bluuebunny/crossref_metadata_2025 huggingface dataset:
Synergetic effect of an autoantigen CII and a mycoplasma superantigen on the onset and development of autoimmune arthritis in mice
Authors: Mu Hong-Hua , Jiang Shaowei , Wang Xingqiong , Meaney Connor , Wang Jingyi
Published: January 2023

An infection can amplify an autoimmune disease by either exacerbating an ongoing disorder, including a relapse, or by leading to chronic progressive disease. We have been studying a mouse autoimmune arthritis induced by M. arthriditis. M. arthritidis produces a potent superantigen (SAg) MAM, which is shown to be partially responsible for the chronic autoimmune arthritis. Although the MAM clearly plays a role in disease induced by live M. arthritidis, MAM alone does not induce overt disease. It does alter the immune system rendering mice more susceptible to disease that caused by other autoimmune agents such as type II collagen (CII). A key question however is how do CII and MAM act together in the host to initiate inflammation and then an autoimmune arthritis? MAM was injected into mice convalescing from CIA or mice suboptimally immunized with CII. In contrast to controls, MAM caused an exacerbation of arthritis in mice that were recovering from CIA. MAM also triggered arthritis onset in mice that had been immunized with CII up to 71 days previously. Injection of MAM during the onset phase of CIA also triggered and enhanced the severity of arthritis in mice given low doses of CII. We also tested the CII-specific immune responses in mice injected with CII alone and also to the mixtures of the CII and MAM. The T cell profile analysis demonstrated that MAM significantly promoted IL-17 and IFNg following exposure to CII in vivo. Of particular interest was that MAM-enhanced IL-17 can stimulate synoviocytes to release a spectrum of chemokines, CXCL1, CXCL2, CXCL12, CCL2 and CCL5, and attracted inflammatory leukocytes. Thus, the results suggest MAM can serve as an enhancer and a trigger by activating inflammatory responses to other bioactive molecules, i.e. CII.
Novel role of T cells to induce development of proliferative plasmablasts in systemic lupus erythematous
Authors: Ojo Oluwagbemiga A , Liu Shanrun , Wu Qi , Yang PingAr , Crossman David K , Chatham Winn , Hsu Hui-Chen , Mountz John D
Published: January 2023

While research on human SLE and mouse models of lupus have focused on mechanisms of B cell tolerance loss, these efforts have been complicated by multiple networks of immune regulatory genes, thereby impeding current understanding of the development of autoantibody producing B cells in SLE. We applied an unsupervised single cell RNA-seq (scRNA-seq) approach to determine the network and pathways-associated with the development of plasmablasts (PBs) in SLE. PBs were isolated as CD19+CD21−IgD−CD27hiCD38hi cells from PBMCs of SLE patients (n=3). A high-throughput scRNA-seq was carried out using a droplet-based 10x Chromium approach (~ 2,000 cells per sample). We identified two populations of PBs based on the expression of MKI67 encoding for Ki67, a nuclear protein associated with cellular proliferation. Representative genes elevated in MKI67+ PBs included cell cycle related genes as well as TNFR2. Gene ontology analysis further suggest that TNFR2+ B cells expressed increased levels of genes that are associated with cell cycle G1/S transition, DNA synthesis and elongation, and replication. Flow cytometry analysis identified TNFR2+ B cells as a population of antibody secreting cells expressing higher levels of CD86, CD11c, and CD38 but lower levels of CD20. As both CD86 and CD11c poise B cells to receive T-cell help, our studies suggest that T-cell stimulation enables development of cycling PBs in SLE. The strong association of TNFR2 with cell cycle genes in PBs suggest that blockade of TNFR2 may be a novel strategy to inhibit PB proliferation and differentiation.
Ikaros mutations can bypass the requirement for second co-stimulatory signal and lead to break of B-cell tolerance
Authors: Schjerven Hilde , Rodriguez Princess D , Howell William , Vestbostad Johanne , Frietze Seth , Schjerven Hilde
Published: January 2023

Autoimmunity is thought to arise due to a combination of genetic and environmental factors. IKZF1, encoding the Zinc finger (ZnF) transcription factor Ikaros, is implicated in human autoimmunity through GWAS and recent discovery of germline IKZF1 mutations in patients with autoimmune diseases. We have previously created mouse models with targeted deletions of Ikaros DNA-binding ZnF1 or ZnF4, and recently found that mice lacking Ikaros ZnF4 (Ik-dF4) displayed very high levels of autoreactive antibodies and elevated levels of the autoimmunity-associated cytokine IL-6 in serum at young age, while mice lacking ZnF1 did not. Furthermore, ex vivo stimulation of peripheral B cells with anti-IgM (aIgM) +/− CD40L revealed that Ik-dF4 B cells responded to BCR-stimulation alone (aIgM), while wt B cells required a second co-stimulatory signal (CD40L). To understand the underlying mechanism, we performed transcriptome profiling of these stimulated wt and Ik-dF4 B cells. Overall, the Ik-dF4 B cells displayed the same pattern of gene-expression changes as wt B cell upon activation by both signals (aIgM + CD40L). Further analysis revealed a set of genes selectively altered upon aIgM alone in Ik-dF4 B cells, and another set of genes that were aberrantly expressed in Ik-dF4 B cells at baseline. Pathway analysis suggest candidate mediators, and we have initiated functional studies. Preliminary results indicate that a small molecule inhibitor can block the aberrant activation with aIgM alone in Ik-dF4 B cells, while displaying only partial inhibition of the normal two-signal activation. Studies are actively ongoing to confirm these preliminary findings, and we will present our results to date at the meeting for how Ikaros regulates B cell tolerance.
Natural Killer Cell Re-Modeling of the Extra-Cellular Matrix by the Degradation of Hyaluronan: Potential Role in Type 1 Diabetes
Authors: Fuchs Bryce E , Wall Valerie , Kang Inkyung , Workman Gail , Evanko Stephen , Wight THomas , Long Sarah Alice
Published: January 2023

