bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of ERK2 in germinal center B cell selection
Authors: Negron Austin Joseph , Jeffreys Sean , Perez Rebecca , Abdul-Baki Nawal , Forsthuber Thomas 
Published: January 2023

Abstract
The regulation of B cell activation and survival is a crucial control point for the maintenance of B cell tolerance in the germinal center (GC) and involves the coordination of several intracellular signaling pathways. Dysregulation of these pathways can lead to the production and survival of autoreactive memory B cells and plasma cells (PCs), resulting in autoimmune disease. The mitogen-activated protein kinase (MAPK) pathway is involved in the transduction of stimulating and apoptotic signals such as those received through the B cell receptor (BCR) and the Fas receptor (CD95), respectively. Extracellular signal regulated kinases 1 and 2 (ERK1/2), important effectors of this pathway, play a major role in B cell activation and survival. Though ERK2 specifically regulates the pro-apoptotic protein, Bmf, its role in regulating GC B cell selection is unknown. Our lab has developed a novel mouse model in which the deletion of Erk2 is accompanied by the expression of the fluorescent reporter protein, eYFP, allowing us to identify and isolate viable Erk2Δ B cells using flow cytometry. Preliminary data using this model has shown that peripheral Erk2Δ B cells express several surface markers associated with follicular T helper cell interactions and immunoglobulin class switching, such as DEC205 and CD80, respectively. Thus we hypothesize that ERK2 is a critical regulator of GC B cell selection. We are currently investigating the ability of Erk2Δ B cells to respond to various activating stimuli in vitro as well as to differentiate into antigen-specific PCs. Our results will contribute to a better understanding of the molecular programs involved in B cell selection, potentially offering new approaches to treating B cell-driven autoimmune diseases.
T-cell signaling in Th17-mediated inflammation
Authors: Tan Tse-Hua , Chuang Huai-Chia 
Published: January 2023

Abstract
MAP kinase kinase kinase kinases (MAP4Ks) are a subfamily of mammalian Ste20-like serine/threonine kinases that activate the JNK kinase cascade. We have cloned and characterized three MAP4Ks, namely HPK1 (MAP4K1), GLK (MAP4K3) and HGK (MAP4K4). Epigenetic downregulation of HGK (MAP4K4) in T cell results in differentiation of IL-6+ Th17 cells, which play important roles in the pathogenesis of Asia-prevalent non-obese T2D.
HPK1 (MAP4K1) is a negative regulator of T-cell signaling through phosphorylation and sequential ubiquitination of the T-cell adaptor SLP-76. GLK (MAP4K3) also interacts with SLP-76 but does not negatively regulate SLP-76. GLK activates PKC-θ during TCR signaling; GLK-deficient mice showed impaired Th17 differentiation. T-cell specific GLK transgenic mice spontaneously developed autoimmune diseases with an induction of systemic inflammation. We found that GLK signaling specifically induced IL-17A transcription in the T cells of GLK transgenic mice. We will present the data on a novel signal transduction mechanism of IL-17A transcriptional activation of AhR and RORγt by GLK in inflammatory T cells and activated T cells. In addition, we found that GLK negatively regulated differentiation and activity of Treg cells through IKKβ. Collectively, MAP4K3/GLK plays a critical role in IL-17A-induced inflammation.
Choline uptake and metabolism modulate macrophage immunity
Authors: Sanchez-Lopez Elsa , Zhong Zhenyu , Stubelius Alexandra , Sweeney Shannon Renee , Booshehri Laela , Antonucci Laura , Liu-Bryan Ru , Lodi Alessia , Terkeltaub Robert , Lacal Juan Carlos , Murphy Anne N. , Hoffman Hal M , Tiziani Stefano , Guma Monica , Karin Michael 
Published: January 2023

