bluuebunny/crossref_metadata_2025 huggingface dataset:
The transcription factor Bhlhe40 is a switch of inflammatory versus anti-inflammatory Th1 cell fate determination
Authors: yu fang , Sharma Suveena , Jankovic Dragana , Su Pan , Rieder Sadiye , Porcella Stephen , Sun Bing , Zhu Jinfang (Jeff)
Published: January 2023

Type 1 T helper (Th1) cells play a critical role in host defense against intracellular pathogens and in autoimmune diseases by producing a key inflammatory cytokine interferon (IFN)-γ; some Th1 cells can be anti-inflammatory through producing IL-10. However, the molecular switch for regulating the differentiation of inflammatory and anti-inflammatory Th1 cells is still elusive. Here we show that Bhlhe40-deficient CD4 Th1 cells produced less IFN-γ but substantially more IL-10 than wild type Th1 cells. Bhlhe40-mediated IFN-γ production was independent of transcription factor T-bet regulation. Mice with conditional deletion of Bhlhe40 in T cells succumbed to Toxoplasma gondii infection and blockage of IL-10 signaling during infection rescued these mice from death. Thus, our results demonstrate that transcription factor Bhlhe40 is a molecular switch for determining the fate of inflammatory and anti-inflammatory Th1 cells.
CD001, an active compound from Astragalus membranaceus, downregulates TH17 cells differentiation and attenuates collagen-induced arthritis through inhibition of IL-6/IL-6R signaling
Authors: Yen Hung-Rong , Pai Fu-Tzu , Lu Cheng-You , Song Ying-Chyi , Wu Mei-Yao , Yu Sheng-Jie , Huang Ming-Cheng
Published: January 2023

Rheumatoid arthritis is a common autoimmune disease affecting approximately one percent of the worldwide population. It causes not only life-long discomfort but also disabilities of the patients. Despite the fact that conventional therapies and biological agents are used to modulate the dysregulated immune response and inflammation; there are still some unmet needs and concerns. We aimed to develop a pharmaceutical agent for targeting IL-6 receptor, which is involved in the differentiation of TH17 and pathogenesis of rheumatoid arthritis. Here we demonstrated an active compound, CD001, from Astragalus membranaceus, inhibited TH17 cells differentiation in a concentration-dependent manner in vitro. To further determine its efficacy in vivo, we administered CD001 in a murine model of collagen-induced arthritis. CD001 ameliorated paw edema and disease incidence as well as the production of IL-17, IL-22 and TNF-a in vivo. Molecular docking revealed that CD001 could couple into the binding site of IL-6 receptor. We further confirmed that CD001 interrupted the binding of IL-6 and IL-6 receptor in an in vitro binding assay. CD001 inhibited the downstream signaling pathways of IL-6 receptor, including JAK/STAT3, ErK1/2, and AKT, in TH17 cells. Our data fit the niche that is required to block IL-6 receptor signaling and inhibit TH17 for immunotherapy. We suggest that, to treat autoimmune disease, administering CD001 could be a promising pharmacologic approach to achieve the goal.
Evaluation of HPV-16 and HPV-18-specific Antibody Measurements in Saliva Collected in Oral Rinses and Merocel® Sponges
Authors: Parker Katherine H , Kemp Troy , Pan Yuanji , Giuliano Anna , Pinto Ligia A
Published: January 2023

Currently, there is some evidencing suggesting that HPV L1 VLP vaccines protect against HPV-16 and HPV-18 infection at the oral cavity in females and males. Although correlates of protection have not been identified, HPV specific antibodies at sites of infection are thought to be the main mechanism of protection afforded by vaccination. Oral sampling has gained increased attention as a potential alternative to serum in monitoring immunity to vaccination and understanding local immunity. The aim of this study was to evaluate if the HPV-16 and HPV-18 ELISAs currently used in sero-epidemiological studies of immunogenicity of HPV vaccines could be used to detect HPV-16 and HPV-18-specific antibodies in saliva following vaccination, using two different oral sampling methods. Data presented here demonstrate that HPV-16 and HPV-18 specific antibodies are detectable in saliva from vaccine recipients, from both mouthwash and Merocel® sponges using L1 VLP-based ELISAs.
Cross-Species Comparison Reveals Molecular and Functional Novelty of Porcine Interferon-Omega Subtype
Authors: Sang Yongming , Liu Qinfang , Lee Jinhwa , Miller Laura C. , Ma Wenjun , Blecha Frank
Published: January 2023

Innate immune interferons (IFNs), particularly type I IFNs, are primary mediators regulating antiviral immunity. These antiviral cytokines have evolved remarkable molecular and functional diversity to confront ever-evolving viral threats. We have annotated IFN gene families across 155 animal genomes, and show that pigs have the largest and an expanding type I IFN family consisting of nearly 60 functional genes that encode seven IFN subtypes including multigene subtypes of IFN-α and -ω. Whereas subtypes such as IFN-α and -β have been widely studied, the unconventional IFN-ω subtype has barely been investigated. We have evolutionarily defined the porcine IFN family, and preliminarily showed that porcine IFN-ω subtype has evolved several novel features including, (1) a signature multi-gene subtype expanding particularly in bats and ungulates, (2) emerging isoforms that have much higher antiviral potency than typical IFN-α, (3) cross-species high antiviral (but little antiproliferative) activity in cells of humans and other mammalian species, and (4) potential action through noncanonical signaling pathways. This study is focused on antiviral potency of porcine IFN-ωs investigating their evolutionary and functional diversity, signaling specificity, and optimization of novel antivirals against devastating viral diseases. This project will, for the first time in an animal species, establish state-of-the-art procedures for efficient characterization of the molecular and functional spectrums of unconventional IFNs, which will further IFN-based novel antiviral design.

