bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surfactant protein-A interacts with TLR4 and affects the phagocytic function of dendritic cells (135.41)
Authors: Awasthi Shanjana , Wolf Roman , White Gary , Awasthi Vibhudutta 
Published: January 2023

Abstract
The surfactant protein (SP)-A and Toll-like receptor (TLR4) proteins are known as secretory and cellular pathogen pattern recognition receptors, respectively, and play an important role in the recognition of pathogens and host defense. In lung, the TLR4 is expressed by immune cells, and SP-A is synthesized by type II epithelial cells and secreted in alveoli. In this study, we investigated the interaction between purified baboon lung SP-A and recombinant TLR4 (extracellular domain)-MD2 proteins and effects of these proteins on phagocytic function of the human myelomonocytic cells (KG1) derived- and primary baboon lung-dendritic cells. The interaction between the two proteins was studied in vitro by a microwell based method. For measuring the changes in phagocytic ability of the dendritic cells, the cells were incubated with pHrodo-labeled, heat-killed Escherichia coli bioparticles in presence of native SP-A and/or recombinant TLR4-MD proteins and fluorescence released from ingested E. coli bioparticles inside the acidic phagosome was read on a fluorometer. We found that the SP-A protein binds to TLR4-MD2 protein. The exogenous addition of SP-A and TLR4-MD2 proteins was found to significantly increase the phagocytosis of E. coli bioparticles by dendritic cells. However, when the SP-A and TLR4-MD2 proteins were added together, the phagocytic ability of dendritic cells either remained unaltered or decreased from those treated with SP-A or TLR4-MD2 alone. These results suggest that the interaction between SP-A and TLR4 affects the bacterial phagocytosis by dendritic cells.
Expression analysis of chicken adaptors MyD88, TRIF, TIRAP, SARM and TRAM used in toll-like receptor signaling (135.45)
Authors: MacKinnon Kathryn M , He Haiqi , Kogut Michael H 
Published: January 2023

Abstract
Activated toll-like receptors (TLR) trigger innate immunity through signaling adaptors including MyD88, TRIF/TICAM-1, TIRAP/MAL, SARM and TRAM/TICAM-2. With limited information available on these adaptors in chickens, we chose to examine the distribution and expression of these adaptors in multiple chicken tissues and cells. All adaptor molecules were detected in ileum, ceca, cecal tonsils, large intestine, bursa, heart, kidney, lung, muscle, skin and spleen tissues using quantitative real-time RT-PCR. Within each tissue, expression of TRAM was greatest and SARM was lowest. Across tissues, spleen and lung tissues had the highest level of expression and muscle had the lowest. Heterophils and peripheral-blood mononuclear cells isolated from 2 to 3-day-old chickens, in addition to the avian macrophage cell line (HD-11), expressed mRNA from all adaptor molecules. However stimulation of HD-11 cells for up to 2 hours with TLR agonists did not induce changes in mRNA expression. Comparison of Salmonella-infected and control birds showed infected birds had a 1.5-fold increase (P &lt; 0.02) in expression of MyD88 in the ileum and a 1.65-fold decrease (P &lt; 0.02) of TIRAP in the cecal tonsils. Overall, these TLR-adaptor molecules appear to be ubiquitously expressed in chicken cells and tissues and expression levels may play a role in immune regulation during infection.
PI3K and potentially autophagy are involved in HSV, Flu, SeV, and CpG A -stimulated IFN-α production by human plasmacytoid dendritic cells (135.51)
Authors: Deng Jing , Singh Sukhwinder , Fitzgerald-Bocarsly Patricia 
Published: January 2023

