Rapid and ultrasensitive detection of pathogen-associated biomarkers is vital for the early diagnosis and therapy of bacterial infections. Herein, we developed a close-packed and ordered Au@AgPt array coupled with a cascade triggering strategy for surface-enhanced Raman scattering (SERS) and colorimetric identification of the Staphylococcus aureus biomarker micrococcal nuclease (MNase) in serum samples. The trimetallic Au@AgPt nanozymes can catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) molecules to SERS-enhanced oxidized TMB (oxTMB), accompanied by the color change from colorless to blue. In the presence of S. aureus, the secreted MNase preferentially cut the nucleobase AT-rich regions of DNA sequences on magnetic beads (MBs) to release alkaline phosphatase (ALP), which subsequently mediated the oxTMB reduction for inducing the colorimetric/SERS signal fade away. Using this "on-to-off" triggering strategy, the target S. aureus can be recorded in a wide linear range with a limit of detection of 38 CFU/mL in the colorimetric mode and 6 CFU/mL in the SERS mode. Meanwhile, the MNase-mediated strategy characterized by high specificity and sensitivity successfully discriminated between patients with sepsis (n = 7) and healthy participants (n = 3), as well as monitored the prognostic progression of the disease (n = 2). Overall, benefiting from highly active and dense "hot spot" substrate, MNase-mediated cascade response strategy, and colorimetric/SERS dual-signal output, this methodology will offer a promising avenue for the early diagnosis of S. aureus infection.

Myeloid derived suppressor cells (MDSCs) are a type of immature, differentiated, heterogeneous cells derived from the bone marrow. MDSC plays a dual role in parasitic infections. On the one hand, the cells can induce helper T cell 1/2 (Th1/Th2) immune responses by inducing host secretion of interferon-γ (IFN-γ), interleukin (IL)-4, and IL-13. On the other hand, they can also secrete IL-10, IL-17 and transforming growth factor-β (TGF-β) to induce regulatory T cells (Treg)/Th17 immune responses, thereby exerting immune protection or immune escape. This article provides a review of the research progress on the immune regulation of host T cells by MDSC in parasitic infections.

The leucine-rich repeat (LRR) containing 15 (LRRC15) protein is one of the members of the LRR superfamily. In the medical field, LRRC15 protein not only participates in parasitic, viral and other pathogen infections, but also plays a role in anti-tumor and rheumatoid arthritis treatment. It also regulates cell autophagy, stem cell ossification, and changes in hair follicle dermal papilla cell characteristics. This article reviews the research progress of LRRC15 protein in the medical field.

Objective:To construct a recombinant plasmid pET30a-leucine-rich repeat (LRR) containing 15 (LRRC15) of Taenia solium, prokaryotically express and purify the LRRC15 recombinant protein, and prepare a rabbit polyclonal antibody. Methods:The LRRC15 protein encoding gene of Taenia solium was obtained by whole gene synthesis; it was cloned into pET30a vector, and the recombinant plasmid pET30a-LRRC15 was constructed and identified by double-enzyme PCR; the recombinant plasmid was transformed into competent cells of Escherichia coli BL21 (DE3), and the recombinant protein LRRC15 was induced to express by isopropyl-beta-D-thiogalactopyranoside (IPTG), the expression product was analyzed and identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE); the LRRC15 recombinant protein was purified by Ni-IDA affinity columns, the purified recombinant protein was analyzed and identified by SDS-PAGE, and the specificity of the purified recombinant protein was identified by Western blot (WB); the New Zealand rabbits were immunized with purified LRRC15 recombinant protein to prepare polyclonal antibodies against LRRC15, and the potency of the purified polyclonal antibody was determined by indirect enzyme-linked immunosorbent assay (ELISA). Results:After PCR identification, a band with a length of 1 506 bp was amplified, which was consistent with the LRRC15 gene; after SDS-PAGE and WB identification, the LRRC15 target protein with a relative molecular mass ( Mr) of about 55.36 × 10 3 was obtained; after immunizing New Zealand rabbits with purified LRRC15 recombinant protein, a polyclonal antibody against LRRC15 was obtained, and its potency was 1∶1 587 200. Conclusion:The recombinant plasmid pET30a-LRRC15 is successfully constructed, the LRRC15 recombinant protein of Taenia solium is prepared, and a high purity and high potency rabbit anti polyclonal antibody against LRRC15 recombinant protein is obtained.

Parasitic infection are an important global public health issue, and parasites can modulate and evade host immune attacks through various ways. In recent years, studies have shown that in the process of parasite infection, transforming growth factor-β (TGF-β)/Smad signaling pathway participates in host T cell immune response, induce T cells to proliferate and differentiate towards regulatory cells (Treg) and helper T cells (Th), regulate Treg/Th17 cell balance, inhibit Th1 cell proliferation and differentiation, and play an important role in the occurrence and development of parasitic diseases and their interactions with the host. This article reviews the research progress of T cell immune responses mediated by TGF-β/Smad signaling pathway in the process of parasite infection.

