bluuebunny/crossref_metadata_2025_split huggingface dataset:
The non-receptor tyrosine kinase ITK is required for type 1 regulatory T cell development
Authors: Huang Weishan , Koylass Nicholas , August Avery 
Published: January 2023

Abstract
Type 1 regulatory T (Tr1)cells lack the expression of Foxp3 but are potent producers of the immunosuppressive cytokine IL-10, with profound regulatory function in suppressing inflammation and promoting tolerance. Tr1 cells differentiate in response to signals engaging T cell receptor (TCR) and/or regulatory cytokine milieu. The non-receptor tyrosine kinase ITK is a key modulator downstream of TCR, playing critical role in T cell development and function. Using mouse models carrying Foxp3-RFP and IL-10-GFP dual reporters, we found that, in the absence of ITK, Foxp3− IL-10+ Tr1 cell development driven by TCR activation is severely impaired in various tissues (spleen, lymph nodes, lung, gut, and fat). Under Tr1 polarizing condition, naïve Foxp3− CD4+T cells isolated from WT mouse thymus and spleen can both give rise to Tr1cells, however, Itk−/− thymic and splenic naïve Foxp3− CD4+ T cells are deficient in Tr1 differentiation. Although Itk−/−CD4+ T cells proliferated under Tr1 differentiating conditions, they failed to up-regulate LAG3, CD49b, ICOS, PD-1, c-Maf, AHR, and IRF4 to levels observed in WT cells, suggesting that ITK is critical for Tr1 cell fate programming. Utilizing transgenic mouse model carrying an allele sensitive mutant of ITK that allows ITK kinase specific blockade by a small molecule 3MB-PP1, we also determined that the expression of the aforementioned markers is dependent on ITK kinas activity. Inhibiting ITK kinase activity also diminished Tr1 differentiation inhuman CD4+ T cells. We conclude that ITK is required for Tr1 cell development and targeting ITK signaling may be a strategy to modulate regulatory immunity for clinical benefit.
Antigen-dependent engagement of brain endothelium by CD8 T cells leads to fatal brainstem pathology during cerebral malaria
Authors: Swanson Phillip A , Hart Geoffrey T , Russo Matthew V , Pierce Susan K , McGavern Dorian B 
Published: January 2023

Abstract
Cerebral malaria (CM) is a severe complication of Plasmodium falciparum infection that results in thousands of deaths each year, mostly in African children. Pathological studies of CM victims reveal vascular hemorrhaging and edema within the brain, yet the underlying mechanisms that lead to this fatal condition are unknown. Using the animal model of experimental cerebral malaria (ECM), we sought mechanistic insights into the factors that drive the pathogenesis of CM. We found that ECM is associated with a large influx of immune cells into the central nervous system (CNS) at the peak of infection. By depleting individual innate and adaptive immune cell populations, we discovered that CD8 T cells alone were capable of mediating the fatal pathology associated with ECM, including breakdown of the blood brain barrier, edema, and extensive neuronal death in the brainstem. Using two-photon microscopy, we observed parasite-specific CD8 T cells slowly crawling and arresting along the CNS vasculature in vivo during ECM. This behavior was facilitated by the IFN-γ-dependent upregulation of antigen presentation and adhesion molecules on CNS endothelial cells (ECs). Antibody therapy against the adhesion molecules VLA-4 and LFA-1 disrupted CD8 T cell interactions with the CNS vasculature and prevented disease. Importantly, infected mice rendered genetically unable to present antigen on ECs had reduced CD8 T cell-brain EC interactions and were resistant to ECM. These results demonstrate that parasite-specific CD8 T cells interact with brain vascular ECs in an antigen-dependent manner to induce fatal vascular and neuronal pathology during ECM.
Low affinity CD8 T cells dominate experimental cerebral malaria resulting from Plasmodium infection
Authors: Neeld Dennis Kyle , King Thayer , Lamb Tracey J , Evavold Brian D 
Published: January 2023

