bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dendritic cells as potential mediators of Mycobacterium tuberculosis infection of the central nervous system in a MHC class II-deficient mouse model.
Authors: Mergaert Aisha M , Hernandez Gianna , Heninger Erika , Gerhart Christian , Sandor Matyas , Fabry Zsuzsanna 
Published: January 2023

Abstract
Mycobacterium tuberculosis (Mtb) infection of the central nervous system (CNS) in a rare, but deadly form of TB affecting immune-compromised individuals. Due to the HIV-AIDS epidemic this population has recently increased, however the pathway by which Mtb gains access to the CNS is poorly understood. Our work seeks to understand the potential ability of dendritic cells to traffic Mtb to the CNS. Preliminarily, we established the importance of mycobacterium infected dendritic cells to the formation of nervous system infection in MHC class II-deficient mice. In this model we used bone marrow derived dendritic cells (BMDC) from a dendritic cell reporter mouse strain (CD11c-eYFP). These cells increased the dissemination of Mtb 6020 to the brain by one log compared to Mtb 6020 alone, though the systemic infection remained the same. When GM-CSF BMDCs were infected with tdTomato H37Rv Mtb and injected IV into MHC class II-deficient mice CFU was detected in the brain, cervical lymph nodes and lung with no Mtb observed in the liver and superficial lymph nodes. After infection with tdTomato Mtb, BMDCs matured using GM-CSF or FLT3 had increased expression of CD11c, eYFP, CD40 and CD86 as detected by flow cytometry. These immunocompromised mice, whose phenotype reflects aspects of immunodeficiency seen in human populations, have a predisposition to CNS infection when BMDCs are directly infected with mycobacterium, suggesting the ability of dendritic cells to facilitate the movement of Mtb across the BBB or choroid plexus to initiate infection. These data support the use of MHC class II-deficient mice as a model for future work.
Visceral adipose tissue contributes to the generation of pro-inflammatory B cell subsets in aging mice
Authors: Blomberg Bonnie , Diaz Alain , Romero Maria , Vasquez Thomas , Frasca Daniela 
Published: January 2023

Abstract
Age-related decrease in B cell function is associated with chronic low-grade inflammation and increased pro-inflammatory mediators. This effect is also associated with an increase in visceral adipose tissue (VAT) and metabolic inflammation. Adipocyte-derived chemokines are involved in the chemotaxis of immune cells which infiltrate the VAT and contribute to the inflammatory process. To identify contributors to the phenotypic and functional changes observed in aged B cells, we undertook studies of B cells in the VAT. We recently analyzed immune cells infiltrating the VAT of obese C57BL/6 mice (age 12–24 months). We found macrophages, B cells and T cells in VAT in a ratio of 1:3:5. As to B cells, we measured the major B cell subsets and found higher percentages of pro-inflammatory (age-associated B cells, ABC) and less Follicular (FO) B cells in VAT as compared to spleen. B cells isolated from VAT express higher levels of inflammatory immune activation markers (TNF-α/IL-6/IL-8), significantly higher NF-kB activation and phospho-STAT3, and secrete higher amounts of Ig antibodies specific for fat antigens as compared to splenic B cells. To evaluate the ability of adipocytes from the VAT to promote inflammation and induce pro-inflammatory B cell subsets, we co-cultured adipocytes from the VAT with splenic B cells from the same mice. Results show that co-culture for 72 hrs significantly changed the relative percentages of the B cell subsets, leading to a higher percentage of ABC, similar to what we have observed in the fat. Moreover, we found that the adipocytes produce several pro-inflammatory chemokines. These results are the first to show a direct effect of adipocytes on pro-inflammatory B cells.
Palmitate-induced MMP-9 expression in the human monocytic cells: Significance in metabolic inflammation
Authors: Al Roub areej Abu , Koshy Merin , Sindhu Sardar , Ahmad Rasheed 
Published: January 2023