Abstract
IFN-α production plays a critical role in the immune system and as "professional" type I interferon (IFN) producing cells, plasmacytoid dendritic cells (pDC) can produce much more IFN-α in response to viruses than other cell types in response to TLR-7 and -9 stimulation. Phosphatidylinositol-3 kinase (PI3K) has been shown to be activated by TLR stimulation in many cell types and is essential in the regulation of many processes, including autophagy. A role for PI3K and autophagy in pDC has been recently described. The role of autophagy in induction of IFN-α in human pDC, however, has not been described. We investigated the effects of wortmannin, a PI3K inhibitor, and 3-methyladenine (3MA), a specific inhibitor of autophagy, but also an inhibitor of PI3K, on IFN-α?production by HSV, Flu, SeV, and CpG A -stimulated human pDC. pDC were pretreated with the inhibitors then stimulated with virus for 6hr for detection of intracellular IFN-α by intracellular flow cytometry or overnight for stimulation and release of IFN-α, which was detected by ELISA. Inhibition of PI3K with wortmannin, inhibited IFN-α production by pDC. Moreover, 3MA also inhibited IFN-α production by HSV, Flu, SeV, and CpG A-stimulated pDC. In addition, 3MA inhibited HSV-induced LC3B aggregation in pDC, a marker for autophagy. These results support key roles for the PI3K pathway and perhaps, autophagy, in mediating IFN-α secretion and virus detection by human pDC. Supported by AI26806.
Characterization, function and targeting of dendritic cell associated c-type lectin-2 (DCAL-2) (135.54)
Authors: Kasahara Shinji , Hayden-Ledbetter Martha , Chen Chang-Hung , Clark Edward A 
Published: January 2023

Abstract
Dendritic Cell (DC) Associated C-type Lectin Receptors (CLRs) play important roles in immunity through their abilities in antigen capturing and presentation, modulation of TLR signaling, co-stimulation and adhesion. Murine DCAL-2 (mDCAL-2/ mMICL/ mKLRL-1) is a type-II CLR with a cytosolic immunoreceptor tyrosine inhibitory motif (ITIM). Using a mAb we developed, we found that mDCAL-2 is expressed at high levels on plasmacytoid DCs (pDCs), CD8α+ DCs and a subset of CD8α- DCs, at moderate levels on immature CD4-CD8- T cells and low levels on a subset of B-cells, but not on mature T cells and NK cells. DCAL-2 expression subdivides CD8α- DCs into mDCAL-2High33D1- and mDCAL-2Low33D1+ populations. These two subsets of DCs express different levels of TLRs. In addition, these subsets have significantly distinct cytokine profiles in response to TLR ligands. Whereas mDCAL-2High33D1- produced high levels of TNFα, IL-6, IL-10 and IL-12, mDCAL-2Low33D1+ DCs produced extremely low levels of these cytokines. Thus, we hypothesize that mDCAL-2High DC subsets induce T-cell responses that are distinct from that of mDCAL-2Low DCs. To investigate what type of T-cell responses are induced through mDCAL-2 in an Ag specific manner, we developed an anti-mDCAL-2 single chain fragment variable (scFv) fused with antigens (OVA or HEL). We found that anti-mDCAL-2 scFv successfully targets mDCAL-2+ DC subsets in vivo. What type of T cell responses are induced by OVA-anti-mDCAL-2 scFv injection in OT-II transgenic mice will be presented.
This study is supported by NIH grants AI52203, DE16381, and RR00166
mRNA Expression of the Avian-Specific Toll-Like Receptor 15 is Induced by Multiple Species of Bacteria (135.58)
Authors: Nerren Jessica R , He Haiqi , Genovese Kenneth J , Kogut Michael H 
Published: January 2023

