Background: Formosan Subterranean termites, Coptotermes formosanus Shiraki are sustaining
in microbe-rich environment of the nest. The successful foraging and survival of termites
within the nest revealed the adaptation of exceptional host-defence mechanism. There is an inherent
need to unravel termites immune defence mechanism for knowledgeable host-pathogen understanding.
Objective: Comparative protein expression pattern among uninfected and immunized Coptotermes
formosanus Shiraki workers was explored for the first time to gain better understanding of host immune
response to entomopathogenic fungi including Metarhizium anisopliae and Beauveria bassiana.
Method: In this study, we analyzed the immune-related proteomic profile of C. formosanus Shiraki workers
infected with entomopathogenic fungi including M. anisopliae and B. bassiana. After immunization
confirmation by antifungal activity bioassays, homogenates were fractionated by cation exchange chromatography.
Antifungal fractions were further analyzed by two-dimensional gel electrophoresis.
Results: We obtained approximately 846 protein spots from uninfected, 709 from workers infected
with M. anisopliae and 776 from B. bassiana. A total of 170 peptide fragments from 44 spots were
identified to be immune-related by MALDI/TOF/MS. Among them, 20 proteins matched with sequences
of C. formosanus. Identified immune related proteins trigger Toll and JAK-STAT pathways
and were categorized into six types: five of them were pattern recognition receptors, five proteins were
signal modulators, five of them involved in signal transduction, two effectors, four antioxidants and
eleven other immune related proteins.
Conclusion: Identified immune-related proteins indicate the existence of sophisticated immune
mechanism against each pathogen and provide more information for further comprehension on the molecular
mechanism of disease resistance among termites.