Natural Killer (NK) cells have been shown to contribute to early insulitis during development of Type 1 Diabetes (T1D). We previously identified increased Hyaluronan (HA) deposition within inflamed pancreatic islets, indicative of remodeling of the extra cellular matrix (ECM) of which HA is a component. NK cells express CD44, a ligand for HA, and granzymes known to facilitate extravasation through the ECM. Thus, we asked whether NK cells may directly interact with the ECM, potentially contributing to HA modification in pancreatic islets. Isolated NK cells activated with IL-12, IL-15, and IL-18 up-regulated Has3, CD44, and Hyal1: genes related ECM re-modeling suggesting that NK cells may act upon the ECM. To test NK-ECM interactions, we used a co-culture system of stimulated NK cells and HA producing fibroblasts. We found down-regulation of Hyaluronidases Hyal1 and Hyal2 and up-regulation of HA Synthases Has1 and Has2. These results are consistent with NK cell modulation of ECM, that was also indicated by depletion of the fibroblast cell layer. Comparatively, CD4 and CD8 T cells did not show depletion of the cell layer and differed in the degree and composition of ECM related transcripts. Together, these data suggest that NK cells play a critical role in ECM re-modeling; this NK-ECM interaction may contribute to pancreatic inflammation in the setting of T1D.
Bromodomain inhibition instructs macrophages to promote beta cell proliferation and suppress autoimmune diabetes
Authors: Yang Meixiang , Wang Ke , Fu Wenxian
Published: January 2023

A hallmark of autoimmune type 1 diabetes (T1D) is the decline of beta cell mass. Any regimen to promote beta cell expansion will have a great therapeutic promise. We have previously demonstrated that an epigenetic inhibitor targeting BET proteins (I-BET) promotes beta cell proliferation in an animal model of T1D. However, the underlying mechanisms remains unknown. Using both gain-of and loss-of function assays, we demonstrate that macrophages play an indispensable role in I-BET-elicited beta cell proliferation. In vivo ablation of macrophages significantly abolishes, while the supplementation of I-BET preconditioned macrophages enhances, I-BET induced beta cell proliferation. On a molecular level, elevated production of platelet-derived growth factor (PDGF) in I-BET treated macrophages mobilizes PDGFR signaling in beta cells. In summary, these findings reveal a novel strategy to expand beta cells by harnessing macrophages.
The GRB2-associated binding protein 3 is required for IL-2 and IL-15 induced NK cell expansion and limits trophoblast invasion during pregnancy
Authors: Sliz Anna , Locker Kathryn C.S. , Lampe Kristin , Godarova Alzbeta , Plas David R , Janssen Edith , Jones Helen , Herr Andrew B , Hoebe Kasper
Published: January 2023

The Grb2-associated binding protein 3 (Gab3) is a scaffolding protein that belongs to the Grb2-assocated binding family of proteins along with Gab1 and Gab2. Gab3 is expressed exclusively in immune cells including NK cells, CD8+T cells, mast cells and macrophages, however the function of Gab3 has remained elusive. Based on two independent mouse models; a hypomorph germline mouse model carrying a missense mutation in the PH domain of Gab3 and complete Gab3-KO mice, we uncovered a key role for Gab3 in peripheral NK cell function. Specifically, loss of Gab3 results in impaired IL-2/IL-15-induced NK cell priming and expansion, due to a selective impairment in MAPK- but not STAT5-signaling. In vivo, we show that Gab3 is required for recognition and elimination of “missing-self” and tumor targets. Gab3-deficient mice exhibit impaired uterine NK cell expansion that is associated with abnormal spiral artery remodeling and increased trophoblast invasion in the decidua basalis. This coincides with stillbirth, retained placenta, maternal hemorrhage and undelivered fetoplacental units at term. Thus, our studies identify Gab3 as a novel component required for IL-2/IL-15-mediated NK cell priming and expansion that is essential for anti-tumor responses and for controlling fetal trophoblast invasion during pregnancy.
The role of Th17 lymphocytes in drug-resistant epilepsy
Authors: Ouédraogo Oumarou , Jamann Hélène , Daigneault Audrey , Clenet Marie-Laure , Lahav Boaz , Bérubé A. , Cossette Patrick , Keezer Mark , Nguyen Dang Khoa , Larochelle Catherine
Published: January 2023

Epilepsy is a chronic neuronal disorder affecting ~65 millions people throughout the world. 1/3 of patients suffer from drug-resistant epilepsy (DRE).

Objective

to assess the relationship between different Th17 markers and the clinical course of epilepsy to uncover new potential immune biomarkers and therapeutic targets of interest for DRE.

Approach

Subjects between 19–55 years old with a focal diagnosed epilepsy were recruited at the CHUM epilepsy clinic. The profile of peripheral blood T lymphocytes from DRE patients (n=48) is compared to well-controlled epilepsy (WCE; n=30) and healthy controls (n=35). Peripheral blood mononuclear cells (PBMCs) were isolated by gradient density centrifugation before ex vivo analysis of surface markers (flow cytometry). Total CD4 T lymphocytes were magnetically isolated from PBMCs and stimulated overnight before analysis of cytokine expression or processed for RNA extraction before analysis of transcription factors expression by qRT-PCR.