Abstract
Pattern recognition receptors (PRRs) are essential for recognition of conserved molecular constituents found on infectious microbes, and Toll-like receptors (TLRs) are a critical component of the PRR repertoire. mRNA expression of the avian-specific TLR 15 has recently been shown to be increased in response to multiple Salmonella serovars, suggesting that the ligand for TLR 15 is some component of Salmonella. The objective of this study was to determine whether mRNA expression of TLR 15 was Salmonella-specific or could be induced by exposure to other species of bacteria commonly found in the chicken. We also wanted to determine whether TLR 15 mRNA expression could be induced by exposure to known TLR ligands that are components of Salmonella. To test this hypothesis, we stimulated chicken heterophils with live Salmonella enterica serovar Enteritidis (SE), heat-killed or formalin-killed SE, an avian isolate of Escherichia coli, and an avian isolate of Enterococcus gallinarum. TLR ligands used as stimuli included LPS, flagellin, and CpG. Gene expression was measured using real-time quantitative RT-PCR. We found that mRNA expression of TLR 15 was significantly increased (P &lt; 0.05) in response to stimulation with all of the bacteria tested. There were no significant differences in stimulation between live and dead bacteria nor between species of bacteria. Across bacteria tested, the average increase in TLR 15 expression was 8-fold greater (range, 6.5 to 9.1) than in unstimulated heterophils. In contrast, stimulation of heterophils with the TLR ligands LPS, flagellin, and CpG induced no significant increase in expression of TLR 15 mRNA. These data demonstrate that TLR 15 recognizes some component of both Gram-positive and Gram-negative bacteria, but that LPS, flagellin, and CpG are likely not the components of these bacteria that are recognized.
Regulation of Notch ligands by the TLR and IFN-γ pathways in macrophages (135.63)
Authors: Foldi Julia , Hu Xiaoyu , Chung Allen Y. , Ivashkiv Lionel B. 
Published: January 2023

Abstract
Jagged and Delta proteins are transmembrane ligands for the Notch family of receptors. The role for Notch and its ligands in innate immunity remains largely unknown. Our lab recently identified a subset of Toll like receptor (TLR)-inducible genes that were activated synergistically, by TLR-ligands and the Notch pathway. Some of these genes were also regulated by interferon (IFN)-γ, a potent macrophage activator. To further elucidate the role of the Notch pathway in innate immunity, we would like to know how Notch ligands are regulated in macrophages. We found that Jagged-1 and Delta-like (Dll)-1 were induced by TLR ligation and were regulated by IFN-γ in CD14+ primary human monocytes and in mouse bone-marrow-derived macrophages. TLR-induced upregulation of Jagged-1 was independent of de novo protein synthesis and the mitogen activated protein kinase (MAPK) pathway, while the nuclear factor (NF)-κB and Notch pathways played a role in this process. IFN-γ pre-treatment of cells super-induced TLR-stimulated Jagged-1, while it inhibited Dll-1 upregulation. In conclusion, Jagged and Delta proteins are synergistically regulated by the TLR, Notch and IFN-γ pathways in macrophages. This work is supported by the Cancer Research Institute (CRI) Predoctoral Fellowship.
Functional Characterization of a Novel Interferon-inducible Protein, Mouse ISG12(b2) (135.66)
Authors: Lu Mei-Yi , Liao Fang 
Published: January 2023

Abstract
Interferons (IFNs) play crucial roles in the host defense against virus. Many interferon-stimulated genes (ISGs) induced by viral infection exert antiviral effects. ISG12(b2) was dramatically induced in liver from dengue-infected mice as well as in Hepa 1-6 (mouse hepatoma cell line) following dengue virus infection. We have biochemically and functionally characterized mouse ISG12(b2). ISG12(b2) is mainly localized to the mitochondria. Overexpression of ISG12(b2) in Hepa 1-6 resulted in the changes in mitochondrial morphology, the mitochondrial membrane potential, the accumulation of Sub-G1 population, the activation of caspase-8, caspase-9, and caspase-3, and the increase of the PARP cleavage. Knockdown of ISG12(b2) by siRNA followed by dengue virus infection in Hepa 1-6 revealed the attenuation of caspase activation and PARP cleavage. Taken together, our results suggest that ISG12(b2) is involved in the activation of the mitochondrial apoptotic pathway, which may subsequently eliminate virus-infected cells.
The immune response of macrophages to Mycobacterium leprae infection via Naip5, a member of Nod-like receptor protein (135.75)
Authors: Kang Tae Jin , Kim Se-Kon , Chae Gue-Tae 
Published: January 2023

