CCL21 attenuates HSV-induced inflammation through up-regulation of CD8+ memory cells

The dynamic immune responses of Mandarin fish (Siniperca chuatsi) to ISKNV in early infection based on full-length transcriptome analysis and weighted gene co-expression network analysis

Mandarin fish (Siniperca chuatsi) been seriously harmed by infectious spleen and kidney necrosis virus (ISKNV) in recent years, but the early immune response mechanism of infection is still unknown. Here, we performed RNA sequencing on the spleens of mandarin fish infected with ISKNV at 0, 12, 24, 48, and 72 h post-infection (hpi) using short-read Illumina RNA sequencing and long-read Pacific Biosciences isoform sequencing to generate a full-length transcriptome. The immune responses of mandarin fish infected with ISKNV at the molecular level were characterized by RNA-seq analysis and weighted gene co-expression network analysis (WGCNA). A total of 26,528 full-length transcript sequences were obtained. There were 2,729 (1,680 up-regulated and 1,112 down-regulated), 1,874 (1,136 up-regulated and 738 down-regulated), 2,032 (1,158 up-regulated and 847 down-regulated), and 4,176 (2,233 up-regulated and 1,943 down-regulated) differentially expressed genes (DEGs) in mandarin fish at 12, 24, 48, and 72 hpi, compared with uninfected fish, respectively. A total of four modules of co-expressed DEGs identified by WGCNA were significantly positively correlated to the four time points after infection, respectively. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the immune-related DEGs in all these modules were mainly enriched in Phagosome, Endocytosis, Herpes simplex infection, and Cytokine-cytokine receptor interaction pathways. Further analysis showed that oher signaling pathways, including CAMs, NOD-like receptor and ER protein processing, Intestinal immune network for IgA production, TLR pathway, and Apoptosis significantly enriched in four modules corresponding to 12, 24, 48, and 72 hpi respectively, had specifically participated in the immune response. Hub genes identified based on the high-degree nodes in the WGCN, including CAM3, IL-8, CCL21, STING, SNX1, PFR and TBK1, and some DEGs such as MHCI, MHCII, TfR, STING, TNF α, TBK1, IRF1, and NF-kB, BCR, IgA and Bcl-XL had involved in dynamic molecular response of mandarin fish to ISKNV infection. In sum, this study provides a set of full-length transcriptome of the spleen tissue of mandarin fish for the first time and revealed a group of immune genes and pathways involved in different temporal responses to ISKNV infection, which has implications for resource conservation and aiding the development of strategies to prevent virus early infection for mandarin fish.

CC chemokine ligand 19 might act as the main bursal T cell chemoattractant factor during IBDV infection

Infectious bursa disease virus (IBDV) pathogenesis is characterized by increased numbers of T cells and decreased numbers of B cells in the bursa. Currently, little is about the key factor that affects T migration into bursa. In humans, CC chemokine ligand 19 (CCL19) recruits monocytes and neutrophils and is usually involved in various inflammatory disorders. The aim of this study was to assess the roles of CCL19 in driving peripheral blood cells infiltration into bursa of Fabricius of chickens infected with IBDV. Bursal samples were collected from chickens of the infection group and the control group on day 1, 3, 5, and 7 post infection (dpi) with IBDV. The mRNA or protein levels of ccl19 and ccr7 genes in bursae were determined by real-time PCR and immunohistochemistry (IHC) methods. Moreover, an in vitro chemotaxis assay was performed to evaluate the chemotaxis ability of CCL19 and bursal total protein. The results have displayed that the mRNA levels of ccl19 were significantly increased on 1, 3, 5, and 7 dpi in the infection group. The highest value amounted to 73.4-fold of the control group. Also, the mRNA levels of CCR7, the receptor of CCL19, began to increase on 3 dpi and reached to the highest value of 206.3-fold on 5 dpi after IBDV infection. Then the gene expression of CCR7 in bursae of the infection group returned to the normal level. IHC results of CCL19 protein level accorded with the mRNA levels of CCL19, with the highest value on 5 dpi. Then, in vitro chemotaxis test demonstrated that the total bursal protein had the ability of recruiting peripheral white blood cells (PWBC) and the migration percentage was a little higher than that of the blank control with only basal medium (P < 0.05). Taken together, these data suggest that CCL19 acts as a chicken PWBC chemotactic factor and facilitate the infiltration of PWBC (especially T cells) into the bursae after IBDV infection.

