bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immune phenotype and IL-6 deficiency modulate the inflammatory response in a mouse model of Irritant Contact Dermatitis
Authors: Calhoun Kaitlin , Luckett-Chastain Lerin , Gallucci Randy 
Published: January 2023

Abstract
Skin diseases are the second most common occupational illness with associated per annum costs exceeding $1 billion. Irritant contact dermatitis (ICD), the most common occupational skin disease, is characterized as an acute inflammatory response that manifests as a result of topical irritant exposure. Immune phenotype, such as Th1- and Th2- dominance, is postulated to contribute to the variability seen between patients. In addition, interleukin 6, which is known to have variably both Th1 and Th2 properties, has been shown to play a key role in ICD. C57BL/6J (“Th1 dominant”), Balb/c (“Th2 dominant”), and IL-6KO mice were utilized to investigate ICD induced by exposure to the occupational irritants, benzoalkonium chloride (BKC) and JP-8 jet fuel. Histopathology revealed epidermal thickening and dermal cellular infiltration in dermatitis lesions, with IL-6KO skin exhibiting the most severe damage. Analysis of skin cytokine and chemokine protein expression showed that IL-1β, TNF-α, TGF-β, CCL2, CCL3 and CXCL1, were elevated in mice exposed to BKC regardless of immune phenotype. In contrast, IL-1β, TNF-α, TGF-β, and CXCL1 varied between mouse strains when JP-8 was compared to control exposure. Flow cytometric analysis and immunohistochemistry indicated neutrophil and monocyte presence within dermatitis lesions; however, IL-6KO showed a greater amount of neutrophils following BKC exposure and decreased neutrophil presence after JP-8 exposure when compared to C57 mice. Overall, it appears that immune phenotype and IL-6 deficiency alters the skin inflammatory response in ICD via differential cytokine and chemokine expression that influence the type of inflammatory cells that infiltrate into the skin.
The microglial cell response to sterile nerve injury in the brain is regulated by IRF8
Authors: Campbell Iain L , Xie Rui Dan , Villacampa Nàdia , Almolda Beatriz , Gonzalez Berta , Castellano Bernardo 
Published: January 2023

Abstract
Microglia, the resident immune cells of the central nervous system (CNS), respond vigorously to insults such as nerve injury. We have shown previously in the normal CNS the properties of microglia are dramatically altered in the absence of IRF8. Here we examined whether IRF8 is involved in the microglial cell response to sterile nerve injury. Facial nerve axotomy (FNA) was performed in wild type (WT) and IRF8−/− (KO) mice and the brain removed at different days post-injury (dpi). In brains from IRF8 KO mice, nucleoside diphosphatase (NDPase) histochemistry revealed gross alterations in the morphology of microglia, which were stunted and hypertrophied but were present in comparable numbers with WT. In WT mice, a progressive increase in microglial cell activation was observed peaking at 7 dpi and was accompanied by dense staining for lectin, NDPase and CD11b. By contrast, in IRF8 KO mice, the microglial cell activation was grossly attenuated with the density of staining for lectin, NDPase and CD11b reduced significantly. The attenuated microglial cell activation in IRF8 KO mice was paralleled by a significant decrease in microglial cell proliferation at 7 and 14 dpi. The wrapping of individual motor neuron cell bodies in the axotomised facial nucleus by microglia involved in synaptic stripping and phagocytosis was incomplete in IRF8 KO mice and was accompanied by an increase in degenerated neurons. These findings show that in addition to maintenance of homeostatic properties, IRF8 also has an important role in regulating a number of key processes in the microglial cell response to neuronal injury.
Role of M1-polarized Macrophages in Parkinson’s Disease Models
Authors: Qin Hongwei , Yan Zhaoqi , Lee Kevin S , Gibson Sara A , Li XInru , Harms Ashley S , Buckley Buckley A , Standaert David G , Benveniste Etty N 
Published: January 2023

