bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heat shock proteins initiate DNA methylome remodeling to drive dichotomous immune responses. (VAC13P.1127)
Authors: Kinner Lauren , Binder Robert 
Published: January 2023

Abstract
Immunization with heat shock proteins (HSPs) can elicit dichotomous immune responses that are dependent on the dose administered. These responses are characterized by Th1 and Treg cells with low and high dose HSP respectively. The immune responses in either situation are dependent on dendritic cells (DCs) expressing HSP receptor CD91, but the exact mechanism controlling them are unresolved. Here, we focus on the molecular events which control gene transcription and drive this dose-dependent dichotomy. Our data demonstrates that HSP-CD91 signaling results GSK3β phosphorylation which stabilizes DNA methyltransferase (DNMT) levels. DNMTs control the epigenetic state of cells and thus regulate gene transcription and splicing. Thus, we hypothesize that HSP-CD91 signaling induces epigenetic remodeling in a dose-dependent manner, which drives cellular responses. We have mapped the DNA methylome of CD91+ cells following low and high dose HSP immunization. Differential methylation was observed across 229 gene regions in isolated CD91+ cells. These regions include genes involved in chemotaxis, signaling, and metabolism. We also show that neuropilin-1 (Nrp1) is differentially regulated in immunized mice. These studies reveal an early requirement for epigenetic changes and a role for Nrp1 in maintaining a Treg response to HSP.
Ebola virus matrix protein trafficking and cellular innate immune response (VIR9P.1149)
Authors: Subbiah Elankumaran , Sooryanarain Harini 
Published: January 2023

Abstract
Ebola virus (EBoV), a negative sense ssRNA virus (NSV) of family Filoviridae, causes severe hemorrhagic fever in humans, with case mortality rates up to 90%. Recent outbreak in 2014 of Ebola virus disease resulted in over 7500 deaths in West Africa. The viral matrix protein (VP40), is a structural protein involved in virus assembly and budding. Several studies have shown NSV matrix proteins are capable of nucleo-cytoplasmic shuttling (Newcastle disease, Nipah and Influenza) and modulate host innate immune response (Influenza and Marburg). Role of EBoV VP40 in disease pathogenesis remains elusive. Here, we analyzed the trafficking of VP40 and cellular innate immune response using wild type and mutant VP40 fused to EGFP. Our data shows that VP40 gets transiently localized to the nucleus at 6-10 h post-transfection with subsequent transport to the plasma membrane by 16-24 h. Blocking tyrosine phosphorylation by inhibiting phosphokinases or mutating tyrosine phosphorylation sites or blocking ubiquitination by a proteasome inhibitor prevent VP40 nuclear export, transport to the membrane and virus-like particle formation. We also found that VP40 expression lead to activation and nuclear translocation of pIRF3, STAT1 and NFkB (p50), and induced increased expression of LC3b at 24 h post-transfection. Our results suggest EBoV VP40 does not inhibit type I interferon pathway, and may have a potential role in disease pathogenesis by enhancing host inflammatory response and autophagy.
Pulmonary macrophage alterations associated with aging and SIV infection in rhesus macaques (VIR9P.1155)
Authors: Didier Elizabeth , Cai Y , Sugimoto C. , Liu D. , Midkiff C. , Walker E , Arainga M , Haupt E , Alvarez X , Fahlberg M , Kuroda Marcelo 
Published: January 2023

Abstract
Accelerated aging occurs in HIV-infected persons HIV, despite ART, as seen by earlier onset of chronic inflammatory diseases and HIV-associated non-AIDS (HANA) conditions than in non-HIV-infected individuals. In the rhesus macaque SIV model, we reported earlier that increasing monocyte turnover associated with tissue macrophage death predicted onset of terminal disease progression. Here, we hypothesize that macrophage dysregulation contributes to accelerated aging that occurs during SIV infection. We compared macrophage populations of the lung in older and younger uninfected and SIV-infected rhesus macaques. We observed that the ratio of alveolar macrophages (AM) to interstitial macrophages (IM) was significantly lower in chronic SIV-infected younger macaques and older uninfected monkeys compared to uninfected young macaques. The mechanisms differed, however, because the lower ratio in the older uninfected monkeys was due to lower numbers of AM while the shift during SIV infection of younger adults was due to increasing numbers of IM. Functionally, AM of older vs younger uninfected animals exhibited higher levels of pro-inflammatory cytokine secretion (TNFα, IL12) during incubation in medium yet produced lower levels of cytokines after induction with LPS ex vivo. During the acute phase of SIV infection, we observed a higher turnover of monocytes and IM in older compared to younger macaques. This suggests that AM become dysregulated during aging and SIV/HIV infection.
Toll-like receptor 8 signaling facilitates West Nile virus infection in mice (VIR9P.1161)
Authors: Paul Amber , Acharya Dhiraj , Le Linda , Stokic Dobrivoje , Leis A , Bai Fengwei 
Published: January 2023

