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ABSTRACT: Serpin or serine proteinase inhibitor is a family of protease inhibitors that are involved in controlling the proteolytic cascade in various biological processes. In shrimp, several serpins have been identified but only a few have been characterized. Herein, the PmSERPIN3 gene identified from Penaeus monodon EST database was studied. By using the 5'-and 3'-Rapid Amplification cDNA End (RACE) techniques, the full-length of PmSERPIN3 cDNA was obtained. The cDNA contained an open reading frame of 1,233 bp encoding for 410 amino acid residues protein. Genome sequence analysis revealed that the PmSERPIN3 was an intronless gene. RT-PCR analysis revealed that it was constitutively expressed in all developmental stages, all shrimp tissues tested, and upon pathogen infections. The recombinant mature PmSERPIN3 protein (rPmSERPIN3) produced in Escherichia coli exhibited inhibitory activity against subtilisin. The rPmSERPIN3 also inhibited the shrimp prophenoloxidase system activation in vitro. Injecting the rPmSERPIN3 along with Vibrio harveyi into the shrimp decreased the clearance rate of bacteria in the hemolymph. Potentially, the PmSERPIN3 functions as a regulator of the proPO activating system.
Developmental and comparative immunology 05/2013; · 3.29 Impact Factor
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ABSTRACT: Several immune-related molecules in penaeid shrimps have been discovered, most of these via the analysis of expressed sequence tag libraries, microarray studies and proteomic approaches. These immune molecules include antimicrobial peptides, serine proteinases and inhibitors, phenoloxidases, oxidative enzymes, clottable protein, pattern recognition proteins, lectins, Toll receptors, and other humoral factors that might participate in the innate immune system of shrimps. These molecules have mainly been found in the hemolymph and hemocytes, which are the main sites where immune reactions take place, while some are found in other immune organ/tissues, such as the lymphoid organs, gills and intestines. Although the participation of some of these immune molecules in the shrimp innate immune defense against invading pathogens has been demonstrated, the functions of many molecules remain unclear. This review summarizes the current status of our knowledge concerning the discovery and functional characterization of the immune molecules in penaeid shrimps.
Fish & Shellfish Immunology 10/2012; · 3.32 Impact Factor
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ABSTRACT: The global shrimp industry still faces various serious disease-related problems that are mainly caused by pathogenic bacteria and viruses. Understanding the host defense mechanisms is likely to be beneficial in designing and implementing effective strategies to solve the current and future pathogen-related problems. Melanization, which is performed by phenoloxidase (PO) and controlled by the prophenoloxidase (proPO) activation cascade, plays an important role in the invertebrate immune system in allowing a rapid response to pathogen infection. The activation of the proPO system, by the specific recognition of microorganisms by pattern-recognition proteins (PRPs), triggers a serine proteinase cascade, eventually leading to the cleavage of the inactive proPO to the active PO that functions to produce the melanin and toxic reactive intermediates against invading pathogens. This review highlights the recent discoveries of the critical roles of the proPO system in the shrimp immune responses against major pathogens, and emphasizes the functional characterizations of four major groups of genes and proteins in the proPO cascade in penaeid shrimp, that is the PRPs, serine proteinases, proPO and inhibitors.
Fish & Shellfish Immunology 08/2012; · 3.32 Impact Factor
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ABSTRACT: An antimicrobial protein crustinPm1 from Penaeus monodon is a WAP domain-containing protein with an antimicrobial activity against Gram-positive bacteria but does not have antiproteinase activity. The lack of antiproteinase is speculated to be due to the P(1)' Met and/or the length of spacing between the conserved Cys2 and Cys3 while the antimicrobial activity may be due to the N-terminal Gly-rich and Cys-rich regions. In this study, the P(1)-P(1)' and the N-terminal Gly-rich and Cys-rich regions of crustinPm1 were mutated by amino acid substitution or deletion. Substitutions of P(1)-P(1)' from Pro-Pro to Leu-Leu, Leu-His, Leu-Met, Leu-Ala and P(1)' from Pro to Met did not make the protein inhibitory to subtilisin, trypsin, chymotrypsin and elastase. The mutations at P(1)-P(1)' positions in rcrustinPm1 had no effect on antibacterial activity. The WAP domain mutant with both Gly-rich and Cys-rich regions deleted did not exhibit antibacterial activity against Staphylococcus aureus while the deletion mutants of either Gly-rich or Cys-rich regions exhibited lower antibacterial activity than the wild type crustinPm1. Therefore, both Gly-rich and Cys-rich regions attached to a WAP domain are essential for efficient antibacterial activity of crustinPm1.
