Antigenicity and immunogenicity of a novel Plasmodium vivax circumsporozoite derived synthetic vaccine construct

Vaccine. 2014 May 30;32(26):3179-86. doi: 10.1016/j.vaccine.2014.04.007. Epub 2014 Apr 13.


Background: The circumsporozoite (CS) protein is a major malaria sporozoite surface antigen currently being considered as vaccine candidate. Plasmodium vivax CS (PvCS) protein comprises a dimorphic central repeat fragment flanked by conserved regions that contain functional domains involved in parasite invasion of host cells. The protein amino (N-terminal) flank has a cleavage region (region I), essential for proteolytic processing prior to parasite invasion of liver cells.

Methods: We have developed a 131-mer long synthetic polypeptide (LSP) named PvNR1R2 that includes the N-terminal flank and the two natural repeat variant regions known as VK210 and VK247. We studied the natural immune response to this region in human sera from different malaria-endemic areas and its immunogenicity in mice.

Results: PvNR1R2 was more frequently recognized by sera from Papua New Guinea (PNG) (83%) than by samples from Colombia (24%) when tested by ELISA. The polypeptide formulated in Montanide ISA51 adjuvant elicited strong antibody responses in both C3H and CB6F1 mice strains. Antibodies from immunized mice as well as affinity-purified human IgG reacted with native protein by IFA test. Moreover, mouse immune sera induced strong (90%) in vitro inhibition of sporozoite invasion (ISI) of hepatoma cell lines.

Conclusions: These results encourage further studies in non-human primates to confirm the elicitation of sporozoite invasion blocking antibodies, to assess cell mediated immune responses and the protective efficacy of this polypeptide.

Keywords: CS protein; Long synthetic peptide; Malaria; Mice; Plasmodium vivax; Vaccine.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic / pharmacology
  • Amino Acid Sequence
  • Animals
  • Antibodies, Protozoan / immunology
  • Antigens, Protozoan / immunology
  • Cell Line, Tumor
  • Humans
  • Immune Sera / immunology
  • Immunity, Humoral
  • Malaria Vaccines / immunology*
  • Malaria, Vivax / prevention & control*
  • Mice, Inbred C3H
  • Molecular Sequence Data
  • Plasmodium vivax*
  • Protozoan Proteins / immunology*
  • Vaccines, Synthetic / immunology


  • Adjuvants, Immunologic
  • Antibodies, Protozoan
  • Antigens, Protozoan
  • Immune Sera
  • Malaria Vaccines
  • Protozoan Proteins
  • Vaccines, Synthetic
  • circumsporozoite protein, Protozoan