Abstract
West Nile virus (WNV) is a neurotropic virus that can cause encephalitis, meningitis or possible death in humans. Human and mouse Toll-like receptor 7 (h/mTLR7) and human Toll-like receptor 8 (hTLR8) detect viral single-stranded (ss)RNA motifs. Importantly, mTLR7 recognizes WNV, as TLR7-/- mice are susceptible to lethal WNV infection. However, the role of TLR8 in WNV pathogenesis is not clear. In this study, we found that mice deficient in TLR8 (TLR8-/-) infected with WNV (2,000 plaque forming units) had improved percentage survival (65%) compared to wild-type (WT) controls (25%), which was coupled to reduced viral burden in the brains of TLR8-/- mice. These data suggest that TLR8 signaling facilities WNV infection in mice. Further mechanistic studies showed that expression of TLR7 and the interferon-induced anti-viral gene Isg-56 (IFIT-1) were significantly increased in TLR8-/- mice whole-brain samples and mixed neuronal cultures following WNV infection, compared to WT controls. These results indicate that TLR8 signaling may down-regulate TLR7 and Isg-56 expression, thus promoting WNV-induced neuroinvasive disease.
Activation of cellular innate immunity during primary hepacivirus infection (VIR9P.1137)
Authors: Manickam Cordelia , Reeves R. 
Published: January 2023

Abstract
Hepatitis C virus (HCV) is estimated to infect 170 million people worldwide causing global morbidity and mortality. The course of infection can either lead to natural resolution or chronicity, but the factors dictating these two phenotypes are poorly understood. In this study we utilized an understudied model of HCV infection, GBV-B infection of common marmosets, to characterize acute and chronic immune responses. Plasma viremia was detectable by day-3 post-infection (p.i.) and greater than 50% of animals remained viremic beyond day-28 p.i. In general, plasma viremia was correlated with elevated serum ALT, AST, ALP and GGT. Primary GBV-B infection was also associated with mobilization of innate natural killer (NK) and myeloid dendritic cells (mDCs), as evidenced by increased surface CXCR3 ­— suggesting trafficking to tissues, and increased intracellular Ki67 expression. Indeed, NK cell and mDC frequencies increased 2- to 5-fold in the liver associated with high viral loads at day-14 p.i. Additional cell accumulation was observed in mesenteric lymph nodes and spleen. Functionally, NK cells demonstrated increased expression of intracellular perforin during acute infection, but had no obvious changes in IFN-g or TNF-a secretion. These data indicate the accumulation of innate cells occurs well before development of adaptive T and B cell responses and is associated with virus clearance, suggesting innate cells could be targeted in future vaccine and immunotherapeutic modalities.
How filovirus innate immune antagonists abrogates maturation of human monocyte-derived dendritic cells (VIR9P.1141)
Authors: Yen Benjamin , Basler Christopher 
Published: January 2023

Abstract
Filoviruses, which includes both Ebolavirus (EBOV) and Marburgvirus (MARV), are negative-sense, single-stranded RNA viruses that cause severe hemorrhagic fever in humans with fatality rates that have approach 90% in some outbreaks. Antigen presenting cells such as dendritic cells (DCs) are early and sustained targets of filovirus infection in vivo, and in vitro filovirus infection potently blocks DC maturation and function. Both EBOV-VP35 and MARV-VP35 proteins block IFN-β production, in part, by inhibiting of the viral RNA sensor RIG-I. Further, EBOV-VP24 can inhibit the production of interferon-stimulated genes (ISGs) by blocking type I IFN signaling. We used a lentivirus-based expression system to determine the impact of these filoviral innate immune inhibitors on DCs. Our data demonstrate that EBOV-VP35 and MARV-VP35 can each suppress not only IFN-α/β production but also proinflammatory responses following stimulation of MDDCs with Sendai virus (SeV) or encephalomyocarditis virus (EMCV). Furthermore, either EBOV-VP35 or MARV-VP35 alone is sufficient to inhibit human DC maturation upon SeV infection. EBOV-VP24, despite having the ability to suppress ISG production, fails to block DC maturation induced by SeV or EMCV. Our work suggest that suppression of innate immune response by filoviral VP35s is sufficient to explain the potent blockade of DC function seen in filovirus infection and could be a potential the immune blockade during infection.
Increased activated platelet-T cell conjugates in patients with HIV infection: relationship between coagulation/inflammation and T cells. (VIR10P.1171)
Authors: Green Samantha , Smith Mindy , Hasley Rebecca , Stephany David , Harned Adam , Nagashima Kunio , Imamichi Tomozumi , Qin Jing , Rupert Adam , Ober Alexander , Lane H. , Catalfamo Marta 
Published: January 2023

