维生素D在自身免疫性肝病中的研究进展

维生素D是一种人体必需的脂溶性维生素,其除了可调节钙磷代谢,参与骨骼生长外,还可通过调节免疫细胞增殖分化和抗炎抗纤维化等参与多种免疫性疾病的发生发展。自身免疫性肝病(autoimmune liver disease,AILD)是由自身免疫反应引起的一组肝脏炎症性病变,有研究发现维生素D与AILD存在相关性,AILD患者血清中维生素D水平普遍降低,补充血清维生素D可降低肝损伤和肝纤维化程度。因此,探究维生素D在AILD发生发展中的作用具有一定的临床价值。本文对维生素D在AILD中的研究进展作一阐述。     

Abrogation of autoimmune disease in Lyn-deficient mice by the deletion of IL-5 receptor alpha chain gene

Lyn, the src-family protein tyrosine kinase, plays a crucial role in the regulation of B cell antigen receptor (BCR)- and IL-5-receptor (IL-5R)-mediated signaling. Lyn-deficient mice have been reported to exhibit an increase in B-1 cell numbers, splenomegaly and accumulation of lymphoblast-like cells in the spleen with age, resulting in hyperimmunoglobulinemia and glomerulonephritis caused by the deposition of autoantibody complexes. To elucidate the role of IL-5 in B-1 cell activation, autoantibody production and autoimmune diseases, Lyn-deficient mice were crossed with IL-5Ralpha chain (IL-5Ralpha)-deficient mice and generated Lyn- and IL-5Ralpha-deficient (DKO) mice. In contrast to Lyn-deficient mice, DKO mice showed significantly reduced splenomegaly and lymphoadenopathy and reduced B-1 cell number in the peritoneal cavity. DKO mice also secreted low levels of IgM and IgG autoantibodies. Biochemical and histological analyses revealed that DKO mice showed milder pathogenesis of autoimmune-like disorders than Lyn-deficient mice. These results suggest involvement of IL-5 in enhanced B-1 cell activation, autoantibody production, and development of autoimmune disease in Lyn-deficient mice.     

基于16S rDNA测序的自身免疫性甲状腺疾病患者肠道菌群研究

探讨Graves病患者、桥本甲状腺炎患者及健康人的肠道菌群结构、多样性和丰度差异。

选取2020年8月至2020年12月于湖北省中医院甲状腺疾病诊疗中心就诊的新诊断且未经治疗的Graves病患者（GD组）、桥本甲状腺炎患者（HT组）各15例以及15例年龄、性别相匹配的健康受试者（健康对照组）。采集参与者粪便样本,采用16S rDNA高通量测序法分析肠道菌群,比较各组对象肠道菌群物种组成及丰度差异。

与健康对照组相比,GD组患者肠道菌群Sobs指数、Ace指数、Chao指数偏低,Coverage指数偏高（均P＜0.05）。GD组与HT组以及HT组与健康对照组比较,其肠道菌群Sobs指数、Ace指数、Chao指数、Coverage指数差异均无统计学意义（均P＞0.05）。3组对象肠道优势菌门为拟杆菌门、厚壁菌门、变形菌门、梭杆菌门。瘤胃球菌属、罗斯伯里菌属、罗姆布茨菌属、链球菌属等在3组对象中差异均有统计学意义（均P＜0.05）,其中GD组患者肠道乳杆菌目、链球菌属、链球菌科的相对丰度较高;HT组患者肠道瘤胃球菌属、消化链球菌科、消化链球菌—蒂氏菌目、罗姆布茨菌、梭菌科、严格厌氧梭状芽胞杆菌1、梭菌目的相对丰度较高;而罗斯伯里菌属、光冈菌属在健康对照组中丰度较高。GD组患者肠道中严格厌氧梭状芽胞杆菌1、Odoribacter、Phocea丰度低于HT组,而Streptococcus的丰度高于HT组（均P＜0.05）。

