In silico discovery and anti-tumor bioactivities validation of an algal lectin from Kappaphycus alvarezii genome.

Lectins are proteins that bind specifically and reversibly to carbohydrates, and some of them have significant anti-tumor activities. Compared to those of lectins from land plants, there are far fewer studies on algal lectins, despite of the high biodiversity of algae. However, canonical strategies based on chromatographic feature-oriented screening cannot satisfy the requirement for algal lectin discovery. In this study, prospecting for novel OAAH family lectins throughout 358 genomes of red algae and cyanobacteria was conducted. Then 35 candidate lectins and 1843 of their simulated mutated forms were virtually screened based on predicted binding specificities to characteristic carbohydrates on cancer cells inferred by a deep learning model. A new lectin, named Siye, was discovered in Kappaphycus alvarezii genome and further verified on different cancer cells. Without causing agglutination of erythrocytes, Siye showed significant cytotoxicity to four human cancer cell lines (IC50 values ranging from 0.11 to 3.95 µg/mL), including breast adenocarcinoma HCC1937, lung carcinoma A549, liver cancer HepG2 and romyelocytic leukemia HL60. And the cytotoxicity was induced through promoting apoptosis by regulating the caspase and the p53 pathway within 24 h. This study testifies the feasibility and efficiency of the genome mining guided by evolutionary theory and artificial intelligence in the discovery of algal lectins.

Genome-wide analysis of lectins in cyanobacteria: from evolutionary mode to motif patterns.

Lectins are glycoproteins that can bind to specific carbohydrates, and different lectin families exhibit different biological activities. They are also present in the cyanobacteria and many of them have shown excellent therapeutic effect, which deserve for bioprospecting. However, in comparison to those from terrestrial plants, the current knowledge on cyanobacterial lectins is very limited. To this end, genome-wide analyses were performed to find out their evolutionary mode and motif patterns in 316 genomes of representative taxa. In results, 196 putative cyanobacterial lectins were dig out and 105 of them were classified into known families. Seven lectins were found to be belonged to distinct two lectin families, and they may have the potential activities of both lectin families. Whereas no MFP-2, Chitin, and Nictaba family lectins were found. What's more, the Legume lectin-like lectin family was found to be the richest and most complex in cyanobacteria, which could be a main research direction for future cyanobacterial lectin bioprospecting and development. Our classification and prediction of cyanobacteria lectins is expected to provide assistance in the development of lectin-based medicine and provide solutions to the current thorny viral and tumor diseases in humans.

Plastid Engineering of a Marine Alga, Nannochloropsis gaditana, for Co-Expression of Two Recombinant Peptides.

The purpose of this study was to establish a plastid transformation system for expressing recombinant proteins in Nannochloropsis gaditana. On the basis of the sequenced plastid genome, the homologous flanking region, 16S-trnI/trnA-23S, and the endogenous regulatory fragments containing the psbA promoter, rbcL promoter, rbcL terminator, and psbA terminator were amplified from N. gaditana as elements of a plastid transformation vector. Then, the herbicide-resistant gene (bar) was used as a selectable marker, regulated by the psbA promoter and rbcL terminator. Finally, two codon-optimized antimicrobial peptide-coding genes linked by endogenous ribosome binding site (RBS) in a polycistron were inserted into the constructed vector under the regulation of the rbcL promoter and psbA terminator. After microparticle bombardment, the positive clones were detected using polymerase chain reaction (PCR), and Southern and Western blotting were used to assess the co-expression of the two antimicrobial peptides from the plastid. Nannochloropsis gaditana showed the potential to express recombinant proteins for biotechnological applications, for example, for the development of oral vaccines in aquaculture.

Critical role of OX40/OX40L in ILC2-mediated activation of CD4+T cells during respiratory syncytial virus infection in mice.

