The Molecular Mechanism of Herpes Simplex Virus 1 UL31 in Antagonizing the Activity of IFN-ß.

Virus infection triggers intricate signal cascade reactions to activate the host innate immunity, which leads to the production of type I interferon (IFN-I). Herpes simplex virus 1 (HSV-1), a human-restricted pathogen, is capable of encoding over 80 viral proteins, and several of them are involved in immune evasion to resist the host antiviral response through the IFN-I signaling pathway. Here, we determined that HSV-1 UL31, which is associated with nuclear matrix and is essential for the formation of viral nuclear egress complex, could inhibit retinoic acid-inducible gene I (RIG-I)-like receptor pathway-mediated interferon beta (IFN-ß)-luciferase (Luc) and (PRDIII-I)4-Luc (an expression plasmid of IFN-ß positive regulatory elements III and I) promoter activation, as well as the mRNA transcription of IFN-ß and downstream interferon-stimulated genes (ISGs), such as ISG15, ISG54, ISG56, etc., to promote viral infection. UL31 was shown to restrain IFN-ß activation at the interferon regulatory factor 3 (IRF3)/IRF7 level. Mechanically, UL31 was demonstrated to interact with TANK binding kinase 1 (TBK1), inducible IκB kinase (IKKi), and IRF3 to impede the formation of the IKKi-IRF3 complex but not the formation of the IRF7-related complex. UL31 could constrain the dimerization and nuclear translocation of IRF3. Although UL31 was associated with the CREB binding protein (CBP)/p300 coactivators, it could not efficiently hamper the formation of the CBP/p300-IRF3 complex. In addition, UL31 could facilitate the degradation of IKKi and IRF3 by mediating their K48-linked polyubiquitination. Taken together, these results illustrated that UL31 was able to suppress IFN-ß activity by inhibiting the activation of IKKi and IRF3, which may contribute to the knowledge of a new immune evasion mechanism during HSV-1 infection. IMPORTANCE The innate immune system is the first line of host defense against the invasion of pathogens. Among its mechanisms, IFN-I is an essential cytokine in the antiviral response, which can help the host eliminate a virus. HSV-1 is a double-stranded DNA virus that can cause herpes and establish a lifelong latent infection, due to its possession of multiple mechanisms to escape host innate immunity. In this study, we illustrate for the first time that the HSV-1-encoded UL31 protein has a negative regulatory effect on IFN-ß production by blocking the dimerization and nuclear translocation of IRF3, as well as promoting the K48-linked polyubiquitination and degradation of both IKKi and IRF3. This study may be helpful for fully understanding the pathogenesis of HSV-1.

Subcellular Localization of Epstein-Barr Virus BLLF2 and Its Underlying Mechanisms.

Epstein-Barr virus (EBV), the pathogen of several human malignancies, encodes many proteins required to be transported into the nucleus for viral DNA reproduction and nucleocapsids assembly in the lytic replication cycle. Here, fluorescence microscope, mutation analysis, interspecies heterokaryon assays, co-immunoprecipitation assay, RNA interference, and Western blot were performed to explore the nuclear import mechanism of EBV encoded BLLF2 protein. BLLF2 was shown to be a nucleocytoplasmic shuttling protein neither by a chromosomal region maintenance 1 (CRM1)- nor by a transporter associated with antigen processing (TAP)-dependent pathway. Yet, BLLF2's two functional nuclear localization signals (NLSs), NLS1 (16KRQALETVPHPQNRGR31) and NLS2 (44RRPRPPVAKRRRFPR58), were identified, whereas the predicted NES was nonfunctional. Finally, BLLF2 was proven to transport into the nucleus via a Ran-dependent and importin ß1-dependent pathway. This mechanism may contribute to a more extensive insight into the assembly and synthesis of EBV virions in the nucleus, thus affording a new direction for the treatment of viruses.

MicroRNA-185 activates PI3K/AKT signalling pathway to alleviate dopaminergic neuron damage via targeting IGF1 in Parkinson's disease.