Abstract
Matrix metalloproteinase (MMP)-9 is predominantly produced by monocytes/macrophages and directs the infiltration of circulatory immune cells into the adipose tissue through damage of vascular endothelial basement membrane. Obese individuals are known to have increased MMP-9 plasma levels and MMP-9 is reported to play an important role in obesity-mediated adipose tissue inflammation. Since in obesity, the levels of circulatory free fatty acid palmitate are increased and modulate the expression of inflammatory mediators, the role of palmitate in the regulation of MMP-9 remains unclear. Therefore, we determined whether palmitate could induce MMP-9 production, and if so, which signaling pathway(s) were involved. Here, we provide the evidence that palmitate induces MMP-9 expression at both mRNA and protein levels in human monocytic cells (P&lt;0.05). Increased NF-κB/AP-1 activity (P&lt;0.05) was also observed in palmitate-treated THP-1 cells. Palmitate-induced MMP-9 secretion was markedly suppressed either by neutralizing anti-TLR-4 antibody or by inhibiting clathrin-mediated endocytosis. Furthermore, MyD88−/− THP-1 cells did not express MMP-9 in response to palmitate treatment. Genetic silencing of TLR4 by siRNA also abrogated the palmitate-induced up-regulation of MMP-9. Altogether, these results show that palmitate induces TLR4-dependent activation of MMP-9 gene expression, which requires the recruitment of MyD88 leading to activation of NF-kB/AP1 transcription factors. Thus, our findings suggest that the palmitate-induced MMP-9 secretion might be an underlying mechanism of its increased levels in obesity and related metabolic inflammation.
Modulatory effect of perforin gene dosage during pathogen associatated blood brain barrier (BBB) disruption
Authors: Willenbring Robin , Jin Fang , Hansen Mike , Johnson Aaron J 
Published: January 2023

Abstract
Neuroinflammation is a putative mechanism of pathogen associated blood brain barrier (BBB) disruption. However, mechanisms of immune mediated vascular permeability remain an active topic of research. Our lab has defined a role for CD8 T cells and perforin in BBB tight junction protein alterations during neuroinflammation. Within the human population, perforin is highly polymorphic, the significance of which is unknown. Therefore, we investigated the capacity of T cells with a single perforin allele, which reduces perforin mRNA and protein expression by half, in modulating BBB disruption in a murine model. We also conducted a genetic analysis to determine the significance of perforin polymorphisms in humans. In vivo, we assessed perforin+/+, perforin+/− and perforin−/− mice using the peptide induced fatal syndrome (PIFS) model for CD8 T cell mediated BBB disruption. Using 3D volumetric analysis of gadolinium enhanced, T1 weighted MRI we determined that perforin alleles are additive in increasing BBB disruption. This finding was not the result of differing immune cell infiltration or virus load. In parallel, we conducted a population genetic analysis of the human perforin allele. Using the Exome Aggregation Consortium and primary literature, we categorized over 450 perforin polymorphisms. Perforin polymorphism rates directly correlated with equatorial distance and environmental pathogen richness. Therefore, our studies demonstrate a single perforin allele alters BBB disruption severity. We hypothesize that diversity at the human perforin allele is a form of inclusive fitness by contributing to differential susceptibility to pathogen associated CNS vascular permeability.
Mechanisms underlying 4-1BB agonist antibody mediated hepatotoxicity
Authors: Bartkowiak Todd , Jaiswal Ashvin R , Ai Midan , Budhani Pratha , Ager Casey , Curran Michael A 
Published: January 2023

Abstract
Agonist antibodies against the T cell costimulatory receptor 4-1BB have proven extraordinarily efficacious in the treatment of a multitude of pre-clinical murine tumors both in mono- and combination therapy settings. Although administration of α4-1BB in Phase I and II clinical trials has led to disease stabilization and partial remission in some cases of melanoma; high grade, dose limiting liver inflammation has slowed the progress of these agents toward FDA approval. We sought to uncover the mechanisms by which 4-1BB agonist antibodies trigger hepatotoxicity in hopes of discovering approaches by which the anti-tumor and hepatotoxic effects could be separated. We show that α4-1BB mediated liver damage initiates through stimulation of myeloid cells, followed by subsequent recruitment and activation of CD8 and CD4 T cells in the liver. Moreover, we show that the inflammatory cytokine IL-27 is essential in myeloid conversion of T cells into mediators of liver damage. Conversely, we show that Foxp3+ regulatory T cells are potent suppressors of 4-1BB agonist mediated hepatotoxicity; as depletion of Tregs exacerbates liver pathology. Our results go on to support the use of combination therapies in the treatment of tumor malignancies, in particular CTLA-4 blockade which may expand Tregs in the liver to ameliorate α4-1BB mediated toxicities while also amplifying anti-tumor immune responses.
Negative regulation of IL-2 signaling by β2 adrenergic receptor
Authors: Ruiz-Medina Blanca E , Esparza Edmundo , Kirken Robert A 
Published: January 2023

