bluuebunny/crossref_metadata_2025_split huggingface dataset:
TGFBR1M318R+/−: A monogenic presentation of eosinophilic esophagitis.
Authors: Laky Karen , Kinard Jessica L. , Guerrerio Anthony , Frischmeyer-Guerrerio Pamela 
Published: January 2023

Abstract
Eosinophilic esophagitis (EoE) is a chronic immune-mediated disease characterized by esophageal dysfunction and accumulation of tissue eosinophils, T cells, and mast cells. The exact causes of EoE are not known. Sequence variants associated with increased EoE susceptibility have been identified, suggesting that there can be a genetic component to the disease. Several of the genes encode proteins involved in TGFβ signaling. Patients and mice heterozygous for a mutation in the kinase domain of TGFbR1 (TGFBR1M318R+/−) exhibit cardiovascular, skeletal, and immune manifestations of Loeys-Dietz syndrome (LDS). Immune symptoms include elevated serum IgE and a propensity to develop EoE. We used TGFBR1M318R+/− mice to determine which cells are responsible for the initiation and perpetuation of EoE. Current dogma posits that EoE occurs when Th2 cells are stimulated by inhaled or ingested antigens to secrete cytokines that then recruit and stimulate eosinophils and mast cells. Thus we were surprised to find that RAG2−/−R1 mice developed disease, illustrating that EoE associated with the TGFBR1M318R mutation was not lymphocyte-dependent. Bone marrow (BM) chimeras were made to confirm that altered TGFβ signaling in radio-resistant cells was sufficient to cause EoE. Lethally irradiated R1mice reconstituted with WT BM developed EoE. In contrast, eosinophils and IgE were not elevated in WT mice reconstituted with R1BM. We looked for other potential sources of type 2 cytokines and discovered that type 2 innate lymphoid cells (ILC2) were increased in the esophagus of R1 mice. We propose that altered TGFβ signaling in epithelial cells leads to EoE by stimulating ILC2 to proliferate and secrete cytokines that result in accumulation of eosinophils.
Distribution and phenotype of HIV-specific CD8 T cells in situ in the rectal mucosa of HIV+ elite controllers
Authors: Li Shengbin , Kovacs Katalin , Kiniry Brenna , Wagstaff Reece , April Ferre , Hunt Peter , Somsouk Ma , Shacklett Barbara L. , Skinner Pamela J 
Published: January 2023

Abstract
Mucosal tissues including the gastrointestinal tract are important reservoirs for HIV replication. HIV-specific CD8 T cells are essential in controlling HIV infection. In order to gain insights into HIV-specific CD8 T cells in elite controllers (EC), we characterized this important cell population in rectal biopsies from EC using in situ tetramer staining combined with immunohistochemistry followed by quantitative analysis. Results showed tetramer+ HIV-specific CD8 T cells distributed unevenly throughout the rectal mucosa including within lymphoid aggregates. Frequencies of tetramer+ HIV-specific CD8 T cells ranged from 2 to 25 cells/mm2. A mean of 55% tetramer+ HIV-specific CD8 T cells expressed the effector protein perforin. Among the perforin+ HIV-specific T cells, the majority expressed low to medium levels of perforin and relatively few expressed high levels. In addition, we also observed a subset of perforin+ HIV-specific CD8 T cells in which perforin was located exclusively within the cell membrane, possibly representing a novel subset of armed resident or effector memory cells. Almost all tetramer+ HIV-specific CD8 T cells in the rectal mucosa were negative for Ki67, a marker for activation and proliferation (mean of 96%); many were PD-1+, a marker for recent T cell stimulation or exhaustion (mean of 59%), and some expressed CD103, a marker for a subset of resident memory T cells (mean of 6%). Taken together, these findings indicate that EC maintain diverse populations of memory HIV-specific CD8 T cells distributed throughout the rectal mucosa including within lymphoid aggregates and suggests that these cells are likely continually being exposed to antigen, but not dividing.
Lymphocyte activation gene-3 regulates mitochondrial biogenesis and metabolism of naive CD4+ T cells
Authors: Previte Dana Michelle , Menk Ashley V. , Wright Rebecca H. , Coudriet Gina M. , Delgoffe Greg M. , Piganelli Jon D 
Published: January 2023

