Identification, expression pattern and functional characterization of IFN-γ involved in activating JAK-STAT pathway in Sebastes schlegeli

Mx of Sebastes schlegelii: expression pattern, antibacterial activity and antiviral mechanism

Myxovirus resistance (Mx) is a classical antiviral molecule that has been well understood in mammals. However, very limited studies on Mx antiviral activities have been documented in teleosts. In the present study, a novel Mx (SsMx) was cloned from black rockfish (Sebastes schlegelii) and the immunological activities of SsMx were examined in vitro and in vivo. SsMx contained conserved structural and functional domains including GTPase domain and GTPase effector domain. Quantitative real-time PCR (qRT-PCR) revealed that SsMx is extensively distributed in the immune cells and tissues examined with higher levels in spleen and liver. The mRNA expression of SsMx was significantly upregulated in head kidney, spleen and head kidney macrophages after pathogen infection. Recombinant SsMx (rSsMx) exhibited apparent binding activities against different bacteria in vitro. In vivo studies showed that rSsMx reduced pathogen dissemination and replication in head kidney and spleen. The subcellular localization results demonstrated that SsMx was predominantly distributed in the cytoplasm of transfected cells. Furthermore, SsMx was observed to inhibit apoptosis in virus-infected cells and reduce viral replication by interfering with the viral entry. SsMx and Spring viremia of carp virus Glycoprotein (SVCV G) were found to interact strongly with each other by co-immunoprecipitation and co-localization. These findings reveal an important role of SsMx in defencing the early stage of SVCV infection, which will be helpful to understand the molecular details of the antiviral mechanisms mediated by Mx proteins in teleosts.

Xianling Lianxia formula enhances the inhibitory effects of trastuzumab on HER2-positive breast cancer

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) is characterized by high invasiveness. Trastuzumab considerably improves the prognoses of HER2-positive BC, but some patients exhibit drug resistance. In this study, the effects of XLLXF combined with trastuzumab on the proliferation, apoptosis, invasion, and migration of HER2-positive BC cells are evaluated, and network pharmacology is performed. Then, we conduct an in vivo study using a xenograft mouse model of HER2-positive BC, and tumor growth is monitored. The expression levels of cytokines are measured by ELISA. Molecular docking is performed to observe the binding stability of IL2, JAK, STAT, and TNF with curcumenol, icariside-II, lobetyolin, and scutellarein. Finally, we observe changes in JAK1 and TNF-α in tumor tissues by immunohistochemistry. The results show that XLLXF enhances the inhibitory effects of trastuzumab on the proliferation, colony formation ability, migration, and invasion of HER2-positive BC cells and promotes apoptosis. Network pharmacology reveals that XLLXF may exert its effects on HER2-positive BC by modulating pathways such as the ErbB, JAK-STAT, and NF-κB pathways. Potential targets include cytokines closely related to immune function. In the in vivo study, XLLXF synergistically enhances the inhibitory effects of trastuzumab on tumor growth. ELISA reveals that XLLXF combined with trastuzumab increases the levels of IL-15, IL-2, TNF-α, and IFN-γ in tumor-bearing mice. Immunohistochemistry confirms that XLLXF can regulate the expressions of JAK1 and TNF-α. This study demonstrates that XLLXF can synergistically enhance the efficacy of trastuzumab in targeting HER2-positive BC. The mechanism may involve the modulation of inflammatory factors.