A new gene family (BAPs) of Cotesia bracovirus induces apoptosis of host hemocytes.

Polydnaviruses (PDVs), obligatory symbionts with parasitoid wasps, function as host immune suppressors and growth and development regulator. PDVs can induce host haemocyte apoptosis, but the underlying mechanism remains largely unknown. Here, we provided evidence that, during the early stages of parasitism, the activated Cotesia vestalis bracovirus (CvBV) reduced the overall number of host haemocytes by inducing apoptosis. We found that one haemocyte-highly expressed CvBV gene, CvBV-26-4, could induce haemocyte apoptosis. Further analyses showed that CvBV-26-4 has four homologs from other Cotesia bracoviruses and BV from wasps in the genus Glyptapanteles, and all four of them possessed a similar structure containing 3 copies of a well-conserved motif (Gly-Tyr-Pro-Tyr, GYPY). Mass spectrometry analysis revealed that CvBV-26-4 was secreted into plasma by haemocytes and then degraded into peptides that induced the apoptosis of haemocytes. Moreover, ectopic expression of CvBV-26-4 caused fly haemocyte apoptosis and increased the susceptibility of flies to bacteria. Based on this research, a new family of bracovirus genes, Bracovirus apoptosis-inducing proteins (BAPs), was proposed. Furthermore, it was discovered that the development of wasp larvae was affected when the function of CvBV BAP was obstructed in the parasitized hosts. The results of our study indicate that the BAP gene family from the bracoviruses group is crucial for immunosuppression during the early stages of parasitism.

Virus and endogenous viral element-derived small non-coding RNAs and their roles in insect-virus interaction.

RNA interference pathways mediated by different types of small non-coding RNAs (siRNAs, miRNAs and piRNAs) are conserved biological responses to exotic stresses, including viral infection. Aside from the well-established siRNA pathway, the miRNA pathway and the piRNA pathway process viral sequences, exogenously or endogenously, into miRNAs and piRNAs, respectively. During the host-virus interaction, viral sequences, including both coding and non-coding sequences, can be integrated as endogenous viral elements (EVEs) and thereby become present within the germline of a non-viral organism. In recent years, significant progress has been made in characterizing the biogenesis and function of viruses and EVEs associated with snRNAs. Overall, the siRNA pathway acts as the primarily antiviral defense against a wide range of exogenous viruses; the miRNA pathways associated with viruses or EVEs function in antiviral response and host gene regulation; EVE derived piRNAs with a ping-pong signature have the potential to limit cognate viral infection.

A Polydnavirus Protein Tyrosine Phosphatase Negatively Regulates the Host Phenoloxidase Pathway.

Polydnavirus (PDV) is a parasitic factor of endoparasitic wasps and contributes greatly to overcoming the immune response of parasitized hosts. Protein tyrosine phosphatases (PTPs) regulate a wide variety of biological processes at the post-transcriptional level in mammals, but knowledge of PDV PTP action during a parasitoid−host interaction is limited. In this study, we characterized a PTP gene, CvBV_12-6, derived from Cotesia vestalis bracovirus (CvBV), and explored its possible regulatory role in the immune response of the host Plutella xylostella. Our results from qPCR show that CvBV_12-6 was highly expressed in hemocytes at an early stage of parasitization. To explore CvBV_12-6 function, we specifically expressed CvBV_12-6 in Drosophila melanogaster hemocytes. The results show that Hml-Gal4 > CvBV_12-6 suppressed the phenoloxidase activity of hemolymph in D. melanogaster, but exerted no effect on the total count or the viability of the hemocytes. In addition, the Hml-Gal4 > CvBV_12-6 flies exhibited decreased antibacterial abilities against Staphylococcus aureus. Similarly, we found that CvBV_12-6 significantly suppressed the melanization of the host P. xylostella 24 h post parasitization and reduced the viability, but not the number, of hemocytes. In conclusion, CvBV_12-6 negatively regulated both cellular and humoral immunity in P. xylostella, and the related molecular mechanism may be universal to insects.

Expression profiling analysis of long noncoding RNAs in a mouse model of ventilator-induced lung injury indicating potential roles in inflammation.