Abstract
T, B, and natural killer (NK) cells are required for normal immune response and regulated by cytokines such as interleukin 2 (IL-2). Cell signals are propagated following receptor-ligand engagement to control recruitment and activation of effector proteins. The IL-2 receptor β subunit (IL-2Rβ) serves in this capacity and is known to be phosphorylated on tyrosine, serine, and threonine residues. Regulation of lymphocytes is also influenced by the nervous system through the β2 adrenergic receptor (β2AR), and both pathways ultimately affect cell trafficking, proliferation, differentiation, and cytokine production. Signaling through either IL-2Rβ or the β2AR has been extensively studied, however, their potential cross-talk has yet to be fully characterized. Here we hypothesize that engagement of β2AR regulates IL-2 receptor signaling. Cells were treated with β2AR agonists and then stimulated with or without IL-2. Agonists reduced IL-2 induced proliferation in a dose dependent manner. To identify the mechanism, receptor phosphorylation and activation of downstream targets was assessed using phosphospecific antibodies. Pretreatment of cells with β2AR agonists diminished IL-2-induced phosphorylation of IL-2Rβ as well as the activation of downstream signaling molecules. In contrast, in the absence of IL-2, a biphasic β2AR agonist-induced phosphorylation of specific serine and threonine residues on IL-2Rβ associated to its activation was observed, while tyrosine phosphorylation changes were not detected. Downstream signaling molecules were differentially activated. In conclusion, the cross-talk between IL-2Rβ and β2AR could represent a novel regulatory mechanism of IL-2 signaling important for immunoregulation.
Low molecular weight compounds which inhibit BAFF binding to its receptor, BR3, suppress activation of monocytes.
Authors: Yoshimoto Keiko , Ishioka Eriko , Nishikawa Ayumi , Suzuki Katsuya , Takeuchi Tsutomu 
Published: January 2023

Abstract

Backgrounds and Purpose
We found that the elevated expression of a BAFF receptor, BR3, in monocytes of patients with primary Sjögren’s syndrome (pSS) was involved in overproduction of IL-6 by BAFF-stimulated pSS monocytes. Additionally, the proportion of BR3-positive monocytes to total monocytes was positively and significantly correlated with the serum IgG level of pSS patients. In this study, we investigated the effects of the compounds, which block BAFF binding to BR3, on BAFF-induced IL-6 production in pSS monocytes.

Methods
High throughput screening (HTS) of a chemical library was carried out to search for compounds that block binding of soluble BAFF (sBAFF) to BR3. THP-1 and peripheral monocytes prepared from pSS patients were cultured in the presence of sBAFF and the binding inhibitors. IL-6 production by the cells was measured by ELISA.

Results
A total of 18,562 compounds were examined for inhibitory activities of sBAFF binding to BR3. To eliminate false positives, inhibitory activities of the HTS-hits against IL-6 production by sBAFF-stimulated THP-1 were measured. As a result, we discovered two pyrrolopyrimidine derivatives which showed substantial inhibition of sBAFF-binding. sBAFF-induced IL-6 production by pSS monocytes was significantly suppressed by these compounds in a dose dependent manner.

Conclusion
We have successfully discovered low molecular weight compounds which have inhibitory activities against BAFF signaling in monocytes.
Recombinant variant of Fasciola hepatica fatty acid binding protein impairs the NF-κB activation in response to toll-like receptors agonists
Authors: Ramos-Benítez Marcos Javier , Ruiz-Jimenez Caleb , Espino Ana M 
Published: January 2023

