bluuebunny/crossref_metadata_2025_split huggingface dataset:
Persistence of cognate antigen dictates effector T cell localization, phenotype, and function during pulmonary tuberculosis (MUC5P.860)
Authors: Moguche Albanus , Larson Ryan , Shafiani Shahin , Clemons Corey , Urdahl Kevin 
Published: January 2023

Abstract
How Mycobacterium tuberculosis (Mtb) evades eradication from the lung despite an apparently robust Th1 response remains poorly understood. We addressed this question using MHCII tetramers to monitor Mtb-specific CD4 T cells in the mouse model. We found that the location, phenotype, and functional capacity of T cells specific for distinct Mtb epitopes differ, and depend upon the expression profile of the specific Mtb antigen recognized. Terminally differentiated Th1 cells (defined by their high expression of the transcription factor T-bet, the inhibitory receptor KLRG1, and an enhanced ability to produce IFN-γ) specific for Mtb ESAT-6, an antigen expressed throughout infection, were surprisingly found to reside in the lung-associated vasculature rather than the lung parenchyma. Those ESAT-6-specific effector T cells within the parenchyma had a reduced capacity to proliferate and produce IFN-γ. In contrast, T cells specific for Mtb Ag85B, an antigen with limited expression during chronic infection, were found to reside primarily within the lung parenchyma and to proliferate and produce IFN-γ robustly. Our results refute the long-held belief that Mtb persists despite an abundance of functional Mtb-specific Th1 cells within the lung, and suggest that only T cells that recognize Mtb antigens with limited expression during chronic infection retain their functional capacity. These findings have obvious implications for vaccine and immunotherapeutic approaches for tuberculosis.
Irgm1 regulates the pulmonary innate immune response (MUC5P.864)
Authors: Azzam Kathleen , Madenspacher Jennifer , Lai Lihua , Gowdy Kymberly , Clayton Natasha , Cunningham Willie , Janardhan Kyathanahalli , Taylor Gregory , Fessler Michael 
Published: January 2023

Abstract
Irgm1 is an IFN-inducible GTPase that mediates host resistance to a variety of intracellular pathogens, and also modulates the LPS response in cultured macrophages. Whether Irgm1 regulates innate immune lung responses and controls host defense against extracellular pathogens is undetermined. We hypothesized that Irgm1 would regulate host defense against extracellular bacteria that cause pneumonia. Compared to wildtype, naïve Irgm1-/- mice had elevated expression of cytokines and chemokines in the lung parenchyma and bronchoalveolar lavage fluid, consistent with steady state inflammation. Moreover, naïve Irgm1-/- lungs displayed abnormal bronchiolocentric lymphocytic infiltration. Compared to wildtype, Irgm1-/- mice had increased influx of PMNs into the airspace after exposure to LPS and S. pneumoniae, but not K. pneumoniae. Bronchoalveolar lavage fluid chemokines, cytokines, and protein concentration (marker of microvascular injury) were all higher in Irgm1-/- mice after LPS and S. pneumonia. Irgm1-/- mice had lower lung CFUs after infection with S. pneumoniae, indicating enhanced pathogen clearance. Irgm1-/- mice also had increased survival after lung infection with S. pneumoniae but not K. pneumonaie. In conclusion, Irgm1-/- mice have an enhanced lung response to LPS and S. pneumoniae, but not K. pneumonaie, implicating a selective role for Irgm1 in host defense. Whether these responses derive from the Irgm1-/- basal lung phenotype is yet to be determined.
Therapeutic efficacy of baicalin on experimental autoimmune encephalomyelitis through down-regulation of JAK-STAT and NF-κB signaling pathways (THER3P.876)
Authors: Zhang Guang-Xian , Zhang Yuan , Li Xing 
Published: January 2023

Abstract
Baicalin (Ba) is a bioactive flavonoid compound derived from the root of Scutellaria baicalensis. It is widely used for the treatment of various inflammatory diseases in traditional Chinese medicine. In this study, we demonstrated that Ba was efficacious in experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis. Treatment with Ba led to amelioration of disease severity in myelin oligodendrocyte glycoprotein-induced EAE, which correlated with reduced spinal cord inflammation and demyelination. The underlying mechanism of Ba-induced effects involved prevention entry of immune cells into the CNS, inhibition of Th1 and Th17 cell differentiation through JAK/STAT and NfκB signaling pathways, and reduction of proinflammatory molecular and chemokine expression. Ba treatment completely abolished the pathogenic Th17 cells responses to MOG35-55 in an adoptive transfer EAE model, and the same treatment significantly inhibited the ability of MOG 35-55-reactive Th1 cells to induce EAE. This study provides new evidence that natural compounds, such as Ba, are of great value in the search for novel anti-inflammatory agents and therapeutic targets for autoimmune diseases.
Ursolic acid ameliorates experimental autoimmune encephalomyelitis by regulating Th1 and Th17 cell differentiation (THER3P.877)
Authors: Zhang Guang-Xian , Li Xing , Zhang Yuan 
Published: January 2023