Abstract
Due to its impact on global health, gaining insight into the immune mechanisms that control Plasmodium infections and specifically the complications associated with cerebral malaria are key for developing appropriate therapeutics. For Plasmodium berghei ANKA infections of C57BL/6 mice, activated CD8 T cells mediate the development of symptoms resembling cerebral malaria (experimental cerebral malaria; ECM). We utilized the sensitivity of the two dimensional (2D) micropipette adhesion frequency assay to define the affinity and frequency of immunodominant glideosome associated protein 50 (GAP50)40-48 epitope in spleen and brain of P. berghei infected mice. Compared to tetramer staining of the spleen on day 5, which shows approximately 1.2% of the CD8 cells are antigen specific, the micropipette assay showed that nearly 30% of the CD8 T cells were specific for GAP5040-48. These differences in frequency are due to the fact the micropipette detects both high and low affinity populations of GAP50 specific cells, whereas tetramers are generally limited to detecting higher affinity cells. In P. berghei ANKA infection low affinity CD8 T cells migrate to the brain in large numbers indicating that they are important components of the pathogenic response. Adoptive transfer experiments with P14 transgenic T cells specific for the GP33 epitope of LCMV show that only Plasmodium-reactive cells migrate to the brain during infection providing further evidence that the low affinity CD8 T cells in the brain are Plasmodium-reactive. Taken together, these results demonstrate for the first time that both low and high affinity CD8 T cells participate in the polyclonal CD8 T cell response to Plasmodium infection.
Early TNFα signaling promotes classical activation of dendritic cells in lung associated lymph nodes to prime development of protective immunity against cryptococcal infection
Authors: XU JINTAO , Eastman Alison J , Flaczyk Adam , Neal Lori , Zhao Guolei , Cheng Daphne , Malachowski Antoni , Yosri Mohammed , Curtis Jeffrey L , Osterholzer John J , Olszewski Michal A 
Published: January 2023

Abstract
Cryptococcus neoformans is a common opportunistic pathogen that requires intact T cell-mediated immunity for protective host defenses. While Th1/Th17 responses contribute to the effective containment and elimination of C. neoformans, Th2 responses are non-protective and can worsen clearance outcomes. Previous studies showed that early tumor necrosis factor alpha (TNFα) signaling is required for optimal clearance, while its absence leads to immune dysregulation and persistent fungal infection.
To determine mechanism(s) of early TNFα signaling in the generation of protective anti-cryptococcal immunity, we evaluated the contribution of TNFα to the priming of the innate immune system for optimal T-cell development. In CBA/J mice depleted of TNFα at the time of infection with C. neoformans, we evaluated DC accumulation, activation profile, and interaction frequencies with T cells in lung associated lymph nodes (LALN) in comparison with the infected control mice.
We found that early TNFα depletion during pulmonary C. neoformans infection resulted in: 1) lack of pulmonary fungal clearance and enhanced dissemination; 2) decreased Th1/Th17 polarization and CD4+ T cell activation in the LALN; 3) diminished DC accumulation in the LALN; 4) decreased expression of classical activation DC signatures (co-stimulatory molecules CD40 and CD86), pro-Th1 and pro-Th17 cytokines (IL-12b, TNFα, IL-23a and IL-21); and 5) increased expression of the alternative activation DC signatures (Fizz and Gal3) and pro-Th2 cytokines (IL4 and IL-10).
Thus, our data indicates early TNFα signaling promotes classical activation of DC in lung associated lymph nodes thereby priming development of protective immunity against cryptococcal infection.
Modulators and signally of Th17 axis in Chagas’ disease heart failure
Authors: Rodrigues Barbara Rocha , Rodrigues Denise Bertulucci , Tostes Sebastião , Rodrigues Virmondes 
Published: January 2023

Abstract
Chagas’ disease, caused by the protozoan parasite Trypanosoma cruzi, remains a leading neglected tropical disease in the Americas, associated with 546,000 disability adjusted life years and 10,300 annual deaths. The immune system plays an important role in the reduction of parasite load, but may also contribute to the development of lesions observed during the chronic phase of the disease. We analyzed in situ mRNA expression in left ventricular section from 14 subjects died with Chagas’ disease. Subjects were grouped in Heart hailure and without heart failure, using clinical and necropsies data available. Quantitative PCR were performed on cDNA copies of total RNA extracted from each ventricular sample. PCR were done using Taqman system to detected IL-6 and IL-23 receptor, Beta Actin was used as a internal gene expression. Ventricular wall obtained from subjects with heart failure presented a significant higher levels of mRNA of Interleukin-6 and Interleukin-23 receptor when compared from samples obtained from heart form subjects without heart failure. These results support the idea that a Th17 facilitators are involved in heart lesions of Chagas’ disease patients.
Immunological control of HSV by CD8+ tissue-resident memory T cells
Authors: Roychoudhury Pavitra , Schiffer Joshua T 
Published: January 2023