Abstract
In recent years, it has been demonstrated that a strong Th2 immune response is able to suppress the inflammatory type or Th1 response; this Th1 response is linked to septic shock and some autoimmune diseases. Fasciola hepatica promotes a Th2 response during chronic infections, hence the production of anti-inflammatory cytokines. Our research group published that fatty acid binding protein (FABP) purified in native form (Fh12) from F. hepatica adult worm impairs the inflammatory cytokines storm typically induced by exposure to Lipopolysaccharides (LPS). Our work aimed to determine whether a recombinant variant of FABP could have a similar effect. We optimized the expression in E. Coli of an isoform of FABP named Fh15 and performed western blot analysis to confirm an immunological similarity between Fh12 and Fh15. Human monocytes THP1-CD14 cells were treated with Fh15, then stimulated separately with specific activation ligands for TLR 2, 4, 5 and 8 in order to determine the capacity to inhibit the NF-κB activation; we used Quanti-Blue medium to quantify the inhibition. Our results showed that both proteins are immunologically similar. Also, Fh15 was able to block the NF-κB activation induced by specific TLR ligands up to 95%, showing similar capacity as Fh12. The use of bacterial expression lead us to conclude that the glycosylation sites described for Fh12 are not required for the effect. We can anticipate that Fh15 has the potential to exhibit an inflammatory cytokines suppression effect. Fh15 impairs the NF-κB activation induced by different TLR-ligands suggesting a broad spectrum of action. We are working to elucidate the mechanisms for this effect and examine the potential of Fh12 and Fh15 as anti-inflammatory molecules in animal models.
Identification of CD163 as an anti-inflammatory receptor for HMGB1-haptoglobin complexes.
Authors: Yang Huan , Wang Haichao , Wang Yongjun , Chavan Sangeeta S , Al-Abed Yousef , Antoine Daniel J , Andersson Ulf , Tracey Kevin J 
Published: January 2023

Abstract
Secreted by activated cells or passively released by damaged cells, extracellular HMGB1 functions as a pro-inflammatory mediator of infection or injury. It was previously unknown whether HMGB1 can be partner with other endogenous proteins to tilt the balance towards anti-inflammatory activities. Here we demonstrated that an acute phase protein, haptoglobin, effectively binds HMGB1, and triggers anti-inflammatory programs in a CD163-dependent fashion. Specifically, the HMGB1 and haptoglobin complexes elicit the production of anti-inflammatory enzymes (heme oxygenase-1) and cytokines (e.g., IL-10) in wild type, but not in CD163-deficient macrophages. Genetic disruption of haptoglobin or CD163 expression renders animals more susceptible to lethal sepsis, whereas administration of haptoglobin to wild type or to haptoglobin-gene deficient animals confers significant protection. These findings reveal a novel mechanism by which an acute phase protein modulates extracellular HMGB1 activities, and provides a novel strategy for treatment of HMGB1-dependent inflammatory diseases.
T cell-intrinsic ASC critically promotes Th17-mediated experimental autoimmune encephalomyelitis.
Authors: Martin Bradley N , Wang Chenhui , Li Xiaoxia 
Published: January 2023

Abstract
In the present study, we uncovered a novel T cell-intrinsic role of the inflammasome adaptor molecule ASC in Th17-mediated EAE pathogenesis. We found that while T cell-intrinsic ASC is required for the effector stage of active EAE, ASC deficiency in T cells specifically impaired Th17- but not Th1-mediated passive EAE. T cells deficient in IL-1β were similarly impaired in their ability to mediate the effector phase of EAE. Mechanistically, TCR signaling induced pro-IL-1β expression and licensed T cells for inflammasome activation. Polarized Th17 cells expressed IL-1R, and produced mature IL-1β in response to ATP via ASC/NLRP3-dependent caspase-8 activation. Additionally, ATP-treated Th17 cells showed enhanced survival compared to ATP-treated Th1 cells, which was abrogated by IL-1Ra, suggesting an autocrine action of Th17-derived IL-1β. Together, these data suggest a critical role for IL-1β produced by a novel Th17 cell-intrinsic ASC-NLRP3-Caspase-8 inflammasome during CNS inflammation.
The human IL-22 binding protein isoforms are a rheostat for IL-22 signaling.
Authors: Lim Chrissie , Hong MeeAe , Savan Ram 
Published: January 2023