Abstract
Ursolic acid (UA) is a plant-derived triterpene with potent anti-inflammatory and immunomodulatory activities. In this study we investigated the potential therapeutic effect of UA on the experimental autoimmune encephalomyelitis (EAE), an accepted experimental model of multiple sclerosis. Treatment with UA at initiation or after the disease onset reduced clinical severity and incidence of EAE, which was associated with a decrease in inflammatory infiltrates in spinal cord and in the subsequent demyelination. UA decreased the presence/activation of encephalitogenic Th1 and Th17 cells in both periphery and nervous system, accompanied by down-regulated various inflammatory cytokines and chemokines. The effect of UA was attributable to its selective inhibition of IFN-γ and IL-17 production in CD4+ T cells, mediated via alteration of the STAT pathway and the transcription factors T-bet and RORγt/ROR α. More important, UA has been found novel properties of directly inhibiting Th1 and Th17 cell differentiation in vitro, and was also effective in reducing ongoing paralysis induced by adoptive transfer of either pathogenic Th1 or Th17 cells. These findings indicate that UA exerts potent anti-inflammatory effects through selective modulation of pathogenic Th1 and Th17 cells by targeting critical signaling pathways.
A mechanistic understanding of the selective clearance of encephalitogenic T cells (THER3P.882)
Authors: McNally Jonathan , Elfers Eileen , Millin Scott , Terrell Catherine , Jordan Michael , Hildeman David , Katz Jonathan 
Published: January 2023

Abstract
Most therapeutic approaches to control multiple sclerosis (MS) target autoimmune effector cells via broad spectrum immunosuppression. In contrast to this approach we have recently described a therapeutic intervention for the MS model experimental autoimmune encephalomyelitis (EAE) that selectively eliminates encephalitogenic T cells, while sparing protective naive and memory T cell responses. Here we report the mechanistic pathway by which our selective therapy acts. The specificity of action that targets encephalitogenic T cell is through the action of the drug, etoposide, which acts by targeting the double stranded break repair mechanism associated with highly activated T cells. In combination with differential expression of Bcl-2 family member leads to the preferential deletion of effector T cells over memory and naive T cells clearance. Based on our understanding of etoposide-mediated clearance of encephalitogenic T cells we expanded our findings to include other genotoxic and non-genotoxic agents that synergize to afford more specific and less toxic means of controlling autoimmunity. This study further defines the mechanism for the selective clearance of self-reactive T cells by establishing a mechanistic understanding and rational approach to the use of agents that target autoreactive T cells in vivo and result in novel and enhanced therapy for autoimmune diseases.
Myeloid-conditioning using Toll-like receptor agonists to restore immune potency against melanoma. (TUM4P.926)
Authors: Foureau David , Carpenter Kendall , Amin Asim , Guo Fei , White Richard , Salo Jonathan 
Published: January 2023

Abstract
Suppressor cells of myeloid origin contribute to the immune imbalance observed in advanced melanoma. Toll-Like Receptor (TLR) signaling regulates myeloid differentiation and maturation. This study sought to determine the distribution of myeloid suppressor cell subsets in B16F10 melanoma-bearing mice, and modulate their immunosuppressive phenotype by employing a regimen of intracellular TLR agonist(s). Tolerogenic dendritic cells (tDC) and granulocytic myeloid-derived suppressor cells (gMDSC) are primarily observed in the periphery (spleen, PBMC, draining lymph node) of B16F10-bearing mice whereas M2 macrophages (M2) are noted to be intratumoral. Toll-Like Receptor-expression analysis by quantitative PCR showed TLR9 was ubiquitously expressed on tDC, gMDSC and M2, while TLR3 was restricted to tDC and M2. Myeloid conditioning regimens employing TLR3 and 9 agonists were tested in vitro on bone marrow-derived tDC (CD11c+, MHCII+, IL-10+) and M2 (F4/80+, CD206+, Arg1+). Combinations of TLR3+9 agonists or Type A+B TLR9 agonists decreased IL-10/Arg1 mRNA expression while triggered IL-12 expression. In vivo, subcutaneous injection of type A+B TLR9 agonists reduced circulating tDC and gMDSC prevalence by 67% and 82% respectively, intratumoral M2 dropped by 35%. In conclusion, we demonstrate combining type A+B TLR9 agonists promoted immune potency by reducing prevalence of peripheral tDC and gMDSC, as well as tumoral M2 in vivo, and triggering IL-12 production by tDC and M2 in vitro.
Tumor-derived exosomes differentially modulate the adenosine pathway in human resting vs activated regulatory T cells (Treg) (TUM4P.927)
Authors: Muller Laurent , Mitsuhashi Masato , Jackson Edwin , Whiteside Theresa 
Published: January 2023