CD4+T cells are crucial cellular source of type 2 cytokines and responsible for RSV-induced asthma-like symptoms and asthma exacerbations. However, the mechanism for regulating the activation of CD4+T cells during RSV infection is not clear completely. We show in this study that infection with RSV may induce an expansion and activation of CD4+T cells in the lungs of BALB/c mice. RSV-induced CD4+T cell expansion and activation seems to depend upon the pulmonary group 2 innate lymphoid cells (ILC2s), since adoptive transfer of lung ILC2s can enhance not only the numbers of CD4+T cells but also the cytokine production by CD4+T cells. Interestingly, blockade of the contact between ILC2s and CD4+T cells, may significantly diminish the CD4+T cell expansion and cytokine production, suggesting that membrane molecules may be involved in ILC2-regulated CD4+T cell activation. In fact, infection with RSV resulted in an increase in the numbers of OX40+CD4+T cells as well as OX40L+ILC2s in the lungs of mice. Moreover, the mRNA expressions of OX40 and OX40L as well as the levels of OX40 and OX40L proteins in the lung CD4+T cells and ILC2s were elevated respectively. When co-culture of CD4+T cells with ILC2s in the presence of anti-OX40L antibody, the cytokine productions by CD4+T cells were reduced markedly, suggesting that lung ILC2s may regulate RSV-induced CD4+T cell expansion and activation perhaps via OX40/OX40L interaction.

Respiratory syncytial virus prevents the subsequent development of ovalbumin-induced allergic responses by inhibiting ILC2 via the IL-33/ST2 pathway.

AIM: How respiratory syncytial virus (RSV) influences the development of ovalbumin (OVA)-induced asthma remains elusive. As potent T helper (Th)2 cytokine producers, group 2 innate lymphoid cells (ILC2s) are known to serve important functions in the pathogenesis of allergic inflammation. However, how RSV infection affects innate immunity, especially with regard to the function of ILC2s in OVA-induced allergic airway inflammation, is largely unknown. MATERIALS & METHODS: RSV was used to infect adult BALB/c mice intranasally prior to sensitization and subsequent challenge with OVA. ILC2 frequencies and Th2 cytokine production by ILC2s were assessed by flow cytometry. Cytokine levels were detected both by real-time PCR and ELISA. RESULTS: Previous infection with RSV attenuated airway inflammation and decreased Th2 cytokine production in mice sensitized and challenged with OVA. Furthermore, previous infection with RSV inhibited the influx of ILC2s into the lung, and constrained their Th2 cytokine production. Adoptive transfer of ILC2s increased asthma-associated airway inflammation in mice previously infected with RSV. These results indicate that previous infection with RSV prevents OVA-induced asthma development via inhibition of ILC2s. Previous infection with RSV attenuated IL-33 production in lung tissue and reduced relative ST2L expression in lung ILC2s, meaning that previous infection with RSV may alter ILC2 function via the IL-33/ST2 signaling pathway. CONCLUSION: These results demonstrate that previous infection with RSV attenuates OVA-induced airway inflammation by inhibiting the recruitment and Th2 cytokine production of ILC2s via the IL-33/ST2 pathway.

Natural helper cells mediate respiratory syncytial virus-induced airway inflammation by producing type 2 cytokines in an IL-33-dependent manner.

AIM: Type 2 cytokine production during respiratory virus infection is considered to be linked with asthma exacerbation. As potent Th2 cytokine producers, natural helper (NH) cells play a key role in influenza virus-induced airway hyper-responsiveness. However, it is unclear whether NH cells contribute to respiratory syncytial virus (RSV)-induced airway inflammation, and how the cytokine profile in NH cells is changed during RSV infection. METHODS: BALB/c mice were infected intranasally with RSV. The number of NH cells in lungs was detected by flow cytometry. The expression of cytokine mRNAs was performed by real-time RT-PCR. Cytokines levels were determined by ELISA. RESULTS: Following intranasal infection with RSV, BALB/c mice showed an increase in the expression of mRNAs for Th2-like cytokines in NH cells. Furthermore, adoptive transfer of pulmonary NH cells resulted in a massive infiltration of mononuclear cells, in particular eosinophils and neutrophils in lungs, in parallel with an augmented production of Th2-associated cytokines, such as IL-4, IL-5 and IL-10 in bronchoalveolar lavage fluids, providing convincing evidence that NH cells contribute to RSV-induced lung pathogenesis by producing type 2 cytokines. It should be noted that blocking IL-33 with antibody can diminish the absolute number of pulmonary NH cells and the relative expression of mRNAs for type 2 cytokines in pulmonary NH cells, suggesting that IL-33 is necessary for activating Th2-type NH cells. CONCLUSION: These results reveal that pulmonary NH cells might participate in RSV-induced airway inflammation by producing large quality of type 2 cytokines in an IL-33-dependent manner.

