bluuebunny/crossref_metadata_2025_split huggingface dataset:
Peptidoglycan recognition protein 3-regulated microbiome maintains healthy levels of Treg cells and protects mice from colitis (INC1P.346)
Authors: Gupta Dipika , Jing Xuefang , Dziarski Roman 
Published: January 2023

Abstract
Peptidoglycan recognition proteins (Pglyrp1, Pglyrp2, Pglyrp3, and Pglyrp4) are bactericidal innate immunity proteins that maintain normal gut microbiome, protect against experimental colitis, and are associated with inflammatory bowel disease in humans. In this study we examined the role of T cells in the increased sensitivity of Pglyrp3-/- mice to dextran sodium sulfate (DSS)-induced colitis. We demonstrate that untreated Pglyrp3-/- mice had significantly lower levels of anti-inflammatory Treg cells (CD4+Foxp3+) and significantly higher levels of pro-inflammatory Th17 (CD4+IL17+) cells in the colon than WT mice. Specifically, Helios- but not Helios+ Treg cells were significantly lower in the colon of Pglyrp3-/- mice than WT mice, which suggests that induced Treg cells were decreased in Pglyrp3-/- mice. WT germ-free mice colonized with Pglyrp3-/- stools had lower levels of Treg cells and higher levels of Th17 cells than WT germ-free mice colonized with WT stools. The lower number of Treg cells and higher number of Th17 cells correlated with the increased sensitivity to colitis in the germ-free mice. We further demonstrate that increasing the numbers of Treg cells in the colon with vitamin A or neutralizing IL17 with antibody protected Pglyrp3-/- mice from increased sensitivity to DSS-induced colitis. Thus our data indicate that Pglyrp3-regulated microbiome promotes Treg cells, inhibits Th17 cells and protects from DSS-induced colitis.
Antigen-specific MAIT cell subsets involved in TB immunity (INC2P.420)
Authors: Sakala Isaac , Kjer-Nielsen Lars , Eickhoff Christopher , Wang Xiaoli , Blazevic Azra , Liu Ligong , Fairlie David , Rossjohn Jamie , McCluskey James , Fremont Daved , Hansen Ted , Hoft Daniel 
Published: January 2023

Abstract
Mucosal associated invariant T (MAIT) cells have a semi-invariant TCRVα chain, and depend on riboflavin metabolites (ribityllumazines, RLAg) produced by commensal flora and presented by the nonpolymorphic class Ib molecule MR1 for optimal development. We used MR1/RLAg tetramers and TCR Vα19 transgenic mice to study MR1-dependency, subset heterogeneity and protective effector functions important for tuberculosis (TB) immunity. We found that Vβ6/8+NK1.1+ MAIT cell subsets maximally expand peripherally in mice expressing MR1. In addition, we show that MR1/RLAg tetramer+ MAIT cells expressing CD4, CD8 or neither contain populations variably co-expressing Vβ6/8 and/or NK1.1, indicating that MAIT cells are more heterogeneous than previously thought. Furthermore, NK1.1 (NKR-P1C) is minimally expressed on mature Vβ6/8+ tetramer+ MAIT cells in the thymus but progressively increases with peripheral activation. Importantly, after virulent mycobacterial pulmonary infection, heterogeneous subsets of tetramer+ MAIT cells (CD4-CD8-&gt;CD4-CD8+&gt;CD4+CD8-) co-expressing Vβ6/8 and NK1.1 and the homing molecules α4β1 and CXCR3, were recruited into the lungs and afforded maximal early protection in MR1-sufficient mice. Surprisingly, MAIT cells developing in the absence of MR1 were partially protective. Overall, we demonstrate diversity of MAIT cells, evidence that NK1.1 is an activation rather than developmental MAIT cell marker, and also that MAIT cells are important for TB protective immunity.
Restoration of electric footshock-induced immunosuppression in mice by Modified Aloe Polysaccharide (INC2P.411)
Authors: Lee Youngjoo , Kim Jiyeon , Lee Sungwon , Kwon Junghak , Kong Hyunseok , Song Youngcheon , Lee Chong-Kil , Kim Kyungjae 
Published: January 2023

