bluuebunny/crossref_metadata_2025_split huggingface dataset:
CD28 regulates T cell metabolic reprogramming through ARS2-dependent effects on alternative splicing
Authors: Holling G. Aaron , Sharda Anand , Honikel Mackenzie M. , Qiao Guanxi , Repasky Elizabeth A , Lee Kelvin P , Olejniczak Scott H 
Published: January 2023

Abstract
An adaptive immune response requires activation of naïve T cells via T cell receptor (TCR) ligation and engagement of costimulatory molecules such as CD28, which enables cell growth, rapid proliferation, and effector differentiation. To accomplish such bioenergetically demanding processes, T cells must dynamically regulate their metabolism upon activation. After initial TCR triggering of aerobic glycolysis, CD28 co-stimulation maintains uptake and catabolism of glucose required for CD8+ T cells to attain full effector status. Despite evidence that CD28 signaling through the PI3-kinase pathway induces glucose uptake via increased GLUT1 surface expression, knockin T cells expressing PI3-kinase signaling-deficient CD28 are functional in vivo and displayed only transient defects in glycolysis. In contrast, knockin T cells expressing Grb2/Vav signaling-deficient CD28 lacked in vivo function and displayed sustained defects in glycolysis. Here we identify a novel link between CD28-Grb2/Vav signaling and T cell glycolytic reprogramming through the RNA binding protein ARS2, a protein central to co-transcriptional processing of nascent RNA polymerase II transcripts. Data show that ARS2 is a critical downstream mediator of CD28-Grb2/Vav signaling that supports alternative splicing (AS) of the rate-limiting glycolytic enzyme pyruvate kinase M from the M1 to M2 isoform. Mechanistically, ARS2 binds known Pkm splicing factors and promotes their interaction with Pkm mRNA. Consistent with this, ARS2 knockout T cells displayed reduced Pkm2 AS, defective glycolytic reprogramming and lacked the ability to control in vivo tumor growth, suggesting a novel mechanism by which co-stimulation drives T cell metabolic reprogramming.
The Inhibition of Phosphatidylinositol-3-Kinase in activated T-cells by Hibiscone C derivatives
Authors: Rawlings Jason S , Irsik Jeremy , Wheibe Elias , Johar Shamael , Besley Caroline , Goess Brian 
Published: January 2023

Abstract
The phosphatidylinositol-3-kinase (PI3K) pathway is of significant interest due to its ability to regulate cell proliferation, growth, and migration in numerous contexts including in T cells. Furthermore, gain-of-function mutations in PI3K can lead to an upregulation of the pathway, resulting in tumorigenesis, autoimmunity, and leukemia. Specific furanosesquiterpenoids, such as wortmannin, have been known to inhibit the PI3K pathway in T cells. However, wortmannin has unfavorable characteristics as a chemotherapeutic or immunomodulatory drug due to its insolubility in neutral buffers, instability, and high toxicity in vivo. Hibiscone C, another furanosesquiterpenoid, lacks many of the functional groups as wortmannin, but contains the same diacyl furan ring that is critical for interacting with the ATP binding pocket of PI3K. Via analysis of phosphorylation of the downstream effector molecule Akt in activated T cells, we demonstrate that Hibiscone C also can irreversibly inhibit PI3K activity, however not as effectively as wortmannin. These results led us to test other derivatives of hibiscone C, to see if modifications to the molecule’s structure would affect potency of the molecule.
Characterization of the bidirectional activity of the human TET2 gene promoters
Authors: Li Hongchuan , Lou Hong , Dean Michael , Anderson Stephen 
Published: January 2023

Abstract
Tet methylcytosine dioxygenase 2 (TET2) is a tumor suppressor gene that is inactivated in a wide range of hematological cancers. TET2 enzymatic activity converts 5-methylcytosine (5-mC) into 5-hydroxymethylcytosine (5-hmC), an essential step in DNA demethylation. Human TET2 is highly expressed in pluripotent cells and down-regulated in differentiated cells. However, transcriptional regulation of the human TET2 gene underlying functional and biological implications has not been investigated in detail. We previously reported three promoters, designated as Pro1, Pro2, and Pro3, generate three alternative first exons, and their presence in TET2 mRNAs varies with cell type and developmental stage. In the present study, we found that the human TET2 promoters has in transcriptional activity in either orientation. The functional identification of these promoters was performed and the results showed distinct bidirectional expression by a broad range of tissues. The antisense activity from Pro2 is significantly higher than Pro1 or Pro3 promoters. The distinct properties and bidirectional nature of the human TET2 promoter elements may play an important role in human cancer development and differentiation and should provide new insights into understanding pathogenesis and development of new therapeutic approaches.
The differential pathological outcome between Chlamydia infection and vaccination is mediated by microRNA dysregulation
Authors: Eko Francis , Howard Simone , Benyeogor Ifeyinwa , Richardson Shakyra S , Lundy Stephanie , Adebayo Olayinka Omoyitola , Igietseme Joseph U. , Omosun Yusuf 
Published: January 2023