Abstract
A major challenge in the field of immunology is to generalize findings from animal models to specific human infections. Here we use a mathematical model of a single herpes simplex virus-2 (HSV-2) genital ulcer to integrate mechanistic observations of the tissue resident CD8+ T-cell (TRM) response derived from animal studies, with viral kinetic and T-cell histology data from human infection studies. Simulation with our agent-based model of HSV-2 infection demonstrates that a sufficiently high density of pathogen-specific TRM will lead to extremely rapid elimination of virally infected cells. However, at lower TRM densities, HSV-2 is likely to spread beyond the initial small core of cells. Once this occurs, our model predicts that contact mediated killing and local mucosal trafficking of TRM within mucosa is insufficient to eradicate infection due to the rapid kinetics of HSV-2 spread. Moreover, trafficking of HSV-2 specific cells from blood alone is also unlikely to occur quickly enough to curb viral expansion. We therefore propose that resident CD8+ T-cells invoke a broad antiviral cytokine response that severely limits viral replication in nearby cells. The rapidity and intensity of this response is predicted by the density of HSV-2 specific CD8+ T-cells in the microenvironment. The observed influx of cells from blood is likely a mechanism to restore TRM levels and provide protection against subsequent HSV-2 reactivation.
Trusting their gut instinct: innate lymphoid cells utilize cytolytic mechanisms to regulate IgA
Authors: Karmele Erik P , Taft Diana H , Moran Michael T , Finkelman Fred D , Waggoner Stephen N 
Published: January 2023

Abstract
Immunoglobulin A (IgA) is important for the maintenance of homeostasis between the host and the intestinal microbiome. Antimicrobial IgA is secreted by IgA+ plasma cells that arise from germinal center (GC) reactions within gut-associated lymphoid tissues (GALT). Dysregulation of IgA production, a common condition with an unknown etiology, can lead to the improper clearance of commensal microbes, allowing for pathogenic strains to flourish and cause disease. Thus, a better understanding of the mechanisms involved in IgA production is critical. Our lab has previously shown that natural killer (NK) cells, a type of innate lymphoid cell (ILC), suppress GC responses and long-lived humoral immunity following systemic viral infection of mice. Here we show that depletion of NK1.1-expressing ILCs (e.g. NK, ILC1, ILC3) in specific-pathogen free mice resulted in enhanced T follicular helper cell and GC B cell numbers within GALT. The numbers of lamina propria IgA+ plasma cells were increased and the expression levels of fecal IgA were elevated for weeks after depletion of NK1.1-expressing ILCs. In addition, NK1.1-depletion was associated with alterations to the intestinal microbiome. In mice with defects in cytolytic granule-mediated killing, including perforin-knockout and beige mice, depletion of NK1.1-expressing ILCs did not enhance GALT GC responses or IgA production. This suggests that a cytolytic mechanism is involved in this regulatory process, although the precise target of this killing remains undefined. Thus, innate lymphoid cells within GALT play an important role in determining the balance between host immunity and microbial commensalism, and may represent new therapeutic targets to enhance efficacy of oral vaccines.
Goblet cell Hypoxia-Inducible Factor (HIF) is necessary for mucin processing and maintenance of mucosal integrity
Authors: Whitney Alyssa K , Schwisow Kayla D , Bayless Amanda J , Golden-Mason Lucy , Mehta Gaurav , Kuhn Kristine A , Colgan Sean P , Campbell Eric L 
Published: January 2023

Abstract
Secreted mucus is essential for intestinal homeostasis, separating luminal bacteria from the colonic epithelium and preventing inappropriate inflammation. Perturbations in goblet cell mucus secretion have been shown to lead to spontaneous colitis in mice. Treatment of mice with a prolyl hydroxylase inhibitor (AKB-4924) leads to stabilization of hypoxia inducible factor-1 alpha (HIF-1α) and regulation of hypoxia-responsive genes that promote mucosal protection. Interestingly, goblet cell hyperplasia was observed following in vivo administration of AKB-4924, which may account for the mucosal protection observed. Thus, we hypothesized epithelial stabilization of HIF-1α leads to goblet cell differentiation.
Utilizing 3D murine colonic organoid system, treated with a gamma secretase inhibitor (DBZ), AKB-4924 or hypoxia, we analyzed changes in differentiation markers by qPCR. Contrary to our hypothesis, neither AKB-4924 nor hypoxia resulted in the induction of goblet cell differentiation factors. Furthermore, mice lacking HIF-1α in the intestinal epithelium (HIF-1αfl/fl-VillinCRE) exhibited normal colonic goblet cell numbers. However, these goblet cells appeared less organized with diffuse mucin granules. Fluorescent in situ hybridization with a eubacterial probe revealed diminished thickness, with reduced proximity to the microbiome in HIF−/− mice. Finally, profiling the composition of the mucus layer revealed significantly altered expression profile of both secreted and adherent mucins.
We conclude that epithelial HIF-1α alters goblet cell function, regulating intestinal mucus, which may contribute to the mucosal-protective role of HIF.
CX3CR1 mononuclear phagocytes utilize the microbiota to promote balanced intestinal immune responses
Authors: Diehl Gretchen , Hill-McAlester Andrea , Ochoa Karina , Galan Carolina 
Published: January 2023