Abstract
A mutual relationship between stress and immune system has long been studied. To investigate the immunomodulatory effects of MAP (modified aloe polysaccharide) on stressed model, we induced electric foot shock on mice for 17days. Oral administration of MAP was found to prevent the atrophy of body weight and immune apparatus weights. The stress-induced disturbances in cellularity were also restored by MAP administration in both thymus and spleen. In addition, MAP treatment improved lymphocytes proliferation induced by several antigens. The model antigen OVA-peptide was designed to examine the restoration effects of MAP in terms of specific immunity. The oral administration of MAP considerably improved the proliferation of OVA-specific CD4+T cells. We also found that MAP treated mice generated more potent ova specific cytotoxic T cells compared to MAP untreated group. In a sense of humoral immunity, OVA specific IgG production level was increased by the oral administration of MAP. According to the analysis of stress-related hormones including dopamine, serotonin and corticosterone, the oral administration of MAP tends to reduce the changes in hormone levels between the stressed and unstressed groups. Lastly, elevated plus-maze (EPM) test showed the anxiolytic effects of MAP in stressed mice. These results consistently demonstrate that oral administration of MAP could increase host defense toward chronic stress induced by electric foot shock.
Identification of polarized macrophage signatures (INM1P.439)
Authors: Guerau-De-Arellano Mireia , Jablonski Kyle , Amici Stephanie , Popovich Phillip 
Published: January 2023

Abstract
Pro-inflammatory (M1) macrophages are implicated in inflammatory diseases while pro-regenerative (M2) macrophages may be beneficial in Central Nervous System disorders. To modulate these phenotypes for therapeutic purposes, we need further understanding of the signaling pathways that define and distinguish M1 versus M2 macrophages. Here, we investigated the signature, i.e., the patterns of gene up/down-regulation, associated with mouse M1 and M2 polarized macrophages through cDNA microarray. The M1 macrophage signature was formed by 629 up-regulated and 732 down-regulated genes while M2 macrophage up-regulated 388 genes and down-regulated 425 genes. Additional analyses revealed that differentiation into M1 or M2 macrophages shared 81 up-regulated and 125 down-regulated genes which we consider to be linked to macrophage activation. In contrast, we identified 548 genes unique to M1 and 307 genes unique to M2 macrophages, including canonical markers previously used to distinguish phenotypes. While some of these genes have been previously identified, novel candidate M1/M2 markers were identified and validated by Real-Time PCR analysis of independent datasets. Our data reveals that macrophage differentiation into opposing M1/M2 phenotypes is formed by a combination of common and distinct genes expression patterns and provides novel genes as candidate differential markers and therapeutic targets.
Natural cytotoxicity receptor NKp44 and NK - astrocyte interactions in HIV-associated neurocognitive disorders (INM1P.443)
Authors: Bowen Kelly , Borgmann Kathleen , Ghorpade Anuja , Mathew Porunelloor 
Published: January 2023

