BACKGROUND: @entity3964 @entity68040 has been shown to localize on the surface of merozoites and ookinetes. Immunization of @entity19 with recombinant @entity3964 @entity68040 (rPfeno) showed partial protection against @entity311 . Anti-rPfeno antibodies inhibited growth of the parasite in in vitro cultures and blocked ookinete invasion of mosquito midgut epithelium. It is hypothesized that parasite specific moonlighting functions (e.g. host cell invasion) may map on to unique structural elements of Pfeno. Since enolases are highly conserved between the host and the parasite, a parasite-specific epitope of @entity68040 was displayed on novel protein nanoparticles produced by a halophilic Archaeon @entity50929 and tested their ability to protect @entity19 against live challenge. METHODS: By genetic engineering, a @entity3964 - @entity68040 specific peptide sequence (104)EWGWS(108) with protective antigenic potential was inserted into the @entity50929 gas vesicle protein GvpC, a protein localized on the surface of immunogenic gas vesicle nanoparticles (GVNPs). Two groups of @entity19 were immunized with the @entity164 ( @entity164 ) and the insert containing recombinant (Rec) GVNPs respectively. A third group of @entity19 was kept as un-immunized control. Antibody titres were measured against three antigens (i.e. @entity164 -GVNPs, Rec-GVNPs and rPfeno) using ELISA. The protective potential was determined by measuring percentage parasitaemia and survival after challenge with the lethal strain @entity501 17XL. RESULTS: Rec-GVNP-immunized @entity19 showed higher antibody titres against rPfeno and Rec-GVNPs, indicating that the immunized @entity19 had produced antibodies against the parasite @entity68040 -specific insert sequence. Challenging the un-immunized, @entity164 -GVNP and Rec-GVNP-immunized @entity19 with a lethal strain of @entity19 @entity4801 showed significantly lower parasitaemia and longer survival in the Rec-GVNP-immunized group as compared to control groups. The extent of survival advantage in the Rec-GVNP-group showed positive correlation with anti-rPfeno antibody titres while the parasitaemia showed a negative correlation. These results indicate that the parasite @entity68040 peptide insert displayed on @entity50929 GVNPs is a good candidate as a protective antigenic epitope. CONCLUSION: The work reported here showed that the parasite-specific peptide sequence is a protective antigenic epitope. Although antibody response of B-cells to the guest sequence in Rec-GVNPs was mild, significant advantage in the control of parasitaemia and survival was observed. Future efforts are needed to display multiple antigens with protective properties to improve the performance of the GVNP-based approach.

Immunogenicity and protective potential of a XXXX spp. @entity68040 peptide displayed on archaeal gas vesicle nanoparticles.

@entity19 :: ('10090', 'Species') :: ['mice'] @entity164 :: ('MESH:D017827', 'Disease') :: ['WT', 'wild type'] @entity68040 :: ('1447828(Tax:64091)', 'Gene') :: ['enolase'] @entity3964 :: ('5833', 'Species') :: ['Plasmodium falciparum', 'Plasmodium'] @entity501 :: ('5861', 'Species') :: ['Plasmodium yoelii'] @entity311 :: ('MESH:D008288', 'Disease') :: ['malaria'] @entity4801 :: ('MESH:D010272', 'Disease') :: ['malarial parasite'] @entity50929 :: ('64091', 'Species') :: ['Halobacterium sp. NRC-1', 'Halobacterium']
@entity3964 :: (5833,Species) :: ['Plasmodium']