Abstract
Tumor-derived exosomes (TEX) suppress functions of human immune cells, while up-regulating functions of others. Here, we show that TEX isolated from supernatants of human cultured tumor cells or plasma of cancer patients differentially modify gene and protein expression of CD39, CD73 and adenosine receptors (ADORs) in Treg, influencing production of suppressive nucleosides. Resting or pre-activated (anti-CD3/CD28 Abs) CD4+CD39+ Treg were co-incubated overnight with TEX. Cellular mRNA was analyzed by qRT-PCR for expression of CD39, CD73, A1R, A2aR, A2bR and A3R genes. Protein expression was studied by flow cytometry and western blots. Nucleoside production by Treg ± TEX in the presence of 20µM ATP was measured by mass spectrometry. In resting Treg + TEX, mRNA expression of CD39/CD73 and ADORs was reduced relative to no TEX baseline (&gt;1 log) except for A1R mRNA expression which was elevated (&gt; 3 logs). CD39 protein expression was up-regulated, suggesting enhanced translation and signaling via A1R. Treg + TEX + ATP produced inosine only (7900ng/mL) and no 5’-AMP or ADO. In activated Treg +TEX, CD39/CD73 mRNA expression and protein levels were elevated (p&lt; 0.05) as was mRNA expression for all ADORs, especially A2aR, and ADO was produced. Thus, TEX differentially regulated gene expression and protein levels of the ADO pathway components in resting vs activated Treg. The TEX-induced shift from inosine to ADO production implies changes in Treg-mediated immunosuppression.
Novel pneumocystis antigen discovery and validation using RNA sequencing and proteomics (VAC7P.977)
Authors: Eddens Taylor , Elsegeiny Waleed , Zheng Mingquan , Cai Yang , Kolls Jay 
Published: January 2023

Abstract
Pneumocystis (PC) is a fungus that causes pneumonia in immunocompromised individuals and remains the most common serious opportunistic infection in individuals diagnosed with HIV. Furthermore, PC has re-emerged in the HIV-negative population, as patients on immunosuppressive therapies for transplantation or malignancy are increasingly susceptible to PC pneumonia. As the at-risk population increases, the discovery of conserved PC antigens could lead to the development of vaccines, enhanced diagnostic tests and monoclonal antibody therapies. To that end, we have used RNA sequencing of separated PC life forms and surface biotinylation of whole PC to identify differentially expressed surface antigens. Histone 2B (H2B) appears to be an extracellular antigen with increased expression in the cyst life form, while a GPI-anchored protein (GPI) is more abundant on the troph life form. We used DNA vaccination to assess the immunogenicity of these antigens followed by CD4 depletion and challenge with live PC. H2B vaccination resulted in a significant increase in PC-specific IgG. After PC challenge, H2B vaccinated mice had a significant half-log reduction in PC lung burden when compared to unvaccinated controls. Similarly, GPI vaccinated mice had an increase in PC- and GPI-specific IgG, while also having a half-log reduction in PC lung burden. Taken together, these results suggest that H2B and GPI are novel PC antigens with vaccine potential in need of further exploration.
Ablation of reactive oxygen species intensifies diabetogenic CD4 T cell effector responses in type 1 diabetes. (BA14P.210)
Authors: Padgett Lindsey , Tse Hubert 
Published: January 2023

