Nonstructural proteins of respiratory syncytial virus suppress premature apoptosis by an NF-kappaB-dependent, interferon-independent mechanism and facilitate virus growth.

The two nonstructural (NS) proteins NS1 and NS2 of respiratory syncytial virus (RSV) are abundantly expressed in the infected cell but are not packaged in mature progeny virions. We found that both proteins were expressed early in infection, whereas the infected cells underwent apoptosis much later. Coincident with NS protein expression, a number of cellular antiapoptotic factors were expressed or activated at early stages, which included NF-kappaB and phosphorylated forms of protein kinases AKT, phosphoinositide-dependent protein kinase, and glycogen synthase kinase.

The FK506-binding protein of the malaria parasite, Plasmodium falciparum, is a FK506-sensitive chaperone with FK506-independent calcineurin-inhibitory activity.

We have identified an immunophilin of the FKBP family in Plasmodium falciparum that contains a conserved peptidyl prolyl isomerase (PPIase) and tetratricopeptide repeat (TPR) domains. The 35 kDa protein was named FKBP35 and expressed in bacteria. Recombinant FKBP35 exhibited potent PPIase and protein folding activities against defined substrates in vitro, suggesting that it is a parasitic chaperone.

Inhibition of respiratory viruses by nasally administered siRNA.

Respiratory syncytial virus (RSV) and parainfluenza virus (PIV) are two respiratory pathogens of paramount medical significance that exert high mortality. At present, there is no reliable vaccine or antiviral drug against either virus. Using an RNA interference (RNAi) approach, we show that individual as well as joint infection by RSV and PIV can be specifically prevented and inhibited by short interfering RNAs (siRNAs), instilled intranasally in the mouse, with or without transfection reagents.