bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adenosine receptor signaling regulates effector T cell activation through the limitation of aerobic glucose metabolism.
Authors: Campillo-Gimenez Laure , Li Michael , Molina Elsa , Ernst Peter B 
Published: January 2023

Abstract

Background
In a mouse model of colitis, we previously reported the protective role of the adenosine axis on effector T (Teff) cell responses and disease progression. Inflammatory reactions are paired with cell metabolic reprogramming from oxidative phosphorylation (OXPHOS) to aerobic glycolysis which is also a hallmark of T cell activation. Thus, we sought to evaluate the role of the adenosine 2A receptor (A2AR) signaling in the regulation of T cell metabolism.

Methods
Teff cells were reactivated in the presence or absence of A2AR agonists. Gene expression of mTOR, HIF-1α and cMyc (transcriptional factors of glycolysis-related genes) were quantified by qPCR. T cell metabolic phenotype was evaluated by transcriptomic profiling (Nanostring nCounter® Metabolic Pathway Panel), as well as real-time extracellular flux analysis, glucose uptake, and ATP production assays.

Results
mTOR, HIF-1α and cMyc gene expression increased as soon as 2hr post stimulation. At this time point, transcriptomic analysis revealed an A2AR agonist-induced downregulation of pathways related to T cell activation (i.e. mTOR, MAPK, PI3K, NFκB and cMyc pathways) and energy metabolism (i.e glycolysis, autophagy, fatty acid synthesis) whereas oxidative metabolism pathways (OXPHOS, fatty acid oxidation, glutamine metabolism) were upregulated (Pathway Score q-value &lt;0.05). Functional assays showed a decreased de novo glucose uptake and glycolysis rate after A2AR agonist treatment while OXPHOS capacity and ATP production were not modulated.

Conclusion
A2AR signaling provokes a rewiring of the activated T cell metabolism towards an oxidative state making adenosine a potential T cell metabolic regulator that can be exploited in the treatment of IBD.
Supported by NIH R01AI079145
Circadian control of macrophages in the tumor microenvironment.
Authors: Clark Amelia M , Altman Brian J 
Published: January 2023

Abstract

Introduction
All leukocytes tested to date have functional circadian clocks, and nearly every arm of the immune response is subject to circadian regulation. Circadian clocks instruct the time-of-day-dependent, rhythmic expression of genes in a tissue- and cell-specific manner. In macrophages (mΦs), the circadian clock regulates several factors that are critical to executing effective immune responses. Tumor-associated mΦs are major contributors to immune suppression in the tumor microenvironment (TME). Evidence suggests that metabolically stressful factors in the TME such as acidic pH and nutrient limitation promote mΦ-mediated immune suppression, and recent data point to dysregulation of the circadian clock downstream of metabolic stress.

Methods
We study the effect of TME-associated metabolic stress on the circadian clock of mΦs in vitro by culturing bone marrow-derived mΦs in conditions mimicking acidic pH and nutrient limitations that have been observed in the TME. To study the impact of mΦ-intrinsic circadian rhythms on tumorigenesis in vivo, we use mice genetically engineered to have a myeloid cell-specific disruption of the circadian clock via deletion of the key clock protein BMAL1.

Results
Oscillation of core clock proteins is altered in mΦs subjected to TME-associated metabolic stress. Additionally, we observe increased tumor growth in mice co-injected with mΦs whose circadian clocks were disrupted compared to mice co-injected with mΦs whose circadian clocks were functional.

Conclusion
Our data suggests that stressful conditions associated with the TME can alter the mΦ circadian clock, and that a functional circadian clock in mΦs can suppress tumor growth in a syngeneic murine tumor model of pancreatic cancer.
This research has been supported by the following fellowships and grants: 2021-Current: Wilmot Predoctoral Cancer Research Fellowship, Wilmot Cancer Institute, University of Rochester Medical Center, Rochester, NY 2020-2021: NIH T32 Training Grant in Cellular, Biochemical & Molecular Sciences, University of Rochester Medical Center, Rochester, NY
Prenatal Rejecter NK Cells Enhance Allo-specific Th17/Tc17 Cell Responses via TGF-beta1, IL-6 and GM-CSF.
Authors: Kang Hee Kap , Ott Katherine , Turner Lucas , Redden Catherine , Langereis Morgan , Alhajjat Amir , Shaaban Aimen 
Published: January 2023