OBJECTIVES: Studies have extensively explored the role of microRNAs (miRs) in Parkinson's disease (PD) and miR-185 is related to autophagy and apoptosis of dopaminergic neurons in PD. However, the role of miR-185 mediating insulin-like growth factor 1 (IGF1)/phosphatidylinositol-3-kinase/protein kinase B signalling pathway (PI3K/AKT) in PD still needs in-depth exploration. METHODS: Rat PD models were established by injection of 6-hydroxydopamine. PD rats were injected with miR-185 or insulin-like growth factor 1 (IGF1)-related sequences. Behaviour tests were performed, oxidative stress-related factors, tyrosine hydroxylase (TH)-, glial fibrillary acidic protein (GFAP)-, ionised calcium-binding adaptor molecule-1 (Iba-1)- and TUNEL-positive cells in the substantia nigra were determined. Levels of miR-185, IGF1 and phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) signalling pathway-related factors were also detected. RESULTS: miR-185 level was reduced in rats with PD. Restoring miR-185 promoted behaviour functions, ameliorated pathological damages and oxidative stress, increased TH-positive dopaminergic neurons, decreased GFAP- and Iba-1-positive cells and restrained neuronal apoptosis in the substantia nigra in PD rats. miR-185 targeted IGF1 to activate PI3K/AKT signalling pathway. Up-regulation of IGF1 mitigated restored miR-185-mediated effects on PD rats. CONCLUSION: This study illustrates that miR-185 ameliorates dopaminergic neuron damage via targeting IGF1 and activating PI3K/AKT signalling pathway in PD, which renews the therapy for PD.

Safety of the Xuesaitong injection in China: results from a large-scale multicentre post-marketing surveillance study in a real-world setting.

OBJECTIVE: The safety profile of traditional Chinese medicine injections has emerged as the greatest challenge to their clinical application. The authors aimed to perform a post-marketing surveillance study in a real-world setting to evaluate the safety of the Xuesaitong (XST) injection in China. METHODS: This multi-centre, post-marketing, observational study enrolled patients who received XST injections in 42 centres in China between March 2015 and November 2017. Adverse drug reactions (ADRs) and adverse drug events (ADEs) were collected and evaluated in a post-marketing database. Logistic regression analysis was performed to analyse the risk factors for ADRs. RESULTS: A total of 30,008 consecutive patients with a mean age of 62.29 ± 14.58 years were included in this post-marketing study. The incidences of ADEs and ADRs were 0.5% and 0.33%, respectively. The most common clinical manifestations were damage to skin and appendages (47.66%). There were four new kinds of ADEs found in the present monitoring study. The majority of ADRs were type B (62.62%) and occurred within 24 h after XST injection treatment. No severe ADRs were reported in this analysis. Multivariate logistic regression analysis showed that the hospital level (OR = 0.607; 95% CI = 0.407-0.906; p = .0144), hypertension (OR = 1.979; 95% CI, 1.323-2.959; p = .0009) and solvent type (OR = 2.951; 95% CI, 1.608-5.417; p = .0005) were risk factors for ADR occurrence. CONCLUSION: XST injection is well tolerated and has a favourable safety profile for patients in a real-world setting. This post-marketing study provided further evidence of the safety of XST injections for clinical applications.

Correction to: Adenovirus-mediated LIGHT gene modification in murine B-cell lymphoma elicits a potent antitumor effect.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

[Effect of IL-8 on the Immune Function of Patients with Acute -Lymphoblastic Leukemia and Its Mechanism].

OBJECTIVE: To investigate the effect of interleukin -8 (IL-8) on immune function in acute lymphoblastic leukemia patients and its related mechanisms. METHODS: Forty-five ALL patients were selected from January 2014 to September 2017 in our hospital. Out of them, 32 relieved patients were included in group A, 13 patients did not relieved patients after treatment and were included in the group B. The serum IL-8 level was detected by ELISA.Th1 and Th2 cells were measured by flow cytometry. After Th cells were treated with different concentration of IL-8, the Western blot was used to detect the translation levels of p-STAT3 and JAK in cells. RESULTS: The difference of white blood cell count and clinical risk level between the 2 groups was statistically significant (P<0.05). The serum IL-8 levels in group A and B were significantly higher than that in control group (P<0.05). The serum IL-8 level in group B was significantly higher than that in group A (P<0.05). After treatment, the level of Th1 cells in group B was 6.15%±1.22%, significantly lower than that in group A (P<0.05), and Th2 cell level in group B was 2.76%±0.24%, significantly higher than that in group A (P<0.05); Th1/Th2 in group B was 2.23%±0.09, significantly lower than that in group A (P<0.05). The protein level of p-STAT3 and JAK in the Th cells was lower than that in control group at different levels of IL-8 after treatment (P<0.05). After stimulating Th cells with 20 ng/ml IL-8, the levels of p-STAT3 and JAK protein in cells were lower than those after 10 ng/ml IL-8 treatment (P<0.05). IL-8 level had no significant effect on the protein expression of STAT3 in Th cells (P>0.05). CONCLUSION: IL-8 can interfere the balance of Th1/Th2 through STAT3 signaling pathway, and has effect on the immune function of ALL patients.

