Description of Fuscovulum ytuae sp. nov, a facultative autotroph isolated from the intertidalite of Yangma island, China.

In this study, we reported a Gram-stain-negative, ovoid to rod-shaped, atrichous, and facultative anaerobe bacteria strain named YMD61T, which was isolated from the intertidal sediment of Yangma island, China. Growth of strain YMD61T occurred at 10.0-45.0 °C (optimum, 30.0 °C), pH 7.0-10.0 (optimum, 8.0) and with 0-3.0% (w/v) NaCl (optimum, 2.0%). Phylogenetic tree analysis based on 16 S rRNA gene or genomic sequence indicated that strain YMD61T belonged to the genus Fuscovulum and was closely related to Fuscovulum blasticum ATCC 33,485T (96.6% sequence similarity). Genomic analysis indicated that strain YMD61T contains a circular chromosome of 3,895,730 bp with DNA G + C content of 63.3%. The genomic functional analysis indicated that strain YMD61T is a novel sulfur-metabolizing bacteria, which is capable of fixing carbon through an autotrophic pathway by integrating the processes of photosynthesis and sulfur oxidation. The predominant respiratory quinone of YMD61T was ubiquinone-10 (Q-10). The polar lipids of YMD61T contained phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, five unidentified lipids, unidentified aminolipid and unidentified aminophospholipid. The major fatty acids of strain YMD61T contained C18:1ω7c 11-methyl and summed feature 8 (C18:1 ω 7c or/and C18:1 ω 6c). Phylogenetic, physiological, biochemical and morphological analyses suggested that strain YMD61T represents a novel species of the genus Fuscovulum, and the name Fuscovulum ytuae sp. nov. is proposed. The type strain is YMD61T (= MCCC 1K08483T = KCTC 43,537T).

CsIL-20, a tongue sole interleukin-20, negatively mediates leucocyte activity and antibacterial defense.

Interleukin-20 (IL-20), as an essential member of IL-10 family, plays vital roles in mammalian immunological response such as antimicrobial, inflammation, hematopoiesis, and immune diseases. In teleost, the study about immune antimicrobial function of IL-20 is largely scarce. In this article, we revealed the expression profiles and the immunological functions of the IL-20 (CsIL-20) in tongue sole Cynoglossus semilaevis. CsIL-20 is composed of 183 amino acid residues, with seven cysteine residues and a typical IL-10 domain which comprises six α-helices and two ß-sheets, and shares 34.4-71.2 % identities with other teleost IL-20. CsIL-20 was constitutively expressed in a variety of tissues and regulated by bacterial invasion, and the recombinant CsIL-20 (rCsIL-20) could bind to different bacteria. In vitro rCsIL-20 could interact with the membrane of peripheral blood leukocytes (PBLs), leading to the attenuation of reactive oxygen species (ROS) production and acid phosphatase activity in PBLs. In line with In vitro results, In vivo rCsIL-20 could obviously suppressed the host immune against bacterial infection. Furthermore, knockdown of CsIL-20 in vivo could markedly enhance the host antibacterial immunity. Collectively, these observations offer new insights into the negative effect of CsIL-20 on antibacterial immunity.

Two novel teleost calreticulins PoCrt-1/2, with bacterial binding and agglutination activity, are involved in antibacterial immunity.

Calreticulin (Crt), a conserved lectin-like pleiotropic protein, plays crucial roles in mammalian immune response. In fish, the immunological function of Crt is limited investigated. Herein, we studied the antibacterial immunity of two type of Crt homologues (i.e. PoCrt-1 and PoCrt-2) in Japanese flounder (Paralichthys olivaceus). PoCrt-1 and PoCrt-2 are composed of 419 and 427 amino acid residues respectively, with 69.09% overall sequence identities with each other. Both PoCrt-1 and PoCrt-2 contain a signal peptide and three functional domains i.e. N-, P- and C-domains. Both PoCrt-1 and PoCrt-2 were constitutively expressed at various tissues with highest expression level in liver, and obviously regulated by Edwardsiella tarda and Vibrio harveyi. Furthermore, recombinant PoCrt-1 and PoCrt-2 (rPoCrt-1 and rPoCrt-2) could bind to different Gram-negative bacteria with highest binding index with E. tarda. At same time, in vitro rPoCrt-1 and rPoCrt-2 could agglutinate E. tarda, V. harveyi, and Vibrio anguillarum, and inhibit the bacterial growth. Similarly, in vivo rPoCrt-1 and rPoCrt-2 could significantly suppress the dissemination of E. tarda. Overall, these observations add new insights into the antibacterial immunity of Crt in P. olivaceus.