Supported by grants from USDA (NIFA AFRI 2013-67015-21236 and NIFA AFRI 2015-67015-23216)
SLP-76 Adaptor Binding to SUMO-RANGAP1 of the Nuclear Pore Complex Regulates Multiple Aspects of T-cell Immunity
Authors: Rudd Christopher E , Jules Felix
Published: January 2023

While immune cell adaptors regulate various proximal events in T cell signaling, the direct regulation of the nuclear pore complex (NPC) has not been reported. On the cytoplasmic side of the NPC, there are cytoplasmic filaments composed of two fundamental proteins RanGAP1 and RanBP2. We previously showed that the immune cell adaptor SLP-76 binds directly to SUMO-RanGAP1 of cytoplasmic fibrils of the NPC, and that this interaction is needed for optimal NFATc1 and NF-κB p65 nuclear entry in T cells (Liu et al., 2015 Mol Cell 59, 840–9). The use of a mutant form of SLP-76 that is unable to bind to RanGAP1 (i.e. K56E) reduced nuclear entry and T-cell cytokine production by >60%. It represents the second step in NFATc1 entry into the nucleus of T-cells following classic NFATc de-phosphorylation by calcineurin. We now show that K56E mutant reduced toll-like receptor induction of NF-κB nuclear entry (innate signaling) and that T-cells from K56E mutant mice show major defects in T-cell proliferation and immunity. Our findings further underscore the importance of this direct regulation of NPC function in T cell function.
NAADP mediated calcium signaling in memory CD4+ T cells
Authors: Chakraborty Anish , Giovannucci David R. , Slama James T. , Wall Katherine Ann
Published: January 2023

Nicotinic acid adenine dinucleotide phosphate (NAADP) is a metabolite of NADP that serves as a Ca2+ mobilizing second messenger in a variety of different eukaryotic cells including lymphocytes. Although the sources of Ca+2 mobilized by NAADP in lymphocytes are still under study and controversial, NAADP-responsive stores in other cells are often acidic, lysosome-related organelles. NAADP-mediated calcium signaling and its downstream physiological responses have been studied in our lab in naïve, effector, and natural regulatory T cells; however, these have not been studied in memory T cells. Since calcium responses vary in different T cell subsets, it is important to examine this pathway in memory cells as well. Memory T cells are important in terms of maintaining a pool in a quiescent state and activating more rapidly than do naïve cells during exposure to cognate antigen. Using a pharmacological approach with the NAADP antagonist Ned-19, we are studying the involvement of NAADP in memory CD4+ T cells during TCR activation and its downstream physiological events, such as proliferation and cytokine production. This study will gain insight into the possible sources of Ca2+ released in response to NAADP-mediated TCR activation of memory CD4+ T cells.
Human germinal center B cells are intrinsically distinct from naive B cells
Authors: Quizon Nicolas , Kwak Kihyuck , Sohn Haewon , Pierce Susan K.
Published: January 2023

In germinal centers (GCs) B cells undergo cycles of proliferation and somatic hyper mutation followed by affinity discrimination. Selection of GC B cells expressing high affinity B cell receptors (BCRs) is driven by the ability of B cells to signal through the BCR and extract antigen to present to follicular helper T cells. Here we provide evidence that human tonsillar GC B cells, as compared to naïve tonsillar B cells, may have a higher threshold for affinity selection but be better able to interact with T cells and, once triggered through the BCR, may form more stable signaling complexes. A comprehensive quantitative analysis of surface proteins showed distinct profiles for naïve and GC B cells. In particular, GC B cells express less of the integrin VLA-4 and as a consequence were less able to engage beads coated with its ligand, VCAM-1. Given that VLA-4 tethers B cells to VCAM-expressing cell surfaces and facilitates BCR-dependent activation, a reduction in VLA-4 expression would be predicted to raise the threshold for affinity selection in GC B cells. GC B cells also tended to have increased surface expression of proteins that mediate T-B-cell interactions, such as CD80 and CD86, suggesting that once antigen is captured and presented GC B cells would be better equipped to engage helper T cells. To explore BCR signaling we imaged synapses formed between B cells with anti-Ig-containing planar lipid bilayers via total internal reflection fluorescence microscopy. GC B cells tended to form more stable signaling complexes showing greater co-localization between their BCRs and components of their signaling pathway. Taken together these data point toward intrinsic differences between GC and naïve B cells that may contribute to the outcome of GC responses.
Regulatory effects of Interleukin (IL)-15 on allergen-induced airway obstruction
Authors: Venkateshaiah Sathisha Upparahalli , Manohar Murli , Verma Alok Kumar , Mishra Anil
Published: January 2023

Airway obstruction is a highly specific term that represents physiologic abnormalities of the airways and induced levels is observed in steroid treated asthmatic patients. We tested the hypothesis that regulation of IL-15 is critical for the preservation of allergen-induced airway hyperresponsiveness (AHR), airway resistance and compliance in response to methacholine. Airway inflammation, AHR, resistance and compliance were assessed in IL-15-deficient mice and IL-15 overexpressed mice in allergen-induced murine model of asthma. Lung histological analysis for eosinophils by anti-MBP immunostaining, Goblet cells hyperplasia by PAS staining, cytokines and chemokine levels by qPCR and ELISA analyses. Herein, we made a novel observation that IL-15 deficiency promotes baseline airway resistance in naïve mice. Moreover, rIL-15 delivery to the lung downregulates expression of inflammatory cytokines, and improves allergen-induced AHR, resistance and compliance. These observations were further validated in DOX-inducible CC-10-IL-15 transgenic mice. DOX exposed Aspergillus extract challenged CC-10-IL-15 bitransgenic mice exhibited significantly reduced levels of inflammatory cytokines (IL-4, IL-5, IL-13) and goblet cell hyperplasia. Airway obstruction, including AHR and resistance was diminished in allergen challenged DOX exposed compare to no-DOX exposed CC-10-IL-15 bitransgenic mice. Mechanistically, we observed that IL-15-induced protection of airway obstruction is associated with the induced IL-10-producing regulatory CD4+CD25+Foxp3+ T cells. We report our novel finding that IL-15 has a potent inhibitory effect on the airway obstruction that occurs in response to environmental allergens/pollutants.
IL-15-deficient mice develop enhanced airway allergic responses in a mouse model of allergic airway disease
Authors: Mathias Clinton B , Schramm Craig M , Guernsey Linda , Polukort Stephanie , Rovatti Jeffrey , Ser-Dolansky Jennifer , Secor Eric , Schneider Sallie S , Thrall Roger S , Aguila Hector L
Published: January 2023