Abstract
Previous studies found that in contrast to immunization with an IL-10 knockout dendritic cell (DC)-based cellular or Vibrio cholerae ghost (VCG)-based subunit vaccine, immunization with live chlamydial elementary bodies does not protect against upper genital tract pathology following Chlamydia genital infection. The molecular mechanism regulating live Chlamydia- and vaccine-induced immunity is currently incompletely understood. To elucidate the mechanisms underlying this intriguing outcome, we examined the characteristic miRNA expression profiles in the upper genital tract (UGT) tissues of mice after immunization with live, subunit and DC-based Chlamydia vaccines using the NanoString nCounter Mouse miRNA assay. There were notable differences in miRNA expression profiles after immunization with the different vaccine formulations, with the DC vaccine-immunized group showing the highest number of uniquely differentially expressed (DE) miRNAs. Only 2 miRNAs, miR-146a and miR-2140 were commonly expressed in the genital tracts of the 3 immunization groups. Pathway analysis showed that the DE miRNAs regulate a number of pathways involved in disease and biological functions and targeted genes regulating immune response and inflammation. A number of central focus molecules associated with the miRNAs, including E2F Transcription Factor 1 (E2F1), Peroxisome Proliferator Activated Receptor Alpha (PPARA), and Interferon gamma (IFNG) were identified. Taken together, the results suggest that miRNA dysregulation plays an important role in the pathological outcome associated with chlamydial infection versus vaccination.
Novel Mechanism of Regulating IL-17 Signaling by 14-3-3zeta
Authors: Chakravarti Ritu , Veerman Brent , McGowan Jenna , Saul-McBeth Jessica , Conti Heather , Chattopadhyay Saurabh 
Published: January 2023

Abstract
Interleukin (IL)-17A is an important cytokine associated with autoimmune diseases and host defense. The mechanism of its action depends upon its ability to induce pro-inflammatory cytokines, e.g., IL-6, IL-8 as well as anti-fungal genes, e.g., b-defensin, CCL-20, CXCL-1. Most non-hematopoietic cells express IL-17 receptors and respond to IL-17A. Several regulators of each of the two independent arms of IL-17A signaling- gene induction and mRNA stabilization of inflammatory genes, are known; however, there is limited knowledge of how two arms influence each other. We previously reported the increased presence of 14-3-3 proteins in the inflamed aortic tissue, an autoimmune disease with increased IL-17A levels. This study led us to investigate the role of 14-3-3zeta(z) in the IL-17A signaling. By genetic manipulations in human and mouse cells, we observed that 14-3-3z is required for the IL-17A-induced IL-6 production by fibroblast and epithelial cells. Contrary to IL-6, 14-3-3z suppressed the CXCL-1 production in response to IL-17A. In the absence of 14-3-3z, IL-17A induction of anti-fungal genes (b-defensin) was completely suppressed. The mechanism of 14-3-3z action depends upon its interaction with Traf/Act1/IL-17R signaling. Our results show that 14-3-3z is an essential component of IL-17A signaling and its interaction with receptor complex provides a new model of regulating the output in IL-17A effector cells. To the best of our knowledge, this is the first report of the 14-3-3z role in regulating IL-17A induced outputs.
IL-21 from CD4 T cells drives differentiation of brain-resident CD8 T cells during polyomavirus CNS infection
Authors: Ren Heather , Ren Mingqiang , Kolawole Elizabeth , Jin Ge , Netherby-Winslow Colleen , Shwetank  , Evavold Brian , Lukacher Aron 
Published: January 2023