IL8 of Takifugu rubripes is a chemokine that interacts with peripheral blood leukocytes and promotes antibacterial defense.

Interleukin 8 (IL8) is a CXC chemokine that plays a crucial role on promoting inflammatory response and immune regulation. In teleost, IL8 can induce the migration and activation of immune cells. However, the biological functions of IL8 are still unknown in Takifugu rubripes. In this study, we examined the biological characteristics of TrIL8 in T. rubripes. TrIL8 is composed of 98 residues and contained a chemokine CXC domain. We found that the TrIL8 expression was detected in diverse organs and significantly increased by Vibrio harveyi or Edwardsiella tarda challenge. The recombinant TrIL8 (rTrIL8) exhibited significantly the binding capacities to 8 tested bacteria. In addition, rTrIL8 could bind to peripheral blood leukocytes (PBL), and increased the expression of immune gene, resistance to bacterial infection, respiratory burst, acid phosphatase activity, chemotactic activity, and phagocytic activity of PBL. In the presence of rTrIL8, T. rubripes was enhanced the resistance to V. harveyi infection. These results indicated that TrIL8 is a chemokine and involved in the activation of immune cells against bacterial infection in teleost.

A soluble TLR5 is involved in PBLs activation and antibacterial immunity via TLR5M-MyD88-signaling pathway in tongue sole Cynoglossus semilaevis.

In higher vertebrates, there is only a membranal TLR5 (TLR5M), which is crucial for host defense against microbes via MyD88 signaling pathway. In teleost, both TLR5M and soluble TLR5 (TLR5S) are identified, whereas the antibacterial mechanism of TLR5S is largely unknown. In this study, we studied the immune antibacterial mechanism of Cynoglossus semilaevis TLR5S homologue (named CsTLR5S). CsTLR5S, a 71.1 kDa protein, consists of 649 amino acid residues and shares 41.7 %-57.8 % overall sequence identities with teleost TLR5S homologues. CsTLR5S contains a single extracellular domain (ECD) composed of 12 leucine-rich repeats. CsTLR5S expression was constitutively identified and upregulated by bacterial infection in tissues. In vitro recombinant CsTLR5S (rCsTLR5S) could interact with bacteria and tongue sole rTLR5M (rCsTLR5M). Furthermore, rCsTLR5S could bind to the membranal CsTLR5M of peripheral blood leukocytes (PBLs), which led to enhancing the activity and the antibacterial role of PBLs via Myd88-NF-κB pathway. In vivo rCsTLR5S could activate the Myd88-NF-κB pathway, facilitate the release of proinflammatory cytokines, and enhance the host antibacterial response against Vibrio harveyi. Moreover, the knockdown of CsTLR5M or the Myd88 inhibitor could significantly suppress the antibacterial effect of rCsTLR5S. Collectively, our findings added important insights into the TLR5S immune antibacterial property in a TLR5M-MyD88-dependent manner.

GBP2 as a potential prognostic predictor with immune-related characteristics in glioma.

Guanylate binding protein 2 (GBP2) is a member of the guanine binding protein family, and its relationship with prognostic outcomes and tumor immune microenvironments in glioma remains elusive. We found GBP2 were increased in glioma tissues at both mRNA and protein levels. Kaplan-Meier curves revealed that high GBP2 expression was linked with worse survival of glioma patients, and multivariate Cox regression analysis indicated that high GBP2 expression was an independent prognostic factor for glioma. Combined analysis in immune database revealed that the expression of GBP2 was significantly related to the level of immune infiltration and immunomodulators. Single-cell analysis illustrated the high expression of GBP2 in malignant glioma cells showed the high antigen presentation capability, which were confirmed by real-time polymerase chain reaction (qRT-PCR) data. Additionally, the hsa-mir-26b-5p and hsa-mir-335-5p were predicted as GBP2 regulators and were validated in U87 and U251 cells. Our results first decipher immune-related characteristics and noncoding regulators of GBP2 in glioma, which may provide insights into associated immunotherapies and prognostic predictor.