Abstract
Lymphocyte Activation Gene-3 (LAG-3) is an inhibitory receptor expressed on the surface of various immune cells, including CD4+ T cells. While LAG-3 is more frequently associated with T cell exhaustion and regulatory T cells, it is also a negative regulator of T cell homeostatic expansion. Current interest in how cellular metabolism dictates immune cell function and fate has elucidated that CD4+ T cell function is tightly coupled to metabolism. Therefore, given that LAG-3 is a regulator of CD4+ T cell homeostatic expansion, and the ability to proliferate is highly dependent upon metabolism, we hypothesized that LAG-3 regulates the metabolic profile of naïve CD4+ T cells. Naive OT.II T cells were isolated from wildtype and LAG-3−/− animals, and analyzed by Seahorse Flux Analyzer. LAG-3−/− OT.II cells demonstrated significantly increased basal respiration, spare respiratory capacity, and aerobic glycolysis, as compared to wildtype OT.IIs, indicating an enhanced metabolic profile. Further analysis indicated that LAG-3-deficient OT.IIs displayed increased mitochondrial biogenesis via enhanced signaling through the AMPK/Sirt-1 pathway. In an adoptive transfer model of homeostatic expansion, LAG-3−/− OT.II cells expanded to a greater extent and continued to demonstrate an enhanced metabolic profile as compared to WT OT.IIs. This proved to be extrinsically regulated, as LAG-3 blockade in WT recipients recapitulated similar results to LAG-3−/− T cells. These results demonstrate that LAG-3 is critical for actively maintaining metabolic quiescence in naïve CD4+ T cells. Future directions include investigating the influence of LAG-3 and its metabolic regulation in the context of autoimmunity.
Single-cell analysis of CCR6+ human Th cells reveals varying degrees of the type-17 phenotype, ranging from cells co-expressing to those fully suppressing opposing pathways
Authors: Singh Satya , Edara Nithin , Zhang Hongwei , Chen Jinguo , Farber Joshua 
Published: January 2023

Abstract
Previously, we found that human type-17 Th cells from blood are fully contained within the CCR6-expressing subset. We also found positive correlations between levels of expression of CCR6 and levels of other type-17 proteins such as IL-17A/F, IL-22, and CCL20, □□□ negative correlations of CCR6 expression with that of genes/proteins associated with non-type-17 (Th1, Th2, TFH) pathways. In the present study, analysis of single Th cells expressing various levels of CCR6 using cell sorting followed by RT-PCR revealed that 1) patterns of expression of individual type-17 genes differed, being either binary (all-or-none-like) or graded, 2) expression levels of type-17 genes were positively correlated with each other and negatively correlated with genes associated with non-type-17 lineages, 3) cells could be identified that co-expressed genes for both type-17 and non-type-17 lineages, and 4) these “multi-lineage” cells expressed intermediate/low as opposed to high levels of the lineage-specific genes. Our data suggest that acquisition of the type-17 (and non-type-17) phenotype(s) is not all or none, but rather that cells occupy many intermediate states in forming a highly heterogeneous memory population, that genes defining “opposing” lineages can be co-expressed, and that expression of genes associated with opposing lineages is extinguished in cells at the far end of the type-17 spectrum. These findings are consistent with pathways of human Th differentiation in vivo that allow for the co-expression of multiple potentials, each to a limited degree, early on, but that subsequently narrow as a single phenotype becomes fully expressed.
Novel function for DEPTOR in CD4+ T cell activation and differentiation
Authors: Wedel Johannes , Bruneau Sarah , Liu Kaifeng , Laplante Mathieu , Briscoe David M 
Published: January 2023

Abstract
In these studies we find that DEPTOR, a modulator of mTOR signaling, is expressed in CD4+ T cells and is markedly reduced upon T cell activation. We isolated CD4+ T cells from a doxycycline-inducible transgenic mouse (rtTA+/+DEPTOR+/+ or ‘iDEP’) and, by Western blot, find that its expression is associated with an inhibition of mTORC1 activity. To test if DEPTOR functions in the modulation of both Teff and Treg cell biology, iDEP naive CD4+CD25− T cells were activated in standard Th/Treg-polarizing conditions, and Th differentiation was analyzed by qPCR and ELISpot. Induced DEPTOR favored IFN-γ production in Th1 polarized cells but dramatically inhibited IL-4 (P&lt;0.01, n=3)/IL-10 (P&lt;0.05, n=3) and IL-17A (P&lt;0.05, n=3) in Th2 and Th17 cultures respectively. In contrast, in iTreg polarizing cultures, Foxp3 expression was not influenced by DEPTOR (85.5±5.3% vs. 84.3±8.1% Foxp3+ cells, n=4; P=n.s.). However, in in vitro suppression assays, induced DEPTOR augmented iTreg function (AUC: 228.8±27.5 vs. 322.0±32.9, n=3; P&lt;0.05). Also, DEPTOR overexpressing iTregs retain higher frequencies of Foxp3 after re-stimulation with anti-CD3/CD28 (46.1±6.0% vs. 9.9±5.8% Foxp3+ cells on day 7, n=3; P&lt;0.001). To confirm that DEPTOR functions in vivo, iDEP CD4+ T cells were adoptively transferred (day 2) into Rag2γc−/− recipients (H-2b) of fully MHC mismatched BALB/c (H-2d) heart transplants. Induced DEPTOR within transferred CD4+ cells resulted in a significant prolongation of graft survival (37 days, n=5 vs. 16 days, n=6; P&lt;0.01).
Collectively, these findings identify CD4+ T cell DEPTOR as a novel cell intrinsic protein that functions to regulate Teff differentiation and Treg function in vitro, and to promote immunoregulation in vivo.
Natural ThPOK− CD4 cytotoxic T lymphocytes : Thymic development of a new distinct self-specific CD4 T cell population.
Authors: Thiault Nicolas , Mushtaq Mohd.Husain , Iwaya Hitoshi , Verstichel Greet , Cheroutre Hilde 
Published: January 2023