Results

Our data suggest that antiepileptic drugs are associated with a relative ‘immunosuppression’, more pronounced in WCE. Epilepsy is associated with an altered distribution of immune cell populations with a higher CD4:CD8 ratio. A higher proportion of CD4 T lymphocytes from DRE subjects express CCR6 and CD161 compared to WCE. The proportion of CD4 T cells expressing pro-inflammatory cytokines from Th17/1 lineage (IL-17A, IL-22, IFN-γ, GM-CSF, TNFα) is higher in DRE than WCE, while anti-inflammatory cytokines (IL-4, IL-10) tend to be lower.

Conclusion

Our preliminary results suggest an increased frequency of pro-inflammatory Th17/1 lymphocytes and their related cytokines in DRE. Pro-inflammatory CD4 T cells could play a role in DRE.
Stress Induced Immune Dysregulation: A Continuum Spanning Antarctica Winterover, Spaceflight, and Terrestrial Patients
Authors: Krieger Stephanie S , Makedonas George , Mehta Satish , Nelman Mayra , Pierson Duane , Tyring Stephen , Choukèr Alexander , Feuerecker Matthias , Strewe Claudia , Sams Clarence , Crucian Brian
Published: January 2023

Spaceflight, a unique environment characterized by stress, microgravity, isolation, circadian misalignment, and radiation exposure, impacts immune health. This analysis compares various aspects of immune dysregulation in astronauts during long-duration orbital spaceflight to ground-analog populations, including hypoxic and normoxic Antarctic winterover. Astronaut data were also compared to a clinical immunodeficiency population, shingles patients, to help interpret clinical risks during deep space missions.

A comprehensive evaluation was performed across all platforms which included plasma and mitogen stimulated cytokine profiles, T cell function, and peripheral leukocyte distribution. A cross platform analysis was then performed to define in-flight immune alterations, determine analog appropriateness, and interpret clinical risk.

Astronauts manifest a distinct pattern of immune alterations, including unaltered leukocyte distribution, reduced T/NK cell function, and increases in plasma cytokines leading to the reactivation of latent herpesviruses. The pattern is similar to that observed in shingles patients, but reduced in magnitude. Immune alterations during interior Antarctic winterover were dissimilar from spaceflight, likely due to hypobaric hypoxia. Normoxic winterover, to date only cytokine data exist, appears more homologous to spaceflight.

Stress induced reductions in immunity can lead to clinical disease. This phenomenon may represent a continuum, where alterations in astronauts may represent more subtle variations which precede the development of disease. Antarctica data, at a magnitude between flight and disease, suggest that stress and circadian issues may be a primary contributor.
Elevated expression levels of the voltage-gated sodium channel 1.7 and BAFF receptor in peripheral monocytes contribute to activation of monocytes of patients with primary Sjögren’s syndrome
Authors: Yoshimoto Keiko , Ikeda Yumi , Suzuki Katsuya , Takeuchi Tsutomu
Published: January 2023

Background & Purpose

We reported that elevated expression of BAFF-receptor (BR3) in peripheral monocytes of patients with primary Sjögren’s syndrome (pSS) resulted in robust increased in IL-6 production by the cells. It has been reported that the pathways via voltage-gated sodium channels, such as Nav1.7, in monocytic lineage are involved in production of inflammatory cytokines, such as IL-6, in inflammatory pain diseases. In this study, we investigated the expression levels of Nav1.7 and BR3 in peripheral monocytes in patients with pSS in an attempt to discriminate the disease from other autoimmune diseases, such as active RA and active SLE.

Methods

The expression levels of Nav1.7 and BR3 in peripheral monocytes were analyzed by FACS using whole blood samples from patients with pSS (n = 28), active RA (n = 15), active SLE (n = 37) and healthy controls (HC; n = 15). Peripheral monocytes were stimulated with BAFF in the presence or absence of an inhibitor against Nav1.7. The amount of IL-6 in the culture supernatants was measured by ELISA.

Results

FACS analysis revealed that the expression levels of Nav1.7 and BR3 in pSS monocytes was significantly higher than those of active RA (p = 0.005, 0.003), active SLE (p <0.001, 0.004) and HC (p < 0.001, 0.002). Interestingly, the expression level of Nav 1.7 in pSS monocytes was significantly and positively correlated with that of BR3 in the cells (p = 0.01). Moreover, a specific inhibitor against Nav 1.7 suppressed IL-6 production by sBAFF-stimulated peripheral monocytes in a dose dependent manner.

Conclusion

Our results strongly suggest that the crosstalk between BAFF signaling and sodium channel is involved in activation of pSS monocytes and can be a therapeutic target for pSS.
Anti-inflammatory effects of xanthohumol in RAW 264.7 macrophages are mediated through the activation of AMP kinase
Authors: Mills Devin M , Samuels Janaiya , Hawkins Meridith , Gavre Adrian , Shashidharamurthy Rangaiah , Rayalam Srujana
Published: January 2023