Interleukin-15 is a pleiotropic cytokine critical for the development of multiple hematopoietic lineages. Mice lacking IL-15 have selective defects in populations of several pro-allergic immune cells including natural killer (NK) cells, NKT cells, and memory CD8+T cells. We therefore hypothesized that IL-15−/− mice will have reduced inflammatory responses during the development of allergic airway disease (AAD). Here we report that IL-15−/− mice developed enhanced allergic responses in an OVA-induced model of AAD. C57BL/6 wild-type (WT) and IL-15−/− mice were sensitized and challenged with ovalbumin (OVA) and the development of AAD was ascertained. In the absence of IL-15, OVA-challenged mice exhibited enhanced bronchial eosinophilic inflammation, elevated IL-13 production, and severe lung histopathology in comparison with WT mice. In addition, increased numbers of CD4+T and B cells in the spleens and broncholaveolar lavage were also observed. Examination of OVA-challenged IL-15R−/− animals revealed a similar phenotype resulting in enhanced airway eosinophilia compared to WT mice. Adoptive transfer of splenic CD8+T cells from OVA-sensitized WT mice suppressed the enhancement of eosinophilia in IL-15−/− animals to levels observed in WT mice, but had no further effects. These data demonstrate that mice with an endogenous IL-15 deficiency are susceptible to the development of severe, enhanced Th2-mediated AAD. Furthermore, the development of disease as well as allergen-specific Th2 responses occurs despite deficiencies in several IL-15-dependent cell types including NK and NKT cells, suggesting that these cells or their subsets are dispensable for the induction of AAD in IL-15-deficient mice.
Toll-like receptor-7-mediated activation of pDCs suppresses the ILC2-mediated airway hyperreactivity and inflammation through type-I interferon
Authors: Maazi Hadi , Banie Homayon , Aleman German , Lewis Gavin , Patel Nisheel , Wang Bowen , Soroosh Pejman , Akbari Omid
Published: January 2023

Type 2 innate lymphoid cells (ILC2s) are newly identified subset of immune cells that play important roles in the pathogenesis of allergic diseases and asthma. The regulatory mechanisms that control the function and homeostasis of ILC2s are incompletely understood. Plasmacytoid dendritic cells (pDCs) have been previously associated with maintaining respiratory tolerance. To identify a novel mechanism for alleviating ILC2-mediated asthma we investigated impact of pDCs on ILC2s and ILC2-mediated airway hyperreactivity and inflammation.

We investigated human and murine ILC2s and used clinically relevant allergen, Alternaria Alternata, as well as IL-33, to activate ILC2s in several mouse models including BDCA-2-DTR transgenic and Interferon alpha receptor-1 deficient mice.

We found that activation of pDCS by a Toll-like receptor-7 agonist, R848, suppresses ILC2-mediated AHR and airway inflammation and that depletion of pDCs reverses this suppression. Moreover, we found that pDCs suppress cytokine production and proliferation of ILC2s through the production of interferon alpha. Transcriptome analysis of both human and murine ILC2s confirms the activation of regulatory pathways in ILC2s by interferon alpha.

In addition, activation of pDCs alleviates airway hyperreactivity and inflammation by suppressing ILC2’s function and survival. Our findings reveal a novel regulatory pathway in ILC2-mediated pulmonary inflammation with important clinical implications.
Role for dysregulated iron in the pathogenesis of murine models of lung disease
Authors: Horvat Jay C , Ali Md Khadem , Johnstone Daniel , Kim Richard Y , Mayall Jemma R , Karim Rafia , Pinkerton James W , Heidari Moones , Martin Kristy L , Donovam Chantal , Liu Gang , Milward Elizabeth A , Hansbro Philip M
Published: January 2023

Altered iron levels and/or dysregulated iron homeostasis have been associated with a number of lung diseases, however, the mechanisms that underpin these associations, and whether iron plays a role in the pathogenesis of disease, are yet to be fully elucidated. In this study, systemic and pulmonary iron and lung structure and function were assessed in transferrin receptor (TFR)2 mutant and wild-type (WT) BALB/c mice fed a high-iron diet (containing 2% carbonyl iron) compared to normal diet controls, respectively. The effects of increased iron loading on murine models of ovalbumin- and house dust mite-induced allergic airways disease (AAD) were also assessed. Excess iron accumulation was observed in the lungs in both the genetic and diet-induced models of iron overloading. Increased iron levels in the lung were associated with emphysema-like alveolar enlargement, small airways collagen deposition, alterations in baseline lung function and increased airways hyper-responsiveness (AHR). Increased iron loading also resulted in altered type 1, 2 and 17 cytokine production, increased eosinophilic inflammation and severe, steroid-resistant AHR in AAD. Interestingly, AAD also results in altered systemic and pulmonary iron levels and iron regulatory molecule expression. These data show that increased iron levels in the lung results in emphysema and airways fibrosis that corresponds with reduced lung function. We also show that lung disease may be closely associated with changes in iron homeostasis. These models will be used to characterize the interplay between iron and immunity in the pathogenesis of lung disease and determine the therapeutic effectiveness of correcting dysregulated iron homeostasis for the treatment of lung disease.
Systemic and unconventional antigen presentation generates insulin autoantibodies targeting the islet of Langerhans
Authors: Wan Xiaoxiao , Thomas James W , Unanue Emil R
Published: January 2023

