We demonstrated previously that the incorporation of a membrane-anchored form of flagellin into influenza virus-like particles (VLPs) improved the immunogenicity of VLPs significantly, inducing partially protective heterosubtypic immunity by intramuscular immunization. Because the efficacy of mucosal vaccination is highly dependent on an adjuvant, and is particularly effective for preventing mucosal infections such as influenza, we determined whether the membrane-anchored flagellin is an efficient adjuvant for VLP vaccines by a mucosal immunization route. We compared the adjuvant effect of membrane-anchored and soluble flagellins for immunization with influenza A/PR8 (H1N1) VLPs by the intranasal route in a mouse model. The results demonstrate that membrane-anchored flagellin is an effective adjuvant for intranasal (IN) immunization, inducing enhanced systemic and mucosal antibody responses. High cellular responses were also observed as shown by cytokine production in splenocyte cultures when stimulated with viral antigens. All mice immunized with flagellin-containing VLPs survived challenge with a high lethal dose of homologous virus as well as a high dose heterosubtypic virus challenge (40 LD50 of A/Philippines/82, H3N2). In contrast, no protection was observed with a standard HA/M1 VLP group upon heterosubtypic challenge. Soluble flagellin exhibited a moderate adjuvant effect when co-administered with VLPs by the mucosal route, as indicated by enhanced systemic and mucosal responses and partial heterosubtypic protection. The membrane-anchored form of flagellin incorporated together with antigen into influenza VLPs is effective as an adjuvant by the mucosal route and unlike standard VLPs, immunization with such chimeric VLPs elicits protective immunity to challenge with a distantly related influenza A virus.

Previously, a modified HIV Env protein with a heterologous membrane anchor was found to be incorporated into HIV virus-like particles (VLPs) at 10-fold-higher levels than those of unmodified Env. To further improve the immunogenicity of such VLPs, membrane-anchored forms of bacterial flagellin (FliC) or a flagellin with a truncated variable region (tFliC) were constructed to be incorporated into the VLPs as adjuvants. HIV-specific immune responses induced by the resulting VLPs were determined in a guinea pig model. The VLPs induce enhanced systemic antibody responses by either systemic or mucosal vaccination and enhanced mucosal immunity by a mucosal immunization route, as demonstrated by high levels of HIV-specific serum IgG and mucosal IgG and IgA. The quality of the antibody responses was also improved, as shown by enhanced neutralization capacity. VLPs incorporating FliC were more effective in inducing systemic responses, while VLPs containing tFliC were more effective in inducing mucosal IgA responses. The IgG titers in sera were found to last for at least 5 months without a significant drop. These results indicate that HIV VLPs incorporating high levels of Env and a molecular adjuvant have excellent potential for further development as a prophylactic HIV vaccine.

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BackgroundSchistosomiasis remains a major public health concern in China and an epidemiological survey has revealed that schistosome-infected bovines and goats are the main transmission sources for the disease. Therefore, development of a sensitive technique for the diagnosis of schistosomiasis in domestic animals is necessary.MethodA novel colloidal gold immunochromatography assay (GICA) strip was developed for detecting Schistosoma japonicum in domestic animals. The colloidal gold was conjugated with recombinant streptococcal protein G (rSPG). As the test and control lines, the schistosome soluble egg antigen and rSPG, respectively, were blotted on nitrocellulose membrane.ResultsThe lowest detectable serum dilution was 1∶640 for schistosome-infected buffaloes. The cross-reaction rate of GICA was 14.29% with Paramphistomum sp. in buffaloes, 16.67% with Haemonchus sp. in goats, and 33.33% with Orientobilharzia sp. in goats. These results were slightly lower and similar to those obtained through ELISA. Moreover, the strips for detecting S. japonicum in mice, rabbits, buffaloes, and goats showed high sensitivity (100.00%, 100.00%, 100.00%, and 100.00%, respectively) and specificity (100.00%, 100.00%, 94.23%, and 88.64%, respectively). And the sensitivity or specificity of the GICA strips did not present any significant differences after storage for 12 months at room temperature. When compared with ELISA, the GICA strips exhibited similar sensitivity and specificity in the diagnosis of schistosomiasis in mice, rabbits, buffaloes, and goats. Besides, only 5 μl of serum are required for the test and the detection can be completed within 5 min.ConclusionThis study is the first to develop a GICA strip using gold–rSPG conjugate for the diagnosing of schistosomiasis in domestic animals, and preliminary results showed that the developed strip may be suitable for large-scale screening of schistosomiasis in endemic areas.Electronic supplementary materialThe online version of this article (doi:10.1186/s40249-017-0297-z) contains supplementary material, which is available to authorized users.

Flowering is a critical agricultural trait that substantially affects tomato fruit yield. Although drought stress influences flowering time, the molecular mechanism underlying drought-regulated flowering in tomato remains elusive. In this study, we demonstrated that loss of function of tomato OPEN STOMATA 1 (SlOST1), a protein kinase essential for abscisic acid (ABA) signaling and abiotic stress responses, lowers the tolerance of tomato plants to drought stress. slost1 mutants also exhibited a late flowering phenotype under both normal and drought stress conditions. We also established that SlOST1 directly interacts with and phosphorylates the NAC-type transcription factor VASCULAR PLANT ONE-ZINC FINGER 1 (SlVOZ1), at residue serine 67, thereby enhancing its stability and nuclear translocation in an ABA-dependent manner. Moreover, we uncovered several SlVOZ1 binding motifs from DNA affinity purification sequencing analyses and revealed that SlVOZ1 can directly bind to the promoter of the major flowering-integrator gene SINGLE FLOWER TRUSS (SFT) to promote tomato flowering transition in response to drought. Collectively, our data uncover the essential role of the SlOST1-SlVOZ1 module in regulating flowering in response to drought stress in tomato and offer insights into a novel strategy to balance drought stress response and flowering.

