MalVac: Database of Malarial Vaccine Candidates

Plasmodium falciparum

Plasmodium vivax

Plasmodium yoelii

MalVac is an information resource for the Malarial Vaccine Candidates. It includes curated information for currently known Malarial Vaccine Candidates obtained from careful literature search.

Apart from this MalVac also contains a detailed analysis of proteins from three plasmodium species- P.falciparum, P.vivax and P.yoelii that have a probability of being involved in the adhesion of Plasmodium pathogens to the host cells. This probability is decided on the basis of MAAP Score. The analysis includes various computational approaches to identify the number of paralogs, orthologs, number of transmenbrane helices, signal peptides, beta wraps and topology of the protein . It also provides information about conserved domains present in the protein and blastp results reflecting similarity to host proteins.

MalVac also contains detailed epitope information for all the selected plasmodial proteins. It contains the linear B cell epitope data obtained from ABCpred and Bcepred servers and conformational B cell epitope data from CEP and Discotope servers.
The T cell epitope data obtained from Propred, MHCPred, NetMHC and Bimas servers are also present. The Allergen data regarding the chances of the protein being an allergen obtained from AlgPred, WebAllergen and Allermatch are also incorporated.

MalVac Layout

Malaria Vaccine Candidate Identification

Malarial Vaccine Candidates were identified from the whole proteome sequences of Plasmodium species provided by PlasmoDb 6.3 release(22 December 2009). These predicted vaccine candidates are the adhesins and adhesin-like proteins from Plasmodium species, P. falciparum, P. vivax and P. yoelii. MAAP server was used to screen out these proteins on the basis of their MAAP scores which provides probability of the protein being an adhesin.
Predicting Location of Identified Vaccine Candidates
Location prediction of a vaccine candidate is important for a better understanding of its site of action and functionality. Location prediction was accompolished for all the identified malarial vaccine candidates with the help of two softwares- TargetP1.1 and SignalP 3.0.
Homology Prediction of Vaccine Candidates
Under homology prediction exhaustive search for orthologs, paralogs, conserved domains and similarity to the host proteins was performed.
A good vaccine candidate should not have similarity to the host proteins. Ortholog information for a vaccine candidate gives idea of the probable use of the vaccine in other related species. Paralog information helps track similar proteins in the same species for a vaccine candidate. Conserved domain information for vaccine candidates can be used for further studies regarding improvement of vaccine efficiency.
BLASTCLUST software was used to fetch paralogs. Orthologs were obtained using the OrthoMCL database. Conserved domains were found using NCBI's CDD Search and similarity of malarial vaccine candidates to the human reference proteins were obtained by performing BlastP of the individual vaccine candidates to the human reference proteins.
Motif and Topology Prediction
Cloning and expression of a vaccine candidate with more than one transmembrane spanning region is not possible. Hence the number of these transmembrane spanning regions for each vaccine candidate were found using TMHMM Server v. 2.0.
Betawrap motifs are associated with many known human pathogens. Hence their presence or absence in the vaccine candidates were determined using BetaWrap software.
Immunoinformatics of Vaccine Candidates
The epitope and antigenic region information for the vaccine candidates are likely to play a major role in vaccine development. The informations regarding antigenic regions, T Cell epitopes, Promiscous epitopes, B Cell epitopes were collected using a number of servers and fed into this MalVac Database.
A good vaccine candidate should not have allergic properties. Hence allergen prediction was also done using a number of softwares for each vaccine candidate.
Literature Survey
A list of known malarial vaccine candidates were collected through extensive literature survey. This list of vaccine candidates can obtained by clicking the "Known Vaccines" tab.