bluuebunny/crossref_metadata_2025_split huggingface dataset:
The expression of membrane-anchored GM-CSF reduces the tumorigenicity of murine breast cancer cells and correlates with a reduction in MDSCs in vivo (46.36)
Authors: Bozeman Erica , Shashidharamurthy Rangaiah , Selvaraj Periasamy 
Published: January 2023

Abstract
Currently under preclinical and clinical investigation are several cancer vaccines using whole tumor cells modified to secrete GM-CSF. However, a potential drawback of such vaccines is the risk of systemic toxicity. To address this concern, we generated a GPI-anchored form of mouse GM-CSF (GPI-mGM-CSF) to be stably expressed on the surface of tumor cells. To determine the immunogenicity of breast cancer cells expressing the GPI-mGM-CSF, we used the TUBO cell line, a highly tumorigenic, non-metastatic tumor cell line that constitutively expresses the HER-2/neu oncogene which is overexpressed in 30% of human breast cancer patients. BALB/c mice were challenged with 1e5 TUBO-WT or TUBO-mGM-CSF cells. At the conclusion of the experiment, mice were sacrificed, spleens were harvested and splenocytes were isolated for flow cytometry analysis following RBC lysis. Splenocytes were stained for the prevalence of immune suppressive cells including myeloid derived suppressor cells (MDSCs). We observed minimal, transient growth of tumors in mice challenged with TUBO-mGM-CSF compared to TUBO-WT. Additionally, we obsesrved a significant reduction in spleen weight and prevalence of CD11b+Gr-1+ MDSCs in these mice. These studies suggest that the addition of a membrane anchored form of GM-CSF to tumor cells can induce an antitumor immune response and inhibit the development of immune suppressive cells such as MDSCs.
Efficacy and mechanism-of-action of a novel superagonist IL-15:IL-15Rα/Fc fusion complex in murine multiple myeloma syngeneic mouse models (46.44)
Authors: Wong Hing , Xu Wenxin , Zhu Xiaoyun , Liu Bai , Edward Anna , Kong Lin , Jeng Emily , Hang Kaiping , Marcus Warren , Rhode Peter 
Published: January 2023

Abstract
ALT-803 is a fusion protein complex consisting of an interleukin-15 superagonist mutein (IL-15N72D) and a dimeric IL-15 receptor alpha (IL-15Rα)/Fc fusion protein. Previous studies have shown that IL-15:IL-15Rα complexes exhibit potent activity against murine melanoma in immunocompetent mice. In this study, we show that ALT-803 treatment significantly prolongs survival of C57BL/6 mice bearing syngeneic murine 5T33P myeloma. ALT-803-treated mice were also protected from paralysis and mortality due to subsequent rechallenge with 5T33P tumor cells. Consistent with these results, a single dose of ALT-803 was capable of significantly reducing the percentage of well-established 5T33P cells in the bone marrow of tumor-bearing mice shortly after ALT-803 infusion and promoted a substantial increase of CD8+ T cells and NK cells in peripheral blood and bone marrow. ALT-803 treatment also increased serum IFN-γ levels but did not affect the level of blood Tregs. Immune cell depletion studies suggest that activated effector and memory CD8+ T cells may play a vital role in the anti-tumor activity of ALT-803 against 5T33P myeloma cells. Similar potent anti-tumor effects of ALT-803 were also observed in BALB/c mice bearing MOPC-315 myeloma cells. The results of these studies support clinical development of ALT-803 as a novel immunotherapeutic agent against multiple myeloma.
Soluble CD80 restores T cell activation and overcomes tumor cell Programmed Death Ligand-1-mediated suppression (46.8)
Authors: Haile Samuel , Dalal Sonia , Clements Virginia , Tamada Koji , Ostrand-Rosenberg Suzanne 
Published: January 2023

