Enhanced antigen-specific CD8 T cells contribute to early protection against FMDV through swine DC vaccination.

Foot-and-mouth disease virus (FMDV) remains a challenge for cloven-hooved animals. The currently licensed FMDV vaccines induce neutralizing antibody (NAb)-mediated protection but show defects in the early protection. Dendritic cell (DC) vaccines have shown great potency in inducing rapid T-cell immunity in humans and mice. Whether DC vaccination could enhance early protection against FMDV has not been elaborately explored in domestic pigs. In this study, we employed DC vaccination as an experimental approach to study the roles of cellular immunity in the early protection against FMDV in pigs. Autologous DCs were differentiated from the periphery blood mononuclear cells of each pig, pulsed with inactivated FMDV (iFMDV-DC) and treated with LPS, and then injected into the original pigs. The cellular immune responses and protective efficacy elicited by the iFMDV-DC were examined by multicolor flow cytometry and tested by FMDV challenge. The results showed that autologous iFMDV-DC immunization induced predominantly FMDV-specific IFN-γ-producing CD4+ T cells and cytotoxic CD8+ T cells (CTLs), high NAb titers, compared to the inactivated FMDV vaccine, and accelerated the development of memory CD4 and CD8 T cells, which was concomitantly associated with early protection against FMDV virulent strain in pigs. Such early protection was associated with the rapid proliferation of secondary T-cell response after challenge and significantly contributed by secondary CD8 effector memory T cells. These results demonstrated that rapid induction of cellular immunity through DC immunization is important for improving early protection against FMDV. Enhancing cytotoxic CD8+ T cells may facilitate the development of more effective FMDV vaccines.IMPORTANCEAlthough the currently licensed FMDV vaccines provide NAb-mediated protection, they have defects in early immune protection, especially in pigs. In this study, we demonstrated that autologous swine DC immunization augmented the cellular immune response and induced an early protective response against FMDV in pigs. This approach induced predominantly FMDV-specific IFN-γ-producing CD4+ T cells and cytotoxic CD8+ T cells, high NAb titers, and rapid development of memory CD4 and CD8 T cells. Importantly, the early protection conferred by this DC immunization is more associated with secondary CD8+ T response rather than NAbs. Our findings highlighted the importance of enhancing cytotoxic CD8+ T cells in early protection to FMDV in addition to Th1 response and identifying a strategy or adjuvant comparable to the DC vaccine might be a future direction for improving the current FMDV vaccines.

Effects of Astragalus Combined with Angelica on Bone Marrow Hematopoiesis Suppression Induced by Cyclophosphamide in Mice.

Danggui Buxue Tang (DBT), a combination of Astragalus and Angelica at a 5 : 1 ratio, mainly promotes hematopoiesis. However, in the clinic, the combination ratio of Astragalus and Angelica to treat low hematopoietic function is not an absolute 5 : 1 ratio, suggesting that the herbs may promote hematopoiesis better after being combined at a certain range of ratios. The objective of this study is to investigate the effect of different ratio combinations of Astragalus and Angelica on bone marrow hematopoiesis suppression induced by cyclophosphamide (CTX) and to probe the interaction and mechanism of Astragalus combined with Angelica in promoting hematopoiesis. Following establishment of the model, mice were administered with Astragalus (6.00 g·kg-1), Angelica (3.00 g·kg-1), and combinations of Astragalus and Angelica at different ratios, including 10 : 1 (Astragalus 9.81 g·kg-1+Angelica 0.98 g·kg-1), 5 : 1 (Astragalus 9.00 g·kg-1+Angelica 1.80 g·kg-1), 2 : 1 (Astragalus 7.71 g·kg-1+Angelica 3.08 g·kg-1), 1 : 1 (Astragalus 5.40 g·kg-1+Angelica 5.40 g·kg-1), 1 : 2.5 (Astragalus 3.08 g·kg-1+Angelica 7.71 g·kg-1), 1 : 5 (Astragalus 1.80 g·kg-1+Angelica 9.00 g·kg-1), and 1 : 10 (Astragalus 0.98 g·kg-1+Angelica 9.81 g·kg-1). Our results suggested that Astragalus mixed with Angelica synergistically promoted hematopoiesis best when the combination ratio of Astragalus and Angelica was 1 : 1, 1 : 2.5 or 1 : 5; moreover, the effect of Angelica was greater than that of Astragalus. The potential mechanisms of the combinations of Astragalus and Angelica that promote hematopoiesis include the dissolution of the effective components, promoting the synthesis and secretion of hematopoietic growth factor (HGF) and the proliferation of hematopoietic progenitor cells (HPCs).