Abstract
NK cells play important role in immunity against pathogens and cancer. NK cell functions are regulated by inhibitory and activating receptors binding corresponding ligands on the surface of target cells. NK cells were shown to be recruited to the CNS following several pathological conditions. NK cells could impact CNS physiology by killing glial cells and by secreting IFN-g. Astrocytes are intimately involved in immunological and inflammatory events occurring in the CNS and reactive astrogliosis is a key feature in HIV-associated neurocognitive disorders (HAND). There is little data on NK-astrocyte interactions and ligands expressed on astrocytes that could impact NK cell function. Natural cytotoxicity receptors (NCRs) play critical role in the cytolytic function of NK cells. Here we have studied the expression and function of natural cytotoxicity receptor NKp44 upon NK-astrocyte interactions in the presence or absence of an HIV peptide (3S peptide) shown to induce NK cell killing of CD4+ T cells during HIV infection. Using a fusion protein consisting of the extracellular domain of NKp44 and human IgG Fc, we determined the expression of a novel ligand for NKp44 (NKp44L) on astrocytes. Incubation of astrocytes with 3S peptide downregulated NKp44L expression on astrocytes implicating protection from NK mediated killing. Thus, our study showed that NKp44 has a protective effect on astrocytes from NK cell mediated killing during HIV infection and impacts astrocyte role in HAND.
Contribution of adipocytes in the regulation of metabolic inflammation: the role of osteopontin (INM1P.429)
Authors: Lyroni Konstantina , Ieronymaki Eleftheria , Patsalos Andreas , Tsatsanis Christos 
Published: January 2023

Abstract
Adipose tissue is not only involved in energy storage but also functions as an immuno-regulatory organ that participates in the establishment of obesity-related chronic low-grade inflammation. In this work we questioned whether adipocytes themselves could acquire a pro- or anti- inflammatory phenotype and determine potential signaling molecules affecting this process. The results showed that MEF-derived adipocytes were activated by LPS or IL-4. Si-RNA library screening allowed the identification of signaling molecules regulating iNOS and Arg1 expression and showed that PPARγ STAT3 and Akt2 were central regulators. In vivo, we found adipocytes from Akt2-/- mice or from HFD-induced obese mice had increased expression of iNOS and Arg1 and the pro-inflammatory cytokine osteopontin (OPN). Surprisingly, genetic deletion of OPN resulted in increased responsiveness of adipocytes to LPS as determined by elevated expression of iNOS and NO production. Despite the increased NO production Arg1 and IL-10 were also higher in OPN-/- adipocytes suggesting that OPN affects additional signaling events that suppress adipocyte activation. Further analysis determined the signaling components affected by OPN that regulate inflammatory factors in adipocytes. Our findings suggest that adipocytes obtain pro- or anti-inflammatory properties, which are affected by obesity. OPN partly regulates the anti-inflammatory properties of adipocytes by initiating anti- inflammatory cascades.
Myeloid-derived suppressor cells contribute to maintaining allogeneic pregnancies (IRC4P.461)
Authors: Sinha Pratima , Carter Darryl , Ostrand-Rosenberg Suzanne 
Published: January 2023

Abstract
In pregnant women the fetus is an allograft and successful human pregnancies require maternal tolerance to fetal alloantigens. Myeloid-derived suppressor cells (MDSC) are potent inducers of T cell tolerance in tumor-bearing hosts. MDSC levels also increase during normal pregnancy; however, whether they mediate maternal tolerance is unknown. To investigate if MDSC are involved, female BALB/c (H-2d) mice were caged overnight with allogeneic C57BL/6 (H-2b) males. The following morning, females with vaginal plugs indicative of copulation, were started on an MDSC depletion regimen. MDSC-depleted mice produced no offspring, while 46% of control-treated mice had healthy litters. One of the mechanisms MDSC use to inhibit anti-tumor immunity is to down-regulate CD62L (L-selectin) on T cells and prevent T cell entry into lymph nodes and subsequent activation. To determine if a similar mechanism is operative during pregnancy, mice were treated with granulocyte colony stimulating factor (G-CSF), an inducer of MDSC. G-CSF-treated, but not control-treated, mice contained elevated levels of MDSC, and elevated levels of naïve, circulating T cells with reduced expression of CD62L. MDSC-depletion of G-CSF-treated mice restored CD62L expression. These results suggest that MDSC promote maternal-fetal tolerance, and that tolerance during successful pregnancies may be due to the failure of T cells to enter lymph nodes where they could become activated to fetal alloantigens.
NSAIDs inhibit NFkβ activation to prevent inflammation (IRC4P.602)
Authors: Johnson Annie , Myers Michael 
Published: January 2023