Abstract
One of the mechanisms tumor cells employ to escape anti-tumor immunity is expression of Programmed Death Ligand 1 (PD-L1or B7-H1). PD-L1 protects tumor cells by binding to its receptor Programmed Death 1 (PD-1) on activated T cells, thereby causing T cell apoptosis. We previously reported that transfection of tumor cells to express the costimulatory molecule CD80 prevents PD-1 binding and restores T cell activation, consistent with the concept that CD80 binds to PD-L1 and inhibits PD-L1/PD-1 interaction. Since it is not therapeutically feasible to transfect tumor cells with CD80, we have tested a soluble form of CD80, consisting of the extracellular domains of the molecule, for its ability to overcome PD-L1-mediated suppression. Treatment of human lung adenocarcinoma, mammary carcinoma, and cutaneous melanoma cells with soluble CD80 prevents PD-L1-mediated suppression and restores T cell activation. Because on-going clinical trials have shown that mAbs to PD-1 facilitate tumor rejection, we have compared the efficacy of soluble CD80 vs. mAbs to PD-1 or PD-L1. Soluble CD80 treatment is more effective in restoring T cell activation than treatment with mAbs to either PD-1or PD-L1. Therefore, soluble CD80 may be a therapeutic agent for facilitating tumor-specific immunity by overcoming PD-L1-induced immune suppression, and is potentially more effective than mAbs to either PD-1 or PD-L1.
Functional abnormality of peripheral CD8 T cells in β5t-deficient mice (47.18)
Authors: Takada Kensuke , Takahama Yousuke 
Published: January 2023

Abstract
Proteasomes play an important role in the production of peptides presented by MHC class I. The thymoproteasome, which contains β5t catalytic subunit, is expressed specifically in cortical thymic epithelial cells. In β5t-deficient mice, the cellularity of CD8SP thymocytes and peripheral CD8 T cells is significantly decreased and their TCR repertoire is altered as characterized by defective responses to alloantigens and viral infections. In the present study, we functionally characterized CD8 T cells generated in β5t-deficient mice. We found that CD8 T cells in the secondary lymphoid organs of β5t-deficient mice were enriched with CD44hiCD122+ cells, which resemble memory T cells. This phenotypic alteration was not detectable in the thymus and was observed in the periphery of mice older than 1 week after birth, suggesting that CD8 T cells generated in the thymus of β5t-deficient mice are aberrantly maintained in the periphery. Enrichment of memory-like CD8 T cells was also seen in β5t-/-Rag-/-OT-I mice. In addition, CD44loCD122- cells obtained from β5t-/-Rag-/-OT-I mice showed enhanced proliferative responses to antigen stimulations. These results suggest that the thymoproteasome-dependent positive selection affects not only TCR repertoire but also functions of CD8 T cells, including the antigen reactivity and the homeostatic capability.
The use of IKK inhibitor as a lymphocyte depleting agent (47.4)
Authors: Lee Chih-Yuan , Lai Ting-Yu , Yeh Tzu-Wen , Chou Chih-Chung , Tsai Meng-Kun , Hsu Li-Chung 
Published: January 2023

Abstract
Purposes: Transcription factor NF-κB and its activating kinase IκB Kinase β (IKKβ) are critical for inflammation and innate immunity. In our previoius report, MLN120B, an IKKβ inhibitor, would cause neutrophilia in mice but their peripheral blood lymphocyte numbers were not affected. We tried other IKK inhibitors; however, we found that feeding with BMS-345541, a highly selective IKKβ inhibitor, would cause lymphopenia in mice. We explored the possibility of BMS-345541 as a therapeutic agent in depleting lymphocytes. Results: To characterize how BMS-345541 affects lymphocyte homeostatsis, C57BL/6 mice received vehicle, or BMS-345541 oral gavage once daily at different dose (10, 25, 50, and 100 mg/kg body weight in 3% Tween 80), and mice were sacrificed on day 3 or day 5. We collected the peripheral blood for blood cell counts and also collected spleen and lymphnodes for histology examination. The lymphocytes, but not neutrophils, were significantly decreased in mice received BMS-345541. Our preliminary results showed that the effect of BMS-345541 on lymphocytes were through apoptosis rather than trapping the lymphocytes in lymphoid organs. BMS-345541 affected both T cells and B cells. Conclusion: We conclude that oral administration of BMS-345541 would reduce lymphocyte counts and could be helpful in depleting lymphocytes in circulation, which would be useful as a therapeutic agent for lymphoproliferative disorder.
Integrin alpha-7+ pericytes are a novel, immunologically relevant lymph node stromal subset found in mice and humans (47.6)
Authors: Fletcher Anne , Malhotra Deepali , Lukacs-Kornek Veronika , Elpek Kutlu , Turley Shannon 
Published: January 2023