[Effects of Astragali Radix combined with Angelicae Sinensis Radix on the proliferation of hematopoietic stem cells senescence model in mice].

The aim is to study the effect and its mechanism of Astragalus Radix combined with Angelicae Sinensis Radix on the proliferation of hematopoietic stem cells(HSCs) in senescence model. After drug-containing plasma of rats was prepared via intragastric administration, HSCs of mice were cultured in vitro, and then they were divided into blank control group, model group, blank plasma group, Astragalus Radix + Angelicae Sinensis Radix 1∶1 group and 10∶1 group, Angelicae Sinensis Radix plasma group, and Astragalus Radix plasma group. HSCs senescence model was induced by using tert-butyl hydrogen peroxide(t-BHP), and intervened by drug-containing plasma. Cells senescence rate was tested by SA-ß-galactosidase staining method; cell cycle distribution was determined by flow cytometry; Cyclin D1, P21, and P53 mRNA were measured with RT-PCR, and Cyclin D1 protein expression was measured by Western blot. Results showed that after being induced by t-BHP, senescence rate of HSCs was increased; cell proliferation ability was decreased; count of G0/G1 phase cells was increased; count of G2/M+S phase cells was reduced; Cyclin D1 expression was down-regulated while P53, P21 expression was up-regulated, which were reversed by Astragalus Radix + Angelicae Sinensis Radix 1∶1 and 10∶1, single Angelicae Sinensis Radix, and single Astragalus Radix plasma. Furthermore, the above effects were most obvious in Astragalus Radix+Angelicae Sinensis Radix 1∶1 group. These results suggested that t-BHP can promote HSCs senescence and reduce cell proliferation ability. Angelicae Sinensis Radix, Astragalus Radix and their combinations can inhibit HSCs senescence, promote HSCs proliferation as well as cell cycle conversion; moreover, the effects of 1∶1 Astragalus Radix+Angelicae Sinensis Radix were strongest. The mechanisms may be related to up-regulating the expression of cell cycle positive regulator, down-regulating the expression of cell cycle negative regulator, thus promoting the cells to enter the proliferation phase from the stationary phase.

Spectrophotometric and ultrasensitive DNA bioassay by circular-strand displacement polymerization reaction.

We demonstrated a new spectrophotometric DNA detection approach based on a circular strand-displacement polymerization reaction for the quantitative detection of sequence specific DNA. In this assay, the hybridization of an immobilized hairpin probe on the microtiter plate, to target DNA, results in a conformational change and leads to a stem separation. A short primer thus anneals with the open stem and triggers a polymerization reaction, allowing a cyclic reaction comprising the release of target DNA and hybridization of the target with the remaining immobilized hairpin probe. Through this cyclical process, a large number of duplex DNA complexes are produced. Finally, the biotin modified duplex DNA products can be detected via the HRP catalyzed substrate 3,3',5,5'-tetramethylbenzidine using a spectrophotometer. As a proof of concept, a short DNA sequence (20-nt) related to the South East Asia (SEA) type deletion of α-thalassemia was chosen as the model target. This proposed assay has a very high sensitivity and selectivity with a dynamic response ranging from 0.1 fM to 10 nM and the detection limit was 8 aM. It can be performed within 2 hours, and it can differentiate target SEA DNA from wild-type DNA. By substituting the hairpin probes used in the present work, this assay can be used to detect other subtypes of genetic disorders.

An enzyme-free and label-free assay for copper(II) ion detection based on self-assembled DNA concatamers and Sybr Green I.