Xanthohumol (XN), a prenylated chalcone extracted from common hop plants, has been studied for its anti-inflammatory properties. In this study, we hypothesize that XN induces M2 polarization of macrophages and the resulting anti-inflammatory effects are mediated through the activation of adenosine monophosphate-activated protein kinase (AMPK) signaling pathway. RAW 264.7 cells were treated with either 0.1% DMSO or XN and the culture supernatant was collected for ELISA and whole cell lysates were collected for western blotting. Our results demonstrate that XN upregulated the secretion of IL10, a signature cytokine for M2 polarization, in RAW264.7 cells. We further demonstrated that XN increased arginase expression, a marker for M2 polarization, and suppressed IFNγ-mediated upregulation of inducible nitric oxide synthase (iNOS) expression, a marker for M1 polarization. Additionally, XN decreased IFNγ – induced elevation of nitrite release, indicating the inhibitory effects of XN against M1 polarization. Furthermore, XN at 25μM increased the secretion of catecholamines from macrophages comparable to IL4, an inducer of M2 phenotype and these effects were accompanied by an increased expression of tyrosine hydroxylase, a rate-limiting enzyme of catecholamine biosynthesis. Finally, XN and AICAR, an AMPK stimulator, upregulated the expression of phospho-AMPK and arginase while dorsomorphin, an established inhibitor of the AMPK pathway failed to do so in RAW264.7 cells. These results provide evidence for the anti-inflammatory effects of XN mediated through the induction of M2 polarization and activation of AMPK signaling pathway.
Characterisation of immune complexes in Kawasaki Disease and other infectious diseases by protein sequencing
Authors: Menikou Stephanie , McArdle Andrew , Kaforou Myrsini , Shimizu Chisato , Wright Victoria J , Herberg Jethro A , Kanegaye John T , Tremoulet Adriana , Burns Jane C , Levin Michael
Published: January 2023

Background

Kawasaki Disease is a paediatric inflammatory disease associated with self-limiting vasculitis. It has a world-wide distribution with an ethnic bias towards East Asian populations and is the most common cause of acquired heart disease in children in developed countries. The immunopathogenesis of KD remains poorly understood. The presence of antibody-antigens (pathogen) known as immune complexes in the blood of children with KD was established in numerous studies leading to the hypothesis that immune complexes contribute to the damages of the coronary artery.

Methodology

Using proteomic technologies we characterised the composition of immune complexes in KD and compare the immune complexes in KD with those in children with other febrile illnesses, TB and healthy children. Immune complexes were precipitated from the blood of 80 children with KD, 80 children with other febrile conditions, 30 with TB and 30 healthy children. We used Lumos Orbitrap mass spectrometry to identify the recovered proteins. Using the bioinformatics program PEAKS, we performed database searches and compared the protein abundances between the different comparator groups.

Conclusions

Immune complexes isolated from children with KD are different from those recovered from other febrile illnesses in terms of the nature of proteins within the complex. The pattern of proteins in the immune complexes containing immunoglobulins, complement proteins as well as other serum proteins, provides insight into the nature of the unique inflammatory response in KD versus the other inflammatory diseases.
Early treatment of a CD137L neutralizing antibody decreases mechanical hypersensitivity and functional recovery time following a sciatic nerve crush
Authors: Wakley Alexa A , Cao Ling
Published: January 2023

To investigate the role of CD137L in pain development and nerve regeneration following peripheral nerve injury, we examined pain-like and functional recovery-related behavioral responses following intrathecal injection (IT) of a CD137L neutralizing antibody (αCD137L; daily day 0–7) after sciatic nerve crush (SNC) in male and female B6 mice. Mice were randomly assigned to 1 of 4 groups: no IT, PBS, 0.1 or 0.5μg of αCD137L, and then were evaluated for sensitivity (von Frey, Hargreaves, & cold plantar test), sensory (pin prick assay) and motor (hind limb grip strength, toe spread reflex and toe spacing score) functional recovery before surgery and on post-surgery days 1–77. On post-SNC day 1, all groups showed changes in sensitivity and decreased sensory and functional responses. By day 7, αCD137L treated mice showed reduced mechanical hypersensitivity compared to no IT and PBS-treated controls and were at baseline levels by day 42, about 1–2 weeks earlier than both control groups. All groups showed hyposensitivity to heat stimulus on day 1, but quickly returned to baseline with no group differences. On days 1–35 hyposensitivity to a cold stimulus was also found in all groups, but αCD137Ltreated mice were slightly more sensitive on days 49–77. Grip strength improved in all groups on day 14 without significant group differences. On days 3–14, αCD137L-treated groups had higher toe space scores compared to controls. Finally, sensory recovery (pin prick) in αCD137L-treated groups emerged on day 3, a week earlier than the control groups. Together, our results suggest that CD137L likely contributes to sensory hypersensitivity and functional changes early on following peripheral nervy injury.
A Toll-like Receptor 5 agonist entolimod mitigates radiation damage through a neutrophil-dependent mechanism
Authors: Brackett Craig M , Greene Kellee , Kandar Bojidar , Trageser Nicholas , Kandefer Rachel , Pal Srabani , Burdelya Lyudmila , Gudkov Andrei
Published: January 2023

The increased risk of exposure to life-threating nuclear and radiation emergencies warrants the development of FDA-approved medical radiation countermeasures (MRC) as radio mitigators, which can be used after exposure to total body irradiation. Currently, Neupogen and Neulasta are the only FDA-approved radio mitigators but are unfortunately limited by adverse side effects and the need for additional medical supportive care. Bacterial flagellin, the natural agonist of Toll-like receptor (TLR) 5, and apharmacologically optimized derivative entolimod developed by us have powerful activity as a single agent MRC in rodents and non-human primates. Currently entolimod is being developed as a MRC under the FDA’s Animal Efficacy Rule, which guides development of drugs for which efficacy testing in humans would be unethical. The lack of induction of cytokine storm post systemically administered entolimod was demonstrated in rodents, non-human primates, and Phase I clinical trials involving nearly 200 subjects. Entolimod stimulates TLR5 on hepatocytes followed by activation of immunoregulatory signaling pathways, production of pro-inflammatory cytokines, and rapid recruitment of immune cells to the liver. Neutrophils are among the first immune cells that are rapidly recruited to both non-lymphoid and lymphoid tissues post-entolimod. We found that this entolimod-elicited neutrophil response was essential to mitigating radiation damage by promoting the recovery of hematopoietic stem cells in the bone marrow. This work underscores the underappreciated importance of TLR5-elicited neutrophils in promoting there generation of hematopoiesis following total body irradiation.
Functional studies to understand immune modifiers in cystic fibrosis
Authors: Lu Shiping , Song Kejing , Bomberger Jennifer , Kolls Jay K
Published: January 2023