The presence of class-switched insulin autoantibodies (IAAs) is a prominent feature of patients with type 1 diabetes (T1D) and the non-obese diabetic (NOD) mice. Although IAAs are commonly used as a biomarker for T1D prognosis, their genesis and whether they play a pathogenic role is largely unknown. In this study, we developed a novel anti-insulin T cell and B cell receptor transgenic mouse model to investigate cognate interactions between insulin-reactive T and B lymphocytes, a process necessary for IAA production. Strikingly, dynamic anti-insulin T-B cell interactions, spontaneous germinal center formation, and active class-switch recombination occurred in multiple lymphoid organs, leading to remarkable IAA production. Naïve anti-insulin T cells differentiated into competent T follicular helper cells that produced critical factors for reversing B cell tolerance, promoting GC selection, and broadening the repertoire of insulin epitope presentation. Furthermore, the IAAs produced in the peripheral sites relocated into the islets of Langerhans, formed deposits on β-cells, and enhanced presentation of diabetogenic antigens by the resident islet macrophages. Overall, these results indicate that insulin presentation is disseminated throughout secondary lymphoid tissues, and is sufficient for generation of autoantibodies that precipitate previously unrecognized pathogenic outcomes in the target organ.
IL-10 producing B cells regulate sex bias in male mice with experimental immune-mediated drug-induced hepatitis
Authors: Njoku Dolores B , Cottagiri Merylin , Nyandjo Maeva
Published: January 2023

Sex modulates severity in autoimmune diseases. In susceptible individuals, drug metabolites induce hepatitis, autoimmunity and liver injury. This drug–induced hepatitis is a leading cause of liver failure and is the most common reason an approved medication is removed from the consumer market. We modeled this hepatitis in BALB/c mice and showed that estrogen and IL-6 increase severity and down-regulate IL-10 and Foxp3+ regulatory T cells; however, additional regulatory cells have not been identified. We induced experimental hepatitis in female and male CD1d−/− mice (NKT and CD1d+B cell-deficient), JH−/− (mature B cell and IgG deficient) and BALB/c (WT) mice by immunizing them with a cytochrome P4502E1 (CYP2E1) epitope (JHDN5) modified by a drug metabolite. Mice were evaluated for CFSE proliferation to drug metabolites as well as CYP2E1 and JHDN5, hepatitis and cytokines by ELISA. CD1d and B cell deficiency abolished sex bias. Male CD1d −/− mice developed more hepatitis than male WT mice (p<0.05); however these mice were also deficient in NKT cells as well as B cells expressing CD1d. Even though CFSE proliferation was 50% of male WT, male JH−/− mice developed more severe hepatitis (p<0.05) and higher TGF-β (p<0.01) levels than male WT. In contrast, IL-10 and IL-17 levels were up-regulated in male WT mice (p<0.05). Prior studies show that IL-17 promotes B cell help in immune responses, while IL-10 supports regulatory T and B cells. Our studies suggest regulatory roles for B cells in male mice and preliminarily suggest regulatory roles for CD1d expression on B cells in the development of sex bias in drug-induced hepatitis. We are currently characterizing B cells to determine their therapeutic potential in drug-induced hepatitis.
Isotype-switch competent anti-insulin B cells promote autoimmune diabetes despite functional silencing
Authors: Felton Jamie Lynn , Bonami Rachel , Hulbert Chrys , Thomas James W
Published: January 2023

Type 1 diabetes (T1D) results from the autoimmune destruction of insulin producing beta cells, leading to chronic hyperglycemia and a lifelong need for exogenous inulin. In humans, T1D can be predicted by the emergence of multiple, islet autoantibodies years before the onset of clinical symptoms, highlighting an early breach in B cell tolerance that is central to disease development. Studies using a transgenic mouse model with increased frequencies of insulin-specific B cells (VH125SD/B6) have demonstrated that these pathogenic B cells are functionally silenced in the B6 mouse. However, mechanisms of tolerance induced by transgenes are often reversed when introduced onto autoimmune backgrounds. To determine whether an autoimmune background alone is necessary to reverse tolerance in T1D, the VH125SD transgene was introduced into the NOD mouse (VH125SD/NOD). Unexpectedly, despite their ability to accelerate disease progression and clear capacity to promote pathogenic inflammatory responses, insulin-specific B cells remained functionally silent (unable to mount antibody or proliferative responses) in the NOD mouse. Together, these results suggest that it is a degree of functional impairment, and not an overt breach in tolerance, that drives autoimmunity in the NOD mouse.
Multiple extrinsic signals are required for the enrichment of dual-reactive B cells in autoimmune mice
Authors: Sang Allison L , Fournier Emilie , Torres Raul M , Pelanda Roberta
Published: January 2023

