Title: Vaccination of chickens against avian influenza using yeast cell surface display of H5 hemagglutinin Authors
Submitted to: International Symposium on Avian Influenza
Publication Type: Abstract Only
Publication Acceptance Date: January 20, 2009
Publication Date: April 5, 2009
Citation: Wasilenko, J.L., Pantin Jackwood, M.J., Sarmento, L., Suarez, D.L., Swayne, D.E., Spatz, S.J. 2009. Vaccination of chickens against avian influenza using yeast cell surface display of H5 hemagglutinin [abstract]. 7th International Symposium on Avian Influenza, April 5-9, 2009, Athens, Georgia, p. 60. Technical Abstract: Traditional vaccination methods for avian influenza (AI) require costly and time-consuming injection of individual birds, often multiple times, in order to produce protection. These vaccines are difficult to change quickly in response to new threats as manufacturing takes time. Yeast are an ideal organism to express viral proteins because yeast glycosylate proteins more similarly to mammals than bacteria, expression of proteins in yeast is fast, inexpensive, and yeast can provide high quality nutrition for the birds. Yeast are generally regarded as safe organisms (GRAS) and would therefore allow long-term feeding of yeast expressing AI recombinant proteins in order to maintain immunity over time with no ill effects. In addition to the convenience of oral vaccination, yeast have been shown to have natural adjuvant activity making the proteins they express more immunogenic when administered with the yeast cell wall components. Display of the foreign proteins on the cell wall of the yeast, using a glycosylphosphatidylinositol-anchored protein, further simplifies the expression process by not requiring lysis of the cells or purification of the proteins prior to administration. In this study we expressed the hemagglutinin (HA) protein from A/Egret/HK/757.2/02 (H5N1) virus on the surface of the yeast strain Pichia pastoris, anchored using the C-terminal end of the Saccharomyces cerevisiae alpha-agglutinin protein. Display of HA on the yeast surface was demonstrated by immunofluorescence and hemagglutinating activity. In order to show protection against high pathogenicity avian influenza (HPAI), yeast displaying HA were used to vaccinate chickens orally and intravenously followed by a HPAI virus challenge.