Immunogenicity of a malaria parasite antigen displayed by Lactococcus lactis in oral immunisations

R Ramasamy, S Yasawardena, A Zomer, G Venema, J Kok, K Leenhouts*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

90 Citations (Scopus)
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Abstract

A putative protective protein from Plasmodium falciparum merozoites, MSA2, was expressed in two different ways on the cell surface of the Gram-positive food-grade bacterium, Lactococcus lactis. The first display format exploits an LPXTG-type anchoring motif of the lactococcal proteinase PrtP to covalently anchor MSA2 to the genetically modified producer cells. In a second display format, MSA2 was fused to the peptidoglycan-binding domain (Protein Anchor) of the lactococcal cell wall hydrolase AcmA and was non-covalently rebound to the surface of non-genetically modified, non-living high-binder L. lactis cells, termed Gram-positive enhancer matrix (GEM) particles. The L. lactis recombinants carrying covalently bound MSA2 were used to immunise rabbits through nasal and oral routes. The highest levels of IgG antibodies reacting with near-native MSA2 on merozoites was elicited by oral administration. Intestinal antibodies to MSA2 were produced only after oral immunisation. MSA2-specific T-h-cell activation could be demonstrated. Based on these results, the immunogenicity in oral immunisations of MSA2, bound non-covalently to non-genetically modified L. lactis GEM particles, was compared with MSA2 that was bound covalently to genetically modified L. lactis. These two forms elicited similar titres of serum antibodies. The results illustrate the potential of using non-genetically modified L. lactis as a safe vaccine delivery vehicle to elicit systemic antibodies, thereby avoiding the dissemination of recombinant DNA into the environment. (c) 2006 Elsevier Ltd. All rights reserved.

Original languageEnglish
Pages (from-to)3900-3908
Number of pages9
JournalVaccine
Volume24
Issue number18
DOIs
Publication statusPublished - 1-May-2006

Keywords

  • surface display
  • Lactococcus lactis
  • gram-positive enhancer matrix (GEM) particles
  • Plasmodium falciparum
  • merozoite surface antigen 2 (MSA2)
  • mucosal vaccines
  • TOXIN FRAGMENT-C
  • PLASMODIUM-FALCIPARUM
  • VACCINE DELIVERY
  • NUCLEOTIDE-SEQUENCE
  • ESCHERICHIA-COLI
  • IMMUNE-RESPONSE
  • BINDING DOMAIN
  • ACID BACTERIA
  • TETANUS TOXIN
  • PROTEINS

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