BackgroundSchistosomiasis is a huge threat to human and animal health. Apart from bovines, goats play an important role in the transmission of schistosomiasis in some endemic areas of China. An accessible, quality-assured goat schistosomiasis diagnostic technique is needed. Recently, our laboratory identified two recombinant diagnostic antigens, SjPGM and SjRAD23 via an immuno-proteomic method. The application of these two recombinant antigens to develop a higher sensitivity and specificity technique for the sheep schistosomiasis diagnosis is urgently needed.MethodsEpitopes of SjPGM and SjRAD23 were predicted and three polypeptides, two from SjRAD23 and one from SjPGM, were selected. Recombinant plasmids containing two to three DNA sequences encoding predicted polypeptides or large hydrophilic region of Sj23 (LHD-Sj23) were constructed and expressed. Eight recombinant schistosome antigens including four multi-epitope proteins and four recombinant single-molecule antigens as well as SEA, were assessed by ELISA in 91 sera from schistosome-infected goats, 44 sera from non-infected goats, 37 sera from Orientobilharzia-infected goats, and 12 from Haemonchus contortus-infected goats.ResultsELISA tests showed that three multi-epitope proteins had higher sensitivity than the four single-molecule antigens (rSjRAD23, rSjPGM, rBSjRAD23-1, rBSj23) and the multi-epitope protein rBSjPGM-BSjRAD23-1-BSj23 had the highest sensitivity (97.8 %, 89/91) and maintained good specificity (100 %, 44/44) as well as low cross-reactivity with haemonchosis (8.33 %, 3/12) and orientobilharziasis (13.51 %, 5/37) in the diagnosis of goat schistosomiasis. In contrast, when SEA was applied as a diagnosis antigen, it had 100 % (91/91) sensitivity, 75 % (33/44) specificity, 25 and 83.78 % cross-reactivity with haemonchosis (3/12) and orientobilharziasis (31/37), respectively.ConclusionsThe application of recombinant multi-epitope proteins may increase the sensitivity of diagnosis technique and retain high specificity of single-molecule antigens for schistosomiasis, and the recombinant antigen rBSjPGM-BSjRAD23-1-BSj23 has the potential to be used as a diagnosis antigen for goat schistosomiasis.

Al-Fe-, Al-Cu-, and Al-Fe-Cu-PILCs were synthesized, characterized and tested in the catalytic wet peroxide oxidation of 4-chlorophenol (4-CP). An apparent induction period followed by a rapid oxidation was observed during the Fenton-like reaction, and the whole reaction could be modeled well using a Fermi's kinetic equation (R 2 = 0.9938~0.9993). The generation of hydroxyl radicals (HO • ) from surface-catalyzed decomposition of H 2 O 2 was the oxidation cause whereas the dissolution of active metals was its result. Accordingly, induction period was the cause of heterogeneous surface activation (catalysis or modification) for more HO • formed by decreasing pH. 4-CP oxidation proceeded via 4-chlorocatechol (major) and hydroquinone (minor) pathways, along the formation of main intermediate (5-chloro-1,2,4-benzentriol). Finally besides CO 2 , H 2 O and Cl − two main compounds (I and II) formed, where the former was identified as 2,4-dioxopentanedioic acid whereas the latter as ferric-oxalate complex. There were marked structural and active differences between Al-Fe-PILC and Al-Cu-PILC in which compared to the latter, the former possessed higher SSA and activity but its optimal calcination temperature was lower and the induction time was also longer. In addition, compound II accounted for a considerable proportion in Al-Fe-PILC system whereas compound I was almost only component in Al-Cu-PILC system.

Discrimination of species and geographical origins of traditional Chinese medicine (TCM) is essential to prevent adulteration and inferior problems. We studied Ephedra sinica Stapf, Ephedra intermedia Schrenk et C.A.Mey. and Ephedra przewalskii Bge. to investigate the relationship between inorganic element content and these three species and their geographical origins. 38 elemental fingerprints from six major Ephedra-producing regions, namely, Inner Mongolia, Ningxia, Gansu, Shanxi, Shaanxi, and Sinkiang, were determined to evaluate the importance of inorganic elements to three species and their geographical origins. The contents of 15 elements, namely, N, P, K, S, Ca, Mg, Fe, Mn, Na, Cl, Sr, Cu, Zn, B, and Mo, of Ephedra samples were measured using inductively coupled plasma mass spectroscopy. Elemental contents were used as chemical indicators to classify species and origins of Ephedra samples using a radar plot and multivariate data analysis, including hierarchical cluster analysis (HCA), principal component analysis (PCA), and discriminant analysis (DA). Ephedra samples from different species and geographical origins could be differentiated. This study showed that inorganic elemental fingerprint combined with multivariate statistical analysis is a promising tool for distinguishing three Ephedra species and their geographical origins, and this strategy might be an effective method for authenticity discrimination of TCM.