Paige Christopher J 
Published: January 2023

Abstract
B cell development in the bone marrow relies upon an organized tissue structure. Maturing progenitors migrate between several distinct niches and towards the sinusoidal vessels before entering circulation. Microenvironments specific for early developmental stages are provided by stroma expressing CXCL12 (pre-pro-B), IL-7 (pro-B), or Galactin-1 (pre-B); however, the identity of a defined niche for immature B cells remains unclear. A DX5+Thy1lo cell has been shown to provide IgM+ progenitors survival signals through direct cell-cell contact; but the cell type responsible, factors provided, and the influence this help may have on B cell function remains unknown. Here, utilizing in vitro B cell selection assays and in vivo depletion experiments, we identify the DX5+Thy1lo cells as basophils. We demonstrate that this population produces chemotactic factors, which act to recruit immature B cells and therefore enable provision of pro-survival signals directly via cell-cell contact. Furthermore, the bone marrow basophil population expanded during the first 24 hours following induction of inflammation by injection of Freund’s incomplete adjuvant. This response correlated with an increase in the number of immature B cells within the marrow, as well as, a reduction of lambda light chain usage in the immature but not mature B cell population. These results reveal that bone marrow basophils actively provide a supportive microenvironment for immature B cells and that the sensitivity of basophils to inflammatory stimuli may modulate BCR repertoire development.
Effects of neonatal antigen exposure on natural antibody repertoire development
Authors: New James Stewart , Dizon Brian L.P. , King R. Glenn , Kearney John F. 
Published: January 2023

Abstract
B-1 B cells produce natural antibodies that contribute significantly to maintenance of immunological homeostasis, however the role exogenous antigens play in the development of the B-1 B cell repertoire is unclear. N-acetyl-D-glucosamine (GlcNAc)-reactive antibodies are universally represented in mammals, and some GlcNAc-reactive B cell clonotypes are autoreactive due to the conservation of orthologous GlcNAc epitopes in mammals and microorganisms. We report here that neonatal immunization with GlcNAc-bearing Group A Streptococcus significantly expands CD5-bearing GlcNAc-reactive B-1 B cell populations, alters the GlcNAc- reactive clonal repertoire, and suppresses class-switch antibody responses upon secondary immunization in adulthood. We further find that in the absence of exogenous antigen stimulation, germ-free mice exhibit log-reductions in the number of GlcNAc-reactive B-1 B cells and the levels of circulating antibodies. Importantly, clonal analyses of B cells from germ-free mice reveals a lack of GlcNAc-reactive innate-like B cell clonotypes that are highly conserved between mice raised under SPF conditions. Collectively, these data indicate that exposure to exogenous antigen during perinatal development can directly influence clonal representation within certain B-1 B cell specificities. These observations suggest that integration of signals derived from exogenous antigen is required for the development of certain clonal specificities that are negatively selected in the absence of exogenous stimuli. Given the functions of natural antibodies, these observations may hold major implications for the roles of environmental factors in the development of autoimmune disease.
Neurokinin A reduces FcɛRI-triggered inflammation mediated by cutaneous mast cells.
Authors: Sumpter Tina L , Tkacheva Olga , Falo Louis D , Larregina Adriana T 
Published: January 2023