Abstract
While antiretroviral therapies can successfully suppress HIV replication, there remains evidence of persistent immune activation, which is correlated with increased risks of all-cause mortality. Patients with elevated biomarkers of coagulation/inflammation such as IL-6, sCD14 and D-dimer (a fibrin bioproduct) are at an increased risk to develop non-AIDS defining illnesses such as cardiovascular disease. The interaction between the coagulation system and the immune system is critical for host defense; however, in HIV infection, the mechanisms underlying the ongoing activation of these pathways remains poorly understood. We hypothesized that interaction between platelets and T cells may play a role. We found that platelets from healthy controls and HIV infected patients bind to CD4 and CD8 T cells, preferentially to those with memory phenotypes. HIV infected patients showed a higher proportion of activated platelet (CD42b+CD62P+)-T cell conjugates and significantly correlated to the D-dimer levels. In vitro thrombin stimulation of PBMCs enhanced formation of platelet-T cell conjugates mediated in part by CD62P released by platelets. These data suggest that platelets can promote trafficking of T cells into injured tissues by upregulation of CD62P leading to enhanced rolling of leukocytes along vascular endothelium. In HIV infected patients, recruitment of T cells by this mechanism may promote a state of inflammation/coagulation and contribute to the pathology of the disease.
Gene expression profiling of citrulline-specific B cells in rheumatoid arthritis (BA3P.118)
Authors: Mahendra Ankit , Agarwal Sandeep , Varadarajan Navin 
Published: January 2023

Abstract
Rheumatoid arthritis (RA) affects ~1% of the world’s population and is the most common autoimmune disease afflicting humans. The elicitation of anti-citrulinated protein antibody (ACPA) responses, has been a major milestone for both the detection and treatment of RA. Given the significance of ACPA in RA, B cells have a central role in the progression of the disease. The identification of the differentiation state and phenotype of autoreactive B cells (ABC) is significant from both a fundamental standpoint in understanding autoimmune biology and from a clinical standpoint in providing new avenues to targeting ABCs. In order to identify novel biomarkers targeting ABCs, we have undertaken comprehensive gene expression profiling of citrulline-specific autoreactive B cells isolated from the peripheral blood of RA patients. We demonstrate the ability to selectively isolate autoreactive B cells for single-cell gene expression profiling. The frequency of citrulline-specific B cells was 0.012 % of the PBMCs. The specificity of the mAb isolated using our approach was confirmed using ELISA. We have undertaken whole transcriptome amplification and single-cell gene expression, and by comparison to pathogen-specific B cells, describe sets of genes that may be used to uniquely define ABCs. We anticipate that the key biomarkers identified from these genes will further improve our understanding of autoimmune pathology and will be evaluated for their clinical relevance.
B cell antigen presentation is sufficient to drive neuro-inflammation in an animal model of multiple sclerosis (BA3P.120)
Authors: Parker Chelsea , Archambault Angela , Sim Julia , Ferris Stephen , Mikesell Robert , Linington Christopher , Russell John , Wu Gregory 
Published: January 2023

