The innate immune response is the first line of defense for the host against viral infections. Targeted degradation of pathogenic microorganisms through autophagy, in conjunction with pattern recognition receptors synergistically inducing the production of interferon (IFN), constitutes an important pathway for the body to resist viral infections. Rubicon, a Run domain Beclin 1-interacting and cysteine-rich domain protein, has an inhibitory effect on autophagy and IFN production. On the one hand, Rubicon, as a component of the phosphoinositide 3-kinase (PI3K) complex, interacts with different domains of vacuolar protein sorting 34 (Vps34), ultraviolet radiation resistance associated gene (UVRAG), guanosine triphosphate (GTP) kinase, and RAS oncogene family member 7 (Rab7) to mediate the inhibition of autophagy maturation; on the other hand, Rubicon inhibits the ubiquitination of nuclear factor κB essential modulator (NEMO) and the dimerization of interferon regulatory factor 3 (IRF3), thereby blocking the signal transduction related to IFN production. Research has revealed that various viruses, such as Kaposi's sarcoma-associated herpesvirus (KSHV), hepatitis B virus (HBV), Sendai virus (SeV), and hepatitis C virus (HCV), achieve innate immune evasion by regulating the expression or function of Rubicon. Rubicon is expected to be a new target for antiviral therapy.
Humans ; Autophagy/immunology* ; Immunity, Innate ; Interferons/immunology* ; Immune Evasion ; Animals ; Virus Diseases/virology* ; Signal Transduction ; Viruses/immunology* ; Intracellular Signaling Peptides and Proteins/immunology* ; Autophagy-Related Proteins

Triptolide (TP) induces severe liver injury, but its hepatotoxicity mechanisms are still unclear. Inflammatory responses may be involved in the pathophysiology. Neutrophils are the first-line immune effectors for sterile and non-sterile inflammatory responses. Thus, the aim of the present study was to investigate the neutrophilic inflammatory response in TP-induced liver injury in C57BL/6 mice. Our results showed that neutrophils were recruited and accumulated in the liver, which was parallel to or slightly after the development of liver injury. Neutrophils induced release of myeloperoxidase and up-regulation of CD11b, which caused cytotoxicity and hepatocyte death. Hepatic expressions of CXL1, TNF-α, IL-6, and MCP1 were increased significantly to regulate neutrophils recruitment and activation. Up-regulation of toll like receptors 4 and 9 also facilitated neutrophils infiltration. Moreover, neutrophils depletion using an anti-Gr1 antibody showed mild protection against TP overdose. These results indicated that neutrophils accumulation might be the secondary response, not the cause of TP-induced liver injury. In conclusion, the inflammatory response including neutrophil infiltration may play a role in TP-induced hepatotoxicity, but may not be severe enough to cause additional liver injury.
Animals ; Chemical and Drug Induced Liver Injury ; etiology ; immunology ; Chemokine CCL2 ; genetics ; immunology ; Diterpenes ; adverse effects ; Drugs, Chinese Herbal ; adverse effects ; Epoxy Compounds ; adverse effects ; Female ; Humans ; Interleukin-6 ; genetics ; immunology ; Intracellular Signaling Peptides and Proteins ; genetics ; immunology ; Liver ; drug effects ; immunology ; Mice ; Mice, Inbred C57BL ; Neutrophil Infiltration ; drug effects ; Neutrophils ; drug effects ; immunology ; Phenanthrenes ; adverse effects ; Tripterygium ; adverse effects ; chemistry ; Tumor Necrosis Factor-alpha ; genetics ; immunology

