Functional Diversity of the Excretory/Secretory Proteins of Nematode Parasites.

Abstract

Parasites release a wide array of protein as excretory and secretory products (ESPs). Irrespective of their mode of propagation, ESPs are found to be secreted or excreted by both naturally occurring and laboratory-cultivated parasites. Mass spectrometry-based approaches have been extensively used to identify and characterize the ESP constituents. ESPs are involved in various cellular activities such as immune modulation, proteolysis, inhibition of proteases and protection of cells against oxidants. Specifically, their role in host immune evasion by down-regulation of pro-inflammatory cytokines and up-regulation of anti-inflammatory cytokines attracts scientific attention. A thorough investigation of functional diversity of ESPs may be helpful in planning control strategies against many parasites. This review focuses on diversity of ES proteins, various approaches to identify them and discusses about the biochemical and functional aspects of such proteins. The diverse array of proteins secreted or excreted (a, GST-1, acetylcholinesterase, GAPDH) by the parasites are also described emphasizing their role in cellular physiology. Finally, it concludes by citing some of these proteins as potential therapeutic agents against helminth challenge.