Abstract
Choline is a vitamin-like nutrient that is taken up via specific transporters and metabolized by choline kinase (ChoKα) which converts it to phosphocholine needed for de novo synthesis of phosphatidylcholine (PC), the main phospholipid of cellular membranes. We found that Toll-like receptor (TLR) activation enhances choline uptake by macrophages through induction of the choline transporter CTL1. Choline is rapidly phosphorylated and mobilized to the Kennedy pathway leading to increased cellular phosphatidylcholine production. Inhibition of choline uptake or phosphorylation attenuated NLRP3 inflammasome activation and IL-1β and IL-18 production in stimulated macrophages. Mechanistically, reduced choline uptake altered mitochondrial lipid profile, attenuated mitochondrial ATP synthesis and activated the energy sensor AMP-activated protein kinase (AMPK). By potentiating mitochondrial recruitment of DRP1, AMPK stimulates mitophagy, which contributes to termination of NLRP3 inflammasome activation. Correspondingly, pharmacological ChoKα inhibition ameliorated acute and chronic macrophage-dependent inflammation in vivo.
Dual function of galectin-1 in microglial activation of the brain
Authors: jeon saebom , yoon hee jung , park eun jung 
Published: January 2023

Abstract
Galectins-1, one of the β-galactosides-binding soluble lectin family, exert various roles in immune responses, and have been reported to be closely linked with several inflammation-associated diseases including cancer. However, their roles and underlying mechanisms remain largely unknown in the brain inflammation. In this study, we provide that galectin-1 could act as a regulatory molecule in the brain pathological conditions. Galectin-1 expression is markedly induced in IFN-g-treated microglial cells. In intracranial brain tumor model, we show that expression level of galectin-1 is significantly higher in B35 brain tumor cells and tumor neighboring microglial cells. Treatment of exogenous galectin-1 changes morphology of microglia, and induces expression of ICAM-1, adhesion molecule. In addition, galectin-1 triggers production of both pro-inflammatory mediators and anti-inflammatory mediators. Galectin-1-treated microglial cells activate lymphocytes. These findings indicate that galectin-1 involved in regulation of M1 and M2 phenotype of microglial cells. Therefore, we strongly suggest that galectin-1 may be dual roles in microglial activation of the brain pathophysiological environment.
PD-1 is not expressed on highly activated Natural Killer cells in human and murine models
Authors: Judge Sean J , Dunai Cordelia , Sturgill Ian , Stoffel Kevin , Darrow Morgan , Canter Robert , Murphy William J 
Published: January 2023

Abstract
PD-1 expression is a hallmark of acute T cell priming and response to chronic antigen exposure with a key role in T cell exhaustion. Though identified on NK cells in select populations, the role of PD-1 on NK cells is less clear. Our objective was to determine the expression of PD-1 on resting and activated NK cells in human and murine models. Human NK cells were isolated and expanded ex vivo using a feeder line or cytokine culture. Murine NK cells were evaluated in vivo in tumor-bearing mice and post-MCMV infection in both immunocompetent and immunodeficient mice. We assessed NK cell surface phenotype, activation markers, and intracellular cytokine by flow cytometry and qRT-PCR. Throughout ex vivo human NK activation and proliferation, NK PD-1+ frequency was consistently less than 1% by flow cytometry and negligible by PCR, with upregulation of TIGIT by PCR and flow cytometry (P&lt;0.05). In cytokine stimulated human PBMCs, NK PD-1 expression was 0–2%. In vivo studies with 4T1-bearing mice showed negligible PD-1 from intra-tumoral and splenic NK cells. NK cells isolated from livers in C57BL/6 mice after acute MCMV infection showed high activation by CD69 (&gt;90% positive) but &lt;2% PD-1 expressing NK cells, while T cells exhibited high activation and a 5-fold increase in PD-1 expression. In Rag2−/− mice exposed to MCMV, NK cells isolated from the liver on post-infection day 3 showed minimal PD-1 expression, but positive PD-L1 and TIGIT expression. Unlike T cells, our results show that highly activated human and murine NK cells do not significantly upregulate PD-1. Our data suggest that PD-1 is not a consistent marker for NK exhaustion, though TIGIT appears to demonstrate consistent upregulation and may represent a more useful marker for NK exhaustion.
Characterization of mouse peritoneal macrophages using novel flow cytometry antibodies
Authors: Stepniak Dariusz , Zahner Sonja , Gerhart Ryan , Navert Robert , Schrantz Nicolas 
Published: January 2023