Abstract
The lineage commitment to either CD4 or CD8 T cells is made in the thymus, where thymocytes with specificity for MHC-II molecules differentiates into the CD4 “helper” linage whereas ones specific for MHC-I molecules commit to the CD8 “cytotoxic” lineage. The molecular regulation is controlled by the action of key transcription factors. Notably ThPOK, which promotes the CD4 fate and suppress the cytotoxic fate of CD4 T cells. Recently, we made a major breakthrough and showed that these lineages is not fixed and the mature peripheral CD4 T cells have the plasticity to lose ThPOK expression and reprogram to ThPOKneg CD4 CTL (cytotoxic T lymphocytes) marked by the expression of CD8a, Granzyme B and potent killer capacity.
Investigating the origin of CD4 CTL, we observed in ThPOK fate maping mouse a strong proportion of CD4 CTL that never expressed ThPOK, suggesting that some CD4 CTL are natural cytotoxic cells that develop in the thymus. Based on a recent works allowing the analysis of mature CD4 cells in the thymus, we observed a substantial number of mature CD4 T cells that do not express ThPOK and display an active-like phenotype. Moreover, once injected, thymic ThPOKneg mature CD4 T cells remain ThPOKneg in the periphery and start to acquire CD8a expression demonstrating that natural CD4 CTL arise from the thymus. We also demonstrated that this population requires a strong TCR signal during their development, suggesting that natural CD4 CTL have a repertoire specific for self-antigens.
We have identified a new distinct population of mature CD4 T cells that develop in the thymus: the natural cytotoxic CD4 T lymphocytes. We also established mechanism underlying these process by demonstrating that CD4 CTL needs a strong TCR signal for their differentiation.
Memory T cells contribute to early pathogen clearance in a site-specific manner in the absence of cognate antigen
Authors: Maurice Nicholas Joseph , Berkson Julia D , Prlic Martin 
Published: January 2023

Abstract
Memory CD8+ T lymphocytes are typically considered to contribute to host immunity when they reencounter their specific antigen; however, in the absence of cognate antigen, inflammatory signals can elicit the rapid expression of Granzyme B and Interferon-γ in memory CD8+ T cells. This is referred to as “bystander activation” and occurs during the early stages of infection, which are dominated by innate immune responses. We and others have demonstrated that bystander-activated cytotoxic T lymphocytes (BA-CTL) can kill target cells in an NKG2D-ssdependent, TCR-independent manner early after infection. This suggests that memory T cells can employ innate-like mechanisms for rapid TCR-independent responses to infection. Here we report that antigen non-specific BA-CTL display clustering and increased functionality at sites of splenic pathogen replication during WT Listeria monocytogenes (LM) infection. These clusters at early time-points closely resemble those of antigen-specific cells during primary and recall responses against recombinant LM. We describe the mechanisms driving this early activation and define distinct stages of this innate-like effector program. We propose that the purpose of recruiting BA-CTL to sites of infection and eliciting these innate-like functional capacities is to limit early pathogen replication.
Characterization of CD31 expression on murine and human neonatal T lymphocytes during development and activation
Authors: Fike Adam J , Nguyen Linda T , Kumova Ogan K , Carey Alison J 
Published: January 2023