Gel properties of blue round scad (Decapterus maruadsi) mince as influenced by the addition of egg white powder.

The use of egg white powder (EWP) to enhance the physicochemical properties, molecular structure, and thermal stability of Decapterus maruadsi mince gels was investigated. The thermal stability was analyzed by adding spray-dried EWP (0, 0.2, 0.4, 0.6, 0.8, and 1%) to the mince, and mince gels were prepared to study the changes in their fracture constant, water distribution, microstructure, and protein conformation of mince gels. In addition, the stress-strain curve of the EWP-mince gel was measured to obtain its compressive modulus (E). The formation of the mince gel was promoted by EWP, and the whiteness, fracture constant, water-holding capacity (WHC), and immobilized water were all enhanced. At 0.8% addition of EWP, the fracture constant increased from 176.715 ± 2.463 N/m to 348.631 ± 3.144 N/m (p < .05), which was a nearly twofold improvement. Additionally, the WHC increased from 75.21% to 79.99%, and the percentage of immobilized water increased from 94.03% to 94.91%. The EWP-mince gel network structure was the most uniform and dense, and there were increases in hydrogen bonds, disulfide bonds, ß-sheets, and ß-turns in mince gels, as well as the storage modulus (G') and enthalpy (ΔH). In contrast to the control group, the relative content of α-helixes decreased from 53.34% to 37.09% and transformed into other secondary structures, and the bulk water and cooking loss also decreased to 2.41% and 8.51%, respectively. Consequently, EWP effectively improved the quality of mince products, and the effect was most apparent when 0.8% was added.

Membrane orthologs of TLR5 of tongue sole Cynoglossus semilaevis: Expression patterns, signaling pathway and antibacterial property.

Mammalian toll-like receptor 5 (TLR5) is crucial for recognizing bacterial flagellin and initiating the inflammatory signaling cascades via myeloid differentiation factor 88 (MyD88) signaling pathway, which plays vital roles in innate immune against pathogenic bacteria. Herein, we reported the signaling pathway and antibacterial property of tongue sole (Cynoglossus semilaevis) membrane forms of TLR5 (i.e. CsTLR5M1and CsTLR5M2). CsTLR5M1/M2 contain 936 and 885 amino acid residues respectively. CsTLR5M1 shares 86.7% overall sequence identities with CsTLR5M2. CsTLR5M1/M2 possess the same extracellular domain (ECD) and transmembrane domain (TMD), but the different toll-interleukin-1 receptor (TIR) domain. CsTLR5M1/M2 expression occurred constitutively in multiple tissues and regulated by bacterial stimulation. Recombinant CsTLR5M1/M2 (rCsTLR5M) could bind to flagellin and Gram-negative/positive bacteria, which could suppress bacterial growth. Stimulation of the CsTLR5M pathway by flagellin resulted in increased expression of MyD88-dependent signaling molecules and inflammatory cytokines. Blocking rCsTLR5M by antibody markedly reduced the phagocytosis and ROS production of peripheral blood leukocytes (PBLs), which in turn in vivo promoted the dissemination of bacteria. Overall, these observations add new insights into the signaling pathway and immune function of teleost TLR5M.

CsIL-11, a teleost interleukin-11, is involved in promoting phagocytosis and antibacterial immune defense.