Dual-reactive B cells expressing two different immunoglobulin heavy or light chains are present in both healthy humans and mice. However, a subset of systemic lupus erythematosus patients are enriched for dual-reactive B cells. To study dual-reactive B cells in an autoimmune background we used congenic mice bearing a gene targeted human Cκ allele which allowed for the identification and tracking of dual-κ B cells within a polyclonal B cell repertoire. We previously showed that dual-κ B cells positively correlated with disease progression and were enriched in the plasmablast and memory B cell compartments of lupus-prone MRL/lpr mice. Recent studies showed that T cells play a major role in the enrichment of dual-κ B cells, as MRL/lpr mice deficient in the IL-21 receptor had a significant reduction in total dual-κ B cells. In addition, IL-21 signaling was required for the maximal differentiation of dual-κ B cells into plasmablasts and was essential for the development of dual-κ memory B cells. Dual-κ B cells were shown to significantly upregulate antigen presenting molecules such as MHCII, CD80, and CD86. While dual-κ B cells are enriched for polyreactive B cells, immunization with a T-dependent antigen elicited a similar response between single and dual-κ B cells. However, the addition of TLR9 stimulation amplified the antigen-specific response exclusively in dual-k B cells. Furthermore, in vivo EdU incorporation studies showed that dual-k B cells have a higher proliferation rate than single-κ B cells in the absence of exogenous stimuli. Overall, elucidating the diverse molecular pathways promoting the enrichment of dual-reactive B cells in autoimmunity will allow for the selective targeting of these cells in autoimmune patients.
Anti-myelin oligodendrocyte glycoprotein (anti MOG) antibodies in Neuromyelitis optica patients
Authors: Zarkesh-Esfahani Sayyed Hamid , Mirmosayyeb Omid , Manouchehri Navid , Shaygannejad Vahid
Published: January 2023

Neuromyelitis Optica (NMO) is an autoimmune disease of the central nervous system. It is associated with optic neuritis and concomitant acute myelitis. As the anti Aquaporine-4 antibodies (NMO-IgG) is routinely used for disease evaluation, other markers are being proposed for a better understanding of the disease. The aim of this study was to assess the status of anti-myelin oligodendrocyte glycoprotein (anti MOG) antibodies in NMO patients and controls.

41 previously diagnosed NMO patients and 30 healthy controls were enrolled. Baseline demographic data, imaging features and disease characteristics were recorded from all patients. Disease characteristics were compared between different patient groups based on their NMO-IgG and anti MOG results.

For anti MOG antibodies, 39 % of the patients and 13.3 % of the controls showed positive results (P = 0.01). There was no significant correlation between the disease longevity and anti MOG levels in patients (r= 0.29, P = 0.08). Also no significant difference was observed between the anti MOG results and EDSS status among patients (P = 0.58). Among the patients, 22% had positive results for NMO-IgG while 29.2% of them tested positive for anti MOG but negative for NMO-IgG. Regarding the MRI results, NMO-IgG positive patients had normal brain appearance and higher rates of longitudinally extended transverse myelitis along with less disease severity while positive anti MOG group included more patients with severe disease and less normal brain appearances; however these findings were not statistically significant.

Anti MOG antibody levels are helpful for better categorization of NMO patients. Presence of anti-MOG in NMO patients may suggests a particular pattern of disease progression.
The association of monocytes and Tregs with disease activity in rheumatoid arthritis
Authors: Eakin Amanda Jayne , Ahmed T , McGeough C M , Alexander H D , Wright G D , Gardiner P V , Bjourson A J , Gibson D S
Published: January 2023

Background

Rheumatoid arthritis (RA) is an autoimmune condition characterised by inflamed joints. Disease-modifying anti-rheumatic drugs (DMARD) are ineffective in 30–40% of patients. CD169 (Siglec-1) is expressed by monocytes and correlates with disease activity in RA. It drives pro-inflammatory processes including the suppression of Tregs through its cognate ligand, CD169L. This study aims to define the relationship between CD169, CD169L and disease activity, as a potential early biomarker of treatment response.

Methods

Peripheral blood mononuclear cells were isolated from healthy controls and RA patients who failed DMARD treatment. FACS was used to: (i) immunophenotype CD169+ monocytes and CD169L+ Tregs, and (ii) assess levels of FoxP3 within Tregs.

Results

RA patients had a significantly higher percentage of CD169+ monocytes (28.47 ± 7.17, (mean ± SEM), n=19) compared to healthy controls (8.03 ± 1.48, n=19, p=<0.01). A negative correlation was also observed between the percentage of CD169+ monocytes and CD169L+ Tregs in RA patients (r=−0.72, n=19, p=<0.01). Furthermore, the ratio of CD169:CD169L percentages has a positive association with DAS28-ESR (r=0.77, n=9, p=0.02). FoxP3 is expressed at lower levels in RA patients (24.14 ± 1.87, n=25) compared with healthy controls (46.65 ± 6.16, n=13, p=<0.01).

Conclusion

These results provide preliminary evidence of a relationship between CD169 and CD169L, and further define how their balance is associated with disease activity. Low levels of FoxP3 in RA patients indicates reduced Treg activation, which may cause increased disease activity. We postulate that this balance of cells is key in the immune response and could be used as a surrogate measure of disease activity.
Microbiota modify inflammatory arthritis through mucosal inflammation and autoantibody generation
Authors: Kuhn Kristi , Jubair Widian K. , Hendrickson Jason D. , Adhikari Sumitra , Ir Diana , Robertson Charles E , Frank Daniel N , Banda Nirmal K.
Published: January 2023