Abstract
CD4 T cells help CD8 T cells differentiate into competent effector and memory cells. We recently showed that CD4 T cells are essential for CD8 T cell differentiation into brain-resident memory (bTRM) during polyomavirus (PyV) infection. Here we identify IL-21 as the CD4 T cell help. Using MHC-II tetramers for two epitopes in mouse PyV, we show brain PyV-specific CD4 T cells express PD-1 and CXCR5. IL21-VFP reporter mice revealed CD4 T cells as the only cellular source of IL-21 in the brain. 2D micropipette adhesion assays, measuring TCR affinity, showed brain IL-21-producing CD4s have higher affinity TCRs than IL-21− cells. RNAseq analysis of IL-21+ vs. IL-21− brain CD4s corroborates that IL-21 production is positively associated with TCR affinity and that IL-21 producers are positively enriched for TFH signature genes. We further found that IL-21 receptor (IL21R) is required for CD8 TRM differentiation. Brain CD8 T cells upregulated IL21R at 15 days post-infection, coincident with expression of the TRM marker CD103. Few CD8 T cells in brains of IL-21R−/− mice expressed CD103, a finding confirmed using donor anti-PyV CD8 T cells lacking IL-21R in infected wild type (WT) recipients. Unlike IL21R-sufficient CD8s, IL21R−/− CD8 T cells are not maintained in the brain upon systemic CD8 antibody depletion. IL21R−/− CD8s also have a diminished response to a rechallenge in the brain than what we observed with WT CD8 T cells. RNAseq analysis revealed IL21R−/− CD8 T cells were negatively enriched for TRM core signature genes and oxidative metabolism genes compared to IL-21R-sufficient CD8 T cells. Thus, we conclude that IL-21 produced by high-affinity, PyV-specific CD4 T cells in the brain is required for differentiation of CD8 bTRM during PyV CNS infection.
PD-1 Signals are Critical for Homeostatic Maintenance of Memory CD8 T Cells
Authors: Sarkar Surojit , Yuzefpolskiy Yevgeniy , Vegaraju Adithya , Xiao Hanxi , Baumann Florian , Jatav Shashank , Church Candice , Earnest-bernhart Kayser , Prlic Martin , Jha Abhishek , Nghiem Paul , Riddell Stanley , Sedensky Margaret , Morgan Philip , Kalia Vandana 
Published: January 2023

Abstract
Inhibitory signaling in dysfunctional CD8 T cells through the PD-1 axis is well established in chronic viral infections and cancers. PD-1 is also transiently induced to high levels during priming of acute infections and immunizations, yet its impact on the development of long-lived antigen-independent T cell memory remains unclear. Here we show that in addition to its expected role in restraining clonal expansion, PD-1 expression on antigen-specific CD8 T cells during priming and activation is critically required for the development of a durable CD8 T cell memory pool after antigen clearance. Loss of T cell-specific PD-1 signaling led to increased contraction and a striking defect in antigen-independent renewal of memory CD8 T cells in response to homeostatic cytokine signals, thus resulting in attrition and near ablation of the memory pool over time. Notably, in the setting of PD-1 checkpoint blockade immunotherapy of chronic viral infection, while the exhausted CTLs expectedly regained function, the pre-existing pool of resting functional memory cells established in response to a previously administered vaccine underwent attrition. Metabolically, PD-1 signals were necessary for regulating the critical balance of anabolic glycolysis and fatty acid oxidation programs through mTOR to meet the bioenergetics needs of quiescent memory. These studies define PD-1 as a key metabolic regulator of protective T cell immunity, and have potential clinical implications for pre-existing T cell memory to prior infections and vaccinations during PD-1 checkpoint-blockade immunotherapy in cancer.
Long-term skin resident memory T cells proliferate clonally and contribute to inflammation in human graft-versus-host disease
Authors: Strobl Johanna M , Pandey Ram V , Krausgruber Thomas , Bayer Nadine , Kleißl Lisa , Vieyra-Garcia Pablo , Wolf Peter , Stingl Georg , Bock Christoph , Stary Georg 
Published: January 2023

Abstract
The skin contains a population of tissue-resident memory T cells (Trm) that is thought to contribute to local tissue homeostasis and protection against environmental injuries. While much information about the regulation, survival program and pathophysiological roles of Trm has been obtained from murine studies, less is known about the biology of human cutaneous Trm. Here we demonstrate that in patients undergoing allogeneic hematopoietic stem cell transplantation host-derived CD69+ αβ memory T cell clones in the epidermis and dermis remain stable and functionally competent over one decade. Transcriptional profiling revealed that long-term persisting T cells in the skin are characterized by high expression of tissue retention genes and stem cell markers and, in addition to known Trm markers, may be defined by galectin-3 and RUNX3. Furthermore, skin lesions from patients developing graft-versus-host disease showed an unprecedented large number of locally proliferating host-derived Trm, suggesting a hitherto unrecognized contribution of these cells to the pathogenesis of this condition. Together, our studies highlight the intimate relationship between the local human skin environment and long-term persisting T cell clones which differs from murine skin. Our results further point towards a new understanding of local tissue destruction through both host- and donor-derived Trm following allogeneic hematopoietic stem cell transplantation.
T cell response during Group B Streptococcus vaginal colonization and ascending infection
Authors: Spencer Brady , Alhajjar Norhan , Doran Kelly 
Published: January 2023