The epitranscriptomic mark N⁶-methyladenosine (m⁶A), which is the predominant internal modification in RNA, is important for plant responses to diverse stresses. Multiple environmental stresses caused by the tea-withering process can greatly influence the accumulation of specialized metabolites and the formation of tea flavor. However, the effects of the m⁶A-mediated regulatory mechanism on flavor-related metabolic pathways in tea leaves remain relatively uncharacterized. We performed an integrated RNA methylome and transcriptome analysis to explore the m⁶A-mediated regulatory mechanism and its effects on flavonoid and terpenoid metabolism in tea (Camellia sinensis) leaves under solar-withering conditions. Dynamic changes in global m⁶A level in tea leaves were mainly controlled by two m⁶A erasers (CsALKBH4A and CsALKBH4B) during solar-withering treatments. Differentially methylated peak-associated genes following solar-withering treatments with different shading rates were assigned to terpenoid biosynthesis and spliceosome pathways. Further analyses indicated that CsALKBH4-driven RNA demethylation can directly affect the accumulation of volatile terpenoids by mediating the stability and abundance of terpenoid biosynthesis-related transcripts and also indirectly influence the flavonoid, catechin, and theaflavin contents by triggering alternative splicing-mediated regulation. Our findings revealed a novel layer of epitranscriptomic gene regulation in tea flavor-related metabolic pathways and established a link between the m⁶A-mediated regulatory mechanism and the formation of tea flavor under solar-withering conditions.
RNA/metabolism* ; Epigenome ; Plant Proteins/metabolism* ; Plant Leaves/metabolism* ; Camellia sinensis/metabolism* ; Flavonoids ; Terpenes/metabolism* ; Tea/metabolism* ; Gene Expression Regulation, Plant

Oolong tea is a semi-fermented tea with strong flavor, which is widely favored by consumers because of its floral and fruity aroma as well as fresh and mellow taste. During the processing of oolong tea, withering is the first indispensable process for improving flavor formation. However, the molecular mechanism that affects the flavor formation of oolong tea during withering remains unclear. Transcriptome sequencing was used to analyze the difference among the fresh leaves, indoor-withered leaves and solar-withered leaves of oolong tea. A total of 10 793 differentially expressed genes were identified from the three samples. KEGG enrichment analysis showed that the differentially expressed genes were mainly involved in flavonoid synthesis, terpenoid synthesis, plant hormone signal transduction and spliceosome pathways. Subsequently, twelve differentially expressed genes and four differential splicing genes were identified from the four enrichment pathways for fluorescence quantitative PCR analysis. The results showed that the expression patterns of the selected genes during withering were consistent with the results in the transcriptome datasets. Further analysis revealed that the transcriptional inhibition of flavonoid biosynthesis-related genes, the transcriptional enhancement of terpenoid biosynthesis-related genes, as well as the jasmonic acid signal transduction and the alternative splicing mechanism jointly contributed to the flavor formation of high floral and fruity aroma and low bitterness in solar-withered leaves. The results may facilitate better understanding the molecular mechanisms of solar-withering treatment in flavor formation of oolong tea.
Camellia sinensis/genetics* ; Gene Expression Profiling ; Plant Leaves ; Plant Proteins/metabolism* ; Taste ; Tea ; Transcriptome/genetics*

Thioredoxin peroxidase (TPx) belongs to the superfamily of peroxiredoxins, which is widely expressed in various growth and development stages of parasites and their excretory secretions. On the one hand, recombinant TPx protein can participate in host immunoregulation; on the other hand, recombinant TPx protein has high sensitivity and specificity as a diagnostic antigen, and can be used for immunodiagnosis of parasitic diseases; in addition, it can also be used as a candidate vaccine molecule for the immunoprophylaxis of parasitic diseases. This paper reviews the research progress on host immunoregulation, immunodiagnosis and immunoprophylaxis by recombinant TPx protein of important human parasites.

Objective:To establish the prokaryotic expression system of Taenia solium (Ts) 14-3-3.2, and observe the expression of Ts14-3-3.2 protein at the stages of Ts adult and cysticercus. Methods:Based on the Ts14-3-3.2 gene sequence obtained by the Department of Parasitology, Zunyi Medical University in the previous study, the whole gene was synthesized by PCR-based accurate synthesis (PAS) method. After double digestion with restriction enzymes Nde Ⅰ and Xba Ⅰ, the plasmid pCzn1 was ligated to construct a recombinant plasmid pCzn1-Ts14-3-3.2. Then it was transformed into Escherichia coli ArcticExpress competent cells to induce the expression of Ts14-3-3.2 protein. The expression products were analyzed and identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and coomassie blue staining. The purified Ts14-3-3.2 recombinant protein was obtained by Ni-affinity chromatography. New Zealand rabbits were immunized with the recombinant protein to produce Ts14-3-3.2 polyclonal antibody. Western blotting was used to detect the expression of Ts14-3-3.2 protein at the stages of Ts adult and cysticercus. Results:The recombinant plasmid pCzn1-Ts14-3-3.2 was successfully constructed. After induced expression, Ts14-3-3.2 target protein bands appeared in the supernatant and precipitated at the relative molecular weight of about 29.31 × 10 3. The purified Ts14-3-3.2 recombinant protein with His label could be recognized by anti-His monoclonal antibody, and the Ts14-3-3.2 polyclonal antibody with titer of 1 ∶ 512 000 was obtained. Western blotting showed that Ts14-3-3.2 protein was expressed at the stages of Ts adult and cysticercus. Conclusions:The prokaryotic expression system of Ts14-3-3.2 is successfully established, and the Ts14-3-3.2 polyclonal antibody with relatively higher purity and titer is obtained. The Ts14-3-3.2 protein is expressed at the stages of Ts adult and cysticercus.

Taeniasis is a kind of zoonotic parasitosis which seriously endangers human health. Drug therapy and vaccine control is one of the hotspots in current research. At present, proteomics has become an important tool for developing vaccines and understanding the pathogenic mechanism. The differences in protein patterns between different developmental stages of parasites may reflect the specific strategies and adaptive mechanisms used in the constantly changing environment and life cycle. Therefore, this article reviews the proteomics research progress of various tapeworms, aiming at providing a reference for prevention and control of Taeniasis.