Abstract
The development and proper functioning of the mammalian immune system relies on a reciprocal relationship between the host and the microbiota. These interactions shape both the composition of the microbiota along with the development and responsiveness of the immune system. Such a relationship requires mechanisms to reduce inflammatory immune responses within the intestine, which can damage the epithelial barrier and lead to the development of disorders such as inflammatory bowel disease. We find that CX3CR1 expressing mononuclear phagocytes (MNPs) are critical for maintaining this intestinal homeostasis. Using mice where we can selectively deplete CX3CR1+ MNPs in vivo, we demonstrate that CX3CR1+ MNPs in the lamina propria promote epithelial repair and, in models of colitis, limit TH1 responses against the microbiota itself. We also find they have functions in immune inductive sites such as the MLN where they limit the generation of inflammatory TH1 immune responses against pathogenic bacteria. Finally, we find they are required for the induction of antigen specific TH17 responses against members of the microbiota such as segmented filamentous bacteria (SFB). We find that the intact microbiota is critical for these homeostatic roles. After disruption of the microbiota with antibiotics, CX3CR1+ MNPs now promote inflammatory immune responses and are unable to promote epithelial barrier repair. Understanding this crucial relationship between the microbiota and intestinal immune cells will allow for selective targeting to modulate responsiveness of the intestinal immune system and promote homeostasis.
Intestinal resident CX3CR1+ cells support gut immune system by helping production of IgA from B cells
Authors: Kim Young-In , Lee Eun-Je , Chang Sun-Young 
Published: January 2023

Abstract
Intestinal resident CX3CR1+ cells are known to sample neighboring or circulatory antigens and present them to CD8+ T cells via cross-presentation. Here we show that intestinal CX3CR1+ cells co-cultured with B cells can induce production of IgA. Unlike intestinal CD103+ DCs, CX3CR1+ cells are independent of retinoic acid and signals from commensal microbiota to induce production of IgA. CX3CR1+ cells express BAFF, APRIL and TNF-α which is required for IgA class-switching of B cells. Intravenous injection of soluble OVA in mice can promote production of IgG and IgA in the serum and feces. Intestinal CD103+ DCs are known to present to CD4+ T cells, however CX3CR1+cells present antigens to CD8+ T cells via cross-presentation. Addition of OT-I cells further enhances production of IgA of B cells co-cultured with CX3CR1+cells. Intestinal CX3CR1+cells are tissue resident cells and do not migrate to the MLN. CCR7 deficiency or FTY720 treatment does not affect the production of intestinal IgA after intravenous injection of OVA in mice. These results suggested that intestinal CX3CR1+cells have an important role in maintaining homeostasis of the intestinal immune system.
A murine model of spontaneous self-reactivity to the ileum
Authors: Jeschke Jonathan C , Mayne Christopher G , Salzman Nita H , Williams Calvin B 
Published: January 2023

Abstract
Inflammatory lesions of Crohn’s disease are commonly found in the ileum yet few mouse models of enterocolitis manifest inflammation at this site. In order to study inflammation targeted to the ileum, we developed a transgenic mouse line (HD5-mHEL/Hb) that expressed a model antigen (mHEL/Hb) using a Paneth cell promoter (HD5). The abundance of Paneth cells is unique to the ileum and variations in their antimicrobial-secreting function are associated with Crohn’s disease. HEL-reactive (3A9) transgenic TH cells accumulate in the ileum of lymphopenic HD5-mHEL/Hb mice following their adoptive transfer. To study spontaneous TH cell reactivity to the ileum, we bred HD5-mHEL/Hb lines to mHEL/Hb-reactive transgenic TH cell lines. A subset of progeny with both the mHEL/Hb antigen and the 3A9 transgene (Bigenic3A9) develop a spontaneous wasting phenotype that is associated with colitis. Bigenic3A9 mice show TH cell activation and accumulate increased numbers of IL-17A-producing TH cells in the ileum. To study the necessity of effector cytokines for the spontaneous disease of Bigenic3A9 mice, Bigenic3A9 mice were bred on IFNγ and IL17A knockout lines. IL17A−/− Bigenic3A9 mice do not show an altered predisposition to the wasting phenotype of IL17A+/+ Bigenic3A9 mice. Unexpectedly, IFNγ−/− Bigenic3A9 mice exhibit an increased incidence of wasting disease which is associated with a skew of TH cell populations towards an IL-17A-producing phenotype. These results identify a significant protective role for IFNγ in Bigenic3A9 mice and suggest protection may result from inhibitory effects on the polarization of IL-17A-producing TH cells.
Discovery of selective RORγ inverse agonists and demonstration of efficacy in inflammatory disease models
Authors: Damarla Ravi Krishna Babu , Ujjinamatada Ravi K , Nellore Kavitha , Dodheri Samiulla S , Chelur Shekar , Charamanna K.B , Mukherjee Subhendu , Reddy CH Sandeep , Balasubramanian Wesley Roy , Rathod Sanjay B , Lakshminarasimhan Anirudha , Rao K Narasimha , Ramanathan Anuradha , Mahalingam Natarajan , Girish AR , Samajdar Susanta , Pandit Chetan , Ramachandra Murali 
Published: January 2023

