Fig 1: STING trafficking from ER to late endosome participate in viral protein degradation. A HUVECs were mock-infected or HTNV-infected (MOI = 1) for 24 h, and incubated with mouse anti-STING and rabbit anti-ERGIC-53 antibodies, following stained with Cy3-conjugated anti-mouse and FITC-conjugated anti-rabbit secondary antibodies. Nuclei were stained with DAPI. Scale bar, 10 μm. B HUVECs were mock-infected or HTNV-infected (MOI = 1) for 24 h, and incubated with mouse anti-STING and rabbit anti-Rab7A antibodies, following stained with Cy3-conjugated anti-mouse and FITC-conjugated anti-rabbit secondary antibodies. Nuclei were stained with DAPI. Scale bar, 10 μm. C HUVECs were mock-infected or HTNV-infected (MOI = 1) for 24 h, and incubated with Lysosome Tracker, mouse anti-1A8 and rabbit anti-STING antibodies, following stained with F488-conjugated anti-mouse and Cy5-conjugated anti-rabbit secondary antibodies, respectively. Nuclei were stained with DAPI. Scale bar, 10 μm. D HEK293T cells were single or co-transfected with Flag-STING (10 μg/well) or Myc-Rab7A (10 μg/well) for 36 h. The cell lysates were immunoprecipitated with anti-Flag antibody, and detected by immunoblotting with anti-Flag or anti-Myc antibody. E HEK293T cells were single or co-transfected with Flag-STING or Myc-NP for 36 h. The cell lysates were immunoprecipitated with anti-Flag antibody, and detected by immunoblotting with anti-Flag or anti-Myc antibody. F–H HVECs were infected with HTNV (MOI = 1) for 24 h and then treated with BAF for 4 h. HTNV NP, STING and LC3B were detected by immunoblotting (F). The grey values of the protein level of HTNV NP bands (G) and LC3B-Ⅰ/LC3B-Ⅱ bands (H) from three independent immunoblot through the software Image J and carry out statistical analysis. Data are expressed as mean ± SEM (n = 3). Statistical significance was calculated using Student's t-test; ∗P < 0.05; ∗∗P < 0.01.
Fig 2: The working model of the STING-induced anti-hantaviral immunity responses. HTNV infection activates RIG-I through IRE1-XBP-dependent signaling. RIG-I interacts with STING via the △CTT domain within STING, leading to STING trafficking from the endoplasmic reticulum to the Golgi apparatus and inducing autophagy. STING localized on late endosomes interacts with Rab7A and fuses with lysosomes, leading to reduced expression of STING and antiviral effects. △CTT STING can serve as a novel therapeutic strategies against hantavirus infection in mice. The black arrow indicates that HTNV infection does not work, while the red arrow indicates that HTNV infection is working.
Supplier Page from Sino Biological, Inc. for Human RAB7A / Rab-7a Gene ORF cDNA clone expression plasmid, C-Myc tag