bluuebunny/crossref_metadata_2025_split huggingface dataset:
CD49a/b-based human natural killer cell subsets in the blood and the liver: phenotypic and functional characteristics (INC6P.312)
Authors: Song Youkyong , Kim Jong Hoon , Shin Eui-Cheol , Yoon Joo Chun 
Published: January 2023

Abstract
Natural killer (NK) cells in the mouse liver sinusoid are divided into CD49a+DX5(CD49b)- and CD49a-DX5+, whereas those in the blood are mostly CD49a-DX5+. We therefore investigated whether human NK cells are also separated into distinct subsets according to CD49a/b expression. Peripheral blood mononuclear cells (PBMC) and intrasinusoidal lymphocytes (ISL) from healthy human donors were used for phenotypic and functional characterization of NK cells. Primary human NK cells expressed CD49a and CD49b and could be split into four subsets: CD49a+CD49b-, CD49a-CD49b+, CD49a+CD49b+, and CD49a-CD49b-. Frequencies of human NK cell subsets, however, differed from mouse NK cell subsets, as majority of NK cells in human PBMC are CD49a-CD49b- or CD49a+CD49b-. NK cells in ISL expressed lower CD49b but higher CD49a than those in PBMC. In addition, CD49a+ subset showed higher affinity to collagen. CD49b+ NK cells expressed more activation marker CD69 and inhibitory receptor ILT2, indicating they are activated subsets. While degranulation capacity was not affected by CD49a/b expression, CD49a-b+ subset produced higher IFN-γ and CD49a+b+ subset expressed more TRAIL upon activation. In conclusion, human NK cells were divided into four subsets based on CD49a/b expression. It appeared that NK cells in the liver have higher capacity to bind to extracelluar matrix. Small amount of CD49b+ NK cell subsets with activated phenotype were found in the blood but healthy liver had few CD49b+ NK cells.
Function of M1-polarized macrophages in the pathogenesis of Parkinson’s disease (INC6P.300)
Authors: Qin Hongwei , Liu Yudong , Fox Thomas , Harms Ashley , Standaert David , Benveniste Etty 
Published: January 2023

Abstract
Parkinson’s Disease (PD) is an age-related, chronic neurodegenerative disorder. Activated microglia/macrophages is associated with the pathogenesis of PD. Accumulation of α-synuclein (α-syn) leads to microglial activation and neurodegeneration. We have recently shown that inhibiting the JAK/STAT pathway prevents inflammation and neurodegeneration by suppressing activation of immune responses, and iNOS, TNF-α and IL-6 expression in an a-syn overexpression PD model. Studies from patients and animal models suggest that M1-polarized macrophage activation promotes the loss of dopaminergic neurons. As such, we investigated the function of M1-polarized macrophages in PD, especially how aggregated a-syn affects M1 phenotype. Our results indicate that expression levels of IFN-γ-induced MHC Class II, CD40, iNOS, TNF-α and IL-6 are synergistically enhanced by α-syn stimulation, along with higher activation of STAT1 and STAT3. We have previously shown that macrophages deficient in SOCS3 have heightened STAT3 activation and M1 phenotype. Stimulation of SOCS3-/- macrophages with a combination of α-syn and IFN-γ promotes a more pronounced M1 phenotype that promote neuronal degeneration. We hypothesize that hyperactivation of JAK/STAT and M1 macrophages promotes more severe synucleinopathy, including neuroinflammation and neurodegeneration. The characteristics of PD pathology in SOCS3fl/fl and LysMCre-SOCS3fl/fl mice with α-syn overexpression is currently under investigation.
Increased expression of CD155 and CD112 on monocytes in septic patients (INC6P.327)
Authors: Yan Zhang 
Published: January 2023

Abstract
The poliovirus receptor CD155 and its family member CD112 (PRR-2 (poliovirus receptor-related family 2), also called nectin-2) are ligands for human and mouse CD226. Human CD112 and CD155 are broadly distributed on epithelial and endothelial cells in many tissues, and overexpressed on certain tumors. Several reports have shown that the interaction between CD155 and CD226 are important for the elimination of target cells by NK and cytotoxic T cells, however, it remains elusive how CD155 and CD112 are regulated in sepsis. In our study, we showed that the expression of CD155 and CD112 on monocytes was significantly upregulated in septic patients which all had a significant reduction in expression of HLA-DR on monocytes, an immunosuppression marker of sepsis, indicating the existence of negative correlation between CD155/122 and HLA-DR. Next studies were undergoing on the mechanisms underlying regulation of the expression of CD155 and CD112 in sepsis and whether signals by CD155/CD112 negatively regulated the expression of HLA-DR.
Alternatively activated brain-resident macrophages rapidly acquire inflammatory properties following CNS infection (INC6P.301)
Authors: Rua Rejane , McGavern Dorian 
Published: January 2023