Abstract
Pre-term birth, miscarriage, and other adverse pregnancy outcomes remain the primary cause of neonatal death and are associated with bacterial ascending infections within the female reproductive tract. Group B Streptococcus (GBS), a vaginal tract colonizer, is a leading contributor to adverse pregnancy outcomes and neonatal invasive disease. We have developed a mouse model of GBS vaginal colonization and ascending infection and have observed increased IL-17 production in mice that cleared GBS colonization compared to those still colonized. Thus, we hypothesize that IL-17 and IL-17-producing cells may be important for host defense; yet, the immune dynamics during GBS vaginal persistence and ascending infection/adverse pregnancy outcomes remain unknown.
T cells are a major source of IL-17 in the mucosa. To assess the role of adaptive immunity during GBS colonization, we colonized RAG1+/+ and RAG1−/− mice with GBS and observed increased persistence of GBS in the vaginal tract of the RAG1−/− mice. To determine the cellular source of IL-17 within the reproductive tract of GBS-colonized mice, we isolated immune cells from vaginal, cervical, and uterine tissues at the time of GBS clearance and performed flow cytometry. TCRɣδ+ cells comprised the highest percentage of RORɣT+ immune cells in the vagina, cervix, and uterus. We further observed an increased percentage of TCRɣδ+ cells in the uterus of GBS-colonized mice compared to naïve mice at day 9 post-inoculation, at which point half the mice had cleared. We hypothesize that IL-17-producing TCRɣδ+ cells contribute to GBS clearance in the murine reproductive tract. Future studies will assess GBS vaginal persistence and ascending infection in IL-17- and TCRɣδ-deficient mouse lines.
Wnt5A Signaling Restrains Leishmania donovani infection in a mouse model
Authors: MAITY SHREYASI , CHAKRABORTY ARIJIT , SEN MALINI 
Published: January 2023

Abstract

Objective
In view of the emergence of drug resistant strains of L. donovani and persistence of Kala-azar, it is important to understand how host derived factors promote immune resistance to L. donovani infection. Accordingly, considering the role of Wnt5A in maintenance of immune homeostasis, our objective is to evaluate the potential of host Wnt5A signaling in restraining L. donovani infection independent of drug sensitivity or resistance, utilizing a mouse model.

Methods
Effect of Wnt5A depletion on L. donovani infection was deciphered using Wnt5A heterozygous mice with reference to wild type cohorts, where mice were infected with L. donovani promastigotes through iv route. Effect of augmented Wnt5A signaling on L. donovani infection was investigated by iv injection of recombinant Wnt5A protein (rWnt5A) prior to infection. Infection load in liver and spleen was enumerated by Leishman Donovan Unit (LDU) and evaluated by histology. Plasma cytokine levels were checked by ELISA.

Results
Wnt5A heterozygous mice display substantially more disorganized splenic germinal centers and liver granulomas and about 50–60% more LDU upon L. donovani infection as compared to their wild type partners. rWnt5A treatment causes 40–80% reduction in infection load, which correlates with decrease or abolition of splenic germinal center disorganization and liver granulomas, and increase in pro-inflammatory cytokine to anti-inflammatory cytokine ratio.