HSV-Induced Systemic Inflammation as an Animal Model for Behçet's Disease and Therapeutic Applications

Behçet’s disease (BD) affects multiple organs. It is mainly characterized by recurrent oral, skin, and genital aphthous ulcers, and eye involvement. Successful management of BD is increasing, although its etiology remains unclear. A number of etiologies have been proposed, including environmental, genetic, viral, and immunological factors. To understand its complex etiology and improve its management, animal models of BD have been used to enable more effective therapeutic applications with increased clinical significance. An herpes simplex virus (HSV) type 1-induced BD mouse model has shown disease characteristics similar to those seen in BD patients. An HSV-induced BD animal model has been used to test various therapeutic modalities. The applied modalities are several materials that are derived from natural products, conventional therapeutics, and possible biologics. In this review, we provided how they regulate inflammation in an HSV-induced BD model.

Baicalin attenuates inflammation in mice with OVA-induced asthma by inhibiting NF-κB and suppressing CCR7/CCL19/CCL21

Baicalin, extracted and purified from the Chinese medicinal plant, Scutellaria baicalensis Georgi (Huang qin in Chinese), exhibits potent anti-inflammatory activity against asthma. However, it remains unknown whether baicalin inhibits the activity of CC chemokine receptor 7 (CCR7) and its ligands, which are crucial for the initiation of airway inflammation. In the present study, we investigated the effects of baicalin on CCR7 and its ligands, CCL19 and CCL21, as well as on the nuclear factor-κB (NF-κB) pathway in a mouse model of asthma. A mouse model of acute asthma was established by exposing the mice to ovalbumin (OVA) (by intraperitoneal injection and inhalational challenge). Within 24 h of the final OVA challenge, lung function was detected by direct airway resistance analysis. Lung tissues were examined for pathological changes. Inflammatory cell counts in bronchoalveolar lavage fluid (BALF) were assessed. ELISA was utilized to evaluate the OVA-IgE, CCL19 and CCL21 levels in BALF. The interleukin (IL)-6 and tumor necrosis factor (TNF)-α levels in serum were also detected by ELISA. The protein expression levels of CCR7, as well as that of phosphorylated IκBα (p-IκBα) and phosphorylated p65 (p-p65) were determined by western blot analysis and RT-qPCR was used to determine the CCR7 mRNA levels. Our data demonstrated that the oral administration of baicalin significantly improved pulmonary function and attenuated inflammatory cell infiltration into the lungs. Baicalin also decreased the levels of OVA-IgE, IL-6, TNF-α and CCR7, as well as those of its ligand, CCL19; the levels of NF-κB were also markedly suppressed by baicalin. The CCR7 mRNA level was substantially decreased. Our results thus suggest that baicalin exerts an inhibitory effect on airway inflammation, and this effect may be associated with the inhibition of CCR7 and CCL19/CCL21, which may provide new mechanistic insight into the anti‑inflammatory effects of baicalin.

Ligustrazine attenuates inflammation and the associated chemokines and receptors in ovalbumine-induced mouse asthma model

Ligustrazine which is isolated from Chinese herb ligusticum chuanxiong hort, has been widely used in traditional Chinese medicine (TCM) for asthma treatment. In this study, we aim to observe the effect of ligustrazine on inflammation and the associated chemokines and receptors in ovalbumin (OVA)-induced mouse asthma model. Our data demonstrates that ligustrazine suppresses airway hyperresponsiveness to methacholine and lung inflammation in OVA-induced mouse asthma model. Ligustrazine also induces inhibition of inflammatory cells including neutrophils, lymphocytes and eosinophils. In addition, ligustrazine significantly reduces IL-4, IL-5, IL-17A, CCL3, CCL19 and CCL21 level in BALF of asthma mice. Furthermore, ligustrazine induces down-regulation of CCL19 receptor CCR7, STAT3 and p38 MAPK protein expression. Collectively, these results suggest that ligustrazine is effective in attenuation of allergic airway inflammatory changes and related chemokines and receptors in OVA-induced asthma model, and this action might be associated with inhibition of STAT3 and p38 MAPK pathway, which indicates that ligustrazine may be used as a potential therapeutic method to treat asthma.

