Protein expression profile of Gasterophilus intestinalis larvae causing horse gastric myiasis and characterization of horse immune reaction

Background: Little information is available on the immunological
aspect of parasitic Gasterophilus intestinalis (Diptera, Oestridae)
larvae causing horse gastric myiasis. The objectives of this
research were to analyze the protein content of larval crude
extracts of the migrating second and third larvae (L2 and L3) of G.
intestinalis in order to characterize the immune response of
horses. Results: The proteomic profile of L2 and L3, investigated
by using one and two dimensional approaches, revealed a migration
pattern specific to each larval stage. Furthermore, Western blots
were performed with horse sera and with sera of Balb/c mice
immunised with the larval crude extracts of L2 or L3, revealing a
different immune reaction in naturally infected horses vs.
artificially induced immune reaction in mice. The comparisons of
the immunoblot profiles demonstrate that the stage L2 is more
immunogenic than the stage L3 most likely as an effect of the
highest enzymatic production of L2 while migrating through the host
tissues. Fifteen proteins were identified by mass spectrometry.
Conclusion: This work provides further information into the
understanding of the interaction between G. intestinalis and their
host and by contributing a novel scheme of the proteomic profile of
the main larval stages.