Graves病患者、桥本甲状腺炎患者的肠道菌群与健康人群有显著差异,促进脂肪累积与能量吸收的菌群在Graves病患者中降低,而条件致病菌在自身免疫性甲状腺疾病患者中丰度增加,这些菌种变化可能通过破坏肠道稳态,干预免疫调节,促进炎症反应介导自身免疫性甲状腺疾病的发病。严格厌氧梭状芽胞杆菌1、Odoribacter、Phocea、链球菌属可能是Graves病和桥本甲状腺炎的关键差异菌属,但还需要进一步的研究以明确这些菌株介导疾病的机制。

     

Transgenic mice expressing osteopontin in hepatocytes as a model of autoimmune hepatitis

Osteopontin, a crucial factor for Th1 immune response, is expressed in stellate cells and macrophages activated in injured liver. To clarify the role of osteopontin in inflammatory changes in the liver, we attempted to establish transgenic mice expressing osteopontin in hepatocytes. Mouse osteopontin cDNA, cloned from concanavalin-A-stimulated spleen cells in C57BL/6 mice, was constructed into the vector containing serum amyloid-P component promoter. This construction was microinjected into fertilized eggs of C57BL/6 mice, and 4 lines of the transgenic mice were obtained. Western blotting and immunohistochemistry revealed that osteopontin was expressed in hepatocytes, but not in non-parenchymal cells, in the transgenic mice. The mean osteopontin concentrations in the liver and plasma in the mice were 13 and 2.6 times higher than those in negative littermates. Antinuclear antibody was positive in the plasma in 50% of the transgenic mice. In the transgenic mice later than 12 weeks of age, mononuclear cell infiltration in the liver developed, and these cells were positive for CD8 and HLA-DR. Plasma ALT activity was increased with focal necrosis in hepatic lobules in the transgenic mice later than 24 weeks of age. The transgenic mice expressing osteopontin in hepatocytes may be useful as a model of autoimmune hepatitis.     

Dynamical properties of autoimmune disease models: tolerance, flare-up, dormancy

The mechanisms of autoimmune disease have remained puzzling for a long time. Here we construct a simple mathematical model for autoimmune disease based on the personal immune response function and the target cell growth function. We show that these two functions are sufficient to capture the essence of autoimmune disease and can explain characteristic symptom phases such as tolerance, repeated flare-ups and dormancy. Our results strongly suggest that a more complete understanding of these two functions will underlie the development of an effective therapy for autoimmune disease.     

A mathematical design of vector vaccine against autoimmune disease

Viruses have been implicated in the initiation, progression, and exacerbation of several human autoimmune diseases. Evidence also exists that viruses can protect against autoimmune disease. Several proposed mechanisms explain the viral effects. One mechanism is “molecular mimicry” which represents a shared immunologic epitope with a microbe and the host. We consider, using a simple mathematical model, whether and how a viral infection with molecular mimicry can be beneficial or detrimental for autoimmune disease. Furthermore, we consider the possibility of development of a vector therapeutic vaccine that can relieve autoimmune disease symptoms. Our findings demonstrate that vaccine therapy success necessitates (i) appropriate immune response function, (ii) appropriate affinities with self and non-self antigen, and (iii) a replicative vector vaccine. Moreover, the model shows that the viral infection can cause autoimmune relapses.     

Tolerogenic effect of mesenchymal stromal cells on gliadin-specific T lymphocytes in celiac disease