Integrated analysis of miRNA/mRNA network in placenta identifies key factors associated with labor onset of Large White and Qingping sows

Labour onset is a very complex physiological process, and its mechanism is poorly understood. Here, we obtained the mRNA and miRNA expression profiles from the placentas of four groups of sows: Qingping sows 112 days after insemination with signs of labour onset (QS), Qingping sows 114 days after insemination with signs of labour onset (QL), Large White sows 114 days after insemination with signs of labour onset (LL) and Large White sows 112 days after insemination without signs of labour onset (LN). A set of differentially expressed genes, including 2164 mRNAs and 39 miRNAs, were found. A DAVID analysis of these differentially expressed genes revealed their critical roles in response to hormone stimulus, immune response. Cytoscape Network analysis of the functional genes found node mRNAs and that the regulatory network between the node mRNAs and miRNAs was established. A comparison of the sequencing data from the shorter gestation period (QS) and the normal gestation period (QL) indicated that these genes were responsible for the quicker and more sensitive reaction to the regulation of labour onset. This research not only detected the key factors that were involved in labour onset but also provided useful information for the research of gynaecological diseases.

IL-2/IL-2 antibody immune complex regulates HSV-induced inflammation through induction of IL-2 receptor alpha, beta, and gamma in a mouse model

The differences of serum IL-2 levels were not consistent between Behçet's Disease (BD) patients and healthy controls, however, the correlation of interleukin-2 receptor (IL-2R) and BD has not been investigated. IL-2R is composed of three subunits; alpha, beta, and gamma. The expression frequencies of IL-2R subunits were analyzed in the peripheral blood mononuclear cells, spleens, and lymph node (LN) cells. The expression of IL-2R subunits was different between BD mice and controls. IL-2R beta expressing cell frequencies were also different between BD patients and healthy controls. The IL-2/anti-mIL-2 antibody complex administration regulated the IL-2R subunits in mice. The change of expression in IL-2R was accompanied by the increase of CD8+CD44+ memory T cells, CD3-NK1.1+CD11b+CD27+ natural killer cells, and improvement of symptoms. In this study, we elucidated the role of IL-2R subunits on BD, a finding that can be connected to therapeutic strategy for patients based on the results from the treatment of BD mice.

TGF-β1-induced EMT promotes targeted migration of breast cancer cells through the lymphatic system by the activation of CCR7/CCL21-mediated chemotaxis

Tumor cells frequently disseminate through the lymphatic system during metastatic spread of breast cancer and many other types of cancer. Yet it is not clear how tumor cells make their way into the lymphatic system and how they choose between lymphatic and blood vessels for migration. Here we report that mammary tumor cells undergoing epithelial–mesenchymal transition (EMT) in response to transforming growth factor-β (TGF-β1) become activated for targeted migration through the lymphatic system, similar to dendritic cells (DCs) during inflammation. EMT cells preferentially migrated toward lymphatic vessels compared with blood vessels, both in vivo and in 3D cultures. A mechanism of this targeted migration was traced to the capacity of TGF-β1 to promote CCR7/CCL21-mediated crosstalk between tumor cells and lymphatic endothelial cells. On one hand, TGF-β1 promoted CCR7 expression in EMT cells through p38 MAP kinase-mediated activation of the JunB transcription factor. Blockade of CCR7, or treatment with a p38 MAP kinase inhibitor, reduced lymphatic dissemination of EMT cells in syngeneic mice. On the other hand, TGF-β1 promoted CCL21 expression in lymphatic endothelial cells. CCL21 acted in a paracrine fashion to mediate chemotactic migration of EMT cells toward lymphatic endothelial cells. The results identify TGF-β1-induced EMT as a mechanism, which activates tumor cells for targeted, DC-like migration through the lymphatic system. Furthermore, it suggests that p38 MAP kinase inhibition may be a useful strategy to inhibit EMT and lymphogenic spread of tumor cells.

Therapeutic potency of Poly I:C in HSV-induced inflammation through up-regulation of IL-15 receptor alpha

Interleukin-15 receptor alpha (IL-15Rα) forms stable complex with IL-15 on the cell surface of activated monocytes and mediates the proliferation of memory CD8+ T cells. Recent studies informed that polyinosinic:polycytidylic acid (Poly I:C) is an immunostimulant which boosts the generation of memory T cells through induction of IL-15Rα. The aim of this study is to evaluate the relevance of IL-15Rα in Herpes simplex virus (HSV)-induced Behçet's disease (BD) mouse model and BD patients. The frequencies of IL-15Rα expression in PBMCs of BD patients and BD-like symptomatic mice were analyzed by flow cytometry. In addition, Poly I:C supplementation could reduce inflammation through the up-regulation of memory T cells and IL-15Rα+ cells accompany with down-regulation of pro-inflammatory cytokine, IL-17A in BD mice. In BD patients, the frequencies of IL-15Rα expression in PBMCs were also significantly different between the inactive and active disease states. These results suggest that IL-15Rα is a relevant factor in BD.