Conclusion
Our results indicate that (i) Wnt5A signaling protects the host from L. donovani infection independent of drug sensitivity or resistance and (ii) rWnt5A has potential as a prophylactic agent for prevention of L. donovani infection and incidence of Kala-azar.
VCAM1/VLA4 interaction mediates Ly6Clow monocyte recruitment to the brain in a TNFR signaling dependent manner during fungal infection
Authors: Shi Meiqing , Sun Donlei , Strickland Ashley , Chen Yanli , Liu Gongguan 
Published: January 2023

Abstract
Monocytes exist in two major populations, termed Ly6Chi and Ly6Clow monocytes. Compared to Ly6Chi monocytes, less is known about Ly6Clow monocyte recruitment and mechanisms involved in the recruitment of this subset. Furthermore, the role of Ly6Clow monocytes during infections is largely unknown. Here, using intravital microscopy, we demonstrate that Ly6Clow monocytes are predominantly recruited to the brain vasculature following infection with Cryptococcus neoformans, a fungal pathogen causing meningoencephalitis. The recruitment depends primarily on the interaction of VCAM1 expressed on the brain endothelium with VLA4 expressed on Ly6Clow monocytes. Furthermore, TNFR signaling is essential for the recruitment through enhancing VLA4 expression on Ly6Clow monocytes. Interestingly, the recruited Ly6Clow monocytes internalized C. neoformans and carried the organism while crawling on and adhering to the luminal wall of brain vasculature and migrating to the brain parenchyma. Our study reveals a substantial recruitment of Ly6Clow monocytes to the brain and highlights important properties of this subset during infection.
Adaptive γδ T cell function is subverted by Yersinia pseudotuberculosis outer proteins
Authors: Chu Timothy H , Khairallah Camille F , Cho Rhea , Zhang Yue , Lin Xun , Bliska James B , Sheridan Brian S 
Published: January 2023

Abstract
γδ T cells are an unconventional subset of multifunctional T cells enriched in mucosal barrier tissues. After foodborne Listeria monocytes (Lm) infection, an activated CD44hiCD27loVγ4 subset of γδ T cells formed in the mesenteric lymph nodes (MLN) that shared numerous characteristics with traditional T cells including anamnestic responses. While attempting to uncover the specificity of Lm-elicited memory cells utilizing heterologous challenge infections we observed that Lm-elicited γδ T cell function was induced with heat-killed Yersinia pseudotuberculosis (Yptb) but not live Yptb suggesting that Yptb employs immune evasion strategies to limit anti-pathogen adaptive γδ T cell functions. Live Yptb inhibited CD44hiCD27loVγ4 T cell IL-17A and IFNγ production integral for anti-pathogen immunity. Tracking Yptb translocation through a FRET-based reporter assay revealed preferential translocation of Yptb outer proteins (Yop) into adaptive γδ T cells over conventional T cells and an abrogated cytokine response compared to their non-translocated counterparts within the same environment. Using a series of Yptb mutants deficient in translocated effector proteins, we determined that YopH inhibited IL-17A production while YopJ inhibited IFNγ production. Inhibition of Stat4 phosphorylation in γδ T cells was observed in a translocation, YopJ, and IL-12/IL-23p40 dependent manner, suggesting that YopJ inhibits IFNγ production through Stat4 phosphorylation. Collectively, these data demonstrate direct inhibitory mechanisms of γδ T cell function mediated by the Yptb effectors YopH and YopJ and identify an unknown pathogenesis pathway utilized by Yptb to subvert immune function.
Metabolic ‘de-programming’ of neutrophils protects against fatal bloodstream fungal infections during kidney disease
Authors: Biswas Partha Sarathi , Jawale Chetan V , Ramani Kritika , Coleman Bianca , Oberoi Rohan S , Kupul Saran , Prokopienko Alexander J , Desai Jigar V , Delgoffe Greg M. , Lionakis Michail S , Nolin Thomas D , Gaffen Sarah L 
Published: January 2023

Abstract
Disseminated candidiasis (DC) is the third most common cause of mortality in hospital acquired infections. Disseminated candidiasis caused by the fungus Candida albicans is a major clinical problem in individuals with kidney disease and accompanying uremia. DC fatality is twice as common in patients with uremia as those without renal impairments. Many antifungal drugs are nephrotoxic, making treatment of these patients challenging. The underlying basis for this impaired capacity to control infections in uremic individuals is poorly understood. Here we show that uremic mice show an increased susceptibility to DC. Uremia inhibits Glucose transporter 1 (Glut1)-mediated uptake of glucose in neutrophils by causing aberrant activation of Glycogen synthase kinase 3 beta (GSK3beta), resulting in reduced ROS generation and hence impaired killing of C. albicans in both mice and human cells. Consequently, pharmacological inhibition of GSK3beta ‘de-programs’ neutrophil function and restores glucose uptake, ROS production and candidacidal activity of neutrophils in uremic mice. These findings reveal a central mechanism of neutrophil dysfunction during uremia and suggest a potentially translatable therapeutic avenue for treatment of DC, with broader implications for other fatal systemic infections.