The genome of the protozoan parasite Cystoisospora suis and a reverse vaccinology approach to identify vaccine candidates.
Vaccine development targeting protozoan parasites remains challenging, partly due to the complex interactions between these eukaryotes and the host immune system. Reverse vaccinology is a promising approach for direct screening of genome sequence assemblies for new vaccine candidate proteins. Here, we applied this paradigm to Cystoisospora suis, an apicomplexan parasite that causes enteritis and diarrhea in suckling piglets and economic losses in pig production worldwide. Using Next Generation Sequencing we produced an ∼84Mb sequence assembly for the C. suis genome, making it the first available reference for the genus Cystoisospora. Then, we derived a manually curated annotation of more than 11,000 protein-coding genes and applied the tool Vacceed to identify 1,168 vaccine candidates by screening the predicted C. suis proteome. To refine the set of candidates, we looked at proteins that are highly expressed in merozoites and specific to apicomplexans. The stringent set of candidates included 220 proteins, among which were 152 proteins with unknown function, 17 surface antigens of the SAG and SRS gene families, 12 proteins of the apicomplexan-specific secretory organelles including AMA1, MIC6, MIC13, ROP6, ROP12, ROP27, ROP32 and three proteins related to cell adhesion. Finally, we demonstrated in vitro the immunogenic potential of a C. suis-specific 42kDa transmembrane protein, which might constitute an attractive candidate for further testing.
Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine, Veterinärplatz 1, A-1210 Vienna, Austria. Electronic address: nicola.palmieri@vetmeduni.ac.at.
Nicola
N
Palmieri
Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine, Veterinärplatz 1, A-1210 Vienna, Austria.
Aruna
A
Shrestha
Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine, Veterinärplatz 1, A-1210 Vienna, Austria.
Bärbel
B
Ruttkowski
Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine, Veterinärplatz 1, A-1210 Vienna, Austria.
Tomas
T
Beck
Institute of Animal Breeding and Genetics, Department of Biomedical Sciences, University of Veterinary Medicine, Veterinärplatz 1, A-1210 Vienna, Austria.
Claus
C
Vogl
Department of Pathology and Pathogen Biology, Royal Veterinary College, Hatfield, Hawkshead Lane, North Mymms AL9 7TA, UK.
Fiona
F
Tomley
Department of Pathology and Pathogen Biology, Royal Veterinary College, Hatfield, Hawkshead Lane, North Mymms AL9 7TA, UK.
Damer P
DP
Blake
Institute of Parasitology, Department of Pathobiology, University of Veterinary Medicine, Veterinärplatz 1, A-1210 Vienna, Austria.
Anja
A
Joachim
D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology*; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D018503:Genome, Protozoan; D059014:High-Throughput Nucleotide Sequencing; D016052:Protozoan Vaccines / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D021745:Sarcocystidae / Q000235:genetics* / Q000276:immunology*; D017422:Sequence Analysis, DNA; D013552:Swine
D000953:Antigens, Protozoan; D016054:DNA, Protozoan; D016052:Protozoan Vaccines
Antigens; Apicomplexa; Coccidia; Illumina sequencing; Transcriptome; Vacceed