Abstract
Within lymph nodes, non-hematopoietic stromal cells attract, arrange, and promote the survival of naïve T cells, while deleting self-reactive T cells in a non-redundant fashion. Despite these important functions, subsets are poorly characterized. One major subset (gp38-CD31- double negative, termed DN) comprises 10-15% of stroma, with transcript for relevant peripheral tissue-restricted antigens (PTAs) and Aire, yet nothing was known of their lineage, localization, phenotype, or capacity to interact with leukocytes. We addressed this through in-depth transcriptomic, protein and functional analyses of DN stroma, in comparison to 5 other stromal subsets. DNs express CCL19, CCL21, CXCL13, CXCL9, CXCL10 and other chemokines, with high levels of Flt3L, BAFF, CSF-1, TGFb family members and lymphangiogenic growth factors. Phylogenetic analysis showed DNs were similar to but distinct from fibroblastic reticular cells, with a unique integrin profile, higher contractility in culture, and a lack of IL-7 expression. In situ, we found a unique surface protein, integrin α7, which identified DNs as lymph node pericytes in the cortex and medulla. Strikingly, DNs strongly alter PTA transcription following inflammation without increasing surface expression of MHC molecules. We subsequently identified DN cells in human lymph nodes. These data identify DNs as a unique, immunologically relevant subset of fibroblastic, contractile pericytes, which we term integrin α7+ pericytes (IAPs).
MicroRNAs and their role in the generation of myeloid derived suppressor cells (MDSC) by cannabidiol in vivo (48.16)
Authors: Hegde Venkatesh , Nagarkatti Prakash , Nagarkatti Mitzi 
Published: January 2023

Abstract
The major non-psychotropic cannabinoid cannabidiol (CBD) induces G-CSF, CXCL1 and massive accumulation of functional CD11b+Gr-1+ MDSC in the peritonea of naïve mice. Role of miRNA in the regulation of MDSC function is unclear. Microarray analysis for 609 mouse miRNA using total RNA from purified cells revealed unique profile and 59 differentially expressed (&gt;2 fold) miRNA in CBD-MDSC as compared to BM CD11b+Gr-1+ cells from control mice. MicroRNA signature of CBD-MDSC closely resembled with that of tumor-MDSC purified from EL4-bearing mice. CBD-MDSC showed significantly lower levels of miR-706 and miR-455 compared to BM controls as validated by qPCR. Target prediction using MicroCosm algorithm suggested that miR-706 and miR-455 bind to 3’ UTR of Stat1 and Stat6 mRNA respectively, which in turn have been shown to positively regulate arginase 1 (ARG1) crucial for MDSC immunosuppressive function. CBD-MDSC showed higher relative expression of Stat1 and Stat6 mRNA transcripts in qPCR as well as higher Stat1/ pStat1, Stat6 and ARG1 protein levels when compared to BM controls. Further, CBD-MDSC transfected with miR-706 mimic had decreased Stat1/ pStat1 and ARG1 protein levels whereas miR-455 mimic did not alter Stat6/ pStat6 or ARG1. In summary, induction of MDSC from BM precursors in response to CBD in vivo is associated with significant changes in global miRNA expression and miR-706 plays a role in the regulation of ARG1 and hence the functional MDSC phenotype by targeting Stat1.
ROLE OF ACCESSORY CELLS IN THE IVIG-MEDIATED INHIBITION OF T CELL ACTIVATION (48.5)
Authors: Padet Lauriane , Bazin Renée 
Published: January 2023

Abstract
Intravenous immunoglobulin (IVIg) is a therapeutic preparation of human IgG isolated from thousands of plasma and is currently used for the treatment of an increasing number of immune disorders. A decreased T cell activation was reported in some patients treated with IVIg. To understand the mechanisms responsible for this anti-inflammatory effect, several groups of investigators have performed in vitro assays in which PBMC were activated with immobilized anti-CD3. The main conclusion derived from these works is that IVIg inhibited the functions of activated T cell. However, direct effect of IVIg on activated T cells has been questioned recently. In the present study, we re-examined the mechanisms by which IVIg interferes with the functions of T cells activated with immobilized anti-CD3. First, the level of T cell activation after anti-CD3 stimulation of PBMC, purified T cells or PBMC depleted from monocytes was measured. Our results showed that in the absence of monocytes, T cells did not proliferate in response to anti-CD3 stimulation, suggesting that monocytes are essential to lead to full T cell activation. Second, we evaluated the effect of IVIg on T cell activation after anti-CD3 stimulation of PBMC. Our results showed that T cells were not activated in the presence of IVIg suggesting that not only T cells but also monocytes could be the target of IVIg. Work is underway to better define the role of monocytes in the effects of IVIg on T cell activation.
Mouse mesenchymal stem cell-derived exosome mediates a immunosuppressive function in Th17 cells (48.8)
Authors: Lee Sunho , Kim Sueon , Park Chung-Gyu 
Published: January 2023