Abstract
Non-steroidal anti-inflammatory drugs (NSAIDs) control inflammation through reductions in Prostaglandin E2 (PGE2) levels. Recent work by this laboratory identified NSAID-induced changes in inflammatory gene expression that appear to be independent of changes in PGE2; however, the molecular mechanism is unknown. Our goal is to determine whether NSAIDs affect gene expression via inhibition of NFkβ. Knowledge of NSAID gene control will provide a mechanism for screening novel drugs claiming anti-inflammatory properties. RAW 264.7 cells transfected with a plasmid under NFkβ control to express Secreted Alkaline Phosphatase (SEAP) were pre-treated with NSAID concentrations ranging from 10-3 to 10-7 M and stimulated with 1μg/mL LPS for 24 hours. NSAIDs from the 5 major classes inhibited SEAP release at 10-3 M, while acetylsalicylic acid (ASA) and acetaminophen did not. HEK293 cells transfected with the same plasmid were pre-treated with flunixin, diclofenac, and ASA at concentrations from 10-3 to 10-7 M and stimulated with 10ng/mL TNFα for 24 hours. Diclofenac and flunixin decreased SEAP release at 10-3 M, whereas ASA failed to inhibit SEAP release. These results demonstrate that NSAIDs prevent SEAP release via NFkβ inhibition, suggesting a new target for novel NSAIDs. Experiments to confirm NSAID inhibition of NFkβ activation by measuring the release of p65 are underway. The results of this research may also provide a screening tool for novel NSAIDs.
Dendritic cells regulate human antibody responses to glycan antigens (IRC4P.449)
Authors: Mendoza Daniel , Xu Yi , Rodriguez-Barradas Maria , Lewis Dorothy , Orson Frank , Tweardy David , Corry David 
Published: January 2023

Abstract
Background. Glycans mediate host-pathogen interactions, cancer and autoimmunity. Glycan antigens directly activate B cells without T cell help to produce antibodies. The role of human dendritic cells (DC) in this process is unclear. We hypothesize that DC regulate human antibody responses to glycan antigens. We use pneumococcal polysaccharides (PS) as glycan antigens because PS are crucial determinants of bacterial virulence and are targeted by existing vaccines. Methods. We incubated PBMC of healthy adults with various PS to identify responding B cell subsets by flow cytometry. We incubated isolated B cells with PS with and without autologous monocyte-derived DC to measure IgG/IgM production by ELISA on day 6. We measured IL-8 in DC exposed to PS by flow cytometry, and uptake of fluorochrome-labeled PS by DC by confocal microscopy. Results. Plasmablasts expand in response to PS. B cells produced IgG to PS only in the presence of DC (B cells alone: 1; B cells+DC: 59 ug/ml, p=0.01). IgG production to PS required direct DC-B cell contact (transwell plates: 3, regular plates: 35 ug/ml, p=0.03). Results for IgM were similar. Percent of DC producing IL-8 to PS: media: 17%, PS: 24%, p&lt;0.02); PS was internalized by DC within 5 min and 16h later was at the DC-B cell interface. Conclusion. Human DC regulate antibody responses to PS. We have identified and essential role for DC in immune responses to glycan antigens with important implications for vaccine design and disease processes.
Effect of glycyrrhizin on the intratracheal infection of Klebsiella pneumoniae in NOD/scid IL-2Rγnull mice inoculated with alcoholic patient white blood cells (IRC4P.609)
Authors: Ito Ichiaki , Asai Akira , Ohama Hideko , Tsuchimoto Yusuke , Suzuki Sumihiro , Kobayashi Makiko , Suzuki Fujio 
Published: January 2023

