ISSN:
0749-503X
Keywords:
Hansenula polymorpha
;
expression system
;
S and L surface antigens
;
hepatitis B vaccine
;
multimeric
;
non-homologous integration
;
Life and Medical Sciences
;
Genetics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
An expression system has been developed for the methylotrophic yeast Hansenula polymorpha and used to co-express both the L (preS1-S2-S) and S hepatitis B surface antigens (HBsAg) under the control of strong methanol-inducible promoters derived from the methanol oxidase and from the formate dehydrogenase genes. A unique feature of this H. polymorpha expression system is the possibility of integrating up to 100 copies of an expression cassette via a multimeric integration mechanism. Several multimeric integrants containing various numbers of L and S expression cassettes were constructed to give a spectrum of strains characterized by different L to S ratios. The expression level of S antigen was 5-8% of the total soluble cell protein. Analysis by sucrose and CsCl density gradient centrifugation and by particle-specific immunoassays demonstrated that the synthesized HBsAg spontaneously assembled into composite subviral particles containing both S and L proteins. Only a minor portion of the L protein was found to be glycosylated. These H. polymorpha-derived composite particles can be used for the production of a hepatitis B virus vaccine with the potential for improved immunogenicity due to the presence of a wider spectrum of epitopes and negligible glycosylation.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/yea.320070502
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