The key regulators of inflammation underlying ventilator-induced lung injury (VILI) remain poorly defined. Long noncoding RNAs (lncRNAs) have been implicated in the inflammatory response of many diseases; however, their roles in VILI remain unclear. We, therefore, performed transcriptome profiling of lncRNA and messenger RNA (mRNA) using RNA sequencing in lungs collected from mice model of VILI and control groups. Gene expression was analyzed through RNA sequencing and quantitative reverse transctiption polymerase chain reaction. A comprehensive bioinformatics analysis was used to characterize the expression profiles and relevant biological functions and for multiple comparisons among the controls and the injury models at different time points. Finally, lncRNA-mRNA coexpression networks were constructed and dysregulated lncRNAs were analyzed functionally. The mRNA transcript profiling, coexpression network analysis, and functional analysis of altered lncRNAs indicated enrichment in the regulation of immune system/inflammation processes, response to stress, and inflammatory pathways. We identified the lncRNA Gm43181 might be related to lung damage and neutrophil activation via chemokine receptor chemokine (C-X-C) receptor 2. In summary, our study provides an identification of aberrant lncRNA alterations involved in inflammation upon VILI, and lncRNA-mediated regulatory patterns may contribute to VILI inflammation.

Parasitic insect-derived miRNAs modulate host development.

Parasitic wasps produce several factors including venom, polydnaviruses (PDVs) and specialized wasp cells named teratocytes that benefit the survival of offspring by altering the physiology of hosts. However, the underlying molecular mechanisms for the alterations remain unclear. Here we find that the teratocytes of Cotesia vestalis, an endoparasitoid of the diamondback moth Plutella xylostella, and its associated bracovirus (CvBV) can produce miRNAs and deliver the products into the host via different ways. Certain miRNAs in the parasitized host are mainly produced by teratocytes, while the expression level of miRNAs encoded by CvBV can be 100-fold greater in parasitized hosts than non-parasitized ones. We further show that one teratocyte-produced miRNA (Cve-miR-281-3p) and one CvBV-produced miRNA (Cve-miR-novel22-5p-1) arrest host growth by modulating expression of the host ecdysone receptor (EcR). Altogether, our results show the first evidence of cross-species regulation by miRNAs in animal parasitism and their possible function in the alteration of host physiology during parasitism.

The protective effects of rutaecarpine on acute pancreatitis.

Acute pancreatitis (AP) is the acute inflammation of the pancreas. The morbidity of AP has increased in recent years. Certain patients eventually develop severe AP (SAP), which rapidly progresses to multiple organ dysfunction; the incidence of this occurring in patients with AP is 20-30%. To date, no specific drugs or methods exist to treat this disease. Rutaecarpine relaxes vascular smooth muscle by stimulating calcitonin gene-related peptide (CGRP) release via activation of vanilloid receptor subtype 1 (VR1). It has been demonstrated that rutaecarpine induces a therapeutic effect on SAP. The present study was conducted to characterize the molecular mechanisms underlying the protective effects of rutaecarpine against AP using a rat model of AP. Gross pathological changes of the pancreas, as well as the pancreatic tissue histopathological score, were assessed following treatment with rutaecarpine, capsazepine or a combination of the two. Serum amylase activity was detected using an automatic biochemistry analyzer. Changes in the serum concentrations of interleukin (IL)-6, tumor necrosis factor (TNF-α), IL-10 and CGRP were assessed by ELISA and radioimmunoassay. The results demonstrated that pre-treatment with rutaecarpine markedly decreased pancreatic inflammation and necrosis, reduced the volume of ascites, and significantly increased the plasma concentration of CGRP and the serum concentration of IL-10, an anti-inflammatory cytokine. However, serum concentrations of the inflammatory cytokines IL-6 and TNF-α were decreased. The effect of rutaecarpine treatment markedly improved with increases in the drug dose. Capsazepine, as a competitive vanilloid receptor antagonist, abolished these protective effects of rutaecarpine against AP. Therefore, the results of the present study indicate that rutaecarpine protects against AP in rats by upregulating endogenous CGRP release via activation VR1 of, to improving the microcirculation of the pancreatic tissue and regulate the expression of inflammatory factors.