Abstract
Parkinson’s Disease (PD) is an age-related, chronic neurodegenerative disorder. Activated microglia/macrophages and subsequent neuroinflammation is associated with the pathogenesis of PD. We have recently demonstrated that inhibiting the JAK/STAT pathway prevents neuroinflammation and neurodegeneration in an α-synuclein (α-syn) overexpression PD model by suppressing activation of immune responses. Our previous studies demonstrated that deletion of SOCS3, a negative regulator of the JAK/STAT pathway, in the myeloid cells (LysM-CreSOCS3fl/fl mice) resulted in polarization of the pro-inflammatory M1 macrophage phenotype, which have been implicated in contributing to PD pathogenesis. To better understand the function of M1 polarized macrophages in PD, we utilized the α-syn overexpression model in LysM-CreSOCS3fl/fl mice. Our results indicate that stimulation of SOCS3-deficient macrophages with a combination of α-syn and IFN-γ promotes a more pronounced M1 phenotype and higher levels of expression of MHC Class II, LRRK2, CD40, iNOS, TNF-α and IL-6, compared to SOCS3fl/fl cells. In the in vivo setting, the numbers of activated and infiltrating macrophages are increased in the midbrain of LysM-CreSOCS3fl/fl mice compared to SOCS3fl/fl mice at 4 weeks of a-syn transduction. Furthermore, there is enhanced MHC Class II expression and STAT3 activation in these activated macrophages from LysM-CreSOCS3fl/fl mice. Our novel findings demonstrate that dysregulation of the JAK/STAT pathway in myeloid cells contributes to neuroinflammation in PD by promoting the M1 macrophage phenotype. As such, targeting the JAK/STAT pathway to abrogate neuroinflammation and neurodegeneration may be a therapeutic strategy for PD patients.
Quantitating dendritic cell clustering in the lymph node.
Authors: Byrum Janie Rae , Fricke Matthew , Tafoya Justyna , Moses Melanie , Cannon Judy L 
Published: January 2023

Abstract
The efficiency of the T cell search for antigen presented by dendritic cells (DCs) in lymph nodes (LNs) is a determinant of the overall timing of the T cell immune response to infection. While there is suggestion that DCs are clustered in LNs, there has been little quantitative analysis done to precisely analyze DC positioning in LNs. We present the quantitation of murine DC motility, surface area, and volume in the lymph node. We also use computational analysis of 2 photon microscopy images of explanted murine lymph nodes from CD11c-YFP mice to determine the degree of clustered-ness of DCs. Our analysis indicates a degree of DC clustering within the lymph node. Previously our lab identified sites in the lymph node visited with greater frequency by T cells than would be expected by random motility. We hypothesize such sites demonstrate that DC clusters may actively attract T cells. Elucidating whether T cell motility around DC clusters is distinctive from T cell motility in areas where DCs are non-clustered will help decipher T cell search strategy and the timing of the adaptive immune response.
MiR-23~27~24 clusters control effector T cell differentiation and function
Authors: Lu Li-Fan , Cho Sunglim , Wu Cheng-Jang , Yasuda Tomoharu , Cruz Leilani Ong , Khan Aly Azeem , Lin Ling-Li , Nguyen Duc T , Miller Marina , Lee Hyang-Mi , Kuo Ming-Ling , Broide David H , Rajewsky Klaus , Rudensky Alexander Y 
Published: January 2023

Abstract
Coordinated repression of gene expression by evolutionarily conserved microRNA (miRNA) clusters and paralogs ensures that miRNAs efficiently exert their biological impact. Combining both loss- and gain-of-function genetic approaches, here we show that the miR-23~27~24 clusters regulate multiple aspects of T cell biology, particularly Th2 immunity. Low expression of this miRNA family confers proper effector T cell function at both physiological and pathological settings. Further studies in T cells with exaggerated regulation by individual members of the miR-23~27~24 clusters revealed miR-24 and miR-27 collaboratively limit Th2 responses through targeting IL-4 and GATA3 in both direct and indirect manners. Intriguingly, while overexpression of the entire miR-23 cluster also negatively impacts other Th lineages, enforced expression of miR-24, in contrast to miR-23 and miR-27, actually promotes the differentiation of Th1, Th17 and iTreg cells, implying that under certain conditions, miRNA families can fine tune the biological effects of their regulation by having individual members antagonize rather than cooperate with each other. Together, our results identify a miRNA family with important immunological roles and suggest tight regulation of miR-23~27~24 clusters in T cells is required to maintain optimal effector function and to prevent aberrant immune responses.
The RNA binding protein HuR is necessary for IL-2 homeostasis and CD4+ T cell differentiation
Authors: Glascock Jacqueline J , Techasintana Patsharaporn , Ellis Jason S , Ridenhour Suzanne , Atasoy Ulus 
Published: January 2023