Abstract
Classic (M1) and alternative (M2) polarization of macrophages has been broadly studied in vitro but its relevance in the context of meningeal inflammation is unknown. The meningeal and perivascular spaces of the central nervous system (CNS) are inhabited by specialized macrophages. To gain novel insights into these cells, we analyzed the naive and virally infected brain using intravital two-photon microscopy (TPM) and flow cytometry. Examination of the naive brain by TPM revealed that meningeal and perivascular macrophages are highly dynamic and constantly survey their immediate surroundings similar to microglia. Under steady state conditions, we uncovered that they are maintained in a M2 state, which likely facilitates brain homeostasis. Interestingly, during the development of fatal viral meningitis induced by lymphocytic choriomeningitis virus, these cells were directly engaged by infiltrating virus-specific CD8+ T cells following acquisition of viral antigen and conversion into an inflammatory M1 phenotype. Mechanistically, the M2 to M1 transition occurred in the absence of CD8+ T cells and relied instead on innate cytokine release. These data indicate that meningeal and perivascular macrophages are highly plastic cells that can rapidly convert from a M2 to M1 phenotype and participate in the antiviral defense against an invading pathogen. This rapid inflammatory transition may explain why most CNS immune responses first develop in the meningeal and perivascular spaces.
Specific deletion of TRAF3 in myeloid cells leads to spontaneous inflammation and tumor development in mice (INC6P.304)
Authors: Lalani Almin , Luo Chang , Morse Herbert , Xie Ping 
Published: January 2023

Abstract
TRAF3, a cytoplasmic adaptor protein, is used in signaling by the TNFR superfamily and pattern recognition receptors. A number of these receptors are constitutively or inducibly expressed by myeloid cells, the crucial players in innate immunity and inflammation. To investigate the in vivo functions of TRAF3 in myeloid cells, we generated myeloid cell-specific TRAF3-/- (M-TRAF3-/-; TRAF3flox/floxLysM+/Cre) mice. We previously showed that young adult M-TRAF3-/- mice have normal frequencies and numbers of lymphocyte and myeloid cell populations in lymphoid organs, suggesting that TRAF3 ablation did not affect the maturation or homeostasis of myeloid cells. Here we report that 15- to 22-month-old M-TRAF3-/- mice spontaneously developed chronic inflammation or tumors, often affecting multiple organs. Diseased M-TRAF3-/- mice exhibited drastically altered lymphocyte and myeloid cell populations in lymphoid organs. Furthermore, we found that M‑TRAF3‑/- mice with spontaneous inflammation or tumor development contained strikingly elevated serum levels of a variety of chemokines and cytokines, including G-CSF, CCL1, IL-17, IP-10, MCP-1, MCP-5, CXCL9, TIMP-1, and TREM-1. This suggests that dysregulation of myeloid cells actively contributes to the pathogenesis of spontaneous inflammation and tumor development observed in aging M‑TRAF3‑/- mice. Taken together, our findings indicate that TRAF3 expressed in myeloid cells inhibits spontaneous inflammation and tumor development in mice.
Critical roles for mTOR signaling in DC homeostasis and function (INC6P.306)
Authors: Sinclair Charles , Loebbermann Jens , Ravindran Rajesh , Johnson Matthew , Bommakanti Gayathri , Li Shuzhao , PULENDRAN BALI 
Published: January 2023