Abstract
Peritoneal resident macrophages are one of the most extensively studied macrophage populations in mouse. These cells can be divided into at least two discrete populations: small peritoneal macrophages (SPM) and large peritoneal macrophages (LPM). Under steady state conditions the monocyte-derived SPM constitute a minor population. They have a F4/80 (low) MHC-II (high) phenotype and constitutively produce cytokine RELM-alpha, known to be involved in anti-helminth response. LPM originate from embryonic progenitors and are normally more abundant. They express high levels of F4/80 and low levels of MHCII, and constitutively produce the B-cell attracting chemokine CXCL13. Here, we examined the homogeneity of each of the populations in C57Bl/6 and Balb/c mice. Our flow cytometric analysis with an array of novel antibodies, including anti-VSIG4 (CRIg), arginase 1, CD206, and CD163, revealed diversity within the LPM population. This phenotypic diversity most likely reflects differences in function and activation status, and will need further investigation.
mGBP7 interacting proteins in Toxoplasma gondii infection and biochemical characteristics of mGBP7
Authors: Legewie Larissa , Loschwitz Jennifer , Smits Sander , Prescher Martin , Wang Xue , Steffens Nora , Degrandi Daniel , Strodel Birgit , Schmitt Lutz , Pfeffer Klaus 
Published: January 2023

Abstract
Toxoplasma gondii (T. gondii) is an obligate intracellular parasite and the causative agent of toxoplasmosis. During host cell invasion, T. gondii forms an unique membranous compartment called the parasitophorous vacuole (PV). Members of the murine guanylate binding protein (mGBP) family localize around the PV leading to its disruption, but the underlying molecular mechanisms are poorly understood. The aim of this project is to provide a better understanding of the biochemistry of mGBPs as well as to elucidate the molecular mechanisms by which this IFNγ-inducible protein family is able to attack the parasite directly.
The GTPase activity of mGBP7 and its oligomerization status were analyzed using a colorimetric assay and multi-angle light scattering (MALS). The structure model of mGBP7 was obtained using I-TASSER homology modeling. For the identification of potential mGBP7 interaction partners co-immunoprecipitation (IP) and mass spectrometry (MS) experiments were performed.
The obtained biochemical data for mGBP7 display a GTPase activity in the μM range and a positive cooperativity of GTP hydrolysis. Furthermore, the MALS results indicate a transient oligomer formation independent of the presence of nucleotides. Homology modeling reveals an extended C-terminal domain for mGBP7 probably responsible for its oligomerization pattern. The initial mGBP7 IP-MS results offer hints about potential mGBP7 interaction partners and indicate that mGBP7 is ubiquitinated and ISGylated even in the absence of T. gondii infection.
The biochemical characterization of mGBP7 as well as the identification of potential mGBP7 interacting proteins will provide new insights into the dynamic interactions at the interface of parasite and host.
TCF1 and LEF1 control Treg competitive survival to maintain immune tolerance
Authors: Fu Wenxian , Yang Bi-Huei 
Published: January 2023

Abstract
CD4+Foxp3+T regulatory (Treg) cells are key players in preventing lethal autoimmunity and deleterious tissue inflammation. To fulfill this role, Treg cells undertake activation and differentiation processes and acquire diverse functional properties. However, how Treg’s differentiation and functional specifications are regulated remains incompletely understood. Here we show that gradient expression of two TCF/LEF family transcription factors, TCF1 and LEF1, distinguishes Treg cells into three distinct populations. Treg-specific ablation of TCF1 and LEF1 renders the mice susceptible to tissue immunopathology and aberrant activation of cellular and humoral responses. TCF1 and LEF1 are essential for promoting Treg’s competitive survival. In addition, the development of T follicular regulatory (Tfr) cells is completely abolished in TCF1/LEF1-conditional knockout mice, leading to unrestrained T follicular helper (Tfh) and germinal center B cell responses. Thus, TCF1 and LEF1 act redundantly to control the maintenance and functional specification of Treg subsets to prevent autoimmune and inflammatory diseases.
Profile of Double Positive T Cells (CD45+CD3+CD4+CD8+) in HIV-Infected Population in Santos City - Brazil
Authors: da Silva Silvano Aparecido , de Almeida Caroline Rossetti , dos Santos Barros Cláudia Renata 
Published: January 2023

Abstract

Background
Double Positive T Cells (CD45+CD3+CD4+CD8+) (DP) are characterized by the presence of CD4 and CD8 receptors during the development of T lymphocytes in thymus. The presence of these immature cells in peripheral blood have been shown to be present in several diseases, including in advanced stages in HIV infections. The objective of this research was to characterize the populations of Double Positive T cells in patients infected with HIV in the city of Santos, Brazil.