Abstract
B cells are increasingly regarded as integral to the pathogenesis of multiple sclerosis (MS). Several B cell-dependent mechanisms contributing to inflammatory demyelination of the central nervous system (CNS) have been explored using the CD4 T cell-dependent animal model for MS, experimental autoimmune encephalomyelitis (EAE). While B cell antigen presentation has been suggested to regulate CNS inflammation during EAE, no direct evidence that B cells independently support antigen-specific autoimmune responses by CD4 T cells in EAE exists. Using a newly generated murine model of in vivo conditional MHCII expression, we previously reported that encephalitogenic CD4 T cells are incapable of inducing EAE when B cells are the only antigen presenting cell expressing MHCII. Using this system we now find that B cells cooperate with dendritic cells to enhance active EAE severity resulting from myelin oligodendrocyte glycoprotein (MOG) immunization. Further, increasing the frequency of MOG-specific B cells, but not supplementation with soluble MOG-specific antibody, is sufficient to drive EAE in mice expressing MHCII solely by B cells. By temporally regulating MHCII expression in MOG-specific B cells, we find induction of EAE reliably occurs upon expression of MHCII. These data support a model in which the expansion of antigen-specific B cells during CNS autoimmunity amplifies cognate interactions between B and CD4 T cells and drives neuro-inflammation at later stages of disease.
BANK1 transgenic mice exhibit lupus-associated B cell phenotypes (BA3P.105)
Authors: Pathak Simanta , Guo Yuyuan , Ding Huihua , Du Yong , Min Soyoun , Vanarsa Kamala , Li Quanzhen , Kozyrev Sergey , Alarcón-Riquelme Marta , Mohan Chandra 
Published: January 2023

Abstract
BANK1 is a B-cell adaptor protein that has been implicated in SLE and systemic sclerosis. Previous studies have interpreted that the overexpression of the full length BANK1 isoform plays a pathogenic and the truncated (∆BANK1) version plays a protective role in lupus. However, there is no mechanistic evidence showing that these 2 isoforms can impact lupus development differentially. We have recently generated 2 transgenic strains on the B6 background, BANK1Tg and ∆BANK1Tg, which will be used to address this knowledge gap. The BANK1Tg mice overexpressing the full length Bank1 under the control of CD19 promoter exhibited a dramatic skewing in the splenic B cell population to MZ and B1a cells with a reduction in FO B cells. These mice also exhibited increased plasma cells along with an increased level of total IgM and anti-dsDNA IgG antibodies. Microarray analysis revealed increased transcript levels of several class switched IgG antibodies with a concomitant increase in the level of activation induced deaminase (AID), a master regulator of class switch recombination (CSR). qPCR confirmed higher level of AID and CSR. Interestingly, these phenotypes are observed only in female Tg mice. In contrast, the ∆BANK1Tg mice don’t exhibit the above phenotypes, supporting the hypothesis that the truncated isoform may play a protective role. These studies indicate that the different isoforms of BANK1 observed in humans contribute differentially to the development of B-cell autoimmunity.
Identifying the cellular interactions that result in autoantibodies to insulin in type 1 diabetic autoimmunity (BA3P.112)
Authors: Wan Xiaoxiao , Thomas James , Unanue Emil 
Published: January 2023

Abstract
The presence of insulin autoantibodies (IAAs) is a consistent feature of patients with type 1 diabetes and non-obese diabetic mice. The mechanisms underlying their production and pathogenic role are poorly understood. IAA production is unexpected because insulin-reactive B (INS-B) cells are maintained in a tolerant state. Furthermore, the source of T cell help required for IAA production is limited because T cells recognizing insulin are deleted in the thymus, and those that escape thymic selection only recognize insulin peptides but not native insulin. Increased titers of IAAs to native insulin were found in a T cell receptor transgenic strain, 8F10, whose T cell reactivity is restricted to insulin peptides. The 8F10 T cell only recognizes peptides from insulin that are found in abnormal granules of beta cells. Furthermore, when an insulin B cell receptor heavy chain transgene was introduced into the 8F10 mice, a marked increase in IAAs specific for native insulin was observed. We found that 8F10 T cells differentiated into follicular helper T cells and selected the insulin specific B cells, helping them to differentiate in germinal centers (GC). These changes took place in lymph nodes at various sites. The results suggest that blood insulin was being taken up by the high affinity BCR for insulin and processed there for presentation to the T cells. Thus, pathogenic insulin-reactive T cells are able to reinforce B cell autoreactivity through unusual T-B cell interactions.
The upregulation of genomic imprinting DLK1-Dio3 miRNAs in lupus-prone mice is associated with DNA hypomethylation (BA4P.133)
Authors: Dai Rujuan , Lu Ran , Ahmed S Ansar 
Published: January 2023

