Suppressive Effects on the Immune Response and Protective Immunity to a JEV DNA Vaccine by Co-administration of a GM-CSF-Expressing Plasmid in Mice

As a potential cytokine adjuvant of DNA vaccines, granulocyte-macrophage colony–stimulating factor (GM-CSF) has received considerable attention due to its essential role in the recruitment of antigen-presenting cells, differentiation and maturation of dendritic cells. However, in our recent study of a Japanese encephalitis virus (JEV) DNA vaccine, co-inoculation of a GM-CSF plasmid dramatically suppressed the specific IgG response and resulted in decreased protection against JEV challenge. It is known that GM-CSF has been used in clinic to treat neutropenia for repopulating myeloid cells, and as an adjuvant in vaccine studies; it has shown various effects on the immune response. Therefore, in this study, we characterized the suppressive effects on the immune response to a JEV DNA vaccine by the co-administration of the GM-CSF-expressing plasmid and clarified the underlying mechanisms of the suppression in mice. Our results demonstrated that co-immunization with GM-CSF caused a substantial dampening of the vaccine-induced antibody responses. The suppressive effect was dose- and timing-dependent and likely related to the immunogenicity of the antigen. The suppression was associated with the induction of immature dendritic cells and the expansion of regulatory T cells but not myeloid-derived suppressor cells. Collectively, our findings not only provide valuable information for the application of GM-CSF in clinic and using as a vaccine adjuvant but also offer further insight into the understanding of the complex roles of GM-CSF

High resolution bio- and chemostratigraphic framework at the Frasnian-Famennian boundary: Implications for regional stratigraphic correlation between different sedimentary facies in South China

© 2017 Elsevier B.V. As one of the “Big Five” mass extinctions in Phanerozoic, the Frasnian-Famennian (F-F) boundary event records the extinction of 40 % of marine invertebrate genera. The F-F boundary is defined by the first appearance of conodont Palmatolepis subperlobata as well as the abundant occurrences of Pa. ultima at the base of the Lower Pa. triangularis Zone. The F-F boundary is also broadly coincident with a positive excursion in carbon isotopes, suggesting the possible linkage between the perturbation of marine carbon cycle and the biotic crisis. However, the correlation between conodont biostratigraphy and carbon isotope chemostratigraphy has not been established yet, preventing the high-resolution regional stratigraphic correlation among different sedimentary facies. In this study, we studied the conodont biostratigraphy and analyzed carbonate carbon (δ13Ccarb) and organic carbon (δ13Corg) isotopes of the Baisha section in the Guangxi Province, South China. The first appearance of index conodont fossil Pa. subperlobata for the Lower Pa. triangularis Zone, i.e. the F-F boundary, is coincident with the onset of a 3‰ positive excursion in δ13Ccarb, while Pa. triangularis and Pa. subperlobata occur nearly simultaneously, but predate the disappearances of Pa. linguiformis and other typical Frasnian elements. In addition, a positive excursion in δ13Corg is associated with the decline of δ13Ccarb near the base of the Middle Pa. triangularis Zone, which is marked by the first appearance of Pa. delicatula. Another important Famenian element Pa. minuta, the index fossil for the Upper Pa. triangularis Zone, first appears when δ13Corg starts to decline. The offset between δ13Corg and δ13Ccarb excursions could be attributed to the oceanic anoxia (the Kellwasser Event) near the F-F boundary, followed by the mixing of surface and deep water in earliest Famenian. The high resolution bio- and chemostratigraphic framework can be used as the standard for regional stratigraphic correlation and identification of the F-F boundary in different depositional environments in South China. We propose that the F-F boundary can be identified from a conodont-poor carbonate section by the onset of the positive excursion in δ13Ccarb, whereas the F-F boundary in a non-fossiliferous siliciclastic section might be placed slightly below the positive excursion in δ13Corg

Biostratigraphy and Chemostratigraphy Across the Lower Kellwasser Boundary in Laye Section, Guizhou Province

© 2018 Peking University. In order to study biostratigraphy and chemical stratigraphy during the Lower Kellwasser event, high resolution conodonts research and chemostratigraphic framework were carried out. The data reveals that the inorganic and organic carbon isotope have a significant positive excursion at the bottom of the Laye section. It is considered that the sample LY-8 is consistent with the Lower Kellwasser boundary. The main reason for the change of carbon isotope in this area is the increase of organic carbon burial, which is caused by the increase of marine primary productivity and anoxia environment possibly

Transcriptional Differences in Peanut (Arachis hypogaea L.) Seeds at the Freshly Harvested, After-ripening and Newly Germinated Seed Stages: Insights into the Regulatory Networks of Seed Dormancy Release and Germination.

Seed dormancy and germination are the two important traits related to plant survival, reproduction and crop yield. To understand the regulatory mechanisms of these traits, it is crucial to clarify which genes or pathways participate in the regulation of these processes. However, little information is available on seed dormancy and germination in peanut. In this study, seeds of the variety Luhua No.14, which undergoes nondeep dormancy, were selected, and their transcriptional changes at three different developmental stages, the freshly harvested seed (FS), the after-ripening seed (DS) and the newly germinated seed (GS) stages, were investigated by comparative transcriptomic analysis. The results showed that genes with increased transcription in the DS vs FS comparison were overrepresented for oxidative phosphorylation, the glycolysis pathway and the tricarboxylic acid (TCA) cycle, suggesting that after a period of dry storage, the intermediates stored in the dry seeds were rapidly mobilized by glycolysis, the TCA cycle, the glyoxylate cycle, etc.; the electron transport chain accompanied by respiration was reactivated to provide ATP for the mobilization of other reserves and for seed germination. In the GS vs DS pairwise comparison, dozens of the upregulated genes were related to plant hormone biosynthesis and signal transduction, including the majority of components involved in the auxin signal pathway, brassinosteroid biosynthesis and signal transduction as well as some GA and ABA signal transduction genes. During seed germination, the expression of some EXPANSIN and XYLOGLUCAN ENDOTRANSGLYCOSYLASE genes was also significantly enhanced. To investigate the effects of different hormones during seed germination, the contents and differential distribution of ABA, GAs, BRs and IAA in the cotyledons, hypocotyls and radicles, and plumules of three seed sections at different developmental stages were also investigated. Combined with previous data in other species, it was suggested that the coordination of multiple hormone signal transduction nets plays a key role in radicle protrusion and seed germination