Cystic fibrosis (CF) is an inherited lethal disease caused by mutated cystic fibrosis transmembrane conductance regulator (CFTR), around 60% with homozygous F508del mutation. Pseudomonas aeruginosa (P. aeruginosa) is the most predominant lung pathogen in CF patients, causing decreased lung function and increased mortality as compromised integrity and function of pulmonary epithelium. Genome-wide association (GWA) studies revealed several single nucleotide polymorphisms (SNPs) in class II major histocompatibility complex (MHCII) of the F508del population are associated with delayed age of colonization, as well as lung function. Up to 7% of lung B-cells in the CF lung are specific for P. aeruginosa but these cells show very little somatic hypermutation. Thus, we hypothesized there may exist differences in antibody isotypes, titer, specificity or affinity, specific to P. aeruginosa, which influence/determine lung function. To test this, we assessed a homozygous F508del mutated cohort of non-progressive CF patients with confirmed P. aeruginosa colonization. In this cohort, we found that the sera of CF patients had significantly higher IgG and IgG1 compared to non-CF controls. We also observed higher surface binding of antibodies from CF sera to P. aeruginosa. And CF sera inhibited bacterial biofilm formation time-dependently. In addition, we are querying T-cell immunity at the single cell level. Taken together these studies should shed light on the role of class II MHC as a gene modifier in CF.
Development of an outbred disease model of Hermansky-Pudlak Syndrome in Threespine Stickleback
Authors: Beck Emily A , Currey Mark C , Niebergall Emily , Bassham Susan , Cresko William A.
Published: January 2023

Mounting evidence shows that humans respond heterogeneously to diseases and treatments due to their genetic variation, leading to the growth of the field of personalized medicine. Research on model organisms is vital to seek scientific understandings of disease in this broader context, but current research in nonhuman disease models struggles to demonstrate the genetic variability of humans. One disease that exemplifies this issue is Hermansky-Pudlak Syndrome (HPS). HPS is a genetic syndrome resulting from mutations in one of ten HPS genes involved in endosome trafficking, which can result in oculocutaneous albinism, blood diathesis, pulmonary fibrosis, vision impairment, and granulomatous enterocolitis phenotypically indistinguishable from Crohn’s Disease. Currently no disease models for HPS exist that accurately demonstrate the variability of the human disease. Here we present an outbred mutant model of threespine stickleback (Gasterosteus aculeatus) fish exhibiting symptoms consistent with HPS. Using genetic mapping approaches we narrowed this mutation to a region of the genome containing hps4the causative disease gene of Hermansky-Pudlak Syndrome Type 4. Using histological staining and imaging we are confirming the presence of each symptom comprising the syndrome and hope to develop the first outbred system to tackle this disease. Ultimately, the application of outbred medical models in diverse organisms will be important for the advancement of personalized medicine, greatly enhancing our understanding of how genetic variation affects disease states.
Epitope profiling of plasma antibody in Alzheimer’s disease dementia patients
Authors: Park Sung-Gyoo , Sim Kyu Young , Byeon Yeongseon , Lee Kun Ho
Published: January 2023

Antibodies show excellent stability in blood; therefore, they can be utilized for screening of convenient blood-based markers of Alzheimer’s disease dementia (AD). This study used unbiased microarrays comprising 29,240 random peptides to screen for AD-specific antibodies. The results showed that 1) antibodies are specifically regulated in AD and certain combinations show high area under the receiver operating characteristic curve values (0.862–0.961); 2) AD-specific IgG antibodies arise from established IgM antibody-secreting cells; and 3) analysis of proteins targeted by differentially regulated antibodies identified AD-related signaling pathways. Thus, plasma antibodies targeting specific epitopes are regulated in AD; these epitopes may facilitate biomarker development.
Unraveling the role of fibrosis in the TB Granuloma
Authors: Evans Stephanie , Wong Eileen A , Flynn JoAnne L , Mattila Joshua T , Kirschner Denise
Published: January 2023

Tuberculosis (TB), a deadly infectious disease caused by the bacterium Mycobacterium tuberculosis (Mtb). The disease is characterized by the development of granulomas consisting of immune cells that form a cluster around the bacteria to limit bacterial growth and disease outcomes. Control of the TB epidemic is limited by a complicated drug regimen, development of antibiotic resistance, and the lack of an effective vaccine against infection and disease. Fibrosis is common in older granulomas, and has been associated with both positive and negative disease outcomes. Little is known about fibrosis in TB, partly due to the fact that fibroblasts are difficult to identify using traditional antibody-based techniques.