Mucosal dysbiosis occurs in patients with rheumatoid arthritis (RA), but its role in disease pathophysiology has not been well defined. Using the collagen-induced arthritis (CIA) murine model, we investigated the importance of microbiota in developing inflammatory arthritis. Dysbiosis in CIA occurred in two phases, at 14 days and 35 days after the initial immunization of bovine type II collagen (CII) in complete Freund’s adjuvant. In parallel, mucosal barrier impairment was observed with an initial insult observed at day 14 that stabilized through day 21 but worsened by day 35. Mucsoal inflammation also was observed as determined by colon histology and elevation of tissue cytokines IL-17A and IL-22. Depletion of microbiota through administration of broad-spectrum antibiotics resulted in decreased disease severity and mucosal inflammation. Unexpectedly, we observed that microbial depletion during the late, effector phase of CIA, resulted in more profound suppression of disease. Both disease severity and serum anti-CII autoantibodies correlated with microbial load, further supporting the role of microbiota driving the disease process. Finally, we confirmed that in CIA, the presence of an intact microbiota associated with the presence of RA-relevant anti-citrullinated protein antibodies, possibly through dysbiosis-stimulated activation of the host’s peptidyl arginine deiminase 4 enzyme. Clearly additional studies are needed to solidify the role of the microbiota in driving CIA, but our data together with those of others’ supports a model in which intestinal dysbiosis triggers mucosal immune responses that stimulate T and B cell activities that lead to inflammatory arthritis.
Role of the innate immune response in the progression of Alzheimer’s disease
Authors: Fulop Tamas , Le Page Aurélie Y , Frost Eric H , Dupuis Gilles
Published: January 2023

Alzheimer’s disease (AD) is a progressive irreversible neurological brain disorder. Inflammation and immune alterations have been linked to AD, suggesting that the peripheral immune system plays a role during the asymptomatic period of AD. NK cells and neutrophils (PMN) participate in innate immune surveillance against intracellular pathogens and malignancy but their role in AD remains controversial. We have investigated changes in peripheral NK cell and PMN phenotypes and functions in amnestic mild cognitive impairment (aMCI, n = 10), patients with mild AD (mAD, n = 11), and healthy elderly controls (n = 10). Patients selected according to NINCDS-ADRDA criteria were classified using neuropsychological assessment tests. Phenotype analysis revealed differences in expression of CD16 (increased in mAD), NKG2A (decreased in aMCI), and TLR2 and TLR9 (both decreased in mAD) for NK and CD14 (increased in MCI). Functional assays revealed that NK cell killing activity and degranulation (CD107 expression) were unchanged in the three groups. In contrast, expression of the CD95 receptor was increased in aMCI and mAD. Granzyme B expression and cytokine production (TNFα, IFNγ) were increased in aMCI but not in mAD. Similarly, PMN phagocytosis and free radical production were differentially modulated in MCI and mAD patients. Our data suggest that the number of alterations observed in peripheral NK cells and neutrophils in aMCI represent an activation state compared to mAD patients and that may reflect an active immune response against a still to be defined aggression.
The miR-122 released by hepatocytes during liver disease binds to TLR7 to promote lung dysfunction
Authors: Liang Hongwei , Liu Yuan , Zen Ke
Published: January 2023

The association between lung dysfunction and hepatic disease has been recognized for more than 100 years. More and more studies have revealed lung dysfunction may occur as a result of hepatic disease from any cause. However, the underlying mechanism remains incompletely understood. Here we report that liver-released miR-122 under hepatic disease plays a key role in eliciting lung inflammation and tissue damage via activating alveolar macrophage inflammatory responses. High serum level of miR-122 is widely detected in mice with liver injury caused by ConA, DEN or HCC and in hepatitis and liver cancer patients. A considerable amount of circulating miR-122 was transferred to alveolar macrophages, in which it stimulates inflammatory responses via activating toll-like receptor-7 (TLR7) signaling by serving as a ligand of TLR7. Adoptive transfer experiments show that depleting serum miR-122 significantly attenuates liver injury-induced lung inflammation and tissue damage. Activation of alveolar macrophages by miR-122 can be abolished by mutating the sequence binding to TLR7 or deleting TLR7 in macrophages. Together, our finding reveals an unconventional role of liver miR-122 in stimulating lung immune injury via activating alveolar macrophage TLR7 signaling.
IL-17RA and not IL-17RE is required for IL-17C-mediated psoriasiform inflammation
Authors: Sigurdardottir Sigrun Laufey , Fritz Yi , Klenotic Philip A , Zhang Xiufen , Diaconu Doina , Zhang Li , Ward Nicole L
Published: January 2023

IL-17C is highly expressed in psoriasis skin and is thought to promote inflammation by binding IL-17RA and IL-17RE. Keratinocyte-overexpressing IL-17C (IL-17C+) mice develop a psoriasiform skin phenotype. To investigate IL-17C-mediated inflammation, IL-17C+ mice were mated with IL-17RE-deficient (KO) mice and skin examined. IL-17C+IL-17REKO mice had similar acanthosis and T cell numbers as IL-17C+ mice (n=8/grp; P>0.1), as did IL-17C+ mice transplanted with bone marrow from CD4-IL-17RE vs. WT mice (n=6–9; P>0.1). These results suggest that IL-17C signaling is IL-17RE independent. Next, IL-17C+IL-17REKO mice were treated with anti-IL-17RA antibodies and a 54% reduction in acanthosis was observed (n=3; P=0.006), suggesting that IL-17C-IL-17RA signaling is critical for skin inflammation. In KC-Tie2 psoriasis mice, skin IL-17A and IL-17C increase ~15-fold (P<0.05) and anti-IL-17A and anti-IL-17RA antibody treatment improves acanthosis and decreases CD4+ T cells (P<0.05 vs. IgG, n=5–11/grp), with anti-IL-17RA having greater efficacy than anti-IL-17A (P=0.02). This suggests that both IL-17C and IL-17A signaling through IL-17RA are critical. Indeed, genetic deletion of IL-17C from KC-Tie2 mice led to a 67% and 58% decrease in acanthosis and CD4+ T cells, respectively (n=8/grp; P<0.001 vs. KC-Tie2 mice). Finally, IL-17A modulation in IL-17C+ mice using anti-IL-17A antibodies, transplanting IL-17AKO bone marrow or introducing intradermal IL-17A, each had no effect on IL-17C+ skin inflammation. Our results demonstrate that IL-17C-mediated skin inflammation occurs in an IL-17RE independent, IL-17RA dependent manner and that a tiered balance between IL-17C-IL-17A-IL-17RA signaling may dictate levels of inflammation.
Innate activation of Th17 cells triggers IL-26 release
Authors: Weiss David Isaac , Dang Angeline Tilly , Montoya Dennis , Wu Aiping , Gilliet Michel , Pellegrini Matteo , Modlin Robert L
Published: January 2023

