Novel interacting proteins identified by tandem affinity purification and mass spectrometry associated with IFITM3 protein during PDCoV infection.

Interferon-induced transmembrane 3 (IFITM3) is a membrane-associated protein that exhibits antiviral activities against a wide range of viruses through interactions with other cellular and viral proteins. However, knowledge of the mechanisms of IFITM3 in Porcine deltacoronavirus (PDCoV) infection has been lacking. In this study, we demonstrate that IFN-α treatment induces the upregulation of IFITM3 activity and thus attenuates PDCoV infection. PDCoV replication is inhibited in a dose-dependent manner by IFITM3 overexpression. To clarify the novel roles of IFITM3 during PDCoV infection, proteins that interact with IFITM3 were screened by TAP/MS in an ST cell line stably expressing IFITM3 via a lentivirus. We identified known and novel candidate IFITM3-binding proteins and analyzed the protein complexes using GO annotation, KEGG pathway analysis, and protein interaction network analysis. A total of 362 cellular proteins associate with IFITM3 during the first 24 h post-infection. Of these proteins, the relationship between IFITM3 and Rab9a was evaluated by immunofluorescence colocalization analysis using confocal microscopy. IFITM3 partially colocalized with Rab9a and Rab9a exhibited enhanced colocalization following PDCoV infection. We also demonstrated that IFITM3 interacts specifically with Rab9a. Our results considerably expand the protein networks of IFITM3, suggesting that IFITM3 participates in multiple cellular processes during PDCoV infection.

Prognosis-related classification and dynamic monitoring of immune status in patients with sepsis: A prospective observational study.

BACKGROUND: The dynamic monitoring of immune status is crucial to the precise and individualized treatment of sepsis. In this study, we aim to introduce a model to describe and monitor the immune status of sepsis and to explore its prognostic value. METHODS: A prospective observational study was carried out in Zhongshan Hospital, Fudan University, enrolling septic patients admitted between July 2016 and December 2018. Blood samples were collected at days 1 and 3. Serum cytokine levels (e.g., tumor necrosis factor-α [TNF-α], interleukin-10 [IL-10]) and CD14+ monocyte human leukocyte antigen-D-related (HLA-DR) expression were measured to serve as immune markers. Classification of each immune status, namely systemic inflammatory response syndrome (SIRS), compensatory anti-inflammatory response syndrome (CARS), and mixed antagonistic response syndrome (MARS), was defined based on levels of immune markers. Changes of immune status were classified into four groups which were stabilization (SB), deterioration (DT), remission (RM), and non-remission (NR). RESULTS: A total of 174 septic patients were enrolled including 50 non-survivors. Multivariate analysis discovered that IL-10 and HLA-DR expression levels at day 3 were independent prognostic factors. Patients with MARS had the highest mortality rate. Immune status of 46.1% patients changed from day 1 to day 3. Among four groups of immune status changes, DT had the highest mortality rate, followed by NR, RM, and SB with mortality rates of 64.7%, 42.9%, and 11.2%, respectively. CONCLUSIONS: Severe immune disorder defined as MARS or deterioration of immune status defined as DT lead to the worst outcomes. The preliminary model of the classification and dynamic monitoring of immune status based on immune markers has prognostic values and is worthy of further investigation.