Effects of γ interferon on hepatic fibrosis of schistosoma japonicum infected mice *

AIM To probe the effect of γ IFN on hepatic fibrosis in schistosomiasis japonica.

IRF family proteins and type I interferon induction in dendritic cells

Dendritic cells （DC）, although a minor population in hematopoietic cells, produce type I interferons （IFN） and other cytokines and are essential for innate immunity. They are also potent antigen presenters and regulate adaptive immunity. Among DC subtypes plasmacytoid DC （pDC） produce the highest amounts of type I IFN. In addition, pro- and anti-inflammatory cytokines such as IL-12 and IL-10 are induced in DC in response to Toll like receptor （TLR） signaling and upon viral infection. Proteins in the IRF family control many aspects of DC activity. IRF-8 and IRF-4 are essential for DC development. They differentially control the development of four DC subsets. IRF-8^-/- mice are largely devoid of pDC and CD8α^＋ DC, while IRF-4^-/- mice lack CD4^＋ DC. IRF-8^-/-, IRF4^-/-, double knock-out mice have only few CD8α CD4^-DC that lack MHC Ⅱ. IRF proteins also control type Ⅰ IFN induction in DC. IRF-7, activated upon TLR signaling is required for IFN induction not only in pDC, but also in conventional DC （cDC） and non-DC cell types. IRF-3, although contributes to IFN induction in fibroblasts, is dispensable in IFN induction in DC. Our recent evidence reveals that type Ⅰ IFN induction in DC is critically dependent on IRF-8, which acts in the feedback phase of IFN gene induction in DC. Type Ⅰ IFN induction in pDC is mediated by MyD88 dependent signaling pathway, and differs from pathways employed in other cells, which mostly rely on TLR3 and RIG-Ⅰ family proteins. Other pro-inflammatory cytokines are produced in an IRF-5 dependent manner. However, IRF-5 is not required for IFN induction, suggesting the presence of separate mechanisms for induction of type Ⅰ IFN and other pro-inflammatory cytokines. IFN and other cytokines produced by activated DC in turn advance DC maturation and change the phenotype and function of DC. These processes are also likely to be governed by IRF family proteins.

Primary Purification of Co-expressed Soluble and Insoluble Alpha-interferon 2b from Recombinant E. coli

Alpha-interferon 2b (IFN 2b) was produced both in soluble and insoluble forms from recombinant E. coli. The dissolution of the expressed IFN 2b in inclusion body was carried out and it was found that the optimal condition to dissolve the expressed protein was 7 mol稬1guanidinium salt solution at pH 3.0. The resultant solution was diluted 20 times using pH 6.0 buffer to refold the protein correctly. The cation exchange column was employed to purify both refolded and soluble IFN 2b. For soluble IFN sample, high IFN 2b recovery yield (92.1%) with 91.7% purity was obtained in the eluate. However, for refolded IFN sample, only 72.7% of IFN 2b was recovered with relatively low purity (56.8%) by cation exchange chromatography. Although the expression level of insoluble IFN was higher than that of co-expressed soluble IFN in this recombinant E. coli cells, the productivity of bioactive IFN 2b was higher with soluble expressed IFN after primary purification process. Soluble expression of foreign proteins in recombinant bacteria might be an alternative strategy for efficient production of heterogeneous pro-teins due to high bioactivity and simple downstream protein purification process.

TRIM4 modulates type I interferon induction and cellular antiviral response by targeting RIG-I for K63-1inked ubiquitination

RIG-I is a pivotal cytoplasmic sensor that recognizes different species of viral RNAs. This recognition leads to activation of the transcription factors NF-κB and IRF3, which collaborate to induce type I interferons （IFNs） and innate antiviral response. In this study, we identified the TRIM family protein TRIM4 as a positive regulator of RIG-I-mediated IFN induction. Overexpression of TRIM4 potentiated virus-triggered activation of IRF3 and NF-κB, as well as IFN-13 induction, whereas knockdown of TRIM4 had opposite effects. Mechanistically, TRIM4 associates with RIG-I and targets it for K63-linked poiyubiquitination. Our findings demonstrate that TRIM4 is an important regulator of the virus-induced IFN induction pathways by mediating RIG-I for K63-Unked ubiquitination.

Interferon-liposomes prepared to make macroglia maintain M1 phenotype

Macroglia is a crucial macrophage only existing in the central nervous system.During the development of glioma,it can be activated as M2 anti-inflammatory type to promote glioma growth.Interferon-γ(IFN-γ)is an important immunomodulator in glioma microenvironment,which can also activate macroglia as M1 pro-inflammatory type to enhance anti-tumor immune response and lead to inhibition of glioma growth.Therefore,we utilized IFN-γto make macroglia maintain M1 phenotype,so that prospectively achieving anti-tumor immunity for glioma therapy.We prepared interferon-γ-liposomes(IFN-Lp)to protect IFN-γfrom elimination.IFN-Lp was proved to have strong capability to be phagocytosed and accumulate in macroglia(BV2 cells)to achieve long-term effect.In addition,IFN-Lp could allow BV2 cells to maintain M1 phenotype,showing no impact on its cell viability.These findings will offer new opportunities to achieve enhanced immunotherapy of glioma.

STING-mediated DNA sensing in cancer immunotherapy

While STING(STimulator of INterferon Genes) has been shown to be essential for cytosolic DNA-triggered innate immune activation, accumulated evidence obtained from various studies suggested that an intrinsic relevance of STING-associated signaling in tumorigenesis can be observed. Also, several clinical trials using immunostimulatory adjuvants, particularly agonistic as well as non-agonistic ligands for STING, have revealed their therapeutic potential not only as vaccine adjuvants but also as anti-tumor agents. However, cases have also been reported where the involvement of STING shows a protective role in tumor growth. Here we summarize recent findings that have pointed towards the STING pathway as an innate immune sensing mechanism driving type I interferon production in the tumor context. Better understanding of this pathway can guide further development of novel immunotherapeutic strategies in the treatment of cancer.