Characterization of a prophenoloxidase from hemocytes of the shrimp Litopenaeus vannamei that is down-regulated by white spot syndrome virus

Immune response and gene expression in shrimp (Litopenaeus vannamei) hemocytes and hepatopancreas against some pathogen-associated molecular patterns

“…In our experiments, laminarin, LPS and poly I:C were able to significantly inhibit proPO transcripts in hemocytes. This is different to previous reports where PO activity was enhanced by components of microorganism cell walls, such as LPS and b-1,3-glucans [50,51], but consistent with previous studies where gene expression of proPO in the lobster Homarus americanus [52] and L. vannamei hemocytes was significantly inhibited by LPS and WSSV [53], which indicated that the regulation of proPO in transcription and translation level may be different. More interesting, in the present study, proPO transcripts showed a dramatic enhancement in hepatopancreas from 6 h to 12 h after LPS injection and moderate increase post-injection with laminarin, suggesting that the transcription of proPO in hepatopancreas could be induced by LPS and laminarin.…”

“…PO activity was significantly inhibited by injection of poly I:C, demonstrating that PO activity could be inhibited by dsRNA. In a recent experiment, similar results were observed that the expression of proPO at transcription level was down-regulated in shrimp challenged with WSSV [53]. These results indicated that the immune response of the proPO system to different types PAMPs was not simultaneous, which mainly based on activation of a serine proteinase from an inactive form to an active form and not on increase in gene expression levels of proPO [54].…”

RNA-Seq analysis reveals genes associated with resistance to Taura syndrome virus (TSV) in the Pacific white shrimp Litopenaeus vannamei

“…Recently, proPO-b was observed that expression was down-regulated in L. vannamei challenged with white spot syndrome virus (WSSV) suggesting that proPO-b is a main transcript form of proPO gene in L. vannamei, and it may play a role in defence against WSSV virus. (Ai et al, 2008). Considering the shrimp prophenoloxidase system (Amparyup et al, 2013), here, we provided more evidence of the critical roles of the proPO system in the shrimp immune responses against major pathogens.…”

Identification of a JAK/STAT pathway receptor domeless from Pacific white shrimp Litopenaeus vannamei

“…vannamei were collected from a shrimp farm in Zhuhai, Guangdong Province, China, which were cultured in a recirculating water tank system filled with the air-pumped sea water (2.5% salinity) at 27 C and fed with a commercial diet at 5% of body weight per day [19]. White spot syndrome virus (WSSV) stock (1 Â 10 6 virions/50 mL) was prepared as previously described [20,21]. Gram-negative Vibrio parahaemolyticus was cultured in Luria broth (LB) medium and finally adjusted to 10 7 CFU ml À1 , as described by Wang et al [22].…”