Abstract
In utero hematopoietic cellular transplantation (IUHCT) has the potential to treat congenital benign cellular disease without chemotherapy or radiation. Prenatal tolerance is essential in this regard. Previous studies involving prenatally created chimeras have shown that immunologically tolerant NK cells (friendly, fNK) from engrafter mice suppress allo Tc1 responses, while intolerant NK cells (hostile, hNK) from rejecter mice enhance allo Tc1 responses. Given that Th17 cells are also involved in allograft rejection, we sought to determine if rejecter hNK cells induce/expand allo-specific Th17/Tc17 cells.
We examined the helper potential of prenatally educated hNK cells in non-tolerant prenatal Balb/c --- &gt; B6.Thy1.2 rejecter chimeras. Naïve Thy1.1+ responder T cells and allogenic target cells were adoptively transferred into rejecter or naïve hosts that had been depleted of endogenous T cells and fNK cells. We found increased Th17/Tc17 alloimmunity in the responder Thy1.1+T cell population in rejecters when compared to naïve hosts. Additionally, through ELISPOT, we confirmed increased IL-17A production by responder T cells when co-cultured with allo-specific hNK cells from rejecter mice. Hostile NK cells from rejecter mice produce higher levels of Th17 driving cytokines, TGF-beta 1, IL-6 and GM-CSF when compared to naïve hNK.
From these results, we conclude that prenatal rejecter hNK cells have an enhanced helper effect on Th17/Tc17 alloimmunity in vivo and in vitro. These findings support an evolving paradigm that prenatally educated NK cell can regulate the balance between Th1/Th17 and Treg functions.
Supported by NIH R01HL103745 Lurie Children’s Hospital Research Foundation (to A.F.S.)
GPR65, a critical regulator of Th17 pathogenicity, is regulated by the CREB/CRTC2 pathway
Authors: Hernandez Jeniffer B 
Published: January 2023

Abstract
GPR65 has been shown to be a critical regulator of Th17 pathogenicity. Loss of GPR65 in mice results in a decrease in Th17 cells and reduced susceptibility to a mouse model of multiple sclerosis. The CREB/CRTC2 pathway has emerged as an important regulator of immune function. We have previously shown that the CREB/CRTC2 pathway modulates autoimmune disease by promoting differentiation of Th17 cells. In this study we performed RNA-seq to identify Th17 genes regulated by the CREB/CRTC2 pathway. Our RNA-seq analysis led us to uncover the first mechanism of regulation of the orphan receptor GPR65 by the CREB/CRTC2 pathway. We show that GPR65 is a target of the CREB/CRTC2 pathway through expression studies and chromatin immunoprecipitation. In addition, we show that targeting of GPR65 with small molecules alters the expression of IL-17A. Understanding the regulation of GPR65 will be crucial in developing small molecules to treat patients with Th17-mediated diseases.
ITK tunes the Th17/Treg switch response by controlling calcium dependent signaling.
Authors: Anannya Orchi , August Avery 
Published: January 2023

Abstract
Naïve CD4+ T cells can differentiate into pro inflammatory T helper type 17 (Th17) and anti inflammatory T regulatory (Treg) lineages following T cell receptor (TCR) activation. The strength of the TCR signal is tuned by Interleukin-2 inducible T cell Kinase (ITK) and ITK can tune the development of Th17 and Treg cells. ITK signals can also tune a Th17/Treg switch under Th17 conditions. How ITK mediated tuning of TCR signal control naïve CD4+ T cell commitment into Th17/Treg lineages is unclear. Here we used ITK inhibitors, conventional ITK and allele specific ITK (ITKas) IL17 GFP/Foxp3 RFP reporter mice, to track naïve CD4+ T cell commitment into Th17/Treg lineages. Under Th17 conditions, reduced TCR signal strength in absence of ITK activity/expression, tuned naïve CD4+ T cell fate by reducing Th17 differentiation and inducing switch to cells resembling Tregs expressing Foxp3. The ITKas model showed this switch is due to specific ITK inhibition. The switched Treg like cells resemble Tregs by expression of Treg markers (CD25, CTLA4, PD1) and suppression of effector T cell proliferation. Transcriptomic analysis of switched Treg like cells by RNA Seq indicate they resemble Tregs, with reduced Th17 (Rorc, Il17) and increased Treg (Foxp3, Nrp1, Ikzf2) gene expression. Analysis of chromatin accessibility by ATAC Seq indicated closed loci for Th17 (Rorc, Il17) genes. Activating intracellular calcium dependent pathways led to a loss of the Th17/Treg switch response in naïve CD4+ T cell commitment, effectively bypassing ITK mediated tuning of the TCR signal critical for the switch response. In conclusion, we show here ITK tunes a Th17/Treg switch response in naïve CD4+ T cell commitment under Th17 conditions by controlling calcium dependent signaling.
Supported by grants from NIH (NIH AI129422).
Splenic T-bet+ B cells exhibit stem-like features and constitutively generate antibody-secreting cells
Authors: Knox James J , Rosenthal Rebecca L , Johnson John L , Zhu Jinfang (Jeff) , Cancro Michael P 
Published: January 2023