An enzyme-free and label-free fluorescence turn on biosensor for amplified copper(II) ion (Cu(2+)) detection has been constructed based on self-assembled DNA concatamers and Sybr Green I. This assay is simple, inexpensive and sensitive, enabling quantitative detection of as low as 12.8 pM Cu(2+).

Influence of zinc oxide nanoparticles on anaerobic digestion of waste activated sludge and microbial communities.

The influence of long-term exposure of zinc oxide nanoparticles (ZnO NPs) to waste activated sludge on anaerobic digestion and microbial communities was studied. The exposure concentrations were 0, 30, 60, 90, 120, and 150 mg g-1-volatile suspended solids (VSS) (dry). ZnO NPs inhibit the degradation of macromolecular organic matter and the reduction of VSS in waste activated sludge during anaerobic digestion. Only slight effects on the activities of protease, cellulase, acetated kinase, and coenzyme F420 were found at ZnO-NP concentrations of less than 30 mg g-1-VSS, whereas the activities of these three enzymes were adversely affected in a dose-dependent manner when the ZnO NP concentrations were increased from 30 mg g-1-VSS to 150 mg g-1-VSS. High-throughput sequencing analysis revealed that ZnO NPs had an adverse influence on the archaeal community diversity but increased the bacterial community diversity to some extent. High-throughput sequencing analysis also revealed that ZnO NPs resulted in different shift trends in the archaeal and bacteria community structure at phylum, class, and genus levels. ZnO NPs have negative impacts on the Euryarchaeota community, which plays a significant role as methanogens in the anaerobic digestion. In addition, ZnO NPs could increase the relative abundance of Clostridia and Bacteroidia, playing an important role in hydrolysis during the anaerobic digestion.

Methylome Variation Predicts Exemestane Resistance in Advanced ER+ Breast Cancer.

BACKGROUND: More than 30% of estrogen receptor-positive breast cancers are resistant to primary hormone therapy, and about 40% that initially respond to hormone therapy eventually acquire resistance. Although the mechanisms of hormone therapy resistance remain unclear, aberrant DNA methylation has been implicated in oncogenesis and drug resistance. PURPOSE: We investigated the relationship between methylome variations in circulating tumor DNA and exemestane resistance, to track hormone therapy efficacy. METHODS: We prospectively recruited 16 patients who were receiving first-line therapy in our center. All patients received exemestane-based hormone therapy after enrollment. We collected blood samples at baseline, first follow-up (after 2 therapeutic cycles) and at detection of disease progression. Disease that progressed within 6 months under exemestane treatment was considered exemestane resistance but was considered relatively exemestane-sensitive otherwise. We obtained circulating tumor DNA-derived methylomes using the whole-genome bisulfide sequencing method. Methylation calling was done by BISMARK software; differentially methylated regions for exemestane resistance were calculated afterward. RESULTS: Median follow-up for the 16 patients was 19.0 months. We found 7 exemestane resistance-related differentially methylated regions, located in different chromosomes, with both significantly different methylation density and methylation ratio. Baseline methylation density and methylation ratio of chromosome 6 [32400000-32599999] were both high in exemestane resistance. High baseline methylation ratios of chromosome 3 [67800000-67999999] (P = .013), chromosome 3 [140200000-140399999] (P = .037), and chromosome 12 [101200000-101399999] (P = .026) could also predict exemestane resistance. During exemestane treatment, synchronized changes in methylation density and methylation ratio in chromosome 6 [32400000-32599999] could accurately stratify patients in terms of progression-free survival (P = .000033). Cutoff values of methylation density and methylation ratio for chromosome 6 [149600000-149799999] were 0.066 and 0.076, respectively. CONCLUSION: Methylation change in chromosome 6 [149600000-149799999] is an ideal predictor of exemestane resistance with great clinical potential.

A universal biosensor for multiplex DNA detection based on hairpin probe assisted cascade signal amplification.

A hairpin DNA probe mediated cascade signal amplification method was developed for visual and rapid DNA analysis with a detection limit of 100 aM. The implementation of tag/anti-tag DNA and gold nanoparticle reporters permits a universal platform for multiplex genotyping without instrumentation.