Interleukin (IL)-11 is a multifunctional cytokine belonging to the IL-6 family, which plays essential roles in immune response. However, much less is known about the immunological functions of IL-11 in teleost. In this study, we investigated the immune properties of a teleost IL-11 homologue (CsIL-11) from tongue sole Cynoglossus semilaevis. CsIL-11 possesses four conserved α-helices and conserved CsIL-11 receptor binding residues L86 and R187, and shares 23.3%-80.1% identities with other IL-11 homologues. CsIL-11 expression was constitutive in tissues, with most abundant in blood and least abundant in spleen, and upregulated by bacterial challenge in blood, spleen, and head kidney. Recombinant CsIL-11 (rCsIL-11) in the native form of monomer, could bind to peripheral blood leukocytes (PBLs) membrane and enhance the activation and phagocytosis of PBLs. When administered in vivo, rCsIL-11 could markedly promote the host to defend against microbial infection. Overall, our findings show that CsIL-11 plays a pivotal role in regulating PBLs phagocytosis and antibacterial immunity.

A teleost interleukin-16 is implicated in peripheral blood leukocytes recruitment and anti-bacterial immunity.

Interleukin-16 (IL-16), as a lymphocyte chemoattractant cytokine, plays a crucial role in regulating cellular activities and anti-pathogen immunity. In teleost, the information about the antibacterial effect of IL-16 is scarce. In our study, we examined the immune functions of an IL-16 homologue (CsIL-16) from tongue sole Cynoglossus semilaevis. The CsIL-16 precursor (proCsIL-16) is comprised of 1181 amino acid residues, sharing 21.1%-67.3% identities with IL-16 precursor from invertebrate and vertebrate. The C-terminal proCsIL-16 containing two PDZ domains was designated as mature CsIL-16 which was released into the supernatant of peripheral blood leukocytes (PBLs). CsIL-16 was expressed in various tissues and regulated by bacterial invasion. Recombinant CsIL-16 (rCsIL-16), as a homodimer, was able to bind to the membrane of PBLs and played essential roles in regulating chemotaxis and activation of PBLs, which in vitro inhibited intracellular survival of E. tarda. Under in vivo condition, rCsIL-16 could dramatically regulate the induction of inflammatory genes, and suppress the bacterial dissemination in fish tissues. Collectively, our results reveal that CsIL-16 plays positive roles in antibacterial immunity, and provide insights into the immune function of CsIL-16.

Whole-Genome Sequencing of Micrococcus luteus MT1691313, Isolated from the Mariana Trench.

Micrococcus luteus MT1691313 is a Gram-positive bacterium isolated from the deep-sea sediment located at a 4,448-m depth in the Mariana Trench. Here, we report the complete genome sequence of this strain, which has a genome size of 2.32 Mb with a GC content of 72.04%.

Pol-miR-150 regulates anti-bacterial and viral infection in Japanese flounder (Paralichthys olivaceus) via the lysosomal protein LMP2L.

MiR-150 is a microRNA (miRNA) present in a number of teleost species, but its target and regulation mechanism are unknown. Similarly, lysosome membrane protein 2-like (LMP2L) is a gene identified in fish but with unknown function. In this study, we examined the regulation mechanism and function of flounder miR-150 (named pol-miR-150) and its target gene LMP2L (named PoLMP2L) in association with bacterial and viral infection. We found that pol-miR-150 expression was not only modulated by the bacterial pathogen Streptococcus iniae but also by the viral pathogen megalocytivirus. Pol-miR-150 targeted PoLMP2L by binding to the 3'-untranslated region (3'-UTR) of PoLMP2L and inhibited PoLMP2L expression in vitro and in vivo. PoLMP2L is a member of the CD36 superfamily of scavenger receptors and homologous to but phylogenetically distinct from lysosomal integral membrane protein type 2 (LIMP2). PoLMP2L was localized mainly in the lysosomes and expressed in multiple organs of flounder. In vivo knockdown and overexpression of PoLMP2L enhanced and suppressed, respectively, S. iniae dissemination in flounder tissues, whereas in vivo knockdown and overexpression of pol-miR-150 produced the opposite effects on S. iniae dissemination. In addition, pol-miR-150 knockdown also significantly inhibited the replication of megalocytivirus. The results of this study revealed the regulation mechanism and immune functions of fish miR-150 and LMP2L, and indicated that LMP2L and miR-150 play an important role in the antimicrobial immunity of fish.