IL-26 is a Th17 cell cytokine with both pro-inflammatory effects and direct antimicrobial activity. We investigated the role of IL-26 in the host response to infection by studying leprosy as a model, finding that IL-26 had direct antimicrobial activity against Mycobacterium leprae. IL-26 mRNA and protein expression was greater in skin lesions from patients with self-limited versus progressive infection, although IL-17 was weakly expressed. To determine the mechanism for IL-26 induction, we examined the kinetics of IL-26 secretion by PBMCs exposed to Mycobacterium leprae sonicate, which revealed induction at 3 hours suggesting activation of the innate response. IL-26 was secreted from PBMCs in response to a variety of pattern recognition receptor (PRR) ligands, correlating with IL-1β release. In PBMCs, IL-1β stimulated IL-26 secretion and blocking IL-1β with either antibodies or depletion of CD14+ cells after PRR ligand stimulation lead to reduction in IL-26 secretion. IL-1β also stimulated IL-26 secretion by both CD4+ and CD8+ T cells, and within the CD4+ compartment IL-26 secretion was limited to memory T cells. Only CD4+ memory Th17 cells, not Th1 or Th2, produced IL-26 in response to IL-1β, and expressed higher amounts of surface IL-1R1. Memory CD4+ T cells stimulated with IL-1β or αCD3/αCD28 secreted IL-26, but only cells stimulated with αCD3/αCD28 secreted IL-17 and IFN-γ. These studies suggest that Th17 cells play a role in the innate immune response by selectively secreting the antibacterial and pro-inflammatory cytokine IL-26 in response to IL-1β.
Maternal microbiota educates neonatal IgA response
Authors: Mu Qinghui , Zhang Husen , Kirby Jay , Luo Xin M
Published: January 2023

Maternal microbiota plays a key role in governing the establishment of neonatal gut microbiota. However, whether and how maternal microbiota from breast milk would affect the development of neonatal immune response remains unclear. Here we report that de novo synthesis of neonatal IgA in pre-weaning Rag1-sufficient mouse pups could be super-induced by the milk of Rag1−/− nursing moms. 16S rRNA sequencing analysis showed that the gut microbiota from the upper intestine of Rag1-sufficient pups were distinct depending on the genotypes of their nursing moms, with those nursed by Rag1−/− moms exhibiting a higher bacterial diversity than those nursed by Rag1-sufficient moms. Interestingly, when Rag1−/− moms were co-housed (littermates) with Rag1-sufficient moms, or treated with antibiotics, the pups that they nursed no longer exhibited the heightened IgA synthesis. Further studies revealed that the number of type 3 innate lymphoid cells (ILC3s) in the pups’ intestine was significantly increased when the pups were nursed by Rag1−/− moms. In addition, the super-induction of neonatal IgA was abrogated when pups were treated with an aryl hydrocarbon receptor antagonist that is known to reduce the number and function of ILC3s. These results suggest that the maternal microbiota may educate neonatal IgA response through an ILC3-dependent mechanism.
Complement drives neurodegeneration in Gaucher disease
Authors: Pandey Manoj K , Magnusen Daniel N , Magnusen Albert F , McKay Mary , Caballero Madison , Rani Reena , Setchell Kenneth D , Zhang Wujuan , Grabowski Gregory A , Köhl Jörg
Published: January 2023

GBA1 mutations result in excess storage of glucosylceramide (GC) and the induction of Gaucher disease (GD). GD is frequently associated with elevated levels of pro-inflammatory cytokines and the development of brain inflammation. The mechanisms underlying GC-driven brain inflammation in GD are ill-defined. Recently, we described immune complexes of GC-specific IgG autoantibodies in experimental and clinical GD, which induced massive complement activation and C5a generation. Further, we found that C5a-mediated activation of its cognate C5a receptor 1 (C5aR1) tips the balance between GC formation and degradation, thereby fueling excess GC accumulation and inflammation in visceral tissues in experimental and clinical GD.

Previously, the C5a/C5aR1 axis was found to regulate the blood brain barrier integrity in systemic lupus and promote neurodegeneration in Alzheimer’s disease. Here, we determined the production of C5a in the brain of Gba1 D409V/knockout (9V/null) GD-prone mice. C5a production in the brain of 9V/null mice was markedly elevated, when compared to WT control mice. Also, 9V/null mice suffered from massive accumulation of GC in the brain and loss of neurons. To assess the relevance of C5a/C5aR1 axis activation for brain inflammation in GD, we targeted glucocerebrosidase (GCase) with conduritol B epoxide (CBE) in WT and C5aR1−/− mice. Strikingly, CBE-injected WT mice died within 30 days. In contrast, all C5aR1−/− mice survived the 60 days observation window, were protected from CBE-induced accumulation of GC in the brain, showed a marked reduction of microglial cell activation and only a minor loss of neurons. Our data suggest that the C5a/C5aR1 axis is a critical driver of neurodegeneration in experimental GD.
Control of type I interferon responses by the AIM2 inflammasome
Authors: Banerjee Ishita , Vanaja Sivapriya Kailasan , Fitzgerald Kate A. , Rathinam Vijay
Published: January 2023

The immune system considers the presence of DNA in the cytosol as a sign of potential pathogen invasion and mounts inflammatory responses. Cytosolic DNA can be sensed by cyclic GMP-AMP synthase (c-GAS) leading to the production of type I Interferons (IFN). It can also be recognized by the PYHIN DNA sensor absent in melanoma (AIM2) resulting in the activation of inflammasome responses i.e. production of pro-inflammatory cytokines IL-1β and IL-18 as well as pyroptosis. Our results show that AIM2 inflammasome activation limits the production of type I IFNs in immune cells such as macrophages and dendritic cells. Further analysis showed that the recognition of cytosolic DNA and the assembly of inflammasome complex appear to be required for AIM2 regulation of IFN-β. Biochemical evidence showed an augmented phosphorylation of the transcription factor IRF-3 resulting in increased IFN-β production in AIM2-deficient macrophages. These findings may have implications in the treatment of autoimmune disorders such as systemic lupus erythematosus (SLE) associated with unregulated type I IFN signaling.