Abstract
CD31, expressed by the majority of the neonatal T cell pool, is involved in modulation of T-cell receptor (TCR) signalling by increasing the threshold for T cell activation. Therefore, CD31 could impact neonatal tolerance or immune responses during infection. Cells were harvested from murine neonates at various days post-birth, human late preterm and term cord blood and adult peripheral blood. The number of CD31 expressing CD4+ and CD8a+ T cells increase in the neonatal mouse over the first week of life, which is consistent with previous work demonstrating an increase in CD31 expression across human gestation. Human samples were activated in vitro over a five-day period to simulate acute inflammation similar to chorioamnionitis or early onset sepsis. The frequency of human CD31+ CD4+ and CD8a+ T cells decrease upon activation, with infants having a lower frequency of CD31+ cells compared to adults. In order to further evaluate the regulation of CD31 during acute infection, murine neonates at 3 and 7 days of age were infected with influenza. There was an increased number of naïve and activated CD31+ T lymphocytes at the site of infection at 6 and 9 days post-infection in the 3-day old neonates (p&lt;0.05), as compared to 7-day old. However, the opposite is true in the periphery; mice infected at 7-days of age have an increased number of activated CD31+ T lymphocytes in the spleen at 9 days post-infection (p&lt;0.05). Trafficking differences of CD31+T lymphocytes to the site of infection suggest a differential regulation in younger mice which could contribute to the dampened adaptive immune response in neonates. Further murine and human mechanistic studies which examine CD31+ cytotoxic T lymphocyte function at the site of infection are needed.
Cholinergic stimulation enhances intestinal antimicrobial activity and prevents systemic dissemination of pathogenic bacteria
Authors: Fernandez-Cabezudo Maria J , Al-Barazei Ray , Bashir Ghada , Mohamed Yassir A. , Qureshi Mohammad M , al-Ramadi Basel B 
Published: January 2023

Abstract
Inflammation constitutes an important component of host defense against pathogenic bacteria. This innate immune response is crucial for clearance of pathogens and survival of the host. However, unrestrained inflammatory reaction may result in systemic manifestations with dire consequences to the host. The extent of activation of the inflammatory response is tightly regulated through immunological and neural pathways. We have previously demonstrated that cholinergic stimulation, by administration of acetylcholinesterase inhibitors, confers enhanced protection in experimental animals orally infected with virulent Salmonella typhymurium. In this study, we investigated the mechanism by which AChE inhibition modulates the immune response to Salmonella infection. Enhanced host survival following oral infection correlated with significantly reduced bacterial dissemination to target organs, including livers and spleens. This protection was not due to increased gut motility or rapid bacterial clearance from the gastrointestinal tract. Moreover, protection was lost when the animals were infected systemically, suggesting that acetylcholine-mediated protective effect was mostly confined to gut mucosal tissue. In vivo imaging demonstrated more localized infection and delay in bacterial dissemination into systemic organs in mice pre-treated with AChE inhibitors. Morphological analysis of small intestine (ileum) showed that AChE inhibition induced degranulation of goblet cells and Paneth cells, two specialized secretory cells involved in innate immunity. Our findings demonstrate a crucial pathway between neural and immune systems that acts at the mucosal interface to protect the host against invading pathogens.
SHP1 alters TCR signal strength and metabolism
Authors: Martinez Hunter , Martinez Ryan J , Kolawole Elizabeth M , Evavold Brian D 
Published: January 2023

Abstract
Recently, we have shown thymocytes lacking SHP1 have decreased cell numbers post selection for both CD4 SP and CD8 SP. This thymocyte selection defect led to decreases in tetramer positive precursor numbers in the periphery. Specifically we analyzed CD8 T cells for LCMV GP33–41:Kd and CD4 T cells for MOG35–55:IAb. Immunization with LCMV Armstrong revealed about 50% reduction of antigen specific T cells, both CD4+ and CD8+. Even though SHP1 deficient T cells have reduced numbers, they exhibit superior proliferation as observed by cell trace violet coupled with increased death. Though SHP1 has many implications in T cell signaling, a novel aspect is impacting metabolism as the SHP1 deficient T cells display increased metabolic activity. Naïve SHP1 deficient CD8 T cells exhibit increased mitochondrial respiration. During expansion, these T cells maintain increased mitochondrial respiration compared to wildtype controls. Comparatively, lack of SHP1 also causes an increase in glucose uptake throughout expansion. Altogether, SHP1 appears to impact TCR mediated signal threshold which leads to increased T cell metabolism in peripheral tissues.
Assessing the immunomodulatory potential of therapeutic agents in cynomolgus macaque cytotoxic T lymphocytes.
Authors: Frank Brendon , Guerrero Abraham , Lebrec Herve , Balazs Mercedesz 
Published: January 2023