A live attenuated Edwardsiella tarda vaccine induces immunological expression pattern in Japanese flounder (Paralichthys olivaceus) in the early phase of immunization.

A previous study showed that an attenuated Edwardsiella tarda strain, TXhfq, as a live vaccine could elicit protective immune effects in fish against E. tarda infection. In the current study, in order to clarify the molecular mechanism of fish immune response at the early stage after TXhfq vaccination, RNA-Seq technology was used to compare the transcriptomes of skin, intestine, and spleen between bath-vaccinated and unvaccinated Japanese flounder (Paralichthys olivaceus). An average of 46.6 million clean reads per library was obtained, ~88.04% of which were successfully mapped to the reference genome, and approximately 24,600 genes were detected in each sample. A total of 565, 878, and 1258 differential expression genes (DEGs) were found in skin, intestine, and spleen, respectively, including 1263 up-regulated genes and 1438 down-regulated genes. The DEGs exhibited different characteristics in each tissue. One hundred and sixteen DEGs belonging to six immune related categories were scrutinized, i.e., inflammatory factors, cytokines, complement and coagulation system, mucins, phagocytosis, and antigen processing and presentation. A protein-protein interaction network was constructed to get the interaction network between immune genes during the early stage of immunization. The top six hub genes highly regulated by TXhfq formed complicated interaction relationship with each other, which were involved in immune processes, notably inflammation and phagocytosis. Our results provide valuable information for the understanding of the immune mechanism underlying the protection of live attenuated vaccines in fish.

Tongue sole (Cynoglossus semilaevis) interleukin 10 receptors are involved in the immune response against bacterial infection.

Interleukin (IL)-10, an immune-regulatory cytokine, exerts various biological functions through interaction with IL-10 receptors. In teleost, very limited functional studies on IL-10 receptors have been documented. In this study, we reported the expression patterns of IL-10 receptor 1 (CsIL-10R1) and receptor 2 (CsIL-10R2) of tongue sole (Cynoglossus semilaevis) and examined their biological properties. The expression of CsIL-10R1 and CsIL-10R2 occurred in multiple tissues and were regulated by bacterial challenge. In vitro binding studies showed that recombinant extracellular region of CsIL-10R1 (rCsIL-10R1ex) rather than rCsIL-10R2ex could bind with rCsIL-10. Cellular study showed that both CsIL-10R1 and CsIL-10R2 were expressed on peripheral blood leukocytes (PBLs), and blockade of CsIL-10R1 or CsIL-10R2 by antibody could reduce inhibitory effect of CsIL-10 on ROS production of PBLs. When injected in vivo, anti-rCsIL-10R1 or anti-rCsIL-10R2 antibody dramatically promoted the expression of proinflammatory cytokines and suppressed bacterial dissemination in tongue sole tissues. Consistently, the overexpression of CsIL-10R1 or CsIL-10R2 significantly enhanced bacterial dissemination, and the overexpression of CsIL-10R1M bearing STAT3 site mutation reduced bacterial dissemination. Overall, these results demonstrate for the first time teleost IL-10 receptors play a negative role in antibacterial immunity and add insight into the function of CsIL-10 receptors.

Differentiation Antagonizing Non-protein Coding RNA Knockdown Alleviates Lipopolysaccharide-Induced Inflammatory Injury and Apoptosis in Human Chondrocyte Primary Chondrocyte Cells Through Upregulating miRNA-19a-3p.