Abstract
Humanized mice created with alcoholic patient white blood cells (patient chimeras) are extremely susceptible to infection with K. pneumoniae. M2Mϕ in patient WBC are responsible for impairing the host antibacterial response of the chimeras. Since glycyrrhizin is known as an inhibitor of M2Mϕ activities, in this study, the effect of glycyrrhizin on K. pneumoniae infection in these chimeras was investigated. Patient chimeras (γ-irradiated-NOD/scid IL-2Rγnull mice inoculated 5 x 106 cells/mouse of alcoholic patient WBC) were infected intratracheally with 100 CFU/mouse of K. pneumoniae, and treated with 10 mg/kg of glycyrrhizin (48 hours before and 2 h after infection, Minophargen Pharmaceutical Co., Ltd., Tokyo, Japan). In the results, severe bacterial growth was demonstrated in the liver (2.7 x 107 CFU/g organ), kidney (2.9 x 107 CFU/g organ), and spleen (1.4 x 109 CFU/g organ) of patient chimeras 24 h after the infection. Contrarily, only 0.15 - 6 x 104 CFU/g organ of the pathogen were detected in these organs of patient chimeras treated with glycyrrhizin. Similarly, bacterial growth was minimal in the organs of healthy chimeras (γ-irradiated-NOD/scid IL-2Rγnull mice inoculated with healthy donor WBC). These results suggest that K. pneumoniae infections in alcoholics may be controllable by glycyrrhizin, an inhibitor of M2Mϕ activities.
Supraphysiological myeloid cell activation during mycobacterial immune reconstitution inflammatory syndrome (IRC4P.456)
Authors: McBerry Cortez , Sakai Shunsuke , Kauffman Keith , Barber Daniel 
Published: January 2023

Abstract
Anti-retroviral therapy (ART) of HIV-infected individuals usually leads to clinical improvement, but some individuals develop a worsening of symptoms following ART, referred to as Immune Reconstitution Inflammatory Syndrome (IRIS). CD4 T cells are thought to be a primary mediator of this paradoxical disease and recent work in patients has correlated activated monocytes with the development of IRIS. Here we use a mouse model of Mycobacterium avium associated IRIS to examine myeloid cell responses in IRIS. We find that CD4 T cell reconstitution of chronically infected TCRaKO mice leads to large increases in neutrophils and Ly6C+ CCR2+ monocytes. Prior to CD4 T cell transfer, myeloid cells in chronically infected TCRaKO mice expressed less iNOS but higher TNF compared to WT mice. Within ~12 days after CD4 T cell reconstitution, multiple myeloid cell subsets dramatically upregulated iNOS and TNF reaching levels far above what is ever observed in WT mice at any time during infection. Transfer of IFNgKO CD4 T cells into chronically infected TCRaKO mice failed to drive myeloid cell expansion or increased function, and mice displayed greatly reduced signs of illness. These data indicate that progression of a chronic mycobacterial infection in the absence of CD4 T cell help predisposes myeloid cells to over respond to T cell stimulation when CD4 T cells are later introduced, indicating myeloid cell hyper responsiveness may underly the immunopathogenesis of IRIS.
Phenotypic models of T cell activation (IRC5P.627)
Authors: Lever Melissa , Maini Philip , van der Merwe P. , Dushek Omer 
Published: January 2023

Abstract
T cell activation is a crucial checkpoint in adaptive immunity, and this activation depends on the binding parameters between the T cell receptor (TCR) and peptide-MHC (pMHC) complexes as well as the dose at which the pMHC is presented. Despite extensive experimental studies, it still remains controversial as to how these parameters govern the resultant activation. We present the development of a model that captures the phenotype of T cell activation. This model is influenced by existing models in the literature as well as a quantitative dataset we have generated that probes T cell activation over wide range of pMHC binding parameters and doses. The dataset was generated by stimulating jurkats and primary cells transduced with a therapeutic high affinity T cell receptor with a panel of plate bound pMHC that are mutations of the HLA-A2 NYESO pMHC. These ligands have a 105-fold range in binding time for the TCR. Activation was quantified by measuring IL8 (jurkats) and IFN-ϒ (primary). We have observed from the data that there is an optimal ligand binding time that gives the most potent activation. Of further interest is the observation of an inhibition in T cell activation at high doses of pMHC presentation. Our analysis indicates that a kinetic proofreading with limited signalling mechanism combined with a negative signalling motif can produce this observed phenotype of optimal ligand binding time and optimal ligand dose.
Interleukin-33 is a mediator of murine familial hemophagocytic lymphohistiocytosis (IRC5P.629)
Authors: Rood Julia , Chu Niansheng , Kreiger Portia , Rao Sheila , Stelekati Erietta , Wherry E. , Behrens Edward 
Published: January 2023

