A single whey acidic protein domain containing protein (SWD) inhibits bacteria invasion and dissemination in shrimp Marsupenaeus japonicus.

The single whey acidic protein (WAP) domain containing proteins (SWDs) in crustacean belong to type III crustins and have antiprotease activities and/or antimicrobial activities. Their functions in vivo in crustacean immunity need to be clarify. In this study, a new single WAP domain containing protein (SWD) was obtained from Marsupenaeus japonicus, designated as MjSWD. The full-length cDNA of MjSWD was 522 bp.The open reading frame of MjSWD encoded a protein of 79 amino acids, with a 24 amino acid signal peptide and a WAP domain. Tissue distribution analysis revealed that MjSWD transcripts were generally expressed in all the tested tissues, including hemocytes, heart, hepatopancreas, gill, stomach and intestine. The time course expression of MjSWD was analyzed by quantitative real time PCR, and the results exhibited that MjSWD was upregulated after bacteria (Vibrio anguillarum, Staphylococcus aureus) and white spot syndrome virus (WSSV) challenge in gills and stomach of the shrimp. The purified recombinant protein of MjSWD could bind to several Gram-negative and Gram-positive bacteria though binding to microbial polysaccharides (peptidoglycan). MjSWD could inhibit the activity of Subtilisin A and Proteinase K and bacteria-secreted proteases. The results of natural infection with MjSWD incubated bacteria showed that the inhibition of MjSWD against bacterial secreted proteases was contributed to inhibiting bacteria invasion and dissemination in the shrimp. The MjSWD is, thus, involved in the shrimp antibacterial innate immunity.

Jiang HS ，Sun C ，Wang T ，Zhao XF ，Wang JX ... -  《-》

Four crustins involved in antibacterial responses in Marsupenaeus japonicus.

Crustins are a family of cationic, cysteine-rich antimicrobial peptides with a whey acidic protein (WAP) domain in the C-terminal. They have diverse functions in antimicrobial immune responses. Four groups of crustins (crustins I, II, III, and IV) have been identified in crustaceans, but type I crustins have not been reported in penaeid shrimp until now. In this study, we identified four crustins in kuruma shrimp Marsupenaeus japonicus, and named them MjCrus I-2, 3, 4 and 5. These four crustins belong to type I crustins, which contain a signal peptide, cysteine-rich region at the N-terminus, and WAP domain at the C-terminus. Tissue distribution demonstrated that MjCrus I-2, 3 and 5 had high expression levels in hemocytes, gills and stomach. whereas MjCrus I-4 was distributed in all tissues detected. MjCrus I-2 to 5 showed different expression patterns in different tissues after Gram-positive bacterial (Staphylococcus aureus), Gram-negative bacterial (Vibrio anguillarum), and white spot syndrome virus (WSSV) challenge. The expression of MjCrus I-2 to 5 was upregulated by bacterial or WSSV challenge. The three crustins were recombinantly expressed in Escherichia coli, and the purified proteins showed few antimicrobial activities. Three MjCrus Is could bind to different bacteria. MjCrus I-2 and 3 showed different inhibitory abilities to secreted bacterial proteases. MjCrus I-4 could not inhibit bacterial proteases. After knockdown of MjCrus I-3, the bacterial scavenging ability to V. anguillarum was impaired. These results suggested that type I crustins played an important role in the innate immunity of shrimp.

Jiang HS ，Jia WM ，Zhao XF ，Wang JX ... -  《-》

Characterization of a 2-Cys peroxiredoxin IV in Marsupenaeus japonicus (kuruma shrimp) and its role in the anti-viral immunity.

Accumulating evidence suggests that peroxiredoxins (Prx) are key molecules in the pathogenesis of various infectious diseases and are potential therapeutic targets for major diseases such as cancers. In this study, we report a peroxiredoxin IV (Prx IV) in Marsupenaeus japonicus, designated as MjPrx IV, which exhibited peroxidase activity and participated in the anti-white spot syndrome virus (WSSV) immune response. MjPrx IV is a 245-amino acid polypeptide with a predicted 19-amino acid signal peptide, an Ahpc-TSA domain, and a 1-Cys PrxC domain. Phylogenetic analysis revealed that the protein belongs to the Prx IV subfamily. MjPrx IV transcripts were detected in the gills, hepatopancreas, heart, stomach, ovaries, spermary, and intestine tissues, and are upregulated in the gonads, gills and hemocytes of shrimp after WSSV challenge. The mature MjPrx IV peptide was recombinantly expressed in an Escherichia coli system. The protein exhibited peroxidase activity. Furthermore, dsRNA suppression of MjPrx IV increased WSSV replication in shrimp, whereas rMjPrx IV injection into shrimp decreased WSSV replication. These data suggest that MjPrx IV has an important role in shrimp antiviral immunity. To our knowledge, this study is the first to report a shrimp Prx IV that has anti-WSSV activity.

Chen XW ，Kang LH ，Ding D ，Liu Q ，Wang JX ，Kang CJ ... -  《-》

Shrimp single WAP domain (SWD)-containing protein exhibits proteinase inhibitory and antimicrobial activities.

Amparyup P ，Donpudsa S ，Tassanakajon A 《DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY》

A double WAP domain (DWD)-containing protein with proteinase inhibitory activity in Chinese white shrimp, Fenneropenaeus chinensis.

Du ZQ ，Ren Q ，Zhao XF ，Wang JX ... -  《-》