Fish & Shellfish Immunology 08/2012; 33(4):977-83. · 3.32 Impact Factor
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ABSTRACT: Two isoforms of plasmolipin were initially identified from the black tiger shrimp (Penaeus monodon) EST database and completed using 5' RACE to reveal complete cDNAs of 558bp (PmPLP1) and 537bp (PmPLP2) with 87% nucleotide sequence identity. The deduced amino acid sequences contained four-transmembrane domains and showed the highest amino acid identity (49% and 51%, respectively) to the honey bee (Apis mellifera) chemokine-like factor (CKLF), with a very similar hydrophobic pattern to other plasmolipins. Transcripts of PmPLP1 and PmPLP2 were observed in all tested shrimp tissues with the highest expression levels in the gill and epipodite for PmPLP1 and in the hemocytes and antennal gland for PmPLP2. PmPLP1 transcript levels were significantly upregulated in hemocytes at 24 and 72h post infection (hpi) with yellow head virus (YHV) (7.4- and 14.7- fold, respectively), but only after 72hpi by white spot syndrome virus (WSSV). In contrast, PmPLP2 was only slightly (but statistically significant) up-regulated with YHV and WSSV. Thus, PmPLPs have the potential to be a part of viral infection mechanism or defense response. This is the first characterization of a plasmolipin gene in crustaceans.
Developmental and comparative immunology 07/2012; 38(2):389-94. · 3.29 Impact Factor
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ABSTRACT: The ubiquitous SERPINs or serine proteinase inhibitors are essential for controlling proteinases in several biological processes in various organisms. A PmSERPIN8, one of eight SERPINs identified from the Penaeus monodon database, is studied and reported herein. The open reading frame of PmSERPIN8 gene derived from a genomic gene contains 5 exons of 320, 139, 244, 239 and 312 bp separated by 4 introns of 447, 657, 326 and 479 bp. The PmSERPIN8 gene is highly expressed at nauplius stage and gradually subsided as the shrimp grow through zoea, mysis and postlarva stages. At sub-adult stage, the PmSERPIN8 gene is expressed mainly in the hemocyte and epipodite. The expression in response to Vibrio harveyi and YHV injection is up-regulated, respectively, at 24 and 48 h post-injection. The number of PmSERPIN8-producing hemocytes, however, is observed highest at 48 h post V. harveyi injection. All three hemocyte cell types: hyaline, semigranular and granular hemocytes are able to produce PmSERPIN8. The recombinant mature PmSERPIN8 (rPmSERPIN8) with a predicted size of 45.5 kDa was over-produced in an Escherichia coli system, solubilized from the inclusion bodies, purified and tested for its activity. We have found that the rPmSERPIN8 is able to inhibit the growth of Gram-positive bacterium, Bacillus subtilis, but not Gram-negative bacterium, V. harveyi 639, and inhibit the shrimp prophenoloxidase system. The PmSERPIN8 is, thus, involved in the shrimp innate immunity.