Abstract
T-bet-expressing B cells (a.k.a. Age-Associated B cells or atypical B cells) directly contribute to antiviral and autoimmune responses and thus represent a promising target for immunomodulatory therapies. T-bet+ memory B cells (MBCs) form and persist long term in the spleen as a resident subset; however, the functional role of this tissue-based population and mechanisms for its maintenance are poorly understood. Here, we use T-bet reporter and fate mapping mouse models to investigate the homeostasis and fate of T-bet+ B cell subsets. We identified an elevated turnover rate of T-bet+ MBCs, with ~1.5% of the population labeling with BrdU per day and 5–10% of T-bet+ MBCs in cell cycle (G1 or S) at any given time. T-bet+ MBCs also displayed resistance to sub-lethal irradiation. Fate mapping and adoptive transfer studies demonstrate that splenic T-bethigh B cells (Tbet++ CD11c+) spontaneously give rise to T-betlow (Tbet+ CD11c−) and ultimately a variety of effector B cell subsets, including GCB-like cells, plasma cells, and T-bet− memory-like B cells, absent exogenous challenge or stimulation. T-bet+ MBCs preferentially give rise to short-lived (CD138+ B220+) versus long-lived (CD138+ B220−) bone marrow and splenic plasma cells, and adoptively transferred T-bet+ MBCs are sufficient to generate plasma IgG2c titers in IgG2a-haptolype naïve recipients. Considering their long-term maintenance in the spleen, these findings suggest T-bet+ MBCs represent a self-renewing, stem-like pool that contribute to the maintenance of antibody titers by constitutive differentiation into antibody-secreting cells.
The circadian clock gene ARNTL regulates the expression of CCR6 and Th17 related genes in human cells
Authors: Singh Satya , Parween Farhat , Edara Nithin , Zhang Hongwei , Gardina Paul , Otaizo-Carrasquero Francisco , Myers Timothy , Farber Joshua M 
Published: January 2023

Abstract
Previously we have shown that CCR6 expression uniquely defines a major branch of the Th effector/memory population that includes cells with both Th17 and Th17-associated phenotypes, therefore, studying the regulation of CCR6 will reveal molecular mechanisms important for controlling broad aspects of the functions of Th17 and associated cell types. Microarray analysis of CD4+ memory T cells from adult blood, based on CCR6 expression, revealed that among many transcription factors which were differentially expressed in the CCR6+ vs CCR6− cells, 8 were identified as regulators of circadian rhythm including ARNTL/BMAL1, a basic-helix-loop-helix-PAS domain transcription factor that as part of a heterodimer with CLOCK/NPAS1 is a central component of the circadian clock within the brain, and functions in analogous transcriptional circuits in peripheral tissues, including cells of the immune system. We found that ARNTL was progressively up-regulated among the CCR6-expressing cells and that it has a predicted binding sites in the promoter region of CCR6. Knocking down ARNTL using siRNA in CD4+ CCR6+ cells from adult blood or using Arntl knockout mice have demonstrated a role for this factor in regulating CCR6 as well as other Th-17 cell associated genes. Studying ARNTL and other clock proteins in Th17 cells opens a new line of investigation into relationships between the molecular control of circadian rhythms and the regulation of adaptive immunity, which may have implications for immune homeostasis and Th17-cell associated disease.
Supported by Intramural Research Program, NIAID, NIH.
Exploring the functionality of CD56+ MAIT cell populations across human tissues
Authors: Kammann Tobias , Parrot Tiphaine , Boulouis Caroline , Buggert Marcus , Leeansyah Edwin , Sandberg Johan K 
Published: January 2023