Abstract
Familial hemophagocytic lymphohistiocytosis (FHL) is a life-threatening disorder caused by uncontrolled, systemic immune activation. The murine model, in which lymphocytic choriomeningitis virus (LCMV) infection of perforin knockout (PKO) mice triggers FHL, demonstrates that the disease is driven by an excess of interferon-γ (IFNγ)-producing LCMV-specific CD8+ T cells. While this overactive T cell response is thought to arise from excess antigen stimulation through the TCR, data from our lab suggest that non-TCR, MyD88-dependent signaling pathways may be equally important. We show that interleukin-33 (IL-33), a cytokine released by damaged tissue, plays a critical role in driving FHL. LCMV-infected PKO mice receiving IL-33 receptor-blocking antibody (α-IL-33R) show markedly improved survival compared to isotype-treated controls (p=0.0005) and reduced severity of multiple disease parameters, including serum IFNγ (p=0.0005). α-IL-33R-treated mice have fewer gp33-specific CD8+ T cells (p=0.0044) and total effector CD8+ T cells (p&lt;0.0001). IL-33R blockade also reduces the frequency and IFNγ MFI of IFNγ+ gp33-specific CD8+ T cells (p=0.0004 and p=0.0016, respectively). We observe similar effects on LCMV-specific CD4+ T cells, as well. These data demonstrate that disruption of IL-33 signaling in the murine model of FHL reduces T cell-mediated production of IFNγ, leading to improved morbidity and mortality, and suggest blockade of this pathway as a viable treatment strategy for FHL.
Effect of 1,25(OH)2D3 on in vitro differentiation of human naïve and CD4+ T cells to Th17 and Treg subsets (IRC5P.630)
Authors: Fawaz Lama , Mrad May , Sayegh Souraya , Kazan Jalal , akika reem , Khoury Samia 
Published: January 2023

Abstract
The balance between Th17 and Tregs influences the pathogenesis of autoimmune diseases. The active form of vitamin D, 1α,25-dihydroxyvitamin D3, was shown to exert anti-inflammatory effect. The aim of this study is to investigate the effect of vitamin D on the differentiation of naïve and total CD4+ T cells into pathogenic Th17 subset and regulatory T cells ex-vivo in healthy controls, and to characterize their phenotype and its modulation by vitamin D. Purified naïve and total CD4+ T cells were activated in Th17 and Treg polarizing conditions in the presence or absence of 1,25(OH)2D3 for 6 days. Cells were processed for multiparameter staining and flow cytometry, and cell culture supernatants were reserved for cytokine quantitation by cytometric bead array for IL-17A, IL-10, IL-6, TNF-α, IL-2, IFN-γ, and IL-4. In Th17 cell cultures, overall expression of CCR6 and the percentage of CCR6+IL-17A+CD4+ T cells is decreased with Vitamin D. Interestingly, IL-23R and IL-23R+IL-17A+ cells, as well as IL-17+IFN-γ+ cells associated with pathogenic Th17 cells are reduced, while Foxp3+ cells are increased. In the presence of vitamin D, Treg polarized CD4+ T cells upregulated CD25 and CTLA4 expression but not Foxp3. Foxp3 expression was reduced in both CD25hi and CD25lo cells. Cytokine analysis by CBA and Treg suppression assays are underway. Results obtained thus far point to an effect for Vitamin D in reducing pathogenic Th17 cells, and modulating the induction of regulatory T cells.