Abstract
Intricate overlap between environmental and pathogen derived signals regulate innate immunity, and the mechanistic target of rapamycin (mTOR) kinase is a key signal integrator. Recent reports show mTOR inhibition increases the proinflammatory activity of DCs in vitro, suggesting that DC-targeted mTOR inhibitors could adjuvant immunity. We deleted mTOR in DCs using the CD11c Cre/LoxP system (mTOR DCKO), and challenged mice with distinct immunological stimuli. In contrast to our expectations, we found no inflammatory enhancement, but rather saw anatomically specific defects in lung immunity following intranasal administration of Th1 promoting (attenuated-influenza) or Th2 promoting (house dust mite, HDM) stimuli. Remarkably, the modality of immunity to HDM was altered by mTOR DCKO, resulting in a Th17 skewed asthma with pronounced neutrophilia. Surprisingly, reduced homeostatic frequencies of specific lung APC populations underlie the defects in lung immunity. Moreover, we identified further defects in homeostatic accumulation of DC populations in several additional organs, whereas others were unaffected. The mTOR dependence of DCs did not correlate with described paradigms of DC subdivision, and we are characterizing metabolomic and transcriptomic profiles to gain further insight into this phenomenon. Together our data reveal an unexpected role for mTOR in DCs, identifying a novel mechanism of immunosuppressive action that may be mediated by mTOR inhibitors.
Inflammasomes are critical for the host protection during bacterial urinary tract infection (INM6P.328)
Authors: Kulkarni Ritwij , Singh Sanjay , Jeyaseelan Samithamby 
Published: January 2023

Abstract
Urinary tract infections (UTI) are the second most common infection in the US. Gram-negative uropathogenic E. coli (UPEC) is the principal causative agent of UTI. The main goal of our work is to gain molecular insights into the role of cytoplasmic pattern recognition receptors, namely inflammasomes, in the protection of urinary tract during the course of bacterial UTI. Inflammasomes are multiprotein complexes made of ASC adaptor protein that facilitates interaction between NOD-like receptors with procaspase-1. Stimulation of caspase-1 activates IL-1b and IL-18. Since, the rapid induction of caspases and IL-1b are important hallmarks of UPEC-induced UTI, we hypothesized that the inflammasomes are critical for protection of the urinary tract during UPEC infection. To address this hypothesis, we challenged female WT (C57Bl6/J) and ASC-/- mice with UPEC strain CFT073 via transurethral catheterization. We observed increased bacterial burden in the bladders of ASC-/- mice as compared to the WT. In comparison to WT mice, CFT073 infection did not induce IL-1b production in the bladders of ASC-/- mice. Taken together these observations suggest for the first time that ASC-inflammasomes play a critical role in the protection of urinary tract during UPEC infection by modulating important innate immune cascades.
Nrf2-mediated pentose phosphate pathway activity promotes macrophage inflammasome activation and bacterial killing in microbial sepsis (INM6P.330)
Authors: Wen Haitao , Li Xinghui , Gillette Devyn , Cairns Bruce 
Published: January 2023

Abstract
Classical activation of the innate immune cells such as macrophages and dendritic cells causes dramatic metabolic changes towards increased glucose uptake, glycolysis and pentose phosphate pathway (PPP) activity. However, the role and mechanism of this metabolic reprogramming in the regulation of macrophage function and its disease relevance is poorly understood. Here we report a critical role of PPP activity in inflammasome activation. Pharmacological inhibition of PPP resulted in a defective inflammasome activation. Macrophages with a mutation in G6pd, the gene encoding a rate-limiting PPP enzyme glucose-6-phosphate dehydrogenase, showed decreased inflammasome activation. Mechanistically, PPP activity was required for the prevention of excessive reactive oxygen species generation and safeguarding an intact extracellular Ca2+ influx, a critical step for inflammasome activation. Nuclear factor E2-related factor-2 (Nrf2) regulates the expression of several key enzymes involved in PPP. Furthermore, Nrf2-/- macrophages showed defective caspase-1 activation after E. coli infection, which caused decreased phagosome acidification and bacterial killing. Nrf2-/- mice and mice with PPP inhibition exhibited an increased bacterial burden in E. coli-induced and cecal ligation and puncture-induced microbial sepsis. In sum, these findings identify a novel function of PPP in inflammasome activation and suggest PPP as a therapeutic target in the treatment of microbial sepsis.
NLRP3 inflammasome controls adipose tissue leukocytosis and inflammation during aging (INM6P.331)
Authors: Camell Christina , Youm Yun-Hee , Nguyen Kim , Ravussin Anthony , Spadaro Olga , Dixit Vishwa 
Published: January 2023