Abstract
Epigenetic factors such as DNA methylation and microRNAs (miRNAs) regulation are now increasingly recognized as vital contributors to lupus pathogenesis. Our recent studies revealed a large cluster of miRNAs, which is located at the genomic imprinted DLK1-Dio3 domain was dramatically increased in splenocytes from MRL-lpr mice when compared to control MRL mice. In this study, we found that MRL-lpr mice have reduced DNA methylation levels in whole splenocytes and also in purified splenic CD4+ T and CD19+ B cells when compared to MRL control, which was associated with the upregulation of DLK1-Dio3 miRNAs in lpr lupus cells. DNA demethylation treatment with 5-Aza-2’-deoxycytidine significantly increased DLK1-Dio3 miRNAs in splenic cells (especially Con A-activated cells) from MRL mice, but not MRL-lpr mice. This data further confirmed the contribution of DNA hypomethylation to the augmented expression of DLK1-Dio3 miRNAs in lupus splenic cells. Although the contribution of DLK1-Dio3 miRNAs to autoimmune disease remains unknown, our preliminary data revealed that inhibition of selected DLK1-Dio3 miRNA such as miR-379 reduced LPS-induced IFNγ in MRL-lpr splenocytes, suggesting a role of miR-379 in the regulation of inflammation. Together, our data is the first to show DNA methylation regulation of genomic imprinting DLK1-Dio3 miRNAs in autoimmune lupus, which may provide novel insight into epigenetic mechanisms in lupus pathogenesis.
PPARγ controls effector T cell functions to prevent autoimmunity in gender different way (BA4P.135)
Authors: Park Hong-Jai , Kim Do-Hyun , Kim WonJu , Choi Je-Min 
Published: January 2023

Abstract
Peroxisome proliferator-activated receptor gamma (PPARγ) is a nuclear receptor that regulates lipid and glucose homeostasis. Although several studies have demonstrated the intrinsic roles of PPARγ in adaptive immunity, its regulatory functions in T cells are not fully elucidated and controversial. We investigated the role of PPARγ in effector T cell functions in CD4-PPARγKO mice and analyzed the mice phenotype. Interestingly, mild autoimmune phenotypes with increase of follicular helper T cells, germinal centers, and auto-antibody production were found in female CD4-PPARγKO mice, however the male mice did not show any significant phenotypes. Whereas female PPARγ-deficient T cells were hyper-reactive to TcR stimulation to produce more cytokines and to proliferate vigorously, the male PPARγ-deficient T cells produced less or comparable cytokines. This gender different response might be due to the decreased expression of Bcl-2 and IL-7Rα in male PPARγ-deficient T cells, and diminished estrogen receptors (ERs) expression in female PPARγ-deficient T cells. Additionally, PPARγ agonist pioglitazone treatment showed selective inhibition on male Th17 cells while it showed pan-decrease of all effector T cell differentiation including female Th1, Th2, and Th17 cells. Collectively, these results suggest that PPARγ has a gender difference in the regulation of effector T cell functions and suggest different strategy is needed for the autoimmune therapeutics for specific gender.
p21 suppresses autoimmunity by regulating ERK1/2 phosphorylation, NF-κB activation and IFNγ production in hyperactivated T cells (BA4P.141)
Authors: Balomenos Dimitrios , Vazquez-Mateo Cristina , Weber Kathrin , Martínez-A Carlos 
Published: January 2023

Abstract
Peripheral tolerance is essential for suppressing autoimmunity and depends on the regulation of T cell activation, proliferation and apoptosis. p21, known originally as a cell cycle inhibitor, is implicated in effector/memory T cell responses and is considered a suppressor of lupus-like autoimmunity. However, the mechanism by which p21 regulates T cell responses and autoimmunity remains unknown. We investigated these questions by studying T cells of C57BL/6 p21-/- and C57BL/6-lpr p21-/- mice. p21 regulated activation of repeatedly stimulated effector/memory T cells in a cell cycle-independent manner, but had no effect on naïve T cells. We identified a previously non-described role for p21, in controlling T cell activation via downstream MAPK and NF-κB pathways in the cytoplasm. Lack of p21 caused hyperactivation of ERK1/2 and NF-κB in reactivated T cells. Importantly, p21-deficiency led to increased IFNγ production due to an effect of p21 on the IL-12- and IL-18-dependent IFNγ induction. Stimulation of TCR-transgenic T cells with specific antigens in vivo confirmed that p21 is involved in effector/memory T cell activation. Lack of p21 dramatically increased the mild lupus symptoms of C57BL/6-lpr mice to full-blown disease and death in C57BL/6-lpr p21-/- mice. The mechanism by which p21 regulates disease severity was based on its control of T cell activation and IFNγ production. Analysis of these p21 functions might be of therapeutic value for Lupus.