Abstract
Mast cells (MCs) are potent effector cells in atopic diseases, like asthma and atopic dermatitis. In the skin, MCs reside in the dermis, in close proximity to sensory nerves. In this shared geographical space, MCs and neurons may have evolved common mechanisms for responding to noxious stimuli and for maintaining homeostasis, including responsiveness to neuropeptides. Sensory nerves release neuropeptides with immune functions including the tachykinin family member, neurokinin A (NKA). Recent studies highlight immune functions for NKA but a role for NKA in MC biology has not been explored. NKA signals with high affinity through the neurokinin 2 receptor (NK2R) that has been reported to be anti-inflammatory in the skin. In the current study, we hypothesized that NKA would dampen MC activation initiated by FcɛRI. Our data demonstrated that, in vitro, mouse bone marrow (BM) derived MCs expressed low levels of the NK2R, which was upregulated following FcɛRI activation and maintained by STAT3 signaling. The addition of NKA to MC cultures downregulated surface expression of the prototypical MC markers, FcɛRIα and c-Kit. This effect was overcome with IgE and cross-linking antigen (Ag). NKA alone did not affect degranulation or cytokine release. But, NKA increased the percentage of MCs releasing granules in response to IgE + Ag, while decreasing the secretion of IL-4, IL-13 and IL-6 in response to IgE + Ag. In vivo, intradermal administration of NKA reduced IgE-dependent MC functions in a murine model of passive cutaneous anaphylaxis. Our data suggest that NKA reduces the inflammatory capacity of MCs and that activation of the NKA/NK2R axis has a therapeutic potential for MC mediated atopic diseases.
Fluvastatin augments IL-33-mediated mouse mast cell function
Authors: Taruselli Marcela T , Kolawole Elizabeth Motunrayo , Ryan John J 
Published: January 2023

Abstract
Statins are HMG-CoA reductase (HMGCR) inhibitors that are the most commonly prescribed class of drugs for treatment of hypercholesterolemia. Recent studies have found that statins suppress some pro-inflammatory immune responses. Similarly, our lab has previously reported that fluvastatin suppresses pro-inflammatory IgE-mediated mast cell function in vitro and in vivo. However, other studies have shown statins can induce pro-inflammatory function in NK cells and monocytes. Due to the differing data on statins, we extended our studies to examine the effect of fluvastatin on IL-33 mediated mast cell function. Contrary to our IgE studies, fluvastatin augmented TNF and IL-6 production in IL-33-stimulated bone marrow derived mast cells. The increase in cytokine production was dependent on the presence of stem cell factor (SCF) during fluvastatin treatment. Mevalonic acid, the product of HMGCR, did not reverse the effect of fluvastatin, suggesting that fluvastatin action is not due to HMGCR targeting. Furthermore, inhibiting protein prenylation downstream of HMGCR with farnesyl transferase and geranylgeranyl transferase inhibitors did not emulate the effects of fluvastatin. The effects of fluvastatin were functionally important, since in vivo fluvastatin treatment enhanced IL-33-mediated neutrophil recruitment and increased plasma IL-6 and TNF. This study may elucidate the pro-inflammatory mechanisms of statins and reveal novel means by which mast cells are activated.
Helminth-induced B1 IgE is protective against allergic disease.
Authors: Martin Rebecca , Damle Sheela , Conrad Daniel H 
Published: January 2023

Abstract
Helminth infection is well known for its ability to generate large amounts of non-specific IgE. This hinders the parasite-specific IgE thereby reducing mast cell (MC) degranulation and anti-helminth immunity. This study shows that the innate-like B1 cells are responsible for the substantial amounts of IgE induced during the Th2 helminth infection, Nippostrongylus brasiliensis (Nb). We utilize a mouse model with defects in hematopoiesis that results in loss of B2 cells, but retains normal B1 development, the ADAM10 transgenic mouse. These mice have equivalent IgE production in Nb when compared to wild type (WT) controls that is T cell dependent. Utilizing the NP-KLH system, we demonstrate that these mice make no antigen-specific IgG1, either high or total affinity. They additionally make no increased overall antibody when boosted with the same antigen. In WT mice, we show a population of B1 plasma cells (CD11b+CD23−B220intCD138+) in vivo, that express secreted IgE message during Nb infection. We additionally show that B1 cells (CD11b+CD23−B220int) sorted from naïve and Nb infected mice make large amounts of IgE in in vitro culture with IL-4, anti-CD40, and IL-5 by ELISA and secreted IgE message by RT-PCR. These B1 cells become CD138+ after 5 days of culture. Finally and most importantly, we show that B1 IgE is first unable to induce MC degranulation in an active cutaneous anaphylaxis model and second, it can block MC degranulation in a model of passive cutaneous anaphylaxis. Overall, these data represents a protective response that has evolved for the helminth, where non-specific B1 IgE blocks MC degranulation and thereby protects the helminth from damage. Excitingly, this could be harnessed as a potential protection against allergic disease.