To provide insight into the role that fibrosis plays at a single granuloma scale, we have developed a computational, agent-based model of granuloma formation in the lung following infection with Mtb. In previously published work we have identified the mechanisms driving fibrosis within a granuloma i.e. how the granuloma environment effects fibrosis. Using immunohistochemistry, we have characterized fibroblasts and early collagen deposition in TB granulomas. Here we have extended this work to look at how fibrosis affects the ability of a granuloma to control bacteria, focusing on the role of both fibroblasts. Predictions show that early fibrosis alters the structure of the granuloma with few long-term effects on bacterial control, however late fibrosis decreases the promotability of bacterial dissemination. This work has implications on treatment options for TB that typically cause early fibrosis to occur.
BET bromodomain targeting suppresses the PD-1/PD-L1 pathway in triple-negative breast cancer and elicits anti-tumor immune response
Authors: Andrieu Guillaume , Shafran Jordan S , Denis Gerald V
Published: January 2023

Therapeutic strategies aiming to leverage anti-tumor immunity are being intensively investigated because they show promising results in several cancer therapies. In tumors able to evade immune clearance, the PD-1/PD-L1 pathway constitutes an important target to restore a functional anti-tumor immune response. Here, we report that BET protein inhibition suppresses the PD-1/PD-L1 axis in triple-negative breast cancer. BET proteins control PD-1 expression in effector T cells, and PD-L1 in breast cancer cells. BET protein targeting reduces T cell-derived interferon-gamma production and signaling, thereby suppressing PD-L1 sustained induction in breast cancer cells. Moreover, BET protein inhibition improves tumor cell-specific T cell cytotoxic function. Overall, we demonstrate that BET protein targeting represents a promising strategy to overcome tumor-reactive T cell exhaustion and improve anti-tumor immune responses, by reducing the PD-1/PD-L1 axis in triple-negative breast cancer.
REV-ERB mediated regulation of dendritic cell maturation and function
Authors: Amir Mohammed , Campbell Sean , Kamenecka Theodore , Solt Laura A
Published: January 2023

The REV-ERBs (REV-ERBα and REV-ERBβ) are members of the nuclear receptor superfamily of ligand-regulated transcription factors and owing to their ability to recruit corepressor, act as transcriptional repressors. The REV-ERBs have well-established roles in regulating various physiological functions, including metabolism and the circadian rhythm. However, little is known about their roles in the immune system. While some evidence exists suggesting the REV-ERBs, particularly REV-ERBα, regulates macrophage inflammatory responses, the REV-ERB’s role in regulating other cells of myeloid origin remains largely unknown.

Dendritic cells (DCs), like macrophages, are of myeloid origin and serve as the master regulator of immune responses by connecting microbial sensing and innate immunity to adaptive immune responses. Given the central role of DCs in regulating immune responses, we investigated if the REV-ERBs regulate DC maturation and function. We found that both REV-ERBα and REV-ERBβ expression is upregulated during the course of bone marrow derived dendritic cell (BMDCs) differentiation. BMDCs from REV-ERBα and REV-ERBβ deficient mice showed enhanced expression of maturation markers like CD86, MHCII, CD83 and proinflammatory cytokines. In contrast, treatment of BMDCs with a REV-ERB-specific agonist, SR9009, inhibited the expression of these maturation markers and proinflammatory cytokines. Our study suggests the REV-ERBs act as negative regulators of dendritic cell maturation and function thus pharmacological modulation of REV-ERB activity could be an attractive strategy in treating inflammatory diseases.
Method development for the analysis of PBMC-mediated killing of K562 cells by bovine colostrum and various fractions
Authors: Vieira-Brock Paula d , Andersen Anna , Vaughan Brent , Vollmer David
Published: January 2023

Background

Colostrum is the first milk that supplies newborns with immune supporting peptides. Due to its heterogeneous and variable characteristic, standardized assays for assessment of its biological activities are a challenge. Current set of studies were aimed to investigate the immune activity of bovine colostrum blends and different fractions as well as validate a method to assess variability across different lots.

Methods

Immune activity of a bovine colostrum blend and different fractions was evaluated by their ability to enhance PBMC-mediated killing of K562 cells. K562 cell killing was assessed by flow cytometry using DAPI. PBMCs derived from multiple healthy donors were initially investigated. Sample from the highest responder was used for subsequent studies. Different lots of product were assessed.

Results

Bovine colostrum blend and different fractions similarly reduced K562 cells number and these effects were generally greater than IL-2 control. Despite consistently effective at enhancing PBMCs-mediated K562 killing, the degree of the effect was significantly variable across different lots. These biological effects were dependable on the solubility of the product.

Conclusion

Assessment of PBMC-mediated killing of K562 cells by flow cytometry using DAPI is a reliable method for measuring immune activity of bovine colostrum and different fractions as long as product is well dissolved into solution and the same biological sample from a single donor is used for investigation of batch-to-batch variability.
Histamine-releasing factor (HRF) is a novel alarmin
Authors: Kasakura Kazumi , Kawakami Yu , Kawakami Yuko , Kawakami Toshiaki
Published: January 2023

Objective

We are investigating how HRF secretion is regulated during allergic conditions.

Results

HRF interacts with a subset of IgE molecules. HRF dimer and oligomers, but not monomer, enhance the antigen sensitivity and magnitude of IgE-dependent mast cell activation. We found that BEAS-2B human bronchial epithelial cells constitutively secrete various forms of HRF (monomer, disulfide-linked dimer/oligomers). Secretion of these forms of HRF was enhanced by allergens such as house dust mites (HDM). HDM-mediated HRF secretion was dramatically enhanced by epithelial-derived cytokines (IL-25, IL-33, TSLP), Th2 cytokines (IL-4, IL-5, IL-13), and proinflammatory cytokines (IL-1b, IL-6, TNF), although the cytokines alone had much less effects. Mechanical injury of BEAS-2B cells and its byproducts (i.e., adenosine and ATP) also enhanced HRF secretion. In contrast, papain and bromelain (occupational allergens) as well as uric acid (NLRP3 inflammasome activator) exhibited limited effects on HRF secretion. Several high-molecular-weight forms (≥150 kDa) of HRF were found in body fluids. Interestingly, rhinovirus infection in humans and nasal instillation of HDM in mice, conditions predisposing asthma exacerbation, induced secretion of these HRF forms into airways. These results suggest that disulfide-linked HRF dimer/oligomers are involved in asthma exacerbation.