Murine bone marrow-derived DCs activated by porcine rotavirus stimulate the Th1 subtype response in vitro.

Rotavirus (RV) infection causes acute, watery dehydrating diarrhea and even death in infants and other young animals, resulting in a severe economic burden; however, little is known about the innate immune mechanisms associated with RV infection. Dendritic cells (DCs), which are professional antigen-presenting cells (APCs), serve as a bridge connecting the innate and adaptive immune system. In this study, the interaction between murine bone marrow-derived DCs (BMDCs) and porcine rotavirus (PRV) was investigated in vitro. Upon stimulation, the expression levels of MHC-II, CD40, CD80, CD86 and CD83 in BMDCs increased in a time-dependent manner, indicating activation and maturation by PRV. In addition, up-regulated Toll-like receptor 2 (TLR2), TLR3 and NF-κB increased the production of interleukin-12 and interferon-γ. The PRV-stimulated BMDCs also showed increased stimulatory capacity in mixed lymphocyte reactions and promoted the Th1 subtype response.

Elastic, conductive, polymeric hydrogels and sponges.

As a result of inherent rigidity of the conjugated macromolecular chains resulted from the delocalized π-electron system along the polymer backbone, it has been a huge challenge to make conducting polymer hydrogels elastic by far. Herein elastic and conductive polypyrrole hydrogels with only conducting polymer as the continuous phase have been simply synthesized in the indispensable conditions of 1) mixed solvent, 2) deficient oxidant, and 3) monthly secondary growth. The elastic mechanism and oxidative polymerization mechanism on the resulting PPy hydrogels have been discussed. The resulting hydrogels show some novel properties, e.g., shape memory elasticity, fast functionalization with various guest objects, and fast removal of organic infectants from aqueous solutions, all of which cannot be observed from traditional non-elastic conducting polymer counterparts. What's more, light-weight, elastic, and conductive organic sponges with excellent stress-sensing behavior have been successfully achieved via using the resulting polypyrrole hydrogels as precursors.

Biosynthesis and immobilization of biofunctional allophycocyanin.

The holo-allophycocyanin-α subunit, which has various reported pharmacological uses, was biosynthesized with both Strep-II-tag and His-tag at the N-terminal in Escherichia coli. The streptavidin-binding ability resulting from the Strep II-tag was confirmed by Western blot. Additionally, the metal-chelating ability deriving from the His-tag not only facilitated its purification by immobilized metal-ion affinity chromatography but also promoted its immobilization on Zn (II)-decorated silica-coated magnetic nanoparticles. The holo-allophycocyanin-α subunit with streptavidin-binding ability was thereby immobilized on magnetic nanoparticles. Magnetic nanoparticles are promising as drug delivery vehicles for targeting and locating at tumors. Thus, based on genetic engineering and nanotechnology, we provide a potential strategy to facilitate the biomodification and targeted delivery of pharmacological proteins.

[Prevalence trend of neural tube defect in Zhengzhou city, 1996-2005].

OBJECTIVE: To describe the prevalence trend and epidemiological characteristics of neural tube defects (NTDs) in perinatal in Zhengzhou city from 1996 to 2005. METHODS: Data collected from hospital were used to depict the epidemiology of NTDs in Zhengzhou. All perinatal fetuses born in hospitals had an access within 7 days after delivery. The prevalence were calculated by perinatal'year, sex, birth area (urban versus rural) and maternal age. All monitored perinatal (162,074) accounted for 32.66% from totals (496,203). RESULTS: All 238 cases were found NTDs, and the overall prevalence rate was 14.68/10,000. The annual prevalence rate presented a decreasing trend during that period. The rates in rural and urban area, in male and female birth were 29.28/10,000 and 9.63/10,000, 11.42/10,000 and 17.74/10,000 respectively. There were significant differences among maternal-age-specific prevalence rates (chi2 = 22.952, P = 0.000). The rates of <20 years group(53.76/10,000) and >35 years group(21.74/10,000) were higher than others. CONCLUSION: The prevalence rates of NTDs in rural area is higher than that in urban, female's is higher than male's in Zhengzhou. The annual prevalence rates of NTDs presents a decreasing trend in the past ten years.