Abstract
The preclinical evaluation of therapeutic agents contributes to the understanding of associated risks and benefits. The non-human primate, and notably the cynomolgus macaque, is often a species of choice for such pharmacological and toxicological assessments. The degree of immunomodulation associated with these agents, intended or not, is a critical point to consider in that context. While there are tools to immunophenotype and enumerate effector T cells, the knowledge gap surrounding the functional characterization of cytotoxic T lymphocytes (CTL) persists. Here we present a multi-parametric cynomolgus macaque CTL functional assay. By using an EGFR expressing target cell line co-cultured with cynomolgus peripheral blood mononuclear cells (PBMC) and an EGFR Bispecific T Cell Engager (BiTE®), we were able to redirect lysis in a target-specific manner. In this assay we simultaneously monitored cytolytic potential (CD107a) and cytokine secretion (IFN-γ and TNF-α) of effector CTL against target cell growth. Overall our results demonstrate the ability to assess cynomolgus CTL function under known immunosuppressive agents, thereby enabling a multi-parametric approach of monitoring the impact of investigational drugs on an important component of the immune system.
Contribution of NKT follicular helper cells to T-dependent and T-independent humoral immunity against bacterial toxins and polysaccharides
Authors: Lang Mark L , Lang Gillian A. , Rampuria Pragya , Shrestha Binu , Ballard Jimmy D 
Published: January 2023

Abstract
Activation of CD1d-restricted Natural Killer T (NKT) cells with the CD1d-binding glycolipid α-galactosylceramide (α-GC), promotes humoral immunity against co-administered T-dependent and T-independent antigens. The discovery of a Bcl6hi/CXCR5+/PD-1hi, IL-21-secreting ‘follicular helper’ NKT subset (NKTfh) led to the hypothesis that NKTfh cells promote humoral immune responses to vaccine candidates including bacterial toxins and surface polysaccharides. We used Cre-Lox technology to ablate Bcl6 expression by CD4-expressing cells in mice and examine the impact on NKT-driven humoral immunity to Clostridium difficile-derived Toxin B (TcdB) and surface carbohydrates (PSI, II, and III) as well as model polysaccharides (Ficoll). In the CD4Cre;Bcl6fl/floffspring, we observed ablation of Bcl6hi/CXCR5+/PD-1hi NKT cells without depleting the parent NKT population. Adoptive transfer of NKT cells from B6 donors capable of NKTfh differentiation demonstrated a contribution to the T-dependent TcdB-specific antibody response. As expected, NP-conjugated Ficoll produced a strong NP-specific IgM and IgG3 response when administered alone, and selective class switch to IgG1 was observed when α-GC was co-administered. In NKTfh cell-ablated mice, the IgG1 response was abolished while the IgM and IgG3 responses remained intact. Experiments are underway to determine if this result will be replicated using C. difficile-derived polysaccharides. In conclusion, NKTfh differentiation driven by glycolipid adjuvants can enhance and/or broaden humoral immune responses against pathogen-derived T-dependent and T-independent antigens.
ADAM10 regulates the ICOS:ICOSL axis
Authors: Lownik Joseph Cornelius , Luker Andrea , Martin Rebecca , Damle Sheela , Conrad Daniel H 
Published: January 2023

Abstract
The interaction between inducible costimulator (ICOS) and its ligand (ICOSL) is essential for proper T-dependent humoral immune responses, especially follicular helper T cell (TFH) development. We have demonstrated that A Disintegrin and Metalloproteinase 10 (ADAM10) is the primary and physiological sheddase of ICOSL. Using an in vivo system in which ADAM10 is deleted only on B cells (ADAM10B−/−) leads to high ICOSL levels which in turn causes downregulation of surface T cell ICOS expression through internalization of ICOS. In an unimmunized state, ICOS is internalized in ADAM10B−/−mice and is preferentially shuttled to the lysosomal compartment for degradation. We have recapitulated these findings in an in vitro system, showing that upon ligation, ICOS is rapidly internalized and is shuttled to endosomal recycling or lysosomal degradation, depending on availability of TCR costimulation. Thus, elevated ICOSL in the absence of TCR stimulation results in loss of ICOS and recapitulates the phenotype of an ICOS knockout with severe defects in T follicular helper (TFH) development and Th2 polarization, as well as enhanced Th1 and Th17 immune responses. Blockade of ICOSL in ADAM10B−/−mice rescues T cell ICOS surface expression and restores both TFH numbers and antibody production. Overall, we propose a novel regulation of the ICOS:ICOSL axis, with ADAM10 directly regulating ICOSL which in turn regulates ICOS levels.