Conclusion

HRF dimer/oligomers secreted by epithelial and other cells enhance allergic inflammation as a novel alarmin.
RNA-binding protein EWS, a novel modulator of LTβR signaling
Authors: Virgen-Slane Richard , Correa Ricardo G , Ramezani-Rad Parham , Rosa-Campos Alexandre , Li Jun , Ware Carl F.
Published: January 2023

Efficient immune responses depend on signaling networks coordinated by dynamic protein-protein interactions. Adaptor proteins, like TRAF3, participates in distinct signaling pathways critical for immune development and host defense. To identify distinct complexes of TRAF3 that may serve as important modulators, we carried out Affinity-Purification-Mass Spectrometry from different human immune cell lines. We identified a core group of cell line-independent protein-protein interactions and then used machine learning to infer distinct functional complexes. Our analysis revealed a unique, switch-like relationship between TRAF3, signaling molecule TRAF2, and RNA-binding protein EWS. With protein-binding experiments, we found that EWS associates with TRAF3 in the absence of TRAF2. Given that formation of the TRAF3:TRAF2 complex is a regulatory mechanism for some Tumor Necrosis Factor Receptor Superfamily members, we hypothesized that EWS may have a novel function downstream of these pathways. To test our hypothesis, we used LTβR as a prototype given its well-studied signaling through the TRAF3:TRAF2 complex. With endogenous proteins, we found that EWS associates with TRAF3 in unstimulated cells; however, dissociation occurs following LTβR stimulation. To infer a potential function of EWS for LTβR signaling, we carried out machine learning analysis of RNAseq expression data generated from unmodified fibroblasts, following LTβR stimulation. Our unsupervised analysis predicts a critical function for EWS in mRNA transport and expression of several NF-κB regulatory molecules. With RNAi, transcriptomics, and a NF-κB reporter system, we show that EWS is required for optimal activation of LTβR signaling.
Genomic Analysis Of Bone Marrow Progenitors During Viral Infection Reveals Novel Dendritic Cell Regulators
Authors: Jo Yeara , Zhang Kai , Wang Wei , Zuniga Elina
Published: January 2023

Dendritic cells (DC) play a central role in immune responses and can broadly subdivided into conventional (c) and plasmacytoid (p) DCs. We and others have described several adaptations of DCs and their progenitors during acute and chronic infections, including impaired DC development, maturation and altered cytokine production. To understand the underlying mechanisms we determined the transcriptional and chromatin landscapes of bone marrow (BM) DC progenitors from lymphocytic choriomeningitis virus (LCMV) infected mice, via RNA-Seq and ATAC-Seq, respectively. Initial analysis indicated that infection induced multiple alterations in gene signatures, including type-I-interferon signaling and metabolic pathways, as well as changes in chromatin accessibility, which were more enriched within intergenic regions. We next used the Taiji algorithm, which integrates chromatin accessibility and gene expression to assess the global importance of transcription factors (TFs) at the systems level. This analysis identified 11 known DC regulators and 24 TFs with no previous connection to DC biology. Knock-down experiments revealed that Glucocorticoid Modulatory Element Binding Protein 1 (Gmeb1), which was predicted to exhibit increased activity in progenitors from LCMV-infected mice, suppressed DC development and maturation. On the other hand, Zinc Finger Protein 524 (Zfp524), whose activity was predicted to be reduced in progenitors from LCMV-infected mice, promoted pDC cytokine production while inhibiting the same function in cDCs. These results highlight two novel TFs that regulate DC development and/or function, deepening our understanding of DC biology and providing potential new targets for DC-based immunotherapies.
Elucidation of long non-coding RNA Snhg7 functions in T Cells
Authors: Varney Melinda , McCall Jamie , Westfall Sydney , Blethen Kathryn , Martinez Ivan , Barnett John B
Published: January 2023

Long non-coding RNAs (lncRNAs) have emerged as important molecules involved in a vast number of biological processes, including transcriptional, prost-transcriptional, and epigenetic regulation. The lncRNA Small Nucleolar RNA Host Gene 7 (Snhg7) has been shown to function as a competing endogenous RNA by sequestering several microRNAs (miRNAs) including miR-34a and miR-216b. Interestingly, these specific miRNAs have been shown to target GalNac transferases in many cancers. Given that O-linked glycosylation contributes to T-cell maturation, trafficking, and survival, the objective of this study was to determine the importance of Snhg7 in T cell maturation through the regulation of GALNAc transferases via miRNA sequestration. We tested the hypothesis that Snhg7 functions to sequester miR-34a and miR-216b, thereby controlling the production of Polypeptide N-acetylgalactosaminyltransferase proteins GALNT7 and GALNT1 in T cells. Our data demonstrate that siRNA knockdown of Snhg7 in T cells leads to miR-34a- and miR-216b-dependent decreases in GALNT7 and GALNT1 protein expression, respectively. Though Snhg7 knockdown has inhibited proliferation in cancer cells lines, it increased proliferation of T cells in a Jurkat cell line in a miR-34a- and miR-216- independent manner. Surprisingly, Jurkat cells produce truncated O-glycans. These data suggests that O-glycosylation contributes to Snhg7-induced cell proliferation. Taken together, our data support the hypothesis that Snhg7 influences critical processes in T cell function and should be considered in future biomarkers of disease or novel therapeutic strategies. Supported by NIH grant ES023845.
NF-κB-targeted intervention of acetaminophen-induced acute liver injury by benzyl indanone
Authors: Song Jin Yong , Jung Da-Eun , Jung Sang-Jun , Han Sang-Bae , Kim Youngsoo
Published: January 2023