Background aimsCeliac disease is caused by a dysregulated immune response toward dietary gluten, whose only treatment is a lifelong gluten-free diet. We investigated the effects of mesenchymal stromal cells (MSCs) on gliadin-specific T cells, which are known to induce intestinal lesions, in view of a possible use as new therapy.MethodsBone marrow–derived MSCs and gliadin-specific T-cell lines were obtained from allogeneic donors and mucosal specimens of celiac patients, respectively. The immunosuppressant effect of MSCs was evaluated in terms of proliferative response and interferon (IFN)-γ production upon gliadin stimulation of long-term T-cell lines; the immunomodulant effect was assessed in terms of apoptotic rate, immunophenotype and cytokine profile of short-term T-cell lines generated in the presence of MSCs. Different MSC:T-cell ratios were applied, and statistics were performed as appropriate.ResultsMSCs inhibited both proliferative response and IFN-γ production of long-term T-cell lines in a dose-dependent manner while limiting the expansion of short-term T-cell lines by increasing the apoptotic rate. Moreover, a reduction of the CD4⁺ population and expansion of the regulatory FoxP3⁺ subset were found in T-cell lines cultured with MSCs, in which a significant decrease of interleukin (IL)-21, IFN-γ and IL-10 paralleled by an upregulation of transforming growth factor-β1, IL-6 and IL-8 were observed. Finally, an increase of the indoleamine 2,3-dioxygenase activity was found, possibly playing a key role in mediating these effects.ConclusionsMSCs exert potent immunomodulant effects on gliadin-specific T cells, which may be exploited for future therapeutic application in celiac disease.     

Peripheral blood values as predictors of autoimmune status in oral cavity squamous cell carcinoma

BackgroundRecent literature has highlighted the role of the host in prognosis in oral squamous cell carcinoma (OSCC). Autoimmune (AI) disease represents a macroscopic depiction of host status. The goal of this study was to predict an AI “status” and to analyze the utility of this “status” as a prognostic indicator in OSCC.MethodsFrom a departmental database of OSCC patients (n = 1377), 125 patients with an AI disorder were identified. PBL values were obtained and standardized for analysis. A LASSO regression model was used to determine the best predictors of AI status and an AI score was developed. The score was then analyzed across various survival endpoints.ResultsWhen AI score was divided into a binary variable, patients in the highest quartile had a significantly worse overall survival (OS), local recurrence-free (LRFP) and distant recurrence-free probability (DRFP). Survival curves showed significant differences for OS, DSS, LRFP, and DRFP.ConclusionsAI diseases are immune dysregulations that could play a role in prognosis. Therefore, development of an AI score is necessary to depict host status in a ubiquitous manner. AI score as a binary variable may be more utilitarian in a clinical setting, compared to the continuous score. This novel tool needs validation and integration into more tumor and host characteristics. This investigation showed utility of such a score, similar to PBL data in OSCC prognosis. Future studies should incorporate other relevant variables known to affect outcome and implement a more comprehensive predictive model.     

Chemokines and chemokine receptors: Insights from human disease and experimental models of helminthiasis

Infection with helminth parasites affects more than 1.5 billion people and is concentrated in global areas of extreme poverty, having a significant impact on public health, social life and the economy. Upon entry into the host, helminth parasites often migrate through specific tissues triggering host immunity. The immune response triggered by helminth infections is complex and depends on parasite load, site of infection, acuteness/chronicity of the infection and is species-dependent. In general, susceptibility or resistance to the infection involves the participation of the innate immune response and then the balance between several effector CD4⁺ T cells subsets, such as Th1, Th2, Th9, Th17, Tfh and Treg, coordinated by immune mediators such as cytokines and chemokines. Chemokines guide the recruitment and activation of leukocytes under inflammatory and homeostatic states. The chemokine system has been associated with several diseases and experimental models with a significant inflammatory component, including infection with helminth parasites. Therefore, this critical review will highlight the main findings concerning chemokine responses elicited by the interaction between helminth parasites and the hosts’ immune system, hence contributing to the understanding of the relevance of chemokine synthesis and biology in the immunological response to infection by parasitic helminths.     

Paraoxonase and arylesterase levels in autoimmune thyroid diseases

Objective: The aim of this study was to evaluate serum paraoxonase-1 (PON1) activity and its association with oxidative stress in autoimmune thyroid disease (AITD).

Methods: A total of 50 patients with AITD, including 25 with Hashimoto's thyroiditis and 25 with Graves’ disease were enrolled. The control group comprised 27 healthy subjects. Blood samples were obtained in the euthyroid period and 3 months after initiation of medical treatment. Serum samples from patients with AITD and the healthy control group were analyzed for basal PON1, salt-stimulated PON1, and arylesterase (ARE) activities, along with lipid hydroperoxide (LOOH) and total free sulfhydryl (–SH) levels.