Two types of lysozymes from the whitefly Bemisia tabaci: Molecular characterization and functional diversification.

Lysozyme is well-known as an immune effector in the immune system. Here we identified three genes including one c-type lysozyme, Btlysc, and two i-type lysozymes, Btlysi1 and Btlysi2, from the whitefly Bemisia tabaci. All three lysozymes were constitutively expressed in different tissues and developmental stages, but the two types of lysozymes showed different expression patterns. The expression levels of Btlysi1 and Btlysi2 were dramatically induced after the whitefly fed with different host plants while the expression level of Btlysc kept unchanged. After fungal infection and begomovirus acquisition, Btlysc expression was significantly upregulated while Btlysi1 and Btlysi2 expression were basically not induced. Furthermore, we found that Btlysc showed muramidase and antibacterial activities. Altogether, our results suggest that the two types of lysozymes act in two different ways in B. tabaci, that is, Btlysc is involved in the whitefly immune system while Btlysi1 and Btlysi2 may play a role in digestion or nutrition absorption.

Serologic testing of a panel of five antibodies in inflammatory bowel diseases: Diagnostic value and correlation with disease phenotype.

The aim of the present study was to evaluate the diagnostic value of five serological antibodies, perinuclear antineutrophil cytoplasmic antibody (pANCA), anti-Saccharomyces cerevisiae antibodies [ASCA; ASCA-immunoglobulin (IgG)and ASCA-IgA], Escherichia coli outer membrane porin C antibody (anti-OmpC) and CBir1 flagellin antibody for detection in inflammatory bowel diseases. Whether the antibody status correlated with the disease phenotype was also evaluated. Sera from 71 patients with Crohn's disease (CD), 41 patients with ulcerative colitis (UC), 78 patients with other gastrointestinal diseases and 31 healthy control subjects were investigated. Clinical data were gathered at the time of serum sampling and enzyme-linked immunosorbent assay was used to determine titers of the above mentioned five antibodies. The pANCA test exhibited a sensitivity of 53.7% for UC and the ASCA test had a sensitivity of 66.2% for CD. The prevalence of anti-OmpC was significantly higher in CD than in intestinal tuberculosis (TB), indicating that anti-OmpC may be a serologic marker distinguishing CD from TB. The pANCA+/ASCA- exhibited the best specificity for differentiating between CD and UC. In UC, the presence of pANCA was greater in the patients with moderate to severe activity than in those with mild activity. ASCA was more positive in ileal CD. Furthermore, positive ASCA-IgG or anti-OmpC implied that complicated CD and pANCA was associated with colonic CD. Seropositivity of anti-CBir1 was lowest in colonic CD.

RNA interference of an antimicrobial peptide, Btdef, reduces Tomato yellow leaf curl China virus accumulation in the whitefly Bemisia tabaci.

BACKGROUND: The whitefly Bemisia tabaci (Gennadius) is considered one of the main pests for agriculture. One important problem with the whitefly is its notorious status as a vector for plant viruses, primarily begomoviruses. We have previously identified a defensin-like antimicrobial peptide, Btdef, from the whitefly B. tabaci MEAM1. However, the function of Btdef in the immune system of the insect vector and begomovirus transmission has yet to be explored. RESULTS: To explore the role of Btdef during begomovirus transmission, we firstly investigated the transcriptional response of Btdef following acquisition of Tomato yellow leaf curl China virus (TYLCCNV). The expression of Btdef was up-regulated in the viruliferous whiteflies. After RNA silencing of the Btdef gene in adult whiteflies fed with dsRNA, they were allowed to feed on TYLCCNV-infected plants and then quantified for TYLCCNV DNA titre. Unexpectedly, silencing the Btdef gene reduced both the abundance and expressions of TYLCCNV genes in the whiteflies. In the meantime, the density of the endosymbiont Rickettsia was significantly reduced in dsBtdef-fed whiteflies. CONCLUSION: Our data provide evidence that Btdef is involved in begomovirus infection, possibly through symbiont-mediated alteration of begomovirus-whitefly interactions. These findings indicate that Btdef may be targeted for the development of new technology for the control of whitefly-transmitted begomoviruses. © 2016 Society of Chemical Industry.

