title: Effects of immunostimulants targeting Ran GTPase on phagocytosis against virus infection in shrimp.
abstract: The global shrimp aquaculture has been consistently beset by diseases that cause severe losses in production. To fight various harmful pathogens, the enhanced shrimp immunity by immunostimulants would play key roles against the invading pathogens. In aquaculture, however, the target proteins/genes which can be used for the screening of immunostimulants are very limited. Based on our previous study, in the present study, the shrimp Ran protein, which was required in shrimp antiviral phagocytosis, was used as the target protein to screen for immunostimulants. The GTPase activity assays showed that the IL-4 and lysophosphatidylcholine molecules could enhance the activity of Ran protein, suggesting that the two molecules might function in phagocytosis. When the IL-4 and lysophosphatidylcholine were respectively injected into shrimp, the results indicated that the two molecules enhanced the hemocytic phagocytosis against white spot syndrome virus (WSSV), suggesting that they improved the activity of phagocytosis through the activation of the Ran protein. It was evidenced that the enhancement of phagocytosis activity effectively inhibited the WSSV infection in shrimp, which further led to the decrease of mortalities of WSSV-infected shrimp. Therefore, our study presented a novel strategy for the screening of immunostimulants by using the key proteins in immune responses of aquatic organisms as the target proteins, which would be very helpful for the development of efficient approaches to prevent the aquatic organisms from pathogen infections.
authors.affiliation: Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education, and College of Life Sciences, Zhejiang University, No. 388 Yuhangtang Road, Hangzhou 310058, People's Republic of China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Zhao
authors.forename: Chunxia
authors.initials: C
authors.lastname: Jiang
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000704:Analysis of Variance; D000818:Animals; D017931:DNA Primers / Q000235:genetics; D004926:Escherichia coli; D005434:Flow Cytometry; D005453:Fluorescence; D033561:Penaeidae / Q000276:immunology* / Q000821:virology*; D010587:Phagocytosis / Q000187:drug effects* / Q000502:physiology; D060888:Real-Time Polymerase Chain Reaction; D046848:White spot syndrome virus 1 / Q000276:immunology*; D020931:ran GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D000276:Adjuvants, Immunologic; D017931:DNA Primers; D020931:ran GTP-Binding Protein