IFT46 is one of the important components of intraflagellar transport complex B in Chlamydomonas reinhardtii, and plays important roles in the assembly, movement and perception of ciliary. To study its functional mechanism, a GST-tagged and an MBP-tagged prokaryotic expression plasmid, pGEX-2T-ift46 and pMAL-C2X-ift46 were constructed, respectively, by inserting ift46 into the pGEX-2T and pMAL-C2X vector, and then transformed into Escherichia coli BL21 (DE3) for protein expression. SDS-PAGE (15%) analysis results showed that the molecular weights of the fusion protein GST-IFT46 and MBP-IFT46 were 70 kDa and 86 kDa, respectively. We used the fusion protein GST-IFT46 purified by affinity adsorption purification (more than 95% purity) for immunity to New Zealand white rabbits. The 5th immune serum was collected and the antibody titer was determined to be 256 000 by ELISA. The antiserum was purified by Protein A affinity adsorption purification and immobilized MBP-IFT46 purification, and the specificity of polyclonal antibodies was evaluated by Western blotting and immunofluorescence. Results showed that the polyclonal antibody prepared could specifically and precisely bind IFT46 in C. reinhardtii, and IFT46 was mainly concentrated at basal body regions and few localized along the entire length of the flagellum as punctuated dots, which will make a foundation to further study the mechanism of IFT46 in cilia related diseases such as obesity, diabetes and polycystic kidney disease.
Algal Proteins ; biosynthesis ; immunology ; Animals ; Antibodies ; chemistry ; Blotting, Western ; Chlamydomonas reinhardtii ; chemistry ; genetics ; Electrophoresis, Polyacrylamide Gel ; Enzyme-Linked Immunosorbent Assay ; Escherichia coli ; Fluorescent Antibody Technique ; Intracellular Signaling Peptides and Proteins ; biosynthesis ; immunology ; Plasmids ; Rabbits ; Recombinant Fusion Proteins ; biosynthesis

OBJECTIVETo investigate the effect of tumor necrosis factor-α-induced protein 8 like-2 (TIPE2) on apoptosis of CD4T lymphocytes in a murine model of severe burn injury.

METHODSA total of 140 male mice were randomly allocated into 6 groups. Small RNA interference technique was used to construct a siTIPE2-overexpressing lentivirus, and severe burn injury models were established in the mice. CD4T cells were purified from spleen of the mice, and the expressions of TIPE2, Smad2/Smad3, P-Smad2/P-Smad3 and Bcl-2/Bimprotein in CD4Tregs were detected. The changes in mitochondrial membrane potential and cytochrome C in CD4T cells were detected, and the activities of caspase-3, caspase-8, and caspase-9 were analyzed.

RESULTSDown-regulation of TIPE2 promoted the apoptosis of CD4T lymphocytes in siTIPE2-burn group, in which the protein expressions of P-smad2/P-Smad3 decreased, Bcl-2 expression increased and Bim expression decreased significantly as compared with the other groups (P<0.01 or 0.05). The mitochondrial membrane potential and cytochrome C expression in CD4T cells were down-regulated in siTIPE2-burn group (P<0.05) with a lowered caspase-3 activity compared with TIPE2-burn group (P<0.01) and decreased caspase-8 and caspase-9 compared with the other groups (P<0.05). The apoptosis rate was the highest in TIPE2-burn group, whose Smad2/Smad3 was higher than that in the sham group (P<0.05) and the expression of P-smad2/P-Smad3 significantly increased compared with the other groups (P<0.05). In TIPE2-burn group, the mitochondrial membrane potential in CD4T cells was decreased (P<0.01), the expression of cytochrome C increased markedly (P<0.01), and the activities of caspase-3, caspase-8, and caspase-9 were all obviously higher than those in the other groups (P<0.05).

CONCLUSIONAs an important immunoregulatory molecule, TIPE2 can promote the apoptosis of CD4T lymphocyte in mice with sever burn injury.