Abstract
In Type 1 diabetes (T1D), infiltrating leukocytes secrete reactive oxygen species (ROS) and pro-inflammatory cytokines that collectively participate in β-cell destruction and enhance autoreactive T cell responses. Our lab previously demonstrated that superoxide-deficient Non-Obese Diabetic (NOD.Ncf1m1J) mice were T1D-resistant due to skewed T cell responses. To dissect the role of ROS on autoreactive T cells, we generated the NOD.BDC-2.5.Ncf1m1J mouse, possessing diabetogenic, superoxide-deficient CD4 T cells and hypothesized that like NOD.Ncf1m1J, dampening ROS would diminish autoreactive T cell responses. Surprisingly, IFN-γ was upregulated 2-fold by NOD.BDC-2.5.Ncf1m1J T cells compared to NOD.BDC-2.5 with polyclonal stimulation (p=0.0045). Transfer of activated NOD.BDC-2.5.Ncf1m1J T cells was more diabetogenic, as 63% of NOD.scid recipients (n=11, p=0.0662) by 9 days post transfer were hyperglycemic, in contrast to 17% of wild-type recipients (n=7). To mechanistically explain the exacerbated Th1 cytokine response and diabetogenicity, phosphorylation of lymphocyte-specific protein tyrosine kinase (P-Lck (Y505)) and linker for activation of T cells (P-LAT (Y191)), redox-sensitive T cell receptor (TCR) signaling molecules, was enhanced 2-fold by NOD.BDC-2.5.Ncf1m1J CD4 T cells compared to NOD.BDC-2.5. Future experiments will dissect the redox-sensitive cues that control TCR adaptor molecule activation, as unraveling these signals may pinpoint novel targets for T1D prevention.
The role of CdK5 in the activation and effector function of T cells in experimental autoimmune uveitis (BA14P.216)
Authors: Liu Qi , Kim Byung-Gyu , Lam Eric , Choi Sung Hee , Doller Catherine , Zhang Zili , Letterio John 
Published: January 2023

Abstract
The activation and survival of T cells are both essential for the development and progression of uveitis. Cyclin-dependent kinas 5 (Cdk5) is a unique member of Cdk family that forms a complex with p35 (CDK5R1) and modulates the function of many proteins through proline-directed serine threonine phosphorylation. Our previous study showed that Cdk5 expression and activity is induced during T cell activation, but it is unclear whether CdK5 is implicated in experimental autoimmune uveitis (EAU). In this study, we found that CD4+CD44+ T cells have a higher level of Cdk5 expression. Inhibition of CdK5 by a small molecule inhibitor (roscovitine) led to the decrease in the number of activated CD4+CD44+ T lymphocytes, which coincided with increased T cell apoptosis. We observed increased expression and activity of CdK5, p35 (and its cleaved product p25) in the eyes and lymphocytes of C57BL/6 mice induced to develop EAU by immunization with interphotoreceptor retinoid-binding protein peptide 1-20 (IRBP1-20). In addition, roscovitine significantly suppressed proliferation of and cytokine production in T cells from mice with the disease in vitro. These results demonstrate that CdK5 plays a critical role in T cell activation during the pathogenesis of uveitis and suggests that targeting CdK5 may be a novel therapeutic strategy for treating T cell-mediated uveitis.
Delineating the role of cardiac myosin-specific CD8 T cells in autoimmune myocarditis (BA15P.220)
Authors: Massilamany Chandirasegaran , Steffen David , Reddy Jay 
Published: January 2023

Abstract
Enteroviruses like coxsackievirus B3 are common suspects in patients with myocarditis/dilated cardiomyopathy. Previously, it was shown that autoreactive cytotoxic T lymphocytes, also called CD8 T cells, have a role in the mediation of myocarditis induced by coxsackievirus B3. But identification of their target antigens in cardiac tissues continued to be a challenge. We have discovered that CD8 T cells have the ability to induce myocarditis in A/J mice by recognizing cardiac myosin heavy chain-alpha (Myhc) as the target antigen. We have localized two peptides designated, trunk 4 and trunk 5 within Myhc that can stimulate CD8 T cells and CD4 T cells. Furthermore, expectedly, CD8 T cells recognizing the Myhc peptides produced predominantly, interferon-gamma and tumor necrosis factor-alpha, but not interleukin-17, and A/J mice immunized with the CD8 T cell epitopes, develop myocarditis by active immunization. It has been widely believed that Myhc-induced autoimmune myocarditis is a CD4 T cell-mediated disease. Our discovery creates a paradigm shift in the understanding of how cardiac damage can occur by multiple immune cells that recognize the same target antigens but through different mechanisms.
Modulating the tumor necrosis factor-α induced inflammatory response in human colonic epithelial cells by inhibiting NF-κB signaling (CCR5P.258)
Authors: Rivard James , James Amy , Wegner Greta , Reagan Kevin 
Published: January 2023