Abstract
The immunoregulatory ability of MSCs is demonstrated in their ability to alleviate autoimmune diseases. In this study, by using purified exosomes from mesenchymal stem cell (MSC), we examined the immune-regulatory effect of exomes on activated T cells. Exosomes suppressed the proliferation of T cells by apoptosis and cell cycle arrest, which was confirmed by CFSE staining and FACS analysis. To confirm exosome’s immunoregulatory effect in vivo, EAE was induced in four groups of mice that were treated exosome and exosome-enriched, exosome depleted supernatant, and saline as a control from the point when the symptoms of EAE initiated. As expected, the symptoms were significantly alleviated in exosome and exosome-enriched treated groups. In addition, the level of IL-17 expression in exosome treated group evaluated by ELISPOT and ELISA was about 2 times lower than that in control group. Exosome significantly reduced the levels of stat3 phosphorlation which has been known to activate RORγt. In conclusion, these results indicate that exosomes alleviate EAE by suppressing IL-17 secretion and stat3 phosphorylation which has been known to play a crucial role in development of EAE.
A TNF family receptor regulates epithelial innate responses and host defense against pathogenic bacterial infections of the mucosa (49.1)
Authors: Kronenberg Mitchell , Shui Jr-Wen , Larange Alexandre , Kim Gisen , Vela Jose Luis , Cheroutre Hilde 
Published: January 2023

Abstract
Previously, in a mouse colitis model, we demonstrated an anti-inflammatory role for the herpes virus entry mediator (HVEM), a TNF superfamily receptor, when expressed by a radiation resistant cell population (J. Exp. Med. 205: 1463, 2008). However, the molecular mechanism for HVEM function remained to be determined. We therefore explored the role of HVEM in colonic epithelial cells, a radiation resistant cell type critical for preventing colitis and enhancing host defense. During Citrobacter rodentium infection, Hvem-/- mice had impaired colonic epithelial responses, resulting in higher bacterial burdens, inflammation and increased mortality. HVEM stimulation induced epithelial responses by NIK-dependent Stat3 activation, resulting in the expression of genes important for mucosal immunity. HVEM signaling also induced IL-22R1 expression, which boosted IL-22 signaling, leading to enhanced Stat3 activation in the epithelium. While HVEM or IL-22R signaling alone induced Stat3 activation in epithelial cells in vitro, during infection in vivo, both Stat3-activating pathways were required. Likewise, in Streptococcus pneumoniae infection, HVEM was required not only for survival and bacterial clearance, but also for Stat3 activation and induction of innate responses in the lung. Collectively, our findings establish HVEM as a crucial regulator of innate defense at mucosal surfaces via directly enhancing epithelial Stat3 activation and by inducing epithelial IL-22R1 expression.
Intestinal epithelial cells-derived exosomes provide a bridge between the gut and the liver that prevents liver inflammation through prostaglandin E2 induction of NK T cell anergy (49.11)
Authors: Deng Zhongbin , Ju Songwen , Zhuang Xiaoying , Xiang Xiaoyu , Miller Donald , Zhang Huang-ge 
Published: January 2023

Abstract
The in vivo regulation/induction of NTK anergy has been associated with inhibition of autoimmune and anti-tumor response, but the underlying mechanisms are poorly understood. In this study, we demonstrated that exosomes released from intestinal epithelial cells migrated into liver and induced liver NKT anergy. Unexpectedly, these effects were mediated by an exosomal PGE2 , which were demonstrated in a NKT-mediated liver injury model induced by ConA. Consistent with these findings, blocking PGE2 synthesis attenuated intestinal epithelial cells exosomes mediated inhibition of induction of IFN-γ and IL-4 of α-GalCer stimulated liver NKT cells as a PGE2 receptors mediated and PKA dependent manner. Pro-inflammation condition increased permeability of intestine and thus enhanced accumulation of intestinal epithelial cells exosomes migrated into liver where PGE2 induced NKT anergy in response to subsequently α-GalCer stimulation. Thus, these findings demonstrate a previously unappreciated role for intestinal epithelial cell exosomes served as immune modulator between liver and intestine and maintaining liver NKT homeostasis. Our findings have also important implications for the development of NKT cell-based vaccines and immunotherapies.
Campylobacter jejuni induces mixed Type 1 and 17 responses in a C57BL/6 IL-10−/− mouse model of colitis. (49.12)
Authors: Malik Ankit , Mansfield Linda 
Published: January 2023