Animals ; Apoptosis ; Burns ; immunology ; CD4-Positive T-Lymphocytes ; cytology ; Caspase 3 ; metabolism ; Caspase 8 ; metabolism ; Caspase 9 ; metabolism ; Down-Regulation ; Intracellular Signaling Peptides and Proteins ; metabolism ; Male ; Mice ; Smad2 Protein ; metabolism ; Smad3 Protein ; metabolism ; Spleen

The NOD like receptors (NLRs), a class of intracellular receptors that respond to pathogen attack or cellular stress, have gained increasing attention. NLRC5, the largest member of the NLR protein family, has recently been identified as a critical regulator of immune responses. While NLRC5 is constitutively and widely expressed, it can be dramatically induced by interferons during pathogen infections. Both in vitro and in vivo studies have demonstrated that NLRC5 is a specific and master regulator of major mistocompatibility complex (MHC) class I genes as well as related genes involved in MHC class I antigen presentation. The expression of MHC class I genes is regulated by NLRC5 in coordination with the RFX components through an enhanceosome-dependent manner. And the involvement of NLRC5 in MHC class I mediated CD8+ T cell activation, proliferation and cytotoxicity is proved to be critical for host defense against intracellular bacterial infections. Nevertheless, the role of NLRC5 in innate immunity remains to be further explored. Here, we review the research advances on the structure, expression regulation and function of NLRC5.
Animals ; CD8-Positive T-Lymphocytes ; immunology ; metabolism ; Histocompatibility Antigens Class I ; genetics ; metabolism ; Humans ; Immunity, Innate ; Intracellular Signaling Peptides and Proteins ; chemistry ; genetics ; metabolism

A20 was originally identified as a TNFα-induced protein 3 (TNFAIP3), a key regulator of inflammation signalling pathways, as well as a NF-κB inhibitor. It plays a critical role in regulation of innate and adoptive immunity. Recently, A20 has also been proposed to function as a tumor suppressor. Lacking A20 gene is involved in inflammation-mediated autoimmune disease and tumorigenesis in several human B-cell lymphomas. Current advance concerning the feature of A20 expression in immune cells, the biological function, the immune regulated function in native immunity, humoral and cellular immunity, the inactivation of A20 in lymphocytic malignancies and the polymorphism and abnormal expression of A20 in autoimmune disease indicate that the clinical significance of A20 should be worthy to recognize and to be further employed in induction of immune tolerance, antitumor immuno-regulated therapy and antiviral immunotherapy and so on.
Adaptive Immunity ; Autoimmune Diseases ; immunology ; DNA-Binding Proteins ; immunology ; Genes, Tumor Suppressor ; Humans ; Inflammation ; immunology ; Intracellular Signaling Peptides and Proteins ; immunology ; NF-kappa B ; immunology ; Nuclear Proteins ; immunology ; Tumor Necrosis Factor alpha-Induced Protein 3 ; Tumor Necrosis Factor-alpha ; immunology

Allergic diseases have become global social health problems. The binding of IgE with its high affinity receptor FcepsilonRI plays a key step in I-type allergy. Recently, more and more key molecules on the IgE/FcepsilonRI signaling transduction pathway were to be the drug candidates against allergic diseases, with in-depth study of FcepsilonRI signal pathway gradually. The main drugs include molecule antibodies, peptides, vaccines, fusion proteins, small molecules, and other drugs related to IgE/FcepsilonRI. The recent progress in the study of mechanisms of representative drugs targeting on IgE/FcepsilonRI signaling pathway was reviewed in this article.
Aminophenols ; pharmacology ; therapeutic use ; Animals ; Anti-Allergic Agents ; pharmacology ; therapeutic use ; Antibodies, Anti-Idiotypic ; pharmacology ; therapeutic use ; Antibodies, Monoclonal, Humanized ; pharmacology ; therapeutic use ; Humans ; Hypersensitivity ; drug therapy ; immunology ; Immunoglobulin E ; metabolism ; Intracellular Signaling Peptides and Proteins ; antagonists & inhibitors ; Molecular Targeted Therapy ; Omalizumab ; Protein-Tyrosine Kinases ; antagonists & inhibitors ; Pyrimidines ; pharmacology ; therapeutic use ; Receptors, IgE ; metabolism ; Signal Transduction ; Syk Kinase