Abstract
Aging is associated with chronic inflammation and increased risk for degenerative disorders and diseases. In the elderly there is increased visceral adiposity and increased numbers of fat-associated lymphocyte clusters within adipose tissue (AT); however the role for AT in age-induced immune defects is unclear. Our prior studies have identified that the canonical inflammasome, NLRP3, is required for diet-induced AT inflammation and age-related inflammation in multiple organs. We hypothesized that NLRP3 is required for age-induced changes in AT immune cells and metabolic dysfunction. We found that aging increases AT lymphocytes; compared to 24month old control mice, Nlrp3-/- animals were protected from increases in AT leukocytosis. RNA sequencing analysis of AT macrophages and B cells from aged mice revealed distinct inflammatory signatures that were regulated by NLRP3. AT displayed immunological properties, as during infection, a higher frequency of antigen specific T cells are recruited to AT than to spleen. Our results show that NLRP3 is required for age-induced T follicular cell and B cell infiltration into visceral AT. Furthermore, our data suggests that pharmacological inhibition of NLRP3 activation and IL-1β signaling may improve AT inflammation and insulin resistance in aged mice. These data demonstrates that macrophage-expressed NLRP3 inflammasome controls age-related inflammation and AT microenvironment by secondary effects on T and B cell subpopulations.
Somatic MyD88 mutations and a germline IRAK2 variant contribute to lymphoma by differential effects on NF-κB (INM7P.354)
Authors: Wolz Oliver , Wang Hui , El Maadidi Souhayla , Fischer Janett , Flannery Sinead M. , Dickhöfer Sabine , Butterbach Katja , Nieters Alexandra , Bowie Andrew , Weber Alexander 
Published: January 2023

Abstract
Within innate immune signaling pathways, Myeloid differentiation (MyD) 88 and Interleukin-1 receptor associated kinases (IRAKs) fulfill pivotal roles downstream of multiple Toll-like receptors (TLR). Somatic MyD88 mutations in B cells were reported to affect lymphomagenesis by constitutive hyperactivation of NF-κB. We here show that oncogenic mutants augment spontaneous TIR domain oligomerization into so-called Myddosome signaling complexes driving NF-κB activation. Blocking of MyD88 oligomerization consequently induced the death of MyD88-mutated but not unmutated lymphoma cells. In line with the involvement of the MyD88 axis in lymphomagenesis we detected a genetic association of a coding germline variant of IRAK2, a MyD88 interactor, with increased risk (OR = 1.43, 95% confidence interval 1.06-1.93, p=0.018) to develop lymphoma in a German cohort (n=387). This variant is frequently found in 15-44% of individuals of different ethnic groups. Unexpectedly, this variant was associated with reduced NF-κB activation and cytokine responses to TLR agonists in healthy donors. Mechanistically, the IRAK2 variant retained intact binding to but impaired ubiquitination of TRAF6, a vital step in signal transduction. Thus our findings confirm the involvement of MyD88/IRAK in lymphoma but suggest that MyD88 and IRAK2 may contribute differently to oncogenic signaling. Additionally we highlight IRAK2 genetic variants as a critical factor and potentially novel biomarker for human lymphomagenesis.
Genomic networks of inflammatory response (INM7P.355)
Authors: Poltorak Alexander , Ilyuha Vladimir , Bagina Uliana , Belova Lubava 
Published: January 2023

Abstract
Mediated by a family of Toll-like Receptors (TLRs) responses lead to transcriptional activation and synthesis of many inflammatory genes. As an example, thousands of genes are up-regulated in response to LPS (lipopolysaccharide), with many of them undergoing specific program of activation and silencing. To investigate the breadth and specificity of LPS-induced gene expression in macrophages, we compared expressional activation in response to LPS in genetically diverse mice of subspecies M.m.musculus and M.m.domesticus using next generation (NGS) RNA-sequencing. To characterize the genetic basis of LPS-response in detail, we applied a systems genetics approach, using mapping of gene expression traits with on a panel of a second-generation F2 intercross mice. Specifically, RNA from LPS-activated F2 macrophages was RNA-sequenced and hundreds of activated genes were used as phenotypic read-outs for mapping the traits. We identified several hundreds cis- and trans-acting QTL contributing to expression variation (eQTL). Many trans eQTL cluster into major groups, some of which are confined to genomic loci that do not contain known regulators of innate immune responses. We identified 227 cis-expression quantitative trait loci (cis-eQTL) that control expression. Our data provide the first genome-wide map of major regulators of the inflammatory responses in macrophages.
The effects of circadian rhythms on Toll-like receptor responses in murine macrophages (INM7P.357)
Authors: Sidhu Kiran , Cox Emily , Yanez Amanda , Heipertz Erica , Walker Wendy 
Published: January 2023

