varDB: A database of antigenic variant sequences-Current status and future prospects

Antigenic variation is a common mechanism employed by many pathogenic organisms to avoid recognition of surface proteins by the host immune system. The malaria parasite, Plasmodium falciparum, among many others, exploits this mechanism and manages to survive in an otherwise hostile environment. Although similarities in the mechanisms used among different species to generate antigenic variation are broadly recognized, there is a lack of studies using cross-species data. The varDB project (http://www.vardb.org) was created to study antigenic variation at a range of different levels, both within and among species. The project aims to serve as a resource to increase our understanding of antigenic variation by providing a framework for comparative studies. In this review we describe the varDB project, its construction, and the overall organization of information with the intent of increasing the utility of varDB to the research community. The current version of varDB supports 27 species involved in 19 different diseases affecting humans as well as other species. These data include 42 gene families that are represented by over 67,000 sequences. The varDB project is still in its infancy but is expected to continue to grow with the addition of new organisms and gene families as well as input from the general research community.