Abstract
The nuclear hormone receptor RORγ controls the differentiation of Th17 cells that plays a key pro-inflammatory role in a variety of autoimmune diseases. RORγ inverse agonists from multiple structural classes were discovered and screened in a RORγ radio-ligand binding assay as well as in a cell based reporter assay and functional effect was evaluated using primary mouse/human CD4+ve T-cells differentiation to Th17 cells. Pharmacokinetic profile of potent compounds was determined to support evaluation of efficacy as well as safety profile in rodents.
Lead compounds have demonstrated good activity (&lt; 100 nM) in reporter assay. Crystal structure of RORγ in complex with known inverse agonists as well as novel compounds, were solved to support lead optimization. Selected compounds demonstrated &gt;100 fold selectivity against RORα as well as other nuclear receptors with significant inhibition of IL-17 release in Th17 differentiation assay. Lead compounds have shown optimal physicochemical profile including good solubility and high free fraction, leading to excellent pharmacokinetic profile in mice and rats. Efficacy of lead compounds has been demonstrated in multiple disease models including asthma, psoriasis, Experimental auto immune encephalomyelitis and collagen induced arthritis. Potential lead candidates have been identified with excellent in-vitro safety profile including CEREP-44 safety panel, Ames test and cytotoxicity. One of the lead candidates has also demonstrated good therapeutic window as determined by a 7 day rat toxicity study.

Conclusions
We have identified structurally diverse small molecule inverse agonists of RORγ and have demonstrated efficacy in relevant disease models as well as good therapeutic window.
Targeting the PDE8A-Raf-1 kinase signaling complex to treat autoimmune inflammation
Authors: Basole Chaitali P , Nguyen Rebecca , Lamothe Katie , Vang Amanda , Clark Robert , Epstein Paul , Baillie George , Brocke Stefan 
Published: January 2023

Abstract
The levels of cAMP are regulated by phosphodiesterases (PDE), which are targets for the treatment of inflammatory disorders. We previously showed that PDE8A regulates T cell motility. We report here that PDE8A exerts its control of T cell function through the Raf-1 kinase signaling pathway. To mimic T cell migration under physiologic conditions, we performed flow chamber assays. The highly PDE8-selective enzymatic inhibitor PF-04957325 significantly suppresses rolling and adhesion of in vivo MOG35-55 activated inflammatory CD4+ T effector (Teff) cells while interacting with inflamed brain endothelial cells under shear flow conditions. Recently, PDE8A was shown to associate with Raf-1 creating a compartment of low cAMP around Raf-1 thereby protecting it from protein kinase A mediated inhibitory phosphorylation. To test this in Teff cells, we used a cell permeable peptide (DP) that disrupts the PDE8A-Raf-1 signaling complex. Disruption of the PDE8A-Raf-1 complex by DP significantly reduces adhesion of Teff cells to endothelial cells. We further observed that disrupting PDE8A-Raf-1 through DP specifically reduces adhesion, spreading and locomotion of Teff cells while interacting with the vascular adhesion molecule ICAM-1. Our investigation of the effect of PDE8 inhibitor on chronic and relapsing-remitting experimental autoimmune encephalomyelitis (EAE) in vivo indicate suppression of clinical and histopathological signs of disease. Collectively, our studies demonstrate that PDE8A inhibition by enzymatic inhibitors or PDE8A-Raf-1 kinase signaling complex disruptors significantly decreases Teff cell adhesion and migration on endothelial cells, and represents a novel approach to treat autoimmune inflammation in vivo.