Fish & Shellfish Immunology 05/2012; 33(2):332-41. · 3.32 Impact Factor
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ABSTRACT: An important characteristic of the innate immune systems of crayfish and other arthropods is the activation of a serine proteinase cascade in the hemolymph, which results in the activation of prophenoloxidase and subsequently leading to the formation of toxic quinones and melanin. Although no true complement homologues have been detected in crayfish or crustaceans, several proteins with similarities to vertebrate pattern recognition receptors (PRRs), which are involved in the lectin pathway of complement activation in vertebrates, are present. One is a C-type lectin, a mannose-binding lectin (Pl-MBL), which is secreted from granular hemocytes. Here we report that Pl-MBL has LPS-binding capacity and is dependent upon high Ca(2+) for its solubility and Pl-MBL interferes with proPO activation in vitro when HLS is prepared at high Ca(2+). The proPO-activating system is efficiently activated by microbial polysaccharides and it has to be neatly regulated to avoid activation in places where it is inappropriate and the active enzyme PO should be prevented from spreading throughout the body of the animal. This may be particularly important during molting when proPO is involved in hardening of a new cuticle and the animal is vulnerable to microbes. The presence of high amount of Pl-MBL in the granular hemocytes may play a role in this process. Since a hemocyte lysate supernatant (HLS) prepared at 100mM Ca(2+) could become activated when the concentration of LPS was increased up to 3mg/ml, this may indicate that Pl-MBL acts as a scavenger for LPS to prevent spreading of LPS in the hemolymph to avoid further activation of the proPO-system.
Immunobiology 02/2012; · 3.20 Impact Factor
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ABSTRACT: The protein expression profiles of the lymphoid organ, taken from mock and systemic Vibrio harveyi-infected Penaeus monodon at 6 and 48 h post infection, were revealed. The considerable changes in the expression level of several proteins were observed between the mock and V. harveyi-infected shrimps. From 30 analyzed protein spots with 27 differentially expressed, 21 were known proteins with the most common of these being cytoskeleton proteins (33%) which were all down-regulated upon systemic bacterial infection. Other six proteins including four proteins that are involved in the shrimp immunity (alpha-2-macroglobulin, transglutaminase, heat shock protein 1 and hemocyanin subunit Y), and two proteins that are involved in metabolism (triosephosphate isomerase) and cell signaling (14-3-3 like protein), displayed significantly decreased expression levels. There was, however, an increase in the expression level of the ATP synthase beta subunit, a protein involved in energy balance. Transcription levels of ATP synthase beta subunit and 14-3-3 like protein were up- and down-regulated, respectively, in accord with the observed protein expression levels, but the alpha-2-macroglobulin transcript levels were significantly increased in contrast to the decreased protein expression levels. Interestingly, partial gene silencing of ATP synthase beta subunit revealed a high cumulative mortality of the knockdown shrimps (73.3%) and a dramatic reduction of the total hemocyte numbers in the survival shrimps. These altered proteins are likely to play essential roles in shrimp defense against the pathogenic bacterium V. harveyi.
Molecular Biology Reports 02/2012; 39(5):6367-77. · 2.93 Impact Factor
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ABSTRACT: The prophenoloxidase (proPO) system is activated upon recognition of pathogens by pattern recognition proteins (PRPs), including a lipopolysaccharide- and β-1,3-glucan-binding protein (LGBP). However, shrimp LGBPs that are involved in the proPO system have yet to be clarified. Here, we focus on characterizing the role of a Penaeus monodon LGBP (PmLGBP) in the proPO system. We found that PmLGBP transcripts are expressed primarily in the hemocytes and are increased at 24 h after pathogenic bacterium Vibrio harveyi challenge. The binding studies carried out using ELISA indicated that recombinant (r)PmLGBP binds to β-1,3-glucan and LPS with a dissociation constant of 6.86 × 10(-7) M and 3.55 × 10(-7) M, respectively. Furthermore, we found that rPmLGBP could enhance the phenoloxidase (PO) activity of hemocyte suspensions in the presence of LPS or β-1,3-glucan. Using dsRNA interference-mediated gene silencing assay, we further demonstrated that knockdown of PmLGBP in shrimp in vivo significantly decreased the PmLGBP transcript level but had no effect on the expression of the other immune genes tested, including shrimp antimicrobial peptides (AMPs). However, suppression of proPO expression down-regulated PmLGBP, proPO-activating enzyme (PmPPAE2), and AMPs (penaeidin and crustin). Such PmLGBP down-regulated shrimp showed significantly decreased total PO activity. We conclude that PmLGBP functions as a pattern recognition protein for LPS and β-1,3-glucan in the shrimp proPO activating system.