Abstract
Naip5 is a member of the NOD-like receptors (NLRs) involved in the cytosolic recognition of pathogen-associated molecular patterns. Recently, A/J mice have been found to have amino acid differences in the Naip5, one of the adaptor proteins for caspase-1 activation, and this defect is associated with a susceptibility to Legionella infection suggesting an important role of Naip5 in the immune response to intracellular pathogens, such as M. tuberculosis and M. leprae. In this study, the immune responses of macrophages from A/J mice against M. leprae infection were studied and compared to those of macrophages from C57BL/6 (B6) mice. A/J and B6 macrophages induced high levels of NF-¥ê B activation when infected with M.leprae. Caspase-1 activation and IL-1beta secretion were also induced in both macrophages. However, macrophages from A/J mice have impaired caspase-1 activation, IL-1beta expression, and nitric oxide (NO) production, partially, compared to macrophages from B6 mice. These results suggest that NOD family proteins may have a role in the innate immune response to M. leprae.
Inflammasome-activating biodegradable nanoparticulates as vaccine delivery systems (135.80)
Authors: Fahmy Tarek M , DEMENTO Stacey , Eisenbarth Stephanie C , Caplan Michael J , Saltzman W Mark , Mellman Ira , Ledizet Michel , Fikrig Erol , Flavell Richard 
Published: January 2023

Abstract
Inflammasome activation requires signaling of both the Toll-like receptor (TLR) and NLRP3 in antigen-presenting cells. We present a class of nanomaterials endowed with these two signals for rapid optimization of vaccine design. We constructed this system using an approach that incorporates lipopolysaccharides (LPS) onto the surface of nanoparticles constructed from a biocompatible polyester loaded with antigen. We demonstrate that LPS-modified particles, elicits potent humoral and cellular immunity against a model antigen, ovalbumin. Wild type macrophages pulsed with LPS-modified nanoparticles resulted in production of the proinflammatory cytokine IL-1β consistent with inflammasome activation. In comparison, NLRP3-deficient and caspase-1-deficient macrophages showed negligible production of IL-1β. Furthermore, when endocytosis and lysosomal destabilization were inhibited, inflammasome activity was diminished, supporting the notion that nanoparticles rupture lysosomal compartments and behave as 'danger signals'. The generality of this vaccination approach is tested by encapsulation of a recombinant West Nile envelope protein and demonstrated by protection against a murine model of West Nile encephalitis. The design of such an antigen delivery mechanism with the ability to stimulate two potent innate immune pathways represents a new approach to simultaneous antigen and adjuvant delivery.
Chlamydial-induced TLR2 signaling leads to increased neutrophil production of proinflammatory molecules and delayed spontaneous apoptosis (135.9)
Authors: Frazer Lauren , O'Connell Catherine , Darville Toni 
Published: January 2023

Abstract
Chlamydial-induced TLR2 signaling is involved in development of genital tract pathology. We hypothesized that chlamydial-induced activation of PMN TLR2 induces the release of cytokines and matrix metalloproteinases (MMPs), and prolongs PMN longevity. Human PMNs were incubated with wild-type C.trachomatis strain D/UW-3/Cx, TLR2 signaling deficient strain CTD153, TLR2 agonist Pam3Cys, or media for 4 or 20 hrs. Supernatants were analyzed for cytokine and MMP9 production via bead array. TNFa, IL-6, IL-8, G-CSF, and IL-1β were increased in PMNs incubated with D/UW-3/Cx or Pam3Cys vs. CTD153 for 20 hrs (p&lt; 0.05). MMP9 production was increased in PMNs incubated with D/UW-3/Cx or Pam3Cys vs. CTD153 for 4 hrs. or 20 hrs.. At 20 hrs, MMP9 = 455 ± 61 ng/ml, D/UW-3/Cx; 435 ± 64 ng/ml, Pam3Cys; 322 ± 144 ng/ml, CTD153; 132 ± 84 ng/ml, media; p&lt;0.02 for D vs. CTD153; p &lt; 0.001 for D or Pam3Cys vs. UI. Flow cytometric enumeration of TUNEL and microscopic analysis of Giemsa staining revealed incubation with D/UW/3Cx for 20 hrs but not 4 hrs. induced significant protection from spontaneous apoptosis when compared to CTD153 (Giemsa: % apoptotic = 37 ± 2%, D/UW/3Cx; 78±2%, CTD153; 76±3%, media; (p&lt;0.01 for D vs. CTD153 and media). PMNs have increased longevity, cytokine and MMP9 production when incubated with chlamydiae capable of activating TLR2. Chlamydial-induced activation of PMN TLR2 may contribute to development of tissue pathology.
NIH A1054624; Pennsylvania Department of Health; Howard Hughes Institute Research Training Fellowship
mRNA stability influences the temporal order of inflammatory gene induction (136.1)
Authors: Hao Shengli , Baltimore David 
Published: January 2023