Abstract
RNA binding proteins, such as HuR (ELAVL1), fine tune gene expression in activated T cells by interacting with their 3′ UTR AU-rich elements (AREs) via posttranscriptional gene regulation. IL-2 and many Th2 cytokine mRNAs contain 3′ UTR AREs. Thus, we hypothesized that HuR may play a critical role in CD4+ T cell differentiation by regulating IL-2 signaling pathways. We conditionally ablated HuR in CD4+ T cells (distal lck-Cre ROSA HuRfl/fl) to test this hypothesis. HuR KO T cells are able to develop and egress the thymus normally. However, these cells cannot shut off IL-2 production and display defects in Th2 differentiation and cytokine expression. Proliferation defects, decreased p-stat5, and reductions in CD25 and prdm-1 transcription were also observed in the HuR KO T cells. In the absence of HuR, Il2ra (CD25) mRNA recruitment to heavy polysomes is reduced, indicating that HuR plays a critical role in its translation. This suggests that HuR regulates T cell activation and IL-2 homeostasis by controlling CD25 expression. When activated under Th0 conditions, 97% of HuR KO cells expressed IL-2 on day 5 compared to HuR WT cells (50%). HuR KO cells also had large increases in steady state IL-2 mRNA (30-fold) and 7-fold increases in secreted IL-2 protein. Furthermore, HuR KO cells produced scant amounts of the Th2 cytokines at the protein level. These findings led us to investigate the fate of other T cell lineages when HuR is absent. When polarized to Treg, Th17, and Tfh lineages, HuR KO T cells showed reduced levels of the signature transcription factors Foxp3, RoRγt, and Bcl6, respectively, as compared to controls. Thus, we conclude that HuR plays an indispensable role in normal IL-2 homeostasis and CD4+ T cell differentiation.
CD28 signals through tyrosine residues in its cytoplasmic tail to promote CD4+ T cell clonal expansion during infection
Authors: Krueger Peter D , Burbach Brandon , Malhotra Deepali , Miller Jim , Jenkins Marc K 
Published: January 2023

Abstract
CD28 is required for maximal proliferation of CD4+ T cells stimulated through their TCRs. Polyclonal peptide: MHCII-specific CD4+ T cells in mice lacking CD28 or its cytoplasmic tail produced one tenth as many effector and memory cells as wild-type T cells after bacterial infection. However, mutations in the canonical signaling sites, the membrane proximal YMNM and distal PYAP sequences, located in the cytoplasmic tail failed to suppress T cell expansion, suggesting additional sequences are sufficient for signaling. We therefore tested the contribution of the four tyrosine (4Y) residues in the cytoplasmic tail by establishing bone marrow chimeras in which CD28-deficient donor cells were first transduced with either wild-type CD28-CFP or mutated CD28-4Y-YFP and subsequently transferred to irradiated congenically mismatched CD28-sufficient mice. CD28-4Y MHCII-specific CD4+T cells produced one tenth as many effector cells as wild-type CD28-CFP cells after infection with bacterial expressing antigenic peptides. These results implicate that the tyrosine residues located in the cytoplasmic tail are required for CD28 signal transduction in effector CD4+ T cells in vivo.
Regulatory T cells evade restimulation-induced cell death by FOXP3-mediated repression of the SAP promoter.
Authors: Voss Kelsey , Katz Gil , Yan Toria , Kim Yong Chan , Scott David W , Snow Andrew L 
Published: January 2023

Abstract
An efficient adaptive immune response relies on the rapid clonal expansion of effector T cells, paired with timely disposal of those cells in order to avoid damage to host tissues and maintain immune homeostasis. Restimulation-induced cell death (RICD) is one programmed apoptotic pathway that ensures effector T cell expansion remains in check, triggered by repeated stimulation through the T cell receptor (TCR) in the presence of interleukin-2 (IL-2). CD4+ regulatory T cells (Tregs) require IL-2 and experience frequent TCR stimulation, but are highly resistant to RICD. Although the mechanism remains unclear, previous work has shown that RICD resistance in Tregs is dependent on the forkhead box P3 (FOXP3) transcriptional repressor, the master regulator of Treg function. We have previously shown that T cells from patients with X-linked lymphoproliferative disease (XLP-1), caused by null mutations in the signaling adaptor molecule SLAM-associated protein (SAP), are resistant to RICD. In fact, SAP is required for optimal RICD in effector T cells. We now demonstrate that Tregs express very low levels of SAP compared to conventional T cells (Tconv). Using chromatin immunoprecipitation and reporter assays, we show that FOXP3 reduces SAP expression in Tregs by binding to and repressing the SH2D1A (SAP) promoter. Indeed, knockdown of FOXP3 restores SAP-driven RICD sensitivity in Tregs through a FAS ligand-dependent mechanism. Intriguingly, our preliminary data suggest that FOXP3 also confers RICD resistance in Tconv during initial rounds of activation-induced proliferation. Hence our results provide a mechanism by which FOXP3 confers resistance to RICD to help preserve Tregs and protect early effector Tconv cells.
Requirement of EHD family of endocytic recycling regulators for T-cell function.
Authors: Iseka Fany M , Goetz Benjamin , Cypher Luke R , Bielecki Timothy , Storck Matthew , Mosely Lee , Band Vimla , Band Hamid 
Published: January 2023