Results: Serum PON1 activities and –SH levels were significantly lower (P?<?0.001, for each), whereas LOOH levels were significantly higher (P?<?0.001, for each) in patients with AITD, compared to the control group. We observed no significant differences in ARE levels between the patient and healthy control groups (P?>?0.05). PON1 activity was positively correlated with –SH (r?=?0.522, P?<?0.001) and negatively correlated with LOOH (r?=??0.487, P?<?0.001). PON1 phenotype distribution of the subjects was not significantly different among the three groups (P?=?0.961).

Conclusions: Serum PON1 activity is decreased in patients with AITD, and correlated positively with –SH, a well-known antioxidant, and negatively with LOOH, an index of lipid oxidation.     

A new evolutionary paradigm for the Parkinson disease gene DJ-1

The DJ-1 gene is extensively studied because of its involvement in familial Parkinson disease. DJ-1 belongs to a complex superfamily of genes that includes both prokaryotic and eukaryotic representatives. We determine that many prokaryotic groups, such as proteobacteria, cyanobacteria, spirochaetes, firmicutes, or fusobacteria, have genes, often incorrectly called "Thij," that are very close relatives of DJ-1, to the point that they cannot be clearly separated from the eukaryotic DJ-1 genes by phylogenetic analyses of their sequences. In addition, and contrary to a previous study that suggested that DJ-1 genes were animal specific, we show that DJ-1 genes are found in at least 5 of the 6 main eukaryotic groups: opisthokonta (both animals and fungi), plantae, chromalveolata, excavata, and amoebozoa. Our results thus provide strong evidence for DJ-1 genes originating before the origin of eukaryotes. Interestingly, we found that some fungal species, among them the model yeast Schizosaccharomyces pombe, have DJ-1-like genes, most likely orthologous to the animal genes. This finding opens new ways for the analysis of the functions of this group of genes.     

Activation of Toll‐like receptor 9 inhibits lipopolysaccharide‐induced receptor activator of nuclear factor kappa‐ B ligand expression in rat B lymphocytes

B lymphocytes express multiple TLRs that regulate their cytokine production. We investigated the effect of TLR4 and TLR9 activation on receptor activator of NF‐κB ligand (RANKL) expression by rat spleen B cells. Splenocytes or purified spleen B cells from Rowett rats were cultured with TLR4 ligand Escherichia coli LPS and/or TLR9 ligand CpG‐oligodeoxynucleotide (CpG‐ODN) for 2 days. RANKL mRNA expression and the percentage of RANKL‐positive B cells were increased in rat splenocytes challenged by E. coli LPS alone. The increases were less pronounced when cells were treated with both CpG‐ODN and E. coli LPS. Microarray analysis showed that expressions of multiple cyclin‐dependent kinase (CDK) pathway‐related genes were up‐regulated only in cells treated with both E. coli LPS and CpG‐ODN. This study suggests that CpG‐ODN inhibits LPS‐induced RANKL expression in rat B cells via regulation of the CDK pathway.     

Altered expression of talin 1 in peripheral immune cells points to a significant role of the innate immune system in spontaneous autoimmune uveitis

The molecular mechanism which enables activated immune cells to cross the blood-retinal barrier in spontaneous autoimmune uveitis is yet to be unraveled. Equine recurrent uveitis is the only spontaneous animal model allowing us to investigate the autoimmune mediated transformation of leukocytes in the course of this sight threatening disease. Hypothesizing that peripheral blood immune cells change their protein expression pattern in spontaneous autoimmune uveitis, we used DIGE to detect proteins with altered abundance comparing peripheral immune cells of healthy and ERU diseased horses. Among others, we found a significant downregulation of talin 1 in peripheral blood granulocytes of ERU specimen, pointing to changes in β integrin activation and indicating a significant role of the innate immune system in spontaneous autoimmune diseases.     