Abstract
The inflammatory response is regulated by a great number of genes. It is still unknown whether and how these genes are organized to function as groups. We have performed a global analysis of about 200 genes induced in cultured cells by TNF, a proinflammatory cytokine. We found that genes can be divided roughly into three groups with different induction kinetics. Group I genes are activated quickly but then quickly repressed. Group II genes are also activated rapidly but reach maximal activity later and remain at the induced level longer. The Group III genes are activated in a delayed, slow but steady manner. The activation pattern of a gene remains largely the same in different cell types and species and is not specified by the extracellular signals. In addition, some genes within the same group have similar related functions. This suggests that these genes are temporally organized to function as groups. While transcriptional regulation is important, we found that a key parameter characterizing the grouping of genes is the stability of their mRNAs. The early mRNAs are very unstable, while the late mRNAs are highly stable. The instability of mRNAs correlates with the number of AU-rich elements in their 3'-untranslated regions (3'UTR). Changing mRNA stability either through extracellular LPS treatment or by switching the 3'UTRs but not the promoter/enhancer regions that control expression of GFP transgenes resulted in corresponding changes of the gene activation kinetics. These show that the inflammatory response is pre-set at the genome level and that the 3'UTR of a gene is a key element for organizing genes into functional groups.
MECHANISM OF Th-POK GENE REGULATION DURING DIFFERNTIATION OF HELPER-LINEAGE T CELLS (136.10)
Authors: Taniuchi Ichiro , Muroi Sawako 
Published: January 2023

Abstract
CD4+CD8+ double-positive (DP) thymocytes differentiate into CD4+ helper lineage cells upon expression of the transcription factor Th-POK, in whose absence they commit to the CD8+ cytotoxic lineage. An understanding of how cell fate determination of DP thymocytes is regulated therefore requires elucidation of the mechanisms that regulate helper-lineage specific expression of the Th-POK gene. In addition to a transcriptional silencer that represses the Th-POK gene during differentiation of MHC class I-specific thymocytes, we have identified two enhancers in the Th-POK gene. While the proximal enhancer is necessary to maintain Th-POK expression at late developmental stages of helper-lineage T cells, the distal enhancer, located adjacent to the silencer, was thought to be involved in initial induction of the Th-POK gene. Here we show that some MHC class II-specific thymocytes lost Th-POK expression and were re-directed into CD4-CD8+SP thymocytes upon loss of the distal enhancer. However, other MHC class II-specific thymocytes that differentiated into CD4+CD8-SP thymocytes expressed almost normal level of the Th-POK gene in the absence of the distal enhancer. These results indicate that Th-POK itself is involved in regulation of its own expression, supporting an auto-regulatory loop model in which direct antagonism by Th-POK of its own silencer amplifies Th-POK expression.
Evidence of epigenetic suppression of genes involved in lineage commitment in naïve CD4+ T cells following severe sepsis (136.17)
Authors: Carson IV William F , Cavassani Karen A , Schaller Matthew A , Ito Toshihiro , Ishii Makoto , Kunkel Steven L 
Published: January 2023