Methodology
Analysis of 12350 peripheral blood samples from HIV patients in the city of Santos between the years 2014 and 2017. The identification of the DP cells was performed by flow cytometry with CD3, CD4, CD8 and CD45 receptor markers.

Results
The analysis determined the prevalence of 4.7% (585 samples) of DP T cells in the population of Santos. The mean T-lymphocyte population is 1 cell. The absolute means of this population of helper and suppressor lymphocytes are 858.43 cells/μl - 31.33% and 1243.03 cells/μl - 45.39%. Samples with values greater than 5% of DP cells represented 0.11% (14 samples), which presented mean values higher than 1000 cells/μl of suppressor lymphocytes. Only half the samples had viral copies, the others were undetectable. There was a predominance of Double Negative T cells (CD45+CD3+CD4−CD8−) 95.4% (11,784 samples).

Conclusions
The presence of DP T cells was not superior to Double Negative T cells. No changes were found in the absolute counts of helper lymphocytes and only half had viral copies, with lymphocyte counts without compromising. The immune status of people living with HIV is important for understanding the course of the disease and for future therapeutic interventions.
Regulation of cancer playmaker survival: Increased neutrophil life span by the action of cancer derived a2 V-ATPase
Authors: Ibrahim Safaa A. , Kulshrestha Arpita , Katara Gajendra K , Sahoo Manoranjan , Beaman Kenneth D. 
Published: January 2023

Abstract
Pro-tumorigenic tumor associated neutrophils (TAN) have a long life span and are playmakers “supporter” in cancer progression. Identifying cancer associated factors that regulate neutrophil survival will provide new targets for cancer therapy. A peptide (a2NTD) derived from a2 vacuolar ATPase (a2V) in cancer cells promotes the neutrophil pro-tumorigenic properties that enhance angiogenesis and cancer invasion. Here, Immunohistochemical analysis of different human cancer tissues demonstrated a positive correlation between a2NTD expression and neutrophil count with lung cancer showing the highest correlation. Tissues that are heavily infiltrated by neutrophils are either poorly or moderately differentiated that indicates highly aggressive tumors. Furthermore, treatment of freshly isolated neutrophils from blood of healthy volunteers with recombinant a2NTD led to 2 fold increase in neutrophil survival. This enhancement of survival was dependent on NF-kB activation and partially dependent on TLR-2 activation. Further analysis revealed that a2NTD treatment increased the expression of anti-apoptotic proteins as Bcl-xL, Bcl-2-A1 and decreased the expression of pro-apoptotic proteins as Bax, Apaf-1 and caspase-3,-6, -7. Furthermore, a2NTD treatment stabilized the mitochondrial membrane potential and preserved the Cyt-C in the mitochondria that led to decreased caspase-9 activation. Autocrine secretion of pro-survival cytokines as TNF-a and IL-8 from a2NTD treated cells participated in this increased survival. These data provide evidence that cancer associated a2V is regulating the apoptosis of pro-tumorigenic neutrophils by influencing the intrinsic apoptosis pathway.
Reprograming human Treg metabolism via innate TLR signaling for tumor immunotherapy
Authors: Liu Xia , Li Lingyun , Sanders Katherine L. , Edwards James L. , Hsueh Eddy C. , Ford David A. , Hoft Daniel F. , Peng Guangyong 
Published: January 2023

Abstract
Regulatory T (Treg) cells induce an immunosuppressive microenvironment that is a major obstacle to successful tumor immunotherapy. Dissecting the regulations between energy metabolism and functionality in human Treg cells will provide insights for developing novel immunotherapies against cancer. We discovered that human naturally occurring Treg (nTreg) and tumor-associated Treg cells exhibit distinct metabolic profiles with predominant dependence on glucose metabolism compared with effector T cells. Activated nTreg and tumor-associated Treg cells depend on accelerated glucose consumption for their cellular senescence induction and suppressive activity in responder T cells during their cross-talk. We further identified that TLR8 signaling selectively inhibits glucose uptake and suppresses metabolic processes of glycolysis in human Treg cells, resulting in reversal of Treg suppressive function and cellular senescence induction. In addition, TLR8 signaling activation downregulates mTORC1-HIF1α signaling in Treg cells that control molecular processes of Treg glucose metabolism and suppressive functions. Our in vivo studies further demonstrated that TLR8 signaling-mediated reprogramming of glucose metabolism and function in human Treg cells can enhance anti-tumor immunity and immunotherapy efficacy in a melanoma adoptive transfer T cell therapy model. These studies identify novel mechanistic links between innate signaling and metabolic regulation of human Treg suppression, and provide a new strategy and concept for tumor immunotherapy.
Robust immune response and protection generated by a polyanhydride-based nanoparticle vaccine utilizing the RSV prefusion F protein and/or M protein
Authors: Stephens Laura , Ross Kathleen A. , Hartwig Stacey M. , McLellan Jason S. , Narasimhan Balaji , Legge Kevin L. , Varga Steven M. 
Published: January 2023

