C4b Binding Protein Acts as an Innate Immune Effector Against Influenza A Virus

Phenoloxidase Activity Acts as a Mosquito Innate Immune Response against Infection with Semliki Forest Virus

Several components of the mosquito immune system including the RNA interference (RNAi), JAK/STAT, Toll and IMD pathways have previously been implicated in controlling arbovirus infections. In contrast, the role of the phenoloxidase (PO) cascade in mosquito antiviral immunity is unknown. Here we show that conditioned medium from the Aedes albopictus-derived U4.4 cell line contains a functional P...

Drosophila peptidoglycan recognition protein LC (PGRP-LC) acts as a signal-transducing innate immune receptor.

Drosophila peptidoglycan recognition protein LC (PGRP-LC), a transmembrane protein required for the response to bacterial infection, acts at the top of a cytoplasmic signaling cascade that requires the death-domain protein Imd and an IkappaB kinase to activate Relish, an NF-kappaB family member. It is not clear how binding of peptidoglycan to the extracellular domain of PGRP-LC activates intrac...

Complement Inhibitor C4b-Binding Protein

Binding of C4b-Binding Protein to Porin

We screened 29 strains of Neisseria gonorrhoeae and found 16/21 strains that resisted killing by normal human serum and 0/8 serum sensitive strains that bound the complement regulator, C4b-binding protein (C4bp). Microbial surface-bound C4bp demonstrated cofactor activity. We constructed gonococcal strains with hybrid porin (Por) molecules derived from each of the major serogroups (Por1A and Po...

Influenza A virus-encoded NS1 virulence factor protein inhibits innate immune response by targeting IKK.

The IKK/NF-κB pathway is an essential signalling process initiated by the cell as a defence against viral infection like influenza virus. This pathway is therefore a prime target for viruses attempting to counteract the host response to infection. Here, we report that the influenza A virus NS1 protein specifically inhibits IKK-mediated NF-κB activation and production of the NF-κB induced antivi...