Abstract
In colonic epithelia, tumor necrosis factor alpha (TNF-α) secreted by inflammatory cells is a key mediator of inflammatory bowel disease. TNF-α is a well-characterized activator of the NF-κB signaling pathway in intestinal epithelial cells and is known to up-regulate the expression of a subset of chemokines and cytokines. In this study, we used antibody arrays to profile the relative changes in chemokines secreted upon activation of the human colon carcinoma cell line HT-29. Elevated levels of CXCL1, CXCL7, CXCL8, CXCL10 and CCL20 were observed in conditioned media after TNF-α treatment of HT-29 cells. To better understand the contributions of the classical NF-κB signaling pathway to TNF-α activation of HT-29 cells, we used an inhibitor with high selectivity for IKK2 over IKK1, TPCA-1. In addition, both classical and the alternative NF-κB signaling pathways were inhibited at a level downstream of IKK1 and IKK2 by using the NEDD8 activating enzyme (NAE)-inhibitor MLN4924. TPCA-1 and MLN4924 both attenuated TNF-α activated secretion of these chemokines in a dose dependent manner in HT-29 cells. Confirmation of these array data by quantitative ELISAs supports the use of arrays for analysis of inhibitor biomarkers.
PLZF supports the acquisition and maintenance of the Th17 phenotype in human cells (CCR5P.250)
Authors: Singh Satya , Zhang Howard , Tsang Hsinyi , Gardina Paul , Myers Timothy , Farber Joshua 
Published: January 2023

Abstract
All human Th17 cells express the chemokine receptor CCR6, making CCR6 a potential therapeutic target. We hypothesized that the variable levels of CCR6 expression on blood CD4+ T cells reflect a continuum of Th17 differentiation, and that regulators of Th17 differentiation could be identified by evaluating global changes in gene expression in cells with increasing levels of CCR6. We found that ZBTB16, which encodes the BTB-ZF transcription factor PLZF, was expressed at increasing levels from the CCR6- to CCR6bright subsets and was poorly expressed in Th1, Th2, and TFH cells. Knockdown of ZBTB16 mRNA down-regulated CCR6 and other Th17-associated genes such as RORC, IL17A, IL22, and IL23R in CCR6+ memory Th cells from blood and in naïve cells activated under Th17 conditions ex vivo. In naive Th cells from cord blood, ZBTB16 expression was limited to the CD161+, Th17 cell precursors. ZBTB16 was not expressed in mouse Th17 cells and Th17 cells could be made from luxoid mice. Using ChIP for modified histones, p300, and Pol II to analyze CCR6, we identified regulatory regions at -10 and -14 kb from the TSS. We detected PLZF binding at these sites in the CCR6+ cells, which was diminished in cells transfected with ZBTB16 siRNA. These studies demonstrate a novel role for PLZF as a transcriptional activator important both for Th17 differentiation and for the maintenance of the Th17 phenotype in human cells, and an expanded role for the BTB-ZF family in the human immune system.
Differential requirements of IL-17 family cytokines in host defense against oral candidiasis (CCR6P.272)
Authors: Whibley Natasha , Mamo Anna , Conti Heather , Traggiai Elisabetta , Kolbinger Frank , Vogel Beate , Kammueller Michael , Siebenlist Ulrich , Iwakura Yoichiro , Gaffen Sarah 
Published: January 2023

Abstract
Antibodies against IL-17A and IL-17RA are in clinical trials for autoimmunity. Mutations in IL-17 signaling genes (IL17RA, IL17F, ACT1) cause susceptibility to mucocutaneous infection by the fungus Candida albicans. IL-17A, IL-17F and IL-17C all signal via IL-17RA, but their individual roles in controlling candidiasis are poorly defined. Accordingly, in vivo Ab neutralization of cytokines or knockout mice were evaluated in a model of oropharyngeal candidiasis (OPC). Following C. albicans exposure, tongue fungal burden after 4 d, weight change and target gene expression were assessed. Anti-IL-17A-treated mice showed modestly impaired clearance compared to WT at d4, whereas α-IL-17F-treated mice were not affected. However, IL-17RA-/- and Act1-/- mice were far more susceptible to OPC than α-IL-17A treated mice at 4 and 14 d, indicating contributions to immunity beyond IL-17A. Susceptibility was associated with reduced expression of IL-17-regulated genes encoding chemokines and defensins. In contrast to α-IL-17A-treated mice, IL-17A-/- mice showed no significant susceptibility to OPC. This discrepancy was not explained by contributions from IL-17F or IL-17C, because α-IL-17F-treated IL-17A-/- mice and IL-17C-/- mice cleared the infection as well as WT mice. The increased susceptibility of IL-17RA-/- and Act1-/- mice vs. those lacking specific cytokines implies compensation between IL-17 family cytokines and possibly additional antifungal effectors. Funded by Novartis and NIDCR.