A TFPI-1 peptide that induces degradation of bacterial nucleic acids, and inhibits bacterial and viral infection in half-smooth tongue sole, Cynoglossus semilaevis
Shu-Wen He 1, Jian Zhang 2, Ning-Qiu Li 3, Shun Zhou 1, Bin Yue 1, Min Zhang 4
Fish Shellfish Immunol. 2017 Jan;60:466-473. doi: 10.1016/j.fsi.2016.11.029. Epub 2016 Nov 10.
Tissue factor pathway inhibitor 1 (TFPI-1) is a serine protease inhibitor that inhibits tissue factor (TF)-mediated coagulation. The C-terminal region of TFPI-1 could be cleaved off and proved to be antimicrobial against a broad-spectrum of microorganism. In a previous study, a C-terminal peptide, TC24 (with 24 amino acids), derived from tongue sole (Cynoglossus semilaevis) TFPI-1, was synthesized and found antibacterial against Micrococcus luteus. In the present study, the antibacterial spectrum and the action mode of TC24 was further examined, and its in vivo function was analyzed. Our results showed that TC24 also possesses bactericidal activity against Staphylococcus aureus and Vibrio vulnificus. During its interaction with the target bacterial cells, TC24 destroyed cell membrane integrity, penetrated into the cytoplasm, and induced degradation of genomic DNA and total RNA. In vivo study showed that administration of tongue sole with TC24 before bacterial and viral infection significantly reduced pathogen dissemination and replication in tissues. These results indicated that TC24 is a novel antimicrobial peptide against bacterial and viral pathogens, and that the observed effect of TC24 on bacterial RNA adds new insights to the action mechanism of fish antimicrobial peptides. Moreover, TC24 may play an important role in fighting pathogenic infection in aquaculture.
Functional genomics highlights differential induction of antiviral pathways in the lungs of SARS-CoV-infected macaques
Anna de Lang 1, Tracey Baas, Thomas Teal, Lonneke M Leijten, Brandon Rain, Albert D Osterhaus, Bart L Haagmans, Michael G Katze
PMID: 17696609 PMCID: PMC1941749 DOI: 10.1371/journal.ppat.0030112
The pathogenesis of severe acute respiratory syndrome coronavirus (SARS-CoV) is likely mediated by disproportional immune responses and the ability of the virus to circumvent innate immunity. Using functional genomics, we analyzed early host responses to SARS-CoV infection in the lungs of adolescent cynomolgus macaques (Macaca fascicularis) that show lung pathology similar to that observed in human adults with SARS. Analysis of gene signatures revealed induction of a strong innate immune response characterized by the stimulation of various cytokine and chemokine genes, including interleukin (IL)-6, IL-8, and IP-10, which corresponds to the host response seen in acute respiratory distress syndrome. As opposed to many in vitro experiments, SARS-CoV induced a wide range of type I interferons (IFNs) and nuclear translocation of phosphorylated signal transducer and activator of transcription 1 in the lungs of macaques. Using immunohistochemistry, we revealed that these antiviral signaling pathways were differentially regulated in distinctive subsets of cells. Our studies emphasize that the induction of early IFN signaling may be critical to confer protection against SARS-CoV infection and highlight the strength of combining functional genomics with immunohistochemistry to further unravel the pathogenesis of SARS.