Killer Peptide May Offer New Therapy Against Influenza A Virus

In a new study researchers identified what appears to be the first antibody-derived peptide that inhibits the activities of harmful microbes such as influenza A virus and HIV-1. They report their findings in the December 2008 issue of the journal Antimicrobial Agents and Chemotherapy.

Influenza A viruses continue to result in hospitalization and death, especially among infants, the elderly, and immunocompromised patients worlwide. The emergence of avian influenza A virus and its ability to transfer to humans has brought about new concerns of a pandemic outbreak. Although vaccination can be an effective strategy for preventing influenza, researchers are also placing great emphasis on the discovery and development of antiviral drugs.

A killer decapeptide (KP) represents the internal image of a yeast (Pichia anomala) killer toxin that has an antimicrobial effect against pathogenic organisms. In the study activities of a KP against influenza A virus were evaluated and results showed that KP demonstrated a significant inhibitory effect on the replication of two strains of influenza A virus. Further, mice infected with influenza virus A were inoculated with KP once a day for 10 days resulting in an improved survival rate of 40 percent and significantly decreased viral levels in their lungs.

"Overall, KP appears to be the first anti-idiotypic antibody-derived peptide that displays inhibitory activity and that has a potential therapeutic effect against pathogenic microorganisms, HIV-1, and influenza A virus by different mechanisms of action," say the researchers.

Reference: G. Conti, W. Magliani, S. Conti, L. Nencioni, R. Sgarbanti, A.T. Palamara, L. Polonelli. 2008. Therapeutic activity of an anti-idiotypic antibody-derived killer peptide against influenza A virus experimental infection. Antimicrobial Agents and Chemotherapy, 52. 12: 4331-4337.