The membrane molecule RCAS1 induces immune cell apoptosis via the RCAS1-RCAS1R pathway.

Tumor-associated antigen receptor-binding cancer antigen expressed on SiSo cells (RCAS1) has been identified as an estrogen-responsive gene and reportedly acts as a ligand for a putative receptor present in a variety of human cell lines and peripheral lymphocytes, thus leading them to apoptosis. In this study, we investigated the biological function of RCAS1 in vitro in inducing the apoptosis of immune cells. We detected the expression of the RCAS1 receptor (RCAS1R) in the cell lines, and investigated the mechanisms behind the apoptosis induced by RCAS1. HeLa cells were transfected with recombinant adenovirus Ad-RCAS1. RCAS1 induced the apoptosis of activated T cells, K562 cells and phytohemagglutinin (PHA)-activated Jurkat cells via the RCAS1-RCAS1R pathway. The expression of RCAS1R was induced. The intracellular overexpression of RCAS1 inhibited the growth of Jurkat and K562 cells. The expression of RCAS1 negatively correlated with the expression of glycogen synthase kinase 3ß (GSK3ß), but positively correlated with the expression of phosphorylated GSK3ß (phGSK3ß). RCAS1 expression was identified as a brown staining pattern in the breast cancer specimens. These findings may provide insight into the mechanisms through which tumor cells escape from immune surveillance.

Adenovirus-mediated LIGHT gene modification in murine B-cell lymphoma elicits a potent antitumor effect.

Here, we investigated the antitumor effect of adenovirus-mediated gene transfer of LIGHT, the tumor-necrosis factor (TNF) superfamily member also known as TNFSF14, in the murine A20 B-cell lymphoma. LIGHT gene modification resulted in upregulated expression of Fas and the accessory molecule--intercellular adhesion molecule-1 (ICAM-1) on A20 cells and led to enhanced A20 cell apoptosis. LIGHT-modified A20 cells effectively stimulated the proliferation of T lymphocytes and interferon (IFN)-gamma production in vitro. Immunization of BALB/c mice with a LIGHT-modified A20 cell vaccine efficiently elicited protective immunity against challenge with the parental tumor cell line. Adenovirus-mediated gene transfer of LIGHT by intratumoral injection exerted a very potent antitumor effect against pre-existing A20 cell lymphoma in BALB/c mice. This adenovirus-mediated LIGHT therapy induced substantial splenic natural killer (NK) and cytotoxic T lymphocyte (CTL) activity, enhanced tumor infiltration by inflammatory cells and increased chemokine expression of CC chemokine ligand 21 (CCL21), IFN-inducible protein-10 (IP-10) and monokine induced by IFN-gamma (Mig) from tumor tissues. Thus, adenovirus-mediated LIGHT therapy might have potential utility for the prevention and treatment of B-cell lymphoma.

EBAG9 inducing hyporesponsiveness of T cells promotes tumor growth and metastasis in 4T1 murine mammary carcinoma.

