10.3389/fimmu.2019.00613.s002 Veronica Chico Veronica Chico Maria Elizabhet Salvador-Mira Maria Elizabhet Salvador-Mira Ivan Nombela Ivan Nombela Sara Puente-Marin Sara Puente-Marin Sergio Ciordia Sergio Ciordia María Carmen Mena María Carmen Mena Luis Perez Luis Perez Julio Coll Julio Coll Fanny Guzman Fanny Guzman Jose Antonio Encinar Jose Antonio Encinar Luis Mercado Luis Mercado Maria del Mar Ortega-Villaizan Maria del Mar Ortega-Villaizan Image_2_IFIT5 Participates in the Antiviral Mechanisms of Rainbow Trout Red Blood Cells.TIF Frontiers 2019 rainbow trout IFIT5 red blood cells erythrocyte VHSV antiviral immune response immunoprecipitate proteomic 2019-04-16 04:33:24 Figure https://frontiersin.figshare.com/articles/figure/Image_2_IFIT5_Participates_in_the_Antiviral_Mechanisms_of_Rainbow_Trout_Red_Blood_Cells_TIF/7997513 <p>Viral hemorrhagic septicemia virus (VHSV) infection appears to be halted in rainbow trout nucleated red blood cells (RBCs). Diverse mechanisms are thought to be related to the antiviral immune response of rainbow trout RBCs to VHSV. However, the specific rainbow trout RBC proteins that interact directly with VHSV are still unknown. In an attempt to identify VHSV-RBC protein interactions, we characterized the immunoprecipitated (IP) proteome of RBCs exposed to VHSV using an antibody against the N protein of VHSV. The IP proteomic characterization identified 31 proteins by mass spectrometry analysis. Among them, we identified interferon-induced protein with tetratricopeptide repeats 5 (IFIT5), a protein belonging to a family of proteins that are induced after the production of type I interferon. Importantly, IFIT5 has been implicated in the antiviral immune response. We confirmed the participation of IFIT5 in the rainbow trout RBC antiviral response by examining the expression profile of IFIT5 in RBCs after VHSV exposure at transcriptional and protein levels. We detected a correlation between the highest IFIT5 expression levels and the decline in VHSV replication at 6 h post-exposure. In addition, silencing ifit5 resulted in a significant increase in VHSV replication in RBCs. Moreover, an increase in VHSV replication was observed in RBCs when the IFIT5 RNA-binding pocket cavity was modulated by using a natural compound from the SuperNatural II database. We performed a proximity ligation assay and detected a significant increase in positive cells among VHSV-exposed RBCs compared to unexposed RBCs, indicating protein-protein colocalization between IFIT5 and the glycoprotein G of VHSV. In summary, these results suggest a possible role of IFIT5 in the antiviral response of RBCs against VHSV.</p>