Journal of Biological Chemistry 01/2012; 287(13):10060-9. · 4.77 Impact Factor
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ABSTRACT: Proteomic analysis of the hemocytic proteins of Penaeus monodon (Pm) has previously shown that alpha-2-macroglobulin (A2M) was among the proteins that showed substantially altered expression levels upon Vibrio harveyi infection. Therefore, in this study its potentially important role in the response of shrimp to bacterial infection was further characterized. The yeast two-hybrid system revealed that the receptor binding domain of PmA2M interacted with the carboxyl-terminus of one or both of the transglutaminase type II isoforms, which are key enzymes involved in the shrimp clotting system. In accord with this, PmA2M was found to be localized on the extracellular blood clots and to colocalize with clottable proteins. RNA interference (RNAi)-mediated knockdown of A2M transcript levels reduced the PmA2M transcript levels (∼94%) and significantly reduced the bacterial seizing ability of the clotting system, resulting in an up to 3.3-fold higher number of V. harveyi that systemically disseminated into the circulatory system at 5 min post-infection before subsequent clearance by the immune system. Furthermore, an appearance of PmA2M depleted clots in the presence of V. harveyi strikingly demonstrated fibrinolysis zones surrounding the bacteria. This study provides the first evidence of the vital role of PmA2M in enhancing bacterial sequestration by protecting blood clots against fibrinolysis.
PLoS ONE 01/2012; 7(10):e47384. · 4.09 Impact Factor
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ABSTRACT: Anti-lipopolysaccharide factors (ALFs) are antimicrobial peptides previously identified in various crustaceans. Out of five isoforms identified in Penaeus monodon, ALFPm3 is the best characterized, exhibits antibacterial and antifungal activities and can protect the shrimp from viral infections. Herein, the most recent identified ALFPm, called ALFPm6, is characterized for its potential role in the shrimp's immunity. RNA interference-mediated gene silencing was used to study the function of ALFPm6 in comparison to ALFPm3. Knockdown of ALFPm3 gene led to rapid death with a cumulative shrimp mortality of 86% within 7 days, accompanied by a 12- and 50-fold higher bacterial count after 2 days in the haemolymph and hepatopancreas, respectively, compared to the control shrimp injected with GFP dsRNA. In contrast, gene silencing of ALFPm6 alone had no effect on the shrimp mortality, but led to a significant increase in the cumulative mortality and a faster mortality rate following Vibrio harveyi and white spot syndrome virus (WSSV) infections, respectively. These results support the roles of ALFPm6 and ALFPm3 in the protection of shrimp against microbial infections.
Fish & Shellfish Immunology 01/2012; 32(1):26-34. · 3.32 Impact Factor
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ABSTRACT: A Kazal type serine proteinase SPIPm2 is abundantly expressed in the hemocytes and shown to be involved in innate immune response against white spot syndrome virus (WSSV) in Penaeus monodon. The SPIPm2 is expressed and stored in the granules in the cytoplasm of semigranular and granular but not the hyaline hemocytes. Upon WSSV challenge and progression of infection, the SPIPm2 was secreted readily from the semigranular and granular hemocytes. The more they secreted the SPIPm2, the less they were distinguishable from the hyaline cells. The WSSV-infected cells were either semigranular or granular hemocytes or both and depleted of SPIPm2. The rSPIPm2 was able to temporarily and dose-dependently neutralize the WSSV and protect the hemocytes from viral infection judging from the substantially less expression of WSSV late gene VP28. The antiviral activity was very likely due to the binding of SPIPm2 to the components of viral particle and hemocyte cell membrane.