Acetaminophen (APAP, Paracetamol) is a worldwide analgesic ingredient. Acetaminophen overdose accounts for 46% of acute liver failure. The toxic mechanism of acetaminophen-induced liver injury (AILI) consists of two phases: early phase by APAP and late phase by Kupffer cell-mediated inflammation. N-acetyl cysteine, the therapeutic drug of AILI, is effective in early phase but not in late phase. Here, we focus on the innate immunosuppressant to improve AILI and demonstrate protective effect of benzyl indanone derivative on AILI. The survival rate of AILI was increased from 12% to 91% and serum levels of ALT, AST and total bilirubin was decreased by benzyl indanone derivatives. It was associated with decreased hepatic necrosis, DNA fragmentation, neutrophil infiltration and expression levels of pro-inflammatory cytokines and chemokines. We isolated hepatocyte and kupffer cell to determine molecular target of benzyl indanone derivative. Benzyl indanone derivative did not affect primary hepatic damage such as ROS production, JNK phosphorylation, mitochondrial membrane potential and cell death. Benzyl indanone derivative reduced NO production and pro-inflammatory cytokine/chemokine expression in Kupffer cell. Benzyl indanone derivative reduced DNA binding affinity and transcriptional activity of NF-κB but did not affact NF-κB phosphorylation and nuclear import. This study suggest that inhibition of NF-κB activity by benzyl indanone derivative improves AILI.
The cholesterol transporter ABCG1 modulates macrophage polarization in human monocyte-derived macrophages
Authors: Sag Duygu , Purcu Duygu Unuvar , Altunay Meltem
Published: January 2023

The ATP-binding Cassette Transporter G1 (ABCG1) promotes cholesterol efflux from cells and regulates intracellular cholesterol homeostasis. Recent studies have shown that in mice in the absence of ABCG1, macrophages shift from a tumor-promoting M2 phenotype to a tumor-fighting M1 phenotype within the tumor and suppress bladder cancer growth in vivo. Two important aspects of this effect are still unknown: (1) whether ABCG1-would also impact polarization of human macrophages, and (2) the underlying molecular mechanism of this effect. Here, we show that in human monocyte-derived macrophages the inhibition of ABCG1 by siRNA significantly increased the expression of the M1 markers IDO1, CXCL10, CD64 and TNF after LPS/IFNγ (M1) stimulation. In contrast, after IL-4 (M2) stimulation the expression of the M2 markers MRC1, TGM2 and CD163 was significantly reduced. These data indicate that ABCG1-deficiency promotes the polarization of macrophage to an M1 phenotype in human macrophages. To address the molecular mechanism, we analysed cell signalling in bone marrow-derived macrophages from Abcg1−/− mice. These macrophages displayed reduced levels of Akt activation after stimulation with LPS/IFNγ or IL4. In addition, while Abcg1−/− macrophages stimulated with LPS/IFNγ produced more TNF compared to WT macrophages, after treatment with an Akt activator the TNF-production of Abcg1−/− and WT macrophages was comparable. These data suggest that the M1 bias of Abcg1−/− macrophages is mediated through the Akt signalling pathway. In summary, these findings deepen our mechanistic understanding of the M1/M2 switch in macrophages and suggest that ABCG1 could be a potential new target to modulate macrophage polarization for cancer immunotherapy.
Sargassum horneri inhibits particulate matter-induced apoptotic cell death in splenocytes
Authors: Jee Youngheun , Kim Areum , Herath K.H.I.N.M , Kim Hyo Jin , Mihindukulasooriya S.P. , Ko Mi-Ok , Jeon You-Jin
Published: January 2023

Recently, with rapid industrialization, air pollution is a significant public health hazard, and particulate matters (PM), solid or liquid particles small enough to remain airborne, have emerged as the main culprit of it. For instance, exposure to PM is known to induce ROS production, DNA damage, and apoptosis. Sargassum horneri (S. horneri), an brown algae distributed in Korea and Japan, is rich in amino acids, vitamins and polysaccharides. Also, it has been reported to present interesting biological and pharmacological properties including antioxidant, anti-allergic and anti-inflammatory efficacy. The aim of the present study is to examine the cytoprotective effects of S. horneri against PM-induced immune cell death in mice. To identity cytotoxicity of S. horneri, we treated splenocytes with S. horneri alone and could not observe cytotoxicity in the concentrations tested. When we exposed splenocytes to PM with or without S. horneri (62.5–125 μg/ml), we found that S. horneri reduced cytotoxicity due to PM (3.9–1,000 μg/ml). S. horneri treated splenocytes also displayed enhanced proliferation compared to untreated control group. We observed that S. horneri not only decreased oxidative stress due to its notable oxidant scavenging capacity but also reduced PM-induced apoptotic fragments of splenocytes. After S. horneri treatment, cell deaths of PM-challenged splenocytes were decreased. Our results suggest that S. horneri can protect immune cells from PM exposure-induced oxidative stress and cell death. This research is a part of a project titled ‘Development of functional food products with natural materials derived from marine resources’, funded by the Ministry of Oceans and Fisheries, Korea in 2017 (Project NO. 20170285).