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Volume 6, Issue 7(Suppl) J Gastrointest Dig Syst 2016
ISSN: 2161-069X JGDS, an open access journal
Page 47
Notes:
Gastro Congress 2016
October 24-25, 2016
conferenceseries.com
October 24-25, 2016 Valencia, Spain
9th Euro Global
Gastroenterology Conference
Low-dosed lyophilized plant tissue bearing VLPs of HBV small surface antigen as an oral booster
vaccine against hepatitis B
Tomasz Pniewski
Polish Academy of Sciences, Poland
The continued HBV high prevalence coupled with deficiencies in vaccination programs stimulate research on a new type
of vaccines. Potential orally administered plant-based vaccine is highly attractive regarding efficacy, cost-effectiveness and
availability of mass hepatitis B prevention. Freeze-dried oral formulations facilitate elimination of complex purification steps,
size reduction and better stability during storage, as well as ensure controlled administration regime in minimized medical
facilities. The aim of presented study was to develop a lyophilization protocol facilitating successful processing of lettuce leaf
tissue containing S-HBsAg formed into VLPs (Virus-Like Particles). Several drying profiles and excipients as well as effects
of freezing rate and post-process residual moisture were analyzed. The profile of 20 ºC for 20 hours for primary and 22 ºC for
2 hours for secondary drying as well as sucrose proved the most efficient stabilization of S-HBsAg during freeze-drying. The
process was highly reproducible (86-97%) and provided a product with VLP content up to 200 µg per g DW. Atmosphere
of nitrogen proved to preserve S-HBsAg VLPs for minimum one year at temperatures up to 37 °C. Animal trials confirmed
immunogenicity of processed tissue powder with S-HBsAg, used as an oral booster vaccine. Low-dosed (5-200 ng) preparation
elicited anti-HBs response at level of commercial injection vaccine (around 1000 mIU/ml), together with growth population
of specific B and T lymphocytes and only slightly increased population of Tregs. As a result, a plant-derived semi-product with
good long-term stability and immunogenicity of S-HBsAg was obtained for the definite formulation of oral booster vaccine
against HBV.
Biography
Tomasz Pniewski has completed his PhD from the Institute of Bioorganic Chemistry PAS and Postdoctoral studies from Thomas Jefferson University, USA. He has
worked in the Institute of Plant Genetics PAS since 2003. He is the Head of Biotechnology Department and for two years also worked in the Wielkopolska Centre
of Advanced Technologies as an Expert for organization and equipment. He has published more than 25 papers in reputed journals and has gained 6 patents on
plant-derived vaccines.
Tomasz Pniewski, J Gastrointest Dig Syst 2016, 6:7(Suppl)