OBJECTIVE: To confirm the role of long noncoding RNA differentiation antagonizing non-protein coding RNA (DANCR) in chondrocyte inflammatory injury in osteoarthritis (OA) in vitro, as well as its molecular mechanism. METHODS: Human primary chondrocytes were treated with lipopolysaccharide (LPS) to construct a chondrocyte inflammatory injury in human OA cell model. Gene expression was detected using real-time quantitative polymerase chain reaction. Cell inflammatory injury was evaluated by Cell Counting Kit-8 assay, flow cytometry, and enzyme-linked immunosorbent assay. The interplay between miRNA-19a-3p (miR-19a) and DANCR was validated by dual-luciferase reporter assay and RNA immunoprecipitation. RESULTS: Expression of DANCR was upregulated, and miR-19a was downregulated in human OA cartilage and LPS-treated primary chondrocytes in vitro. Moreover, DANCR expression was inversely correlated with miR-19a in OA patients. LPS reduced cell viability and increased the apoptotic rate and secretion of interleukin (IL)-1ß, IL-6, IL-8, as well as tumor necrosis factor (TNF)-α in primary chondrocyte cells in vitro, suggesting an inflammatory injury model of OA. Functionally, knockdown of DANCR could attenuate LPS-induced apoptosis and inflammatory response, as evidenced by improved cell viability, and reduced apoptotic rate and products of IL-1ß, IL-6, IL-8, and TNF-α. Notably, DANCR negatively regulated miR-19a expression, presumably via sponging. Furthermore, miR-19a deletion eliminated the effect of DANCR knockdown on apoptosis and the inflammatory response of primary chondrocytes under LPS stress. CONCLUSION: Differentiation antagonizing non-protein coding RNA silencing could protect human chondrocyte cells against LPS-induced inflammatory injury and apoptosis through targeting miR-19a, suggesting a vital role of the DANCR/miR-19a axis in OA.

Japanese flounder Paralichthys olivaceus interleukin 21 induces inflammatory response and plays a vital role in the immune defense against bacterial pathogen.

Interleukin (IL)-21 is a pleiotropic cytokine and plays a vital role in immunity. In the current study, we examined the immune function of Japanese flounder Paralichthys olivaceus IL-21 (PoIL-21). PoIL-21 shares moderate (25.17%-46.25%) sequence identities with other teleost IL-21. PoIL-21 expression occurred in multiple tissues, especially intestine, and was regulated by bacterial infection in a time dependent manner. PoIL-21 was secreted by peripheral blood leukocytes (PBL) upon LPS stimulation. Recombinant PoIL-21 (rPoIL-21) bound to a wide range of Gram-negative and Gram-positive bacteria and inhibited the growth of the fish bacterial pathogen Streptococcus iniae. rPoIL-21 also interacted with PBL, resulting in enhanced cell proliferation, ROS production, and expression of IL-1ß, TNF-α, CD8ß, T-bet, PoIL-21, PoIL-21 receptor, and STAT. Consequently, the presence of rPoIL-21 significantly reduced bacterial infection in PBL. In vivo study showed that rPoIL-21 upregulated the expression of inflammatory cytokines and PoIL-21. Taken together, these results indicate that PoIL-21 is an inducible, secreted cytokine with a broad range of binding capacities and plays an important role in the regulation of anti-bacterial immunity.

Characterization of Streptococcus iniae-induced microRNA profiles in Paralichthys olivaceus and identification of pol-3p-10740_175 as a regulator of antibacterial immune response.

MicroRNAs (miRNAs) are involved in many biological activities including immune defense against pathogens. In this study, we applied high-throughput sequencing technology to examine miRNAs in Japanese flounder (Paralichthys olivaceus) infected with Streptococcus iniae at different times. A total of 1038 miRNAs were identified, of which, 249 were novel miRNAs, and 81 showed differential expression (named DEmiRNAs) after S. iniae infection. Of the 81 DEmiRNAs identified, 34 and 58 occurred at 6 h and 24 h post-infection, respectively; most DEmiRNAs were strongly time-specific, and only 13.6% of the DEmiRNAs were shared between the two time points. A total of 9582 target genes were predicted for the 81 DEmiRNAs. The putative target genes were enriched in various GO and KEGG pathways of biological processes and molecular/cellular functions, in particular endocytosis, regulation of transcription, lysososme, and the signaling pathways of MAPK, ErbB, and AMPK. One of the DEmiRNAs, pol-3p-10740_175, was found to target dual specificity phosphatase 6 (Dusp6) and repress the expression of the latter. Transfection of flounder FG cells with pol-3p-10740_175 caused a significant inhibition on S. iniae invasion. The results of this study provided the first S. iniae-induced miRNA profile in Japanese flounder and indicated that flounder miRNAs play an important role in antibacterial immunity.