Abstract
Immunosuppression following severe sepsis remains a significant human health concern, as long-term survival rates of patients who have recovered from life-threatening septic shock remain poor. Mouse models of severe sepsis indicate this immunosuppression may be partly due to epigenetic suppression of IL-12 production by dendritic cells. However, the effect of severe sepsis on subsequent CD4+ T cell responses remains unclear. In the present study, CD4+ T cells from mice subject to an experimental model of severe sepsis (cecal ligation and puncture, CLP) were isolated and subjected to ex vivo restimulation. Naïve CD4+ T cells from CLP mice exhibited reduced proliferative capacity ex vivo and dysregulated cytokine production as compared to CD4+ T cells from sham surgery mice. Also, CD4+ T cells from CLP mice exhibit dysregulated cytokine production after in vitro skewing. Additionally, repressive histone methylation marks were evident at promoter regions for the TH1 cytokine interferon-γ (IFN-γ) and the TH2 transcription factor GATA-3 in naïve CD4+ T cells from CLP mice. These results provide evidence that naïve CD4+ T cells from postseptic mice are unable to properly commit to either the TH1 or TH2 lineage, possibly due to repressive histone methylation events associated with genes involved in cytokine production and gene transcription. This work was supported by NIH RO1 HL031237, HL074024, and T32 HL007517.
Characterization of miRNA regulation of T cell differentiation (136.18)
Authors: Bronevetsky Yelena , Ansel Mark 
Published: January 2023

Abstract
During an immune response, antigen-specific CD4 T cells proliferate greatly and differentiate into different sub-populations of effector T cells that act to coordinate the adaptive immune response by selective cytokine production. Major changes in gene expression characterize this transition, and the role that microRNAs play in this process of T cell differentiation remains largely undefined. Effector T cells exhibit decreased expression of numerous miRNAs, as compared to naïve T cells, which is in contrast to the global increase in gene expression that characterizes this differentiation. We have undertaken to investigate the regulation of this miRNA decrease. We have identified differential regulation between different miRNAs at several levels of miRNA biogenesis.
Absence of KIR2DS3, a receptor implicated in NK cell activation is associated with pulmonary sarcoidosis (136.23)
Authors: Luo Lihui , Sharma Surendra K. , Rajalingam Raja 
Published: January 2023

Abstract
By interacting with certain HLA class I molecules, the killer cell immunoglobulin-like receptors (KIR) control the function of NK cells that trigger early immune response against infection and tumors. To determine whether certain KIR and HLA genes are associated with pulmonary sarcoidosis (PS), a chronic inflammatory disease characterized with pulmonary granuloma, we have characterized KIR and HLA genes in 149 PS patients and 186 healthy controls. There was a significant decrease in the frequencies of KIR2DL2 (56.4% vs. 71.5%, P = 0.0041; 95% CI, 0.33-0.81, OR = 0.52), 2DL5 (61.7% vs. 76.3%, P = 0.0041; 95% CI, 0.31-0.80, OR = 0.50) and 2DS3 (28.2% vs. 45.2%, P = 0.0015; 95% CI, 0.30-0.75, OR = 0.48) in PS compared to controls. Interestingly, these three KIR genes 2DL2, 2DL5 and 2DS3 are closely linked together in the cetromeric half of the KIR gene complex, and thus any of these KIRs or other linked loci may contribute to the risk for PS. Particularly, the decrease in activating receptor KIR2DS3 in PS is consistent with the clinical anergy and diminished cellular immunity evidenced in PS. The individuals missing KIR2DS3 may fail triggering early NK cell response to clear antigenic stimuli, which may contribute granulomas formation. This study offers new insights into the molecular mechanisms of granuloma formation in sarcoidosis and provides a framework for developing new therapeutic strategies. This work was supported by UCLA Department of Pathology and Laboratory Medicine to RR.