Abstract
Mucosa-associated invariant T (MAIT) cells are an evolutionarily conserved population of T cells serving a sentinel function at mucosal barrier sites to mediate immune protection. MAIT cells utilize their semi-invariant T cell receptor (TCR) to react to non-peptidic antigens derived from microbial riboflavin metabolites, presented on monomorphic MHC-class I-like MR1 molecules. In addition to TCR-dependent recognition of vitamin B2metabolites, MAIT cells sense and respond to local inflammatory cytokines in an innate-like manner. Surface expression of CD56 was previously shown to be associated with enhanced MAIT cell sensitivity to TCR-independent activation. However, the regulation, frequency, or relevance of CD56 expression on human MAIT cells is currently not well understood. Flow cytometry revealed heterogeneity of CD56 expression across donor-matched tissues obtained from human organ donors. Strikingly, the majority of liver MAIT cells expressed CD56, whereas expression was consistently lower in other tissues. We evaluated de novo CD56 expression on blood-derived sorted CD56-negative MAIT cells following IL-7 or antigen exposure which is likely to occur in the hepatic acute phase response. CD56-negative MAIT cells strongly upregulated CD56 expression after IL-7 stimulation and maintained CD56 expression for up to 19 days. Exposure to MR1-presented antigen induced CD56 expression similarly but required prior cell proliferation. In summary, we identify heterogeneity between MAIT cell populations of different tissue origin and determine the dynamic regulation of the CD56-associated innate-like characteristics to shed light on unknown aspects of MAIT cell diversity and immunobiology.
The unusual peptidoglycan cell wall of Borrelia burgdorferi and it’s role in Lyme disease pathogenesis
Authors: McClune Mecaila E , Dressler Julianne , Davis Mari , Jutras Brandon 
Published: January 2023

Abstract
Borrelia burgdorferi — the Lyme disease agent — does not produce typical bacterial proinflammatory compounds, so the genesis of Lyme arthritis (LA) is largely unknown. To better understand this manifestation, we’ve begun investigating B. burgdorferi peptidoglycan (PG). PG is a large polymer that protects bacteria from various stressors. While most double-membraned bacteria recycle PG fragments during cell wall turnover, B. burgdorferi lack this pathway, instead releasing ~45% of their total PG into their host per generation. Released PG can interact with the immune system as a pathogen associated molecular pattern (PAMP). To that end, we discovered PG lingers in the synovial fluid of LA patients and PG, alone, can cause arthritis in a mouse model. Virtually all bacteria produce PG, but the chemical composition of B. burgdorferi PG is unlike any previously described. We hypothesize the unique chemical structure of B. burgdorferi PG, coupled with shedding, impact host immune responses, and contribute to cell wall half-life and LA pathogenesis. To study this relationship, we developed an in vivo imaging system to track the real-time biodistribution of B. burgdorferi PG in mice. Our results suggest certain organs act as reservoirs, retaining material well after arthritis resolution. Apart from half-life, transcriptomic studies reveal that B. burgdorferi PG induces unique immunological responses in human PBMCs, that appear to be dictated by PG chemistry. Our findings provide a fundamental basis for understanding the complex interplay between a unique PAMP and a host, in addition to deciphering the role of the B. burgdorferi cell wall in Lyme disease pathogenesis, results that may lead to new therapeutic approaches to alleviate LA symptoms.
Supported by grants from NIH (R21 AI159800), USDA (VA-160113), the Steven & Alexandra Cohen Foundation, and the Bay Area Lyme Foundation
Basophil depletion alters host immunity, intestinal permeability and mammalian host-to-mosquito transmission in malaria.
Authors: Donnelly Erinn L , Céspedes Nora , Van de Water Judy A , Luckhart Shirley L 
Published: January 2023