Fish & Shellfish Immunology 12/2011; 31(6):1179-85. · 3.32 Impact Factor
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ABSTRACT: Several isoforms of crustin have been identified in the black tiger shrimp Penaeus monodon. These cationic cysteine-rich antimicrobial peptides contain a single whey acidic protein (WAP) domain at the C-terminus and exhibit antimicrobial activity against both Gram-positive and Gram-negative bacteria. In this paper, we investigate the binding properties and antimicrobial actions of crustinPm1 and crustinPm7, the two most abundant crustin isoforms found in the haemocyte of P. monodon. Previously, crustinPm1 showed strong inhibition against Gram-positive bacteria, whilst crustinPm7 acted against both Gram-positive and Gram-negative bacteria. A binding study showed that both crustins can bind to Gram-positive and Gram-negative bacterial cells. Enzyme-linked immunosorbent (ELISA) assay suggested that crustins bind to the cell wall components, lipoteichoic acid (LTA) and lipopolysaccharide (LPS) with positive cooperativity of Hill slope (H)>2. This indicates that at least two molecules of crustins interact with one LTA or LPS molecule. In addition, both crustins can induce bacterial agglutination and cause inner membrane permeabilization in Escherichia coli. Scanning Electron Microscopy (SEM) revealed the remarkable change on the cell surface of Staphylococcus aureus, Vibrio harveyi and E. coli after the bacteria were treated with the recombinant crustinPm7. Meanwhile, crustinPm1 can cause a visible change on the cell surface of S. aureus and E. coli only. This is in agreement with the fact that crustinPm1 has shown no antimicrobial activity against V. harveyi. It is likely that the antimicrobial activity of crustins mainly relies on their ability to agglutinate bacterial cells and to disrupt the physiochemical properties of bacterial surface.
Developmental and comparative immunology 08/2011; 36(1):208-15. · 3.29 Impact Factor
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ABSTRACT: Two isoforms of 14-3-3 protein, namely 14-3-3A and 14-3-3B, from the shrimp Penaeus monodon were investigated for their potential role in adaptation to salinity stress. Transcripts of 14-3-3A were found in various shrimp tissues whilst expression of 14-3-3B transcripts was more specific being observed in the osmoregulatory tissues, that is in the gills and epipodites. In shrimp gills, the 14-3-3A transcript levels slightly changed after transfer of the shrimp from 3 to 25 or to 40 ppt. In contrast, significant change in the mRNA levels in response to salinity stress was detected for 14-3-3B, where a significant decrease of 14-3-3B transcript was observed in gills of shrimp transferred from hypo-osmotic (3 ppt) salinity to iso-osmotic or hyper-osmotic (25 and 40ppt, respectively) salinity. On the other hand, shrimp transferred from 40 ppt to 3 ppt showed a strong induction of 14-3-3B mRNA expression in the gills. These transcript expression analyses suggest that 14-3-3B is likely to be involved in the hyper-osmotic regulation in P. monodon. In addition, 14-3-3B appeared to regulate ATPase function since suppression of the gene by RNA interference resulted in a significant decrease in the total ATPase activity.
Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology 08/2011; 159(4):244-51. · 1.61 Impact Factor
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ABSTRACT: Penaeid shrimp aquaculture has been consistently affected worldwide by devastating diseases that cause a severe loss in production. To fight a variety of harmful microbes in the surrounding environment, particularly at high densities (of which intensive farming represents an extreme example), shrimps have evolved and use a diverse array of antimicrobial peptides (AMPs) as part of an important first-line response of the host defense system. Cationic AMPs in penaeid shrimps composed of penaeidins, crustins, and anti-lipopolysaccharide factors are comprised of multiple classes or isoforms and possess antibacterial and antifungal activities against different strains of bacteria and fungi. Shrimp AMPs are primarily expressed in circulating hemocytes, which is the main site of the immune response, and hemocytes expressing AMPs probably migrate to infection sites to fight against pathogen invasion. Indeed, most AMPs are produced as early as the nauplii developmental stage to protect shrimp larvae from infections. In this review, we discuss the sequence diversity, expression, gene structure, and antimicrobial activities of cationic AMPs in penaeid shrimps. The information available on antimicrobial activities indicates that these shrimp AMPs have potential therapeutic applications in the control of disease problems in aquaculture.