Abstract
Respiratory syncytial virus (RSV) is the leading cause of lower respiratory infections in young children, resulting in 34 million new infections each year. Natural RSV infection is insufficient to establish long-lived and complete protective immunity from reinfection, and there is no licensed vaccine for RSV. We developed a vaccine utilizing a prefusion-stabilized variant of the RSV fusion (F) protein (DS-Cav1) and/or the RSV matrix (M) protein. The vaccine is encapsulated within 20:80 1,8-bis(p-carboxyphenoxy)-3,6-dioxoctane (CPTEG):1,6-bis(p-carboxyphenoxy) hexane (CPH) copolymer nanoparticles with CpG 1668 ODN. The prefusion conformation of RSV F allows for better exposure of the major antigenic site, termed site Ø, a primary target of neutralizing antibody responses found in human serum. The RSV M protein contains epitopes that are known targets of both CD4 and CD8 T cells. To evaluate this vaccine candidate, BALB/c mice were vaccinated intranasally and subsequently boosted intranasally 4 weeks later. Vaccination with the prefusion RSV F nanovaccine significantly ameliorated weight loss and pulmonary dysfunction compared to unvaccinated mice in response to an RSV challenge. This protection remained until at least 100 days post prime vaccination. Additionally, peak viral gene copy numbers in the lung were reduced in vaccinated mice. The prime/boost prefusion RSV F vaccination induced activated lung-localized T cells, as well as tissue-resident memory CD4 and CD8 T cells in the lungs. Vaccination also induced lung tissue-resident B cells. Given the strong immune response generated as well as the protection provided from challenge, this prefusion RSV F nanoparticle formulation may be a promising vaccine candidate.
The role of mTOR, TRAF1, and local antigen in 4-1BB-dependent establishment of Trm in the lung
Authors: Batista Nathalia Vieira , Zhou Angela C , Watts Tania H 
Published: January 2023

Abstract
The tumour necrosis factor receptor (TNFR) superfamily receptor 4-1BB is important in the establishment of a tissue-resident memory (Trm) population in the lung tissue following influenza infection. Moreover, supraphysiological boosting of 4-1BB during the boost phase of a prime-boost immunization regimen can greatly enhance the establishment of a long-lived Trm population that protects against lethal heterotypic challenge (Zhou et al. Mucosal Immunology 2017). However, little is known about how 4-1BB contributes to the establishment of the lung Trm population. Here, we investigated the mechanism by which 4-1BB induces lung Trm cells. Using competitive mixed bone marrow chimeras, we found that the effect of 4-1BB on lung resident influenza-specific T cells does not substantially change between day 9 and 45 post-infection, suggesting that the main effect of 4-1BB is to allow the persistence of CD8 T effector cells as they transition to Trm. The signaling adaptor TRAF1, downstream of 4-1BB was also shown to be important in enhancing the numbers of Teffectors and Trm in the lung. Using supraphysiological stimulation of 4-1BB in the boost phase of a prime boost immunization, we show 4-1BB-mediated Trm generation is dependent on local delivery of both antigen and costimulation and that this process is inhibited by rapamycin, suggesting a role for mTOR in this process. Also, using this prime-boost model we demonstrate that TRAF1 contributes to the effect of 4-1BB on Trm generation. Taken together, these data point to an important role for 4-1BB, TRAF1 and mTORC1 in allowing the lung effector T cells in the lung parenchyma to survive through the transition to tissue resident memory T cells.
This work was funded by CIHR grant FDN-143250 to THW