Abstract
Malaria-induced bacteremia has been shown to result from intestinal mast cell (MC) activation (Chau et al. 2013, Potts et al. 2016, Céspedes et al. 2020). The appearance of MCs in the ileum and increased permeability to enteric bacteria are preceded by an early Th2-biased host immune response to infection, characterized by the appearance of IL-4, IL-10, mast cell protease (Mcpt)1 and Mcpt4, and an increase in circulating basophils and eosinophils. Given the functional similarities of basophils and MCs in the context of allergic inflammation and the capacity of basophils to produce IL-4 in large amounts, we sought to define the role of basophils in the development of increased intestinal permeability and in MC influx and the development of bacteremia in the context of malaria. Upon infection with non-lethal Plasmodium yoelii yoelii 17XNL, mice that lack basophils exhibited increased intestinal permeability and increased ileal MC numbers, without any increase in bacterial 16S ribosomal DNA copy numbers in the blood, relative to non-depleted mice. Analysis of cytokines, chemokines and MC-associated factors in the ileum revealed significantly increased TNFα and IL-13 at day 6 post infection (PI) in basophil-depleted mice compared to non-depleted mice. Moreover, network analysis revealed profound differences between depleted and non-depleted mice over time following infection in both systemic and local immune responses to parasites and translocated bacteria. Finally, basophil depletion was associated with significantly increased gametocytemia and parasite transmission to mosquitoes, suggesting that basophils play a previously undescribed role in controlling gametocytemia and in turn, mammalian host-to-mosquito transmission.
This work was supported by NIH NIAID RO1 AI131609 to Shirley Luckhart.
PD-1 restrains B cell dependent CD4+ T cell responses that promote susceptibility to Brucella infection
Authors: Dadelahi Alexis S , Ateya Mostafa Farghal Namish , Ponzilacqua-Silva Bárbara , Chambers Catherine A , Lacey Carolyn A , Moley Charles R 
Published: January 2023

Abstract
Brucellosis, caused by intracellular pathogens of the Brucella genus, often results in chronic and/or lifelong infection. While T cells can contribute to control of Brucella, this typically does not result in sterile immunity, and the mechanisms underlying the inability of T cells to clear infection remain unclear. We previously found that B cells promote susceptibility to Brucella in a CD4+ T cell dependent manner. Here we report that B cell MHCII expression enhances susceptibility to infection, and investigated the role of B cell antigen specificity and presentation in this process. We found that B cell receptor specificity facilitates enhanced susceptibility to infection as well as Brucella entry into B cells in vivo. Investigation of the role of individual B cell subsets demonstrated that follicular B cells can inhibit protective CD4+ T cell responses. Evaluation of CD4+ T cell populations revealed that B lymphocytes promote FoxP3 expression preferentially amongst T follicular cell populations following Brucella infection. Additionally, CD40L blockade enhances protection against Brucella in a B cell dependent manner concomitant with a decrease in T follicular regulatory cells (TFR). Interestingly, PD-1 blockade resulted in an increase in TFR populations as well as an increased susceptibility to Brucella infection in a B and CD4+ T cell-dependent manner. Together, these data suggest B and CD4+ T cell interactions within the follicle promote TFR cell populations which in turn could promote susceptibility to Brucella infection.
Supported by NIH Grant:1R21AI135160 NIH Grant:1R01AI150797
Cellular dynamics of immune evasion during Leishmania major infection
Authors: Zayats Romaniya , Mou Zhirong , Yazdanpanah Atta , Koh Wan Hon , Lopez Paul , Uzonna Jude E , Murooka Thomas 
Published: January 2023

Abstract
Despite the generation of a strong T cell response, clearance of Leishmania major is incomplete. Understanding of the persistence mechanisms is lacking, but Leishmania major driven induction of the immunosuppressive microenvironment through recruitment of regulatory T cells has been proposed to prevent parasite clearance in vivo. In the presented study, we used a novel TCR transgenic mouse model, where CD4+ T cells recognize an immunodominant peptide derived from Leishmania-glycosomal phosphoenolpyruvate carboxykinase (PEPCK), to visualize the dynamics of anti-L. major CD4+ T cell responses and to characterize mechanisms which restrain their effector function. We show that macrophage:T cell interaction dynamics were prolonged upon antigen recognition. This leads to a production of high levels of IFNγ and can be significantly suppressed by PEPCK-specific Tregs in vitro, as compared to polyclonal Treg controls. Treg antigen activation leads to a substantial increase in IL-10 levels, while decreasing IL-12, TNF, and IL-2 production. Intravital microscopy studies characterizing PEPCK-specific CD4+ T cell migration within skin lesions in mice show a significant recruitment of adoptively transferred effector T cells to the lesion site in vivo, displaying behaviours consistent with antigen recognition at early stages, but not at chronic stages. Imaging of infected FoxP3-GFP reporter mice show recruitment of Tregs to the lesion site, where they localize in the lesion, unlike the effectors cells which surround it. Collectively, our findings show for the first time that Leishmania-specific Tregs influence effector CD4+ T cell responses and this could be a mechanism that derives antigen persistence in L. major infection.
Research funded by a grant from the GSK-CIHR Partnered Chair Program