title: Immunomodulatory effects of hyperthermia on resisting WSSV infection in Procambarus clarkii.
abstract: White spot disease remains a constant threat to aquaculture worldwide. Hyperthermia has been shown to reduce mortality in white spot syndrome virus (WSSV)-infected shrimps, but the mechanism still remains unclear. In this study, we sought to identify host immune factors that contribute to inhibition of WSSV infection during hyperthermia. In WSSV-infected red swamp crayfish Procambarus clarkii (Girard) cultured at 24 ± 1 °C, transcriptional levels of the heat shock protein 70 (Hsp70) gene showed a modest, 2.2-fold increase in haemocytes following 48 h post-infection (hpi). In contrast, in WSSV-infected crayfish cultured at 32 ± 1 °C, Hsp70 gene expression showed a rapid, 19.5-fold induction by 4 hpi. This suggests that Hsp70 plays a positive regulatory role in resistance to WSSV infection during hyperthermia. Furthermore, total haemocyte counts (THC) and phenoloxidase (PO) activity were both significantly increased in WSSV-infected crayfish cultured at 32 ± 1 °C by 48 hpi. Both may be critical for crayfish survival in the late stages of WSSV infection. Collectively, the up-regulation of host protein Hsp70 expression and increase in THC and PO activity suggest that hyperthermia has immunomodulatory effect that enhanced the resistance of P. clarkii to WSSV infection.
authors.affiliation: Feed Science Institute, College of Animal Science, Zhejiang University, Hangzhou, China.
authors.forename: X
authors.initials: X
authors.lastname: Wu
authors.forename: H
authors.initials: H
authors.lastname: Xiong
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Du
mesh_terms: D000818:Animals; D003400:Astacoidea / Q000276:immunology* / Q000821:virology*; D005786:Gene Expression Regulation; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D006434:Hemocytes / Q000166:cytology / Q000201:enzymology / Q000276:immunology; D006358:Hot Temperature; D014442:Monophenol Monooxygenase / Q000378:metabolism; D046848:White spot syndrome virus 1 / Q000502:physiology*
chemical_list: D018840:HSP70 Heat-Shock Proteins; D014442:Monophenol Monooxygenase
keywords: Hsp70; Procambarus clarkii; hyperthermia; immune response; white spot syndrome virus