Carrier Proteins ; genetics ; metabolism ; Cell Line, Tumor ; Gene Library ; Hepatitis B Surface Antigens ; immunology ; metabolism ; Hepatitis B virus ; genetics ; immunology ; Humans ; Immunoprecipitation ; Intracellular Signaling Peptides and Proteins ; metabolism ; Nerve Tissue Proteins ; metabolism ; Viral Proteins ; immunology ; metabolism

This study was aimed to explore the immune escaping mechanisms based on expression and abscission of human natural killer (NK) cell activating receptors NKG2D and their ligands MICA/B, ULBP-1, 2, 3 in patients with acute leukemia (AL). 30 de novo AL patients and 10 healthy persons (control) were enrolled in study. Flow cytometry was used to detect the expression levels of MICA/B, ULBP-1, 2, 3 on leukemic cells. ELISA was used to detect the levels of soluble MICA (sMICA), solube MICB (sMICB) and soluble ULBP-1, -2, -3 in the serum. The results showed that sMICA, sMICB and ULBP-1, -2, -3 were not expressed or expressed at very low levels on leukemia cells of the patients; the levels of free sMICA and sMICB in serum of AL patients were higher than that in serum of healthy persons, there was significant difference (p<0.01). But the levels of ULBP 1-3 in serum of AL patients did not show obvious statistical difference as compared with healthy persons (p>0.05). It is concluded that the negative or low expression of NKG2D ligands (MICA, MICB and ULBPs) on surface of acute leukemia cells may lead to the immune escape of leukemia cells, the abscission of MICA and MICB, and the deficiency of ULBP expression on leukemia cells may be one of immune escape mechanisms of leukemia cells.
Case-Control Studies ; Female ; Flow Cytometry ; GPI-Linked Proteins ; immunology ; metabolism ; Gene Expression Regulation, Leukemic ; Histocompatibility Antigens Class I ; immunology ; metabolism ; Humans ; Intercellular Signaling Peptides and Proteins ; immunology ; metabolism ; Intracellular Signaling Peptides and Proteins ; immunology ; metabolism ; Leukemia ; blood ; immunology ; Male ; NK Cell Lectin-Like Receptor Subfamily K ; immunology ; metabolism ; Tumor Escape

Down syndrome critical region 1 (DSCR1), an oxidative stress-response gene, interacts with calcineurin and represses its phosphatase activity. Recently it was shown that hydrogen peroxide inactivates calcineurin by proteolytic cleavage. Based on these facts, we investigated whether oxidative stress affects DSCR1-mediated inactivation of calcineurin. We determined that overexpression of DSCR1 leads to increased proteolytic cleavage of calcineurin. Convertsely, knockdown of DSCR1 abolished calcineurin cleavage upon treatment with hydrogen peroxide. The PXIIXT motif in the COOH-terminus of DSCR1 is responsible for both binding and cleavage of calcineurin. The knockdown of overexpressed DSCR1 in DS fibroblast cells also abrogated calcineurin proteolysis by hydrogen peroxide. These results suggest that DSCR1 has the ability to inactivate calcineurin by inducing proteolytic cleavage of calcineurin upon oxidative stress.
Adenoviridae/genetics ; Adult ; Animals ; Calcineurin/antagonists & inhibitors/*metabolism ; Cells, Cultured ; Chromatin Immunoprecipitation ; Down Syndrome/*metabolism/pathology ; Fibroblasts/metabolism/pathology ; Humans ; Hydrogen Peroxide/pharmacology ; Immunoglobulin G/immunology ; Intracellular Signaling Peptides and Proteins/*physiology ; Male ; Mice ; Mice, Inbred ICR ; Muscle Proteins/*physiology ; Neuroblastoma/genetics/metabolism/pathology ; Neurons/cytology/metabolism ; Oxidants/pharmacology ; Oxidative Stress ; Peptide Fragments/immunology ; RNA, Messenger/genetics/metabolism ; RNA, Small Interfering/pharmacology ; Rabbits ; Reverse Transcriptase Polymerase Chain Reaction ; Skin/pathology ; Young Adult