Marine Biotechnology 05/2011; 13(4):639-57. · 3.43 Impact Factor
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ABSTRACT: Antimicrobial peptides (AMPs) are some of the important host molecules required to resist pathogen infection. Two novel AMPs (arasin-likeSp and GRPSp) were identified from the hemocytes of the mud crab, Scylla paramamosain, by analysis of a hemocyte expressed sequence tag library. The deduced open reading frames of the arasin-likeSp and GRPSp cDNAs are 198 and 168 bp, and encode for predicted peptides of 65 and 55 amino acid residues, respectively. The calculated molecular mass of the mature peptides was 4373 and 2995 Da with an estimated isoelectric point (pI) of 11.03 and 9.66, respectively. The mature peptide of arasin-likeSp is predicted to contain an N-terminal region rich in glycine and arginine and a C-terminal region containing four cysteine residues. Its amino acid sequence has an overall sequence identity of 53% to arasin-2 from the spider crab, Hyas araneus. The mature protein of GRPSp contains two cysteine residues at the C-terminus and two glycine-rich repeats (GGYG and GYGG). In healthy crabs, both arasin-likeSp and GRPSp transcript levels were found to be high in the hemocytes and were further increased at 3 h after challenge with the bacterium, Aerococcus viridans. A synthetic arasin-likeSp peptide revealed the antimicrobial activity against both Gram-positive and Gram-negative bacteria including some crustacean pathogens (A. viridans, Vibrio harveyi and V. anguillarum), whilst the synthetic GRPSp peptide exhibited antibacterial activity against some Gram-positive (A. viridans and Micrococcus luteus), but not Gram-negative, bacteria. These results indicate that arasin-likeSp and GRPSp are potentially novel AMPs involved in the immune responses of mud crab, S. paramamosain.
Fish & Shellfish Immunology 02/2011; 30(2):706-12. · 3.32 Impact Factor
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ABSTRACT: A homolog of mammalian secretory leucocyte proteinase inhibitor or SLPI known as a double WAP domain (DWD) protein has been found in penaeid shrimp and believed to play an important role in innate immune system of the shrimp. The PmDWD identified from the Penaeus monodon EST database was investigated for its expression under pathogen infection. Infections by Vibrio harveyi and white spot syndrome virus (WSSV) up-regulated the expression of the PmDWD, which was peaked at about 24 h post infection and, then, subsided to more or less normal level. The PmDWD was expressed in various tissues of normal, 24-h WSSV-injected and leg-amputated shrimp, predominantly in the hemocytes. The expression was dramatically increased in lymphoid organ upon WSSV infection and leg amputation. The recombinant PmDWD (rPmDWD) was not active against the commercial proteinases: trypsin, chymotrypsin, elastase and subtilisin while its mutant rPmDWD_F70R was active against the subtilisin. By using agar diffusion assay, the rPmDWD inhibited the crude proteinases from lymphoid organs of leg-amputated and WSSV-infected shrimp. It inhibited the crude proteinases from Bacillus subtilis as well. Unlike the mammalian SLPIs, the rPmDWD had no antimicrobial activity against various bacteria.