A peptidoglycan recognition protein acts in whitefly (Bemisia tabaci) immunity and involves in Begomovirus acquisition.

Peptidoglycan recognition proteins (PGRPs) are multifunctional pattern recognition proteins. Here, we report that a PGRP gene, BtPGRP, encodes a PGRP from the whitefly Bemisia tabaci (MEAM1) that binds and kills bacteria in vitro. We analyzed BtPGRP transcriptional profiling, and the distribution of the cognate protein within the midgut. Fungal infection and wasp parasitization induced expression of BtPGRP. Silencing BtPGRP with artificial media amended with dsRNA led to reduced expression of a gene encoding an antimicrobial peptide, B. tabaci c-type lysozyme. Begomovirus infection also led to increased expression of BtPGRP. We propose that BtPGRP has a potential Tomato yellow leaf curl virus (TYLCV) binding site because we detected in vitro interaction between BtPGRP and TYLCV by immunocapture PCR, and recorded the co-localization of TYLCV and BtPGRP in midguts. This work addresses a visible gap in understanding whitefly immunity and provides insight into how the whitefly immunity acts in complex mechanisms of Begomovirus transmission among plants.

Cell motility and spreading promoted by CEACAM6 through cyclin D1/CDK4 in human pancreatic carcinoma.

Carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) belongs to the human carcino-embryonic antigen (CEA) family. Numerous lines of studies have indicated that altered expression of CEACAM6 may have a role in carcinogenesis and development. However, few studies have defined functional roles and mechanisms of action. In the present study, the relationship between clinical and pathological parameters was also analyzed. The relative CEACAM6 protein expression of pancreatic carcinoma was significantly higher than that in non-cancerous tissue. Different clinical stages and lymph node metastasis between groups were significantly different (P<0.05). We used siRNA and forced-expression in multiple cell lines to define the role of CEACAM6 in the regulation of proliferation of pancreatic carcinoma in vitro and in vivo. Knockdown of endogenous CEACAM6 decreased proliferation of BxPC-3 and SW1990 cells. These changes significantly reduced cyclin D1 and CDK4 protein levels. Conversely, overexpression of CEACAM6 in MIA PaCa-2 cells stimulated proliferation and increased cyclin D1 and CDK4 protein levels. Our results confirm that CEACAM6 promoted cell proliferation, and these changes were mediated by cyclin D1/CDK4. These observations contribute to our understanding of the important roles of CEACAM6 in pancreatic carcinoma development and progression and could be a promising molecular target for the development of new diagnostic and therapeutic strategies of pancreatic carcinoma.

Identification and characterization of defensin genes from the endoparasitoid wasp Cotesia vestalis (Hymenoptera: Braconidae).

Defensins are members of a large and diverse family of antimicrobial peptides (AMPs) containing three or four intramolecular disulfide bonds. They are widely distributed from vertebrates to invertebrates, and serve as critical defense molecules protecting the host from the invasion of pathogens or protozoan parasites. Cotesia vestalis is a small endoparasitoid wasp that lays eggs in larvae of Plutella xylostella, a cosmopolitan pest of cruciferous crops. We identified and characterized three full-length cDNAs encoding putative defensin-like peptides from C. vestalis, named CvDef1, CvDef2 and CvDef3. Phylogenetic analyses of these sequences showed that they are present in two clades, CITDs and PITDs, indicating a diversity of defensins in C. vestalis. We analyzed their expression patterns in larvae, pupae and adults by semi-quantitative RT-PCR. The results showed that CvDef1 mRNA was expressed from the end stage of the second instar larva, CvDef3 mRNA from the early stage of the second instar larva, and CvDef2 mRNA was expressed in all developmental stages of C. vestalis. Furthermore, CvDef1 showed antimicrobial activity against gram-positive and gram-negative bacteria. Growth kinetics of Staphylococcus aureus indicated that CvDef1 had much better antimicrobial ability than ampicillin, making it a potential candidate for practical use. Transmission electron microscopic (TEM) examination of CvDef1-treated S. aureus cells showed extensive damage to the cell membranes. Our results revealed the basic properties of three defensins in C. vestalis for the first time, which may pave the way for further study of the functions of defensins in parasitism and innate immunity of C. vestalis.