Particle and bacteria uptake by Japanese flounder (Paralichthys olivaceus) red blood cells: Size dependence and pathway specificity.

Red blood cells (RBCs) are traditionally considered non-professional phagocytes functioning predominately in oxygen transport. In the present study, we examined the ability of Japanese flounder (Paralichthys olivaceus), a teleost species with important economic values, RBCs to uptake inorganic particles and bacteria in different size/form, as well as the involving endocytic pathways. We found that flounder RBCs exhibited relatively high uptake/attachment capacities for 0.1 µm-1.0 µm (diameter) latex beads, but not for 2.0 µm beads. For the 0.1 µm beads, the uptake/attachment was executed through macropinocytosis and caveolae-mediated pathway, while for 0.5 µm and 1.0 µm beads, the uptake/attachment depended primarily on macropinocytosis and partially on the caveolin-mediated pathway. In addition to latex beads, flounder RBCs also exhibited an apparent capacity to engulf both live and inactivated bacteria. For live bacteria, the endocytosis was clathrin-mediated, while for inactivated bacteria, clathrin- as well as non-clathrin-mediated endocytosis were involved. Taken together, these results demonstrated that teleost RBCs possess particle uptake/attachment and bacteria phagocytosis capacities via different pathways that depend on the physical size and biological nature of the engulfed objects.

Tongue sole (Cynoglossus semilaevis) interleukin 10 plays a negative role in the immune response against bacterial infection.

Interleukin-10 (IL-10) is a pleiotropic cytokine and plays a crucial role in immunity. In the current study, we examined the expression patterns and biological functions of tongue sole Cynoglossus semilaevis IL-10 (CsIL-10). CsIL-10 is composed of 186 amino acid residues and shares 46.3%-71.7% identities with other teleost IL-10. Csil-10 expression occurred in multiple tissues and was regulated by bacterial infection. Recombinant CsIL-10 (rCsIL-10) in the form of a dimer bound to a wide range of bacterial species but did not affect bacterial growth. rCsIL-10 could interact with peripheral blood leukocytes (PBL) and significantly reduce the phagocytic activity, ROS production, and apoptosis of PBL. When injected in vivo, rCsIL-10 significantly suppressed the expression of proinflammatory cytokines and promoted bacterial dissemination in tongue sole tissues. Consistently, knockdown of Csil-10 significantly inhibited bacterial infection in tongue sole. Taken together, these results indicate that CsIL-10 plays a negative regulatory role in the immune response against bacterial infection.

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In this study, the effects of intercropping with alfalfa and nitrogen application on the functional diversity of soil microbial community in mulberry rhizosphere were examined by Biolog-EcoplateTM technique, and principal component and canonical analyses. Compared to monoculture with no nitrogen (N) addition, monoculture with N application and intercropping with alfalfa remarkably reduced soil pH and significantly increased the contents of soil organic matter, soil available N, soil water content, and activities of peroxidase and urease. Monoculture with N application and intercropping with alfalfa (with or without N application) increased the AWCD values, diversity index, and the carbon source utilization ratios of soil microbes. Higher increments of these parameters were detected in the treatment of intercropping plus N application. The results of principal component analysis showed that N application and intercropping changed the capacity of the rhizosphere microbial community for utilizing carbon sources. The utilization of carbon sources highly related to the principal components by the rhizosphere microbial communities was similar in the treatments of monoculture with N application and intercropping without N application. The utilization of itaconic acid and D-glucamaminic acid in the latter was more than 4% and was significantly higher than that in the former. The results from redundancy analysis showed that the soil microbial diversity in mulberry rhizosphere of the treatment of monoculture without N application was positively correlated with polyphenol oxidase activity and negatively correlated with soil water content, whereas that of monoculture with N application and intercropping without N application was significantly positively correlated with soil pH and soil water content and negatively correlated with soil N avalaibility. The diversity of the microbes in the rhizosphere soil of mulberries under the treatment of intercropping with N application showed positive correlation with soil N availability and was significantly negatively correlated with soil pH.