Fish & Shellfish Immunology 01/2011; 30(3):783-90. · 3.32 Impact Factor
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ABSTRACT: The prophenoloxidase (proPO) activating system plays an important role in the defense against microbial invasion in invertebrates. In the present study, we report a second proPO-activating enzyme (designated PmPPAE2) from the hemocytes of the black tiger shrimp, Penaeus monodon. PmPPAE2 contained the structural features of the clip domain serine proteinase family and exhibited 51% amino acid sequence similarity to the insect Manduca sexta PAP-1. Amino acid sequence alignment with the available arthropod PPAE sequences demonstrated that PmPPAE2 is a new class of crustacean PPAE. Transcript expression analysis revealed that PmPPAE2 transcripts were mainly expressed in hemocytes. Double-stranded RNA-mediated suppression of PmPPAE2 transcript levels resulted in a significant decrease in the total hemolymph PO activity (41%) and also increased the shrimp's susceptibility to Vibrio harveyi infection. Genomic organization analysis revealed that PmPPAE1 and PmPPAE2 are encoded by different genomic loci. The PmPPAE1 gene consists of ten exons and nine introns, whilst PmPPAE2 comprises of eight exons interrupted by seven introns. Analysis of the larval developmental stage expression of the four key genes in the shrimp proPO system (PmPPAE1, PmPPAE2, PmproPO1 and PmproPO2) revealed that PmPPAE1 and PmproPO2 transcripts were expressed in all larval stages (nauplius, protozoea, mysis and post-larvae), whilst PmPPAE2 and PmproPO1 transcripts were mainly presented in the late larval developmental stages (mysis and post-larvae). These results suggest that the PmPPAE2 functions as a shrimp PPAE and possibly mediates the activation of PmproPO1.
Developmental and comparative immunology 01/2011; 35(1):115-24. · 3.29 Impact Factor
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ABSTRACT: Penaeidin class 5 (PEN5) has so far only been reported in the Chinese shrimp, Fenneropenaeus chinensis, and the black tiger shrimp, Penaeus monodon. The PEN5 homolog from F. chinensis (FenchiPEN5) exhibits antimicrobial activities against both Gram-positive and Gram-negative bacteria as well as fungi. Here, we characterized the PEN5 gene from P. monodon (PenmonPEN5) and evaluated its potential involvement in antiviral immunity. The deduced open reading frame of PenmonPEN5 encodes for a predicted 79 amino acid peptide including a 19 amino acid signal peptide. The gene structure of PenmonPEN5 contains two exons interrupted by one intron, whilst the 5' upstream sequence contains a putative TATA box and several GATA, GATA-3, AP-1 and dorsal transcription factor binding sites. PenmonPEN5 mRNA levels in P. monodon shrimps following a systemic infection with white spot syndrome virus (WSSV) were significantly induced at 24 h post infection, but was strongly down-regulated at 48 h post injection, compared to those of the uninfected control shrimps. The suppression of PenmonPEN5 transcript levels by RNA interference mediated gene silencing led to an increased susceptibility of shrimps to WSSV infection, suggesting a possible role of PenmonPEN5 in the shrimp's antiviral immunity.
Developmental and comparative immunology 12/2010; 35(5):530-6. · 3.29 Impact Factor
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ABSTRACT: Serine proteinase inhibitors (SERPINs or serpins) have been found in a diverse range of organisms. Herein, eight serpin genes, namely PmSERPIN1 - 8, were identified from the Penaeus monodon EST database (http://pmonodon.biotec.or.th/home.jsp). Among those, PmSERPIN6 was selected for further characterization. Tissue distribution analysis revealed that PmSERPIN6 transcripts were expressed in the lymphoid organ, hemocyte, heart and gill, but not in the hepatopancreas. Semi-quantitative RT-PCR analysis at 0-48 h after pathogen challenge demonstrated that the PmSERPIN6 gene transcript expression levels in hemocytes was slightly decreased after systemic white spot syndrome virus (WSSV) injection but remained unchanged upon Vibrio harveyi injection. Interestingly, immunocytochemistry using anti-PmSERPIN6 polyclonal antiserum showed an increase in the number of PmSERPIN6 producing hemocytes at 72 h after both WSSV and V. harveyi injections indicating that the expression of PmSERPIN6 responded to pathogen in the late phase of infection. Our results suggest a likely important function of PmSERPIN6 in the shrimp's defense against invading pathogens.
Fish & Shellfish Immunology 11/2010; 29(5):890-8. · 3.32 Impact Factor