Abstract
Regulatory mechanisms that ensure effective antigen-specific responses by T-cells without evoking autoimmune disease are of great interest in basic and clinical immunology. While signaling through T-cell receptor (TCR) and positive and negative co-receptors have received great attention, mechanisms that control the dynamic traffic of such receptors between the cell surface and intracellular compartments have received less attention. Based on the well-known ability of the TCR to undergo constitutive internalization and recycling to the cell surface, we hypothesized C-terminal Eps-15 Homology Domain-containing (EHD) proteins may play important roles in TCR-mediated T-cell functions by regulating the recycling of TCR and other receptors on T-cells. EHD proteins (EHD1-4) are key regulators of endocytic recycling of surface receptors, including the MHC-I and MHC-II proteins, but their role in TCR traffic or T-cell function is unknown. We found EHD1, 3 and 4 to be expressed in CD4+T cells. Accordingly, we generated a conditional knockout model in which floxed EHD1, 3 and 4 are deleted in CD4+T cells (CD4-Cre) of mice bearing a myelin oligodendrocyte glycoprotein (MOG)-specific TCR transgene. In vitro, CD4+T-cells from these mice exhibit reduced antigen-driven cell proliferation and IL-2 secretion. In vivo, these mice exhibit reduced severity of experimental autoimmune encephalomyelitis (EAE) upon immunization with antigen. Initial analyses suggest that the recycling of TCR (CD3ɛ) and the surface levels of TCR, CD28, LFA-1 and CD25 on the surface of CD4+ T cells are reduced by EHD1/3/4 knockout. Our studies reveal a novel role of the endocytic recycling proteins of the EHD family in TCR-mediated T-cell activation.
Differences in NAADP-mediated calcium signaling between natural regulatory T cells and naive or effector T cells.
Authors: Wall Katherine Ann , Ali Ramadan A. , Giovannucci David R. , Slama James T. 
Published: January 2023

Abstract
We previously showed that nicotinic acid adenine dinucleotide phosphate (NAADP), the most potent calcium mobilizing second messenger discovered to date, is involved in the initiation and propagation of calcium signals in naive T cells. Combining live-cell imaging and a pharmacological approach using the NAADP antagonist Ned-19, we determined a role for NAADP in proliferation and cytokine production by Th1, Th2, Th17 and CD8 effector T cells. However, natural T regulatory (nTreg) cells showed a different profile. Ned-19 did not inhibit calcium flux in Tregs in response to T cell receptor stimulation. Externally added NAADP produced a significant calcium flux in naive and effector T cells, but not in nTregs. Ned-19 did not inhibit the proliferation of nTregs, which is very low, although it did inhibit proliferation of naive and effector T cells. These results suggest another way in which signaling pathways differ between effector and regulatory T cells that may be exploited to modify immune responses.
Aryl hydrocarbon receptor activation and IL-2 have synergistic effects that enhance human natural killer cell cytotoxicity.
Authors: Li Jian , Doty Andria , Glover Sarah Camile 
Published: January 2023

Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor. Initial studies of AHR concentrated on its role in the detoxification of xenobiotics. However, recent research has focused on its role in the immune system. AHR has been shown to be involved in the differentiation and maintenance of different immune cell subsets. Little is known about how AHR regulates immune cell effector function. In this study, we were able to show that AHR activation significantly increased IL-2-producing human NK-92MI cell degranulation capacity and cytotoxicity. However, for the FACS-sorted primary human NK cells from blood donor PBMC, AHR activation alone had no influence on NK cell degranulation and cytotoxic functions. We observed similar effector function enhancement of primary NK cells only with the addition of AHR agonist 6-Formylindolo (3,2-b)carbazole (FICZ) in conjunction with IL-2. Moreover, AHR activation significantly increased signaling factor MAPK1 expression in the NK-92MI cells, but not MAPK3 and NF-κB. Surprisingly, FICZ stimulation had no direct impact on human NK cell TNFα production, pre-formed proteins Perforin and Granzyme B production, as well as IL-2 receptor expression, but inhibited IFN-γ production slightly. In summary, AHR agonist FICZ acted synergistically with IL-2 to enhance human NK cell degranulation capacity and cytotoxicity function, possibly through activation of the MAPK1 signaling pathway which is involved in the polarization process of microtubule organizing center(MTOC) and lytic granules, a prerequisite for killing the target. Overall, the modulation of human NK cell response from AHR activation has revealed its potential therapeutic value.
Hemokinin-1 and Substance P provide adjuvancy for T cell activation and survival necessary for innate and adaptive cellular immune responses
Authors: Sumpter Tina L , Tkacheva Olga , Shufesky William , Falo Louis D , Morelli Adrian E , Larregina Adriana T 
Published: January 2023

Abstract
Chronic inflammatory and autoimmune disorders rely on the generation of efficient T cell responses. The pro-inflammatory neuropeptides, hemokinin-1 (HK-1) and substance P (SP) potentiate cellular immunity by signaling via the neurokinin-1 receptor (NK1R) expressed in leukocytes, including T cells. HK-1 is secreted by leukocytes while SP is released by sensory nerves and tissue resident cells. The role of NK1R signaling in the effector functions of T cells remains ill understood. We investigated the effects of signaling via the NK1R in the population of activated T-cells. In vitro, we compared the effects of HK-1 and SP on the survival and effector functions of wild type (WT) and NK1RKO CD4 and CD8 T cells. In vivo, we compared the effect of NK1R-signaling on T cells by using a delayed-type hypersensitivity (DTH) model in hosts with selective deletion of the NK1R in T cells. We demonstrate that NK1R-signaling is necessary for the generation, and maintenance of the survival and effector functions of CD4 and CD8 T cells. T cells secreted HK-1 and SP to promote self-activation and survival. Signaling via the NK1R resulted in Ca2+-influx in T cells, and that effect was impaired in NK1RKO T cells. Downstream, NK1R signaling activated the Ca2+-dependent NFAT1 and NFAT2 pathways, with the consequent increases in the synthesis and secretion of IL-2 that sustained T cell survival. In addition, NK1R-signaling stimulated the MAPK (c-Fos and c-Jun) and NF-kB pathways resulting in T cell activation. In vivo, DTH assays were significantly compromised in mice with selective deletion of NK1R+ T cells compared to WT. Our results elucidate the role and mechanisms of specific NK1R-T cell signaling in the generation and maintenance of potent T cell responses.
Calcium-dependence of cytotoxic granule endocytosis depends on the Flower protein
Authors: Chang Hsin-Fang , Mannebach Stefanie , Beck Andreas , Schirra Claudia , Pattu Varsha , Flockerzi Veit , Rettig Jens 
Published: January 2023

Abstract
Cytotoxic T lymphocytes (CTLs) kill their targets by secreting perforin and granzymes from cytotoxic granules (CGs) at the interface between CTL and target cells, the immunological synapse (IS). Retrieval of membrane proteins at the IS plays a crucial role in CTL effector function by impacting the serial killing ability of CTLs. However, the cellular and molecular mechanism of CG endocytosis is largely unknown. In neuronal synapses, it has been shown that calcium influx is instrumental to trigger endocytosis, but the identity of calcium channel remains unclear. Flower protein has been reported as a potential candidate to regulate synaptic endocytosis in drosophila. We investigated a potential calcium-dependence of CG endocytosis and whether Flower plays a role in this process. We first confirmed that Flower protein is expressed in WT mouse CD8+ CTLs by western blot. We then generated Flower-deficient mice to further study Flower function. While we observed no change of degranulation and CG secretion in Flower-deficient CTLs, CG endocytosis at the IS was entirely blocked upon target cell contact. Re-introduction of Flower protein or elevation of extracellular calcium rescued the endocytosis defect in Flower-deficient CTLs. Interestingly, live imaging data showed that Flower localizes on intracellular vesicles which polarize to the IS upon target cell contact. We conclude from our data that endocytosis of CGs is calcium-dependent and that the Flower protein is providing the required calcium, probably through release from intracellular organelles.