Abstract
Campylobacter jejuni is the leading cause of food-borne enteritis and has also been linked with peripheral neuropathy and arthritis. C57BL/6 IL-10+/+ and congenic IL-10−/− mice serve as C. jejuni colonization and colitis models respectively. We hypothesized that in the absence of regulatory cytokine IL-10, uncontrolled induction of proinflammatory cytokines and infiltration of inflammatory cells is responsible for tissue obliteration in colitis. Colon cytokine analysis revealed significant time-dependent up regulation of IFN-γ, IL-17A, IL-6, TNF-α and IL-1β. A similar panel of cytokines were upregulated in the plasma and draining lymph node cultures of infected mice. Colon flow cytometric and immunohistochemical analysis revealed time-dependent increases in numbers of infiltrating macrophages, neutrophils, T cell subsets, NK cells and Thy1+ CD3- innate lymphocytes. Intra-cellular cytokine staining of colon and lymph node lymphocytes further linked IFN-γ, IL-17 and IL-22 upregulation to specific T cell subsets and innate lymphocytes. Time - dependent up regulation in anti-C. jejuni reactive IgG2b, IgG2c and IgG3, but not IgG1 or IgM were also observed in plasma of infected mice. These data demonstrate a mixed Type 1 and Type 17 induced colitis in C. jejuni 11168 challenged C57BL/6 IL-10-/- mice. Future work is directed towards understanding the relative importance of Type 1 and 17 pathways, and innate and adaptive lymphocytes in C. jejuni induced colitis.
Immune ignorance of a commensal bacterial antigen by endogenous antigen-specific CD4+ T cells in the gut. (49.14)
Authors: Legoux Francois , Moon James 
Published: January 2023

Abstract
The immune system must discriminate between beneficial and harmful microbes in the gut, and failure to maintain a proper balance of immune responsiveness and immune tolerance to gut microbes can lead to intestinal pathology. In particular, inflammatory bowel diseases such as Crohn's Disease and ulcerative colitis are thought to be the result of aberrant immune responses targeting commensal bacteria normally present in the gut lumen. The early events that break steady-state tolerance and trigger an immune response directed to commensal bacterial antigens remain poorly understood. Using a peptide:MHC-II tetramer-based enrichment approach, we characterized endogenous CD4+ T cells specific for Cbir1, a flagellin antigen from commensal bacteria present in the gut of normal mice. Our data show that endogenous Cbir1-specific T cells develop in the thymus of normal mice at the double positive stage. These cells survive negative selection and populate the peripheral lymphoid organs without becoming activated. Following immunization with their cognate antigen, they undergo massive proliferation and upregulate activation markers. Despite the presence of Cbir1 in the gut lumen, Cbir1-specific T cells in the lamina propria do not differentiate into regulatory T cells, nor do they induce colitis in normal mice. These data suggest that immune ignorance, rather than regulatory T cell induction, is a major mechanism of immune tolerance to commensal bacteria flagellin in the gut.
FcRn-mediated transport of IgG can either enhance or neutralize chlamydial infection (49.17)
Authors: Beagley Ken , Armitage Charles , Kuo Timothy , Blumberg Richard , Wijburg Odilia , Timms Peter 
Published: January 2023

Abstract
IgG is the dominant antibody in the female and male reproductive tracts (RT). Furthermore, the neonatal Fc receptor (FcRn) is expressed by epithelial cells in both these tissues. The acidic environment (pH 4.5-6.5) in the RT is optimal for FcRn uptake of IgG by epithelial cells, which suggests that IgG could either enhance or protect against infection by pathogens such as Chlamydia, depending on antibody specificity. We show that IgG is indeed internalized by reproductive tract epithelial cells in an FcRn and pH-dependent manner. Furthermore, IgG specific for the chlamydial major outer membrane protein (MOMP), expressed predominantly on the extracellular elementary body (EB) actually enhanced infection, whilst IgG specific for an antigen expressed during intracellular chlamydial replication (IncA) partially neutralized infection. Both enhancement (IgG-MOMP) and protection (IgG-IncA) were abrogated by knockdown of FcRn expression. Chlamydiae inhibit lysosomal activity to promote infection and the presence of intracellular IncA-IgG enhanced lysosomal activity in infected cells. IgA is also found in RT secretions as is the IgA transport molecule the polyimmunoglobulin receptor (PIgR). Unlike IgG, IgA-MOMP and IgA-IncA both neutralized chlamydial infection in a PIgR-dependent manner. Thus for antibody-mediated protection against Chlamydia, IgG specific for intracellular chlamydial antigens, together with IgA specific for both stages of the replicative cycle may be optimal.