Gene expression alterations in activated human T-cells induced by modeled microgravity

Studies conducted in real Space and in ground-based microgravity analog systems (MAS) have demonstrated changes in numerous lymphocyte functions. In this investigation we explored whether the observed functional changes in lymphocytes in MAS are associated with changes in gene expression. NASA-developed Rotating Wall Vessel (RWV) bioreactor was utilized as a MAS. Activated T lymphocytes were obtained by adding 100 ng/ml of anti-CD3 and 100 U/ml of IL-2 in RPMI medium to blood donor mononuclear cells for 4 days. After that the cells were washed and additionally cultured for up to 2 weeks with media (RPMI, 10% FBS and 100 U/ml IL-2) replacement every 3-4 days. Flow cytometry analysis had proven that activated T lymphocytes were the only cells remaining in culture by that time. They were split into two portions, cultured for additional 24 h in either static or simulated microgravity conditions, and used for RNA extraction. The gene expression was assessed by Affymetrix GeneChip Human U133A array allowing screening for expression of 18,400 genes. About 4-8% of tested genes responded to MG by more than a 1.5-fold change in expression; however, reproducible changes were observed only in 89 genes. Ten of these genes were upregulated and 79 were downregulated. These genes were categorized by associated pathways and viewed graphically through histogram analysis. Separate histograms of each pathway were then constructed representing individual gene expression fold changes. Possible functional consequences of the identified reproducible gene expression changes are discussed.     

Photoperiod and cell mediated immunity of clinically normal dogs

Abstract

Previously, the authors have reported seasonal variations in cell mediated immunity in the dog during the period July, 1977 ‐ October 1978 as measured by whole blood lectin‐induced lymphocyte transformation. Peak activity occurred in the summer, suggesting association with photoperiodicity. Here the authors report on immune response of dogs kept indoors ‐ under controlled physical environment ‐ with a natural (outdoor) photoperiod or under a 12:12 h (LD) regime, and a control group kept in outdoor kennels. Peak immune activity in 1979 occurred in the winter, in both indoor groups as well as the outdoor groups subject to natural photoperiod. Since the indoor dogs were kept at a constant temperature and humidity in clean (filtered) air, photoperiod, temperature, and particulate air contaminants probably are not associated with seasonal variations in immunity. The underlying cause for either the seasonal variations or the shift from peak activity in the summer of 1978 to winter of 1979 is unknown. Dogs under LD = 12:12 light regime had a significantly lowered immunity relative to the dogs with the natural photoperiod.     

Gene expression profiles of normal proliferating and differentiating human intestinal epithelial cells: a comparison with the Caco-2 cell model

cDNA microarray technology enables detailed analysis of gene expression throughout complex processes such as differentiation. The aim of this study was to analyze the gene expression profile of normal human intestinal epithelial cells using cell models that recapitulate the crypt-villus axis of intestinal differentiation in comparison with the widely used Caco-2 cell model. cDNA microarrays (19,200 human genes) and a clustering algorithm were used to identify patterns of gene expression in the crypt-like proliferative HIEC and tsFHI cells, and villus epithelial cells as well as Caco-2/15 cells at two distinct stages of differentiation. Unsupervised hierarchical clustering analysis of global gene expression among the cell lines identified two branches: one for the HIEC cells versus a second comprised of two sub-groups: (a) the proliferative Caco-2 cells and (b) the differentiated Caco-2 cells and closely related villus epithelial cells. At the gene level, supervised hierarchical clustering with 272 differentially expressed genes revealed distinct expression patterns specific to each cell phenotype. We identified several upregulated genes that could lead to the identification of new regulatory pathways involved in cell differentiation and carcinogenesis. The combined use of microarray analysis and human intestinal cell models thus provides a powerful tool for establishing detailed gene expression profiles of proliferative to terminally differentiated intestinal cells. Furthermore, the molecular differences between the normal human intestinal cell models and Caco-2 cells clearly point out the strengths and limitations of this widely used experimental model for studying intestinal cell proliferation and differentiation.