Abstract
The cytokine interleukin-22 (IL-22) activates signal transducer and activator of transcription 3 (STAT3) to drive various processes central to tissue homeostasis and immunosurveillance; its dysregulation causes inflammatory diseases. IL-22 has a soluble receptor, IL-22 binding protein (IL-22BP; IL22RA2), which antagonizes IL-22 activity and has genetic associations with autoimmune diseases. Humans express three IL-22BP isoforms, whereas mice only express an IL-22BPi2 homolog. Given the lack of IL-22BPi1 and IL-22BPi3 expression in mice, there has not been a thorough characterization of their activities to date. In this study, we show that IL-22BPi2 and IL-22BPi3 differentially modulate IL-22 activity: IL-22BPi3 has lower inhibitory activity than IL-22BPi2, but is expressed more abundantly throughout the body during homeostasis. IL-22BPi2 and IL-22BPi3 also differentially alter the cooperative actions between IL-22 and IL-17, which are commonly co-expressed in autoimmune settings. In addition, we demonstrate that IL-22BPi1 is inactive because it is not secreted. Importantly, while IL-22BPi3 is the dominant isoform expressed constitutively, only IL-22BPi2 is induced when myeloid cells are activated by Toll-like receptor 2 (TLR2) or retinoic acid. These data suggest that the IL-22BP isoforms have distinct spatial and temporal roles and coordinately fine-tune IL-22-dependent STAT3 responses in tissues as a rheostat. This work is the first to date to perform a thorough biochemical and molecular characterization of the human IL-22BP isoforms.
Serotonin Receptor Regulation of Eosinophil Transendothelial Migration
Authors: Campbell Jackson Archie , Green Jeremy , Soveg Frank , Abdala-Valencia Hiam , Cook-Mills Joan M 
Published: January 2023

Abstract
Previous research has shown that 5-hydroxytryptophan (5HTP), a metabolic precursor of serotonin, reduces allergic inflammation in the lung by inhibiting eosinophil migration across endothelial monolayers. Furthermore, when the metabolic conversion of 5HTP to serotonin is blocked, 5HTP inhibition of eosinophil migration is reduced. Therefore, 5HTP metabolism to serotonin is required for 5HTP inhibition of eosinophil migration. However, it is currently unknown if serotonin receptors are involved in mediating 5HTP function. We determined serotonin receptor expression on both endothelial cells and eosinophils by western blot and qPCR. Endothelial cells and eosinophils expressed serotonin receptors 1A, 1B, 3A, and 6. We subsequently determined whether inhibition of these serotonin receptors abrogates the effects of 5HTP. Notably, it was shown that blocking serotonin binding to serotonin receptors 1A and 1B by use of selective receptor inhibitors blocks 5HTP inhibition of migration. The function of signaling by serotonin receptors in 5HTP-mediated inhibition of migration is under investigation. Thus, serotonin receptors mediate 5HTP inhibition of transendothelial migration, and may serve as a target for intervention during allergic inflammation. These results will help design ongoing clinical studies addressing whether 5HTP blocks allergic asthmatic responses.
LIGHT, the Tumor Necrosis Superfamily Protein 14 (TNFSF14), Controls Lung and Skin Fibrosis.
Authors: Herro Rana , Sidler Daniel , da Silva Antunes Ricardo , Tamada Koji , Croft Michael 
Published: January 2023

Abstract
Lung and skin fibrosis are characterized by excessive accumulation of collagen and α-smooth muscle actin in these organs. The key molecules that promote these phenotypes are of clinical interest.
Thymic stromal lymphopoietin (TSLP) and Periostin (Pstn) have been found at high levels in patients with Asthma, Idiopathic Pulmonary Fibrosis, and Atopic Dermatitis. TSLP has been proposed as a primary driver of lung fibrotic disease, while Pstn was found to be an important mediator of Asthma and Systemic Sclerosis. We asked whether LIGHT (aka TNFSF14) controls TSLP and Pstn production to initiate fibrosis.
Genetic deletion of LIGHT abolished TSLP and Pstn expression driven by bleomycin used to induce fibrosis, accompanied by near-complete absence of accumulation of lung and skin collagen and α-smooth muscle actin. Furthermore, recombinant LIGHT administered in vivo induced lung and skin expression of both TSLP and Pstn in the absence of other inflammatory stimuli, and strikingly reproduced the primary features of bleomycin-driven disease in a TSLP-dependent manner. Blockade of LIGHT binding to either of its receptors, herpes virus entry mediator and lymphotoxin beta receptor, inhibited clinical symptoms of lung and skin fibrosis, and correspondingly both receptors were found on human epithelial cells and fibroblasts, primary sources of TSLP and Pstn respectively. Moreover, LIGHT induced TSLP directly in human bronchial epithelial cells and keratinocytes and synergized with IL-13 and TGF-β in vivo to promote TSLP expression and drive fibrosis.
These results show that LIGHT is a profibrogenic cytokine that may be a key driver of TSLP and Pstn production during the initiation and development of fibrotic diseases in the lung and skin.