Efficacy of heterologous and homologous heat shock protein 70s as protective agents to Artemia franciscana challenged with Vibrio campbellii.
The Hsp70 class of heat shock proteins (Hsps) has been implicated at multiple points in the immune response of both vertebrates and invertebrates. This class of chaperones is highly conserved in both sequence and structure, from prokaryotes to higher eukaryotes. In view of their high degree of homology, it was assumed that these Hsp70 proteins derived either from the prokaryotes or eukaryotes would have similar functions, especially in relation to their protective ability in a challenge assay. To verify this, we compared two evolutionary diverse Hsp70s, Artemia Hsp70 and Escherichia coli Hsp70 equivalent DnaK (each overproduced in E.coli), for their ability to protect Artemia against Vibrio challenge. Results showed that Artemia fed with E. coli producing Artemia Hsp70 or DnaK proteins, as assessed by immune-probing in western blots, survived better in a Vibrio challenge assay. The observed effects could be due to enhancement of the Artemia immune system as phenoloxidase activity was found to be increased by these proteins. These two Hsp70 proteins exhibit a high degree of homology, particularly in the peptide-binding domain (the putative innate immunity-activating portion) with 59.6% identity, indicating that the observed protective capacity of homologous or heterologous Hsp70 proteins might reside within this peptide-binding domain.
Baruah
Kartik
K
Laboratory of Aquaculture and Artemia Reference Center, Faculty of Bioscience Engineering, Ghent University, Rozier 44, 9000 Ghent, Belgium.
Ranjan
Jayant
J
Sorgeloos
Patrick
P
Bossier
Peter
P
D000595:Amino Acid Sequence; D000704:Analysis of Variance; D000818:Animals; D001156:Artemia / Q000276:immunology* / Q000382:microbiology; D015153:Blotting, Western; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D004926:Escherichia coli; D029968:Escherichia coli Proteins / Q000276:immunology; D018840:HSP70 Heat-Shock Proteins / Q000276:immunology*; D014442:Monophenol Monooxygenase / Q000378:metabolism; D016415:Sequence Alignment; D017385:Sequence Homology; D014733:Vibrio / Q000276:immunology*
D017931:DNA Primers; D029968:Escherichia coli Proteins; D018840:HSP70 Heat-Shock Proteins; D014442:Monophenol Monooxygenase; C063842:dnaK protein, E coli