iTRAQ, the high throughput data analysis of proteins to understand immunologic expression in insect

Abstract

Isobaric tags for relative and absolute quantification of protein expression (iTRAQ®) is a powerful tool which is combined with the accuracy of Mass Spectrometry for protein identification. This tool was approached to detect proteins associated to the innate immune system of Galleria mellonella in response to pathogenesis caused by Fusarium oxysporum. After experimental approaches, iTRAQ data was used to set up computational analysis based on identification and quantification of peptides and proteins against different protein databases by using ProteinPilot™ and Mascot Distiller search engines. iTRAQ battery was able to identify more than 340 peptides corresponding to 39 putative proteins from G. mellonella and close related species. Despite the low level of genomic and proteomic information available for G. mellonella, iTRAQ demonstrated to be reliable strategy to determine changes in protein expression as a consequence of the infection process induced in G. mellonella. Consequently, it was found differential expression in proteins directly involved in innate immune response such as cecropin-D-like peptide, lysozyme, and hemolin, indicating an active response of G. mellonella in early stages of fungal infection. © Springer International Publishing Switzerland 2014.