The estrogen receptor-binding fragment-associated gene 9 (EBAG9) has been identified as an estrogen-responsive gene and was recently identified as a tumor-promoting and prognostic factor for renal cell carcinoma. We investigated whether EBAG9 expression was correlated with primary tumor growth and distant tumor metastasis in a murine breast carcinoma model. Knockdown expression of EBAG9 by small interfering RNA significantly suppressed tumor growth and metastasis in vivo in a highly malignant, spontaneously metastasizing 4T1 mouse mammary carcinoma model. 4T1 cells stably overexpressing EBAG9 developed larger and faster tumor growth and lung metastasis compared with parental 4T1 or 4T1 expressing vector alone. Strong specific cytotoxic T lymphocyte activity and enhanced gamma-interferon and interleukin-2 productions were induced in mice that received EBAG9 small interfering RNA therapy. Gene silencing of EBAG9 prolonged the survival of tumor-bearing mice and induced more intensive infiltration of CD8+ T cells in tumor mass. EBAG9 induced apoptosis of T cells, enhanced glycogen synthase kinase 3beta phosphorylation and inhibited gamma-interferon production of T cells when T lymphocytes were cocultured with 4T1 cells overexpressing EBAG9. Furthermore, overexpression of EBAG9 in 4T1 cells was accompanied with enhanced expression of chemokine (C-X-C motif) receptor 4, which might be involved in tumor metastasis. Taken together, our results suggested that EBAG9 promoted primary 4T1 mammary carcinoma growth and distant metastasis, and EBAG9 small interfering RNA exerted overt regression of tumor growth and metastasis. These findings might provide insights into the mechanism through which tumors evade immunosurveillance and provide a strategy for therapeutic intervention of cancer metastases.

Membrane protein hMYADM preferentially expressed in myeloid cells is up-regulated during differentiation of stem cells and myeloid leukemia cells.

We report here the molecular cloning and characterization of a novel human gene (hMYADM) derived from a human bone marrow stromal cell (BMSC) cDNA library, which shares high homology with mouse myeloid-associated differentiation marker (MYADM). hMYADM is also closely related to many other eukaryotic proteins, which together form a novel and highly conserved MYADM-like family. hMYADM with 322-residue protein contains eight putative transmembrane segments and confocal microscopic analysis confirmed its membrane localization by using anti-hMYADM monoclonal antibody. hMYADM mRNA was selectively expressed in human monocytes, dendritic cells, promyeloid or monocytic leukemia cell lines, but not in CD4+, CD8+, CD19+ cells, nor in T cell leukemia or lymphocytic leukemia cell lines. hMYADM expression was also found in normal human bone marrow enriched for CD34+ stem cells, and the expression was up-regulated when these cells were induced to differentiate toward myeloid cells. The mRNA expression level of hMYADM significantly increased in acute promyelocytic leukemia HL-60 and chronic myelogenous leukemia K562 cell line after phorbol myristate acetate (PMA)-induced differentiation. Our study suggests that hMYADM is selectively expressed in myeloid cells, and involved in the myeloid differentiation process, indicating that hMYADM may be one useful membrane marker to monitor stem cell differentiation or myeloid leukemia differentiation.

[Construction of recombinant GST-RCAS1 fusion gene and its expression in E. Coli].

OBJECTIVE: To construct the recombinant plasmid of RCAS1, to express and purify its fusion protein GST-RCAS1, and to investigate its biological function. METHODS: RCAS1 encoding gene was amplified by RT-PCR from total RNA extract of MCF-7 cells and was ligated with expression plasmid vector pGEX-2T by T4 DNA ligase after digested by the restricted endonucleases BamH I and EcoR I. Then the ligated products were inserted into competence JM109 E. Coli and the positive recombinants were identified by restriction endonuclease digestion assay and DNA sequencing. The GST-RCAS1 fusion protein expression was induced by IPTG in BL21 E. Coli and was purified with GST column and identified by SDS-PAGE and Western blotting with anti-GST monoclonal antibody, anti-RCAS1 (N-18) and anti-RCAS1 (C-20) polyclonal antibody. The apoptosis of activated T cells induced by GST-RCAS1 fusion protein was detected by flow cytometry with Annexin V and propidium iodide (PI) staining. RESULT: A 642 bp product was cloned by RT-PCR and the recombinant plasmid was constructed successfully. The GST-RCAS1 fusion protein was recognized by GST monoclonal antibody and RCAS1(N-18 and C-20) polyclonal antibody. FACS analysis showed that GST-RCAS1 fusion protein induced apoptosis in activated T cells. CONCLUSION: The recombinant plasmid of RCAS1 has been successfully constructed and the GST-RCAS1 fusion protein expressed and purified. The apoptosis inducing effect of GST-RCAS1 fusion protein on activated T cells is demonstrated.