Abstract
Circadian rhythms refer to the endogenous oscillations of biological processes with 24-hour periodicity in response to environmental cues. On a molecular level, circadian rhythms are accomplished through positive and negative feedback loops among the core Clock genes: Clock, Period, Cryptochrome and Bmal. These oscillations in gene expression regulate a myriad of cellular functions and activities. Recently, circadian rhythms have been found to promote comparable oscillations in components of the innate and adaptive immune system. Synchronization of the circadian clock can be induced in vitro via a process known as serum shock. Here, we took advantage of this model to investigate the effects of circadian oscillations on Toll-like receptor (TLR) responses in murine macrophages. Serum shock induced a 24h oscillation in mRNA expression for the clock gene Period 2, as well as for a period2-luciferase fusion reporter gene, confirming synchronization of the circadian clock. Serum-shocked cells were then stimulated with a panel of TLR agonists and cytokine secretion was quantified over time to investigate the impact of circadian rhythms on TLR responses. Our findings suggest circadian oscillation with regard to interleukin (IL)-12p40 production upon stimulation of TLR2 and TLR7. Suggestive oscillations were also observed with regard to IL-6 production upon stimulation of TLR2. These data suggest that circadian rhythms control TLR responses at the cellular level.
Src family kinase members Fyn and Lyn mediate type I interferon production by plasmacytoid dendritic cells. (INM7P.345)
Authors: Dallari Simone , Macal Monica , Hesser Charles , Zuniga Elina 
Published: January 2023

Abstract
Plasmacytoid dendritic cells (pDCs) are the most powerful type I interferon (IFN-I) producing cells and are therefore important for antiviral defense and for autoimmune diseases such as systemic lupus erythematosus. However, the signaling factors that regulate pDC IFN-I production are not completely understood. Here we investigate the role of Src Family Kinases (SFKs), a family of non-receptor tyrosine kinases, in pDC responses to toll like receptor (TLR) stimulation. We first found that while human pDCs expressed mostly Lyn, mouse pDCs expressed both Lyn and Fyn, two members of SFKs. Importantly, we observed that pDCs from either Fyn or Lyn deficient mice exhibited impaired IFN-I and pro-inflammatory cytokine production after TLR-9 and TLR-7 stimulation, whereas no difference was observed in conventional DCs. Consistently, incubation of murine or human pDCs with a pan-SFKs inhibitor resulted in a dramatic ablation of pDC IFN-I and cytokine production in a dose dependent manner. Finally, treatment of a human pDC cell line (CAL-1) or pDCs from human peripheral blood with Bafetinib (a selective dual Bcr-Abl/Lyn inhibitor) profoundly ablated their IFN-I production after TLR stimulation. Taken together, our data indicate that the SFKs members Fyn and Lyn promote pDC IFN-I and pro-inflammatory cytokine production and suggest that Bafetinib could be considered as a therapeutic candidate for attenuating pDC responses in autoimmune diseases.
PTP1B preferentially regulates IRF7-ISRE-IFN pathway and negatively impacts host defense against Pseudomonas aeruginosa infection. (INM7P.348)
Authors: Lin Tong-Jun , Yue Lei , Xie Zhongping , Li Hua , Junkins Robert , Tremblay Michel , Chen Xiaochun 
Published: January 2023

Abstract
Pseudomonas aeruginosa is a major opportunistic pathogen in immune-compromised individuals. Toll-like receptors (TLRs) contribute to innate immunity against P. aeruginosa through activation of transcription factors IRF7/IRF3 and NFκB. However, mechanisms involved in the regulation of P. aeruginosa-induced TLR pathway activation remain incompletely defined. Here, we demonstrate that protein tyrosine phosphatase-1B (PTP1B) is a critical negative regulator in P. aeruginosa infection. PTP1B-deficient mice display greatly enhanced bacterial clearance which is accompanied with increased neutrophil infiltration and cytokine production. Interestingly, PTP1B-deficiency mainly up-regulates the production of IFN-stimulated response elements (ISRE)-regulated cytokines and chemokines including CCL5 (RANTES), CXCL10 (IP-10) and IFN-β production. Further studies reveal that PTP1B-deficiency leads to increased IRF7 activation. Importantly, PTP1B is physically associated with IRF7 in dendritic cells. These findings demonstrate a novel regulatory mechanism of the immune response to P. aeruginosa infection through PTP1B-IRF7 interaction. This novel PTP1B-IRF7-ISRE pathway may have broader implications in TLR-mediated innate immunity.