(Supported by NIH R01AI119015 and Charles Hood Child Health Research Award)
An arrayed genome-wide RNAi screen for the discovery of novel inflammasome regulators
Authors: Rabinovich-Ernst Orna , Sun Jing , LIN BIN , Fraser Iain D
Published: January 2023

Bacterial lipopolysaccharide (LPS) is a prominent PAMP implicated as the primary causative agent of septic shock in a wide range of bacterial infections. LPS is known to activate two receptors: the plasma membrane receptor, TLR4, and the cytosolic receptor, Caspase 11. We have conducted a genome-wide siRNA screen to identify novel gene products involved in the non-canonical inflammasome response to cytosolic LPS. A ‘prime-trigger’ assay was established in which macrophages were primed with Pam3CSK4, triggered by transfection of the active component of LPS, Lipid A, and IL-1α secretion measured by a screening-optimized HTRF assay, and pyroptosis was evaluated using an LDH assay. The screen was designed to identify and distinguish regulators at multiple stages of the non-canonical inflammasome activation process, from TLR priming, to cytosolic LPS detection, pyroptosis and IL-1α release. Initial analysis of the primary screen data identified a high canonical pathway hit rate in both the TLR priming step and the response to cytosolic LPS, with Irak4, Irak2, Casp4, Gsdmd and Gsdmc among the strongest gene hits. Among the genes not previously linked to regulation of the non-canonical inflammasome, we observed an enrichment for mitochondrial proteins. In order to further validate this finding, we have created a CRISPR/Cas9 knock-out macrophage cell line and knock-out mouse for one of the mitochondrial screen hits, confirming the effect of this novel hit on IL-1α release in response to cytosolic LPS. Our results suggest a critical role for mitochondria in regulation of the non-canonical inflammasome response.

This work was generously supported by the Intramural Research Program of the National Institute of Allergy and Infectious Diseases.
Abrogation of IL-13Rα2 ameliorates acute inflammatory bowel disease
Authors: Karmele Erik P , Vannella Kevin M , Kasaian Marion T , Urban Joseph F , Wynn Thomas A
Published: January 2023

Anti-TNFα agents are commonly used for treatment of patients with inflammatory bowel disease (IBD), yet up to 40% of patients are non-responders for unknown reasons. IL13RA2 mRNA was more abundant in mucosal biopsy samples of patients with active IBD who are non-responders compared to responders, serving as a potential predictive marker for non-responsiveness. IL-13Rα2 is a high affinity decoy receptor for IL-13, a cytokine with both anti-inflammatory and wound healing functions. In this study, we hypothesized that TNFα and IL-17 produced during the initiation of IBD induces IL-13Rα2 production that neutralizes the endogenous anti-inflammatory activity of IL-13. Using an acute dextran sodium sulfate (DSS) model of mouse colitis, we show that DSS increases the production of both systemic and colonic IL-13Rα2 compared to naive controls. DSS-induced colitis was less severe in Il13ra2−/− mice compared to wild type controls as no shortening in the length of the colon was observed. Histological analysis of the distal colon revealed less goblet cell depletion, inflammatory cell infiltration, and submucosal inflammation in DSS-administered Il13ra2−/− mice compared to DSS-administered wild type mice. However, when Il13ra2−/− mice were infected with the nematode Heligmosomoides polygyrus bakeri, the increased IL-13 activity led to significant morbidity during DSS-colitis. Together, these findings suggest that the absence of IL-13Rα2 enhances endogenous IL-13 bioactivity, which protects mice from acute IBD. Yet, results from the nematode infection model suggest this protective activity must be carefully regulated. Collectively, these results suggest that IL-13Rα2 functions as a key regulator of IBD pathogenesis.
Cigarette smoke attenuated colon inflammation through the induction of regulatory T cells in ulcerative colitis model
Authors: Kitabatake Masahiro , Tomoda Koichi , Kubo Kaoru , Ito Toshihiro
Published: January 2023

Background

Ulcerative colitis (UC) is a chronic inflammatory disease induced by dysregulation of immune response in intestinal mucosa. Several cohort studies have shown that cigarette smoke (CS) is the protective factor for UC, but the underlying mechanisms are not fully elucidated. Here, we evaluated the influence of CS in the experimental UC model.

Methods

UC was induced by dextran sodium sulfate (DSS) during three weeks of CS exposure, and mice were sacrificed at day 7 following UC induction. Colon pathology, lymphocytes recruitment into intestinal mucosa, and gut microbiota were analyzed.

Results

CS exposure suppressed colon inflammation and disease activity in DSS-induced colitis model. CS exposed mice displayed significant reduction of activated CD8+ T cells in colon lamina propria, whereas regulatory T cells (Tregs) were significantly increased. In addition, Ruminococcus, which belongs to Clostridium cluster IV, increased in fecal microbiota of CS exposed mice, suggesting that Tregs are induced by CS exposure through the alteration of microbiota composition.

Conclusions

CS might suppress colon inflammation in UC through the alteration of microbiota composition and immune system including Tregs.