Identification of a potential antigen stimulating immune response against Vibrio parahaemolyticus infection in hybrid tilapia (Oreochromis aureus♂ × Oreochromis niloticus♀).

Vibrio parahaemolyticus (V. parahaemolyticus) is a major pathogen that causes substantial losses in the marine fishery. With the emergence of antibiotic resistance, vaccines have become the most effective approach against V. parahaemolyticus infection. Adhesion factors on the cell surface are pivotal in the colonization and pathogenesis of V. parahaemolyticus within the host, highlighting their potential as vaccine candidates. This study aims to assess the immunogenicity and potential of recombinant V. parahaemolyticus MAM7 (rMAM7) as a vaccine candidate. Initially, we cloned and purified the MAM7 protein of V. parahaemolyticus. Moreover, after 4 weeks of vaccination, the fish were challenged with V. parahaemolyticus. rMAM7 demonstrated a certain protective effect. Immunological analysis revealed that rMAM7 immunization-induced antibody production and significantly increased acid phosphatase (ACP) and alkaline phosphatase (AKP) activity in hybrid tilapia. Furthermore, serum bactericidal tests demonstrated a lower bacterial survival rate in the rMAM7 group compared to PBS and rTrxa. qRT-PCR results indicated that rMAM7 significantly upregulated CD4, CD8 and IgM gene expression, suggesting the induction of Th1 and Th2 responses in hybrid tilapia. Overall, these findings highlight the potential application of MAM7 from V. parahaemolyticus in the development of protein vaccines.

Mass flow, enrichment and potential environmental impacts of mercury in a preheater-precalciner cement plant using multiple mining and industrial wastes.

Cement plants (CPs) are one of the most important anthropogenic sources of mercury (Hg) emissions in China. Over 1000 cement production lines operate in China and use various raw materials; however, little data on Hg emissions is recorded on site. This study investigated a CP in Guizhou Province that uses multiple mining and industrial wastes as part of the circular economy policy. Among the various raw materials, carbide slag had the highest Hg content (2.6 mg/kg) and contributed half of the Hg input. High Hg concentration (27 mg/kg) in the kiln tail dust and a strong Hg enrichment factor (39) was found, which was determined as the ratio of total Hg accumulated within the clinker production process to the daily Hg input from raw materials and fuel. The clinker had negligible Hg (0.001 mg/kg), while the Hg in cement products (0.04 mg/kg) mostly came from additives and retarders. The estimated atmospheric emission factor of Hg from this CP was 161.5 mg Hg/t clinker, which was much higher than those of other CPs in Guizhou that employ low-Hg raw materials. A five-step sequential extraction experiment with kiln tail dust indicates that Hg mainly existed in fraction of F4 (73-96% of the total Hg, possibly as Hg2Cl2) and that some samples had high proportions of water-soluble Hg (up to 21% of the total), which may be easily released into surrounding water bodies and pose high environmental risks. Using low-Hg raw (or alternative raw) materials and conducting proper disposal of kiln tail dust will reduce the environmental risk of Hg from CPs.

Fluorotrifluoromethylation of Alkenes Mediated by a Hypervalent Trifluoromethyl-Iodine(III) Reagent.

Herein, we present a novel strategy for synthesizing polyfluorinated compounds by the fluorotrifluoromethylation of olefins, which was achieved through a new trifluoromethyl-iodine(III) reagent TFNI-1. TFNI-1 was readily synthesized via a three-step process, and its structure was characterized by NMR spectroscopy and X-ray crystallography. It is shown by radical trapping and radical clock experiments that the reaction involves the CF3 radical intermediate.

Mechanism study of cross presentation of exogenous antigen induced by cholera toxin-like chimeric protein.

Tumor subunit vaccines have great potential in personalized cancer immunotherapy. They are usually administered with adjuvant owing to their low immunogenicity. Cholera toxin (CT) is a biological adjuvant with diverse biological functions and a long history of use. Our earlier study revealed that a CT-like chimeric protein co-delivered with murine granulocyte-macrophage colony stimulating factor (mGM-CSF) and prostate cancer antigen epitope could co-stimulate dendritic cells (DCs) and enhance cross presentation of tumor epitope. To further study the molecular mechanism of CT-like chimeric protein in cross presentation, major histocompatibility complex class I (MHC I)-restricted epitope 257-264 of ovalbumin (OVAT) was used as a model antigen peptide in this study. Recombinant A subunit and pentameric B subunit of CT protein were respectively genetically constructed and purified. Then both assembled into AB5 chimeric protein in vitro. Three different chimeric biomacromolecules containing mGM-CSF and OVAT were constructed according to the different fusion sites and whether the endoplasmic reticulum (ER) retention sequence was included. It was found that A2 domain and B subunit of CT were both available for loading epitopes and retaining GM1 affinity. The binding activity of GM1 was positively correlated with antigen endocytosis. Once internalized, DCs became mature and cross-presented antigen. KDEL helped the whole molecule to be retained in the ER, and this improved the cross presentation of antigen on MHC I molecules. In conclusion, hexameric CT-like chimeric protein with dual effects of GM1 affinity and ER retention sequence were potential in improvement of cross presentation. The results laid a foundation for designing personalized tumor vaccine based on CT-like chimeric protein molecular structure.

Synthesis and antitumor activity of aza-brazilan derivatives containing imidazolium salt pharmacophores.

The synthesis of a series of novel aza-brazilan derivatives containing imidazolium salt pharmacophores is presented. The biological activity of such imidazolium salts was further evaluated in vitro against a panel of human tumor cell lines. The results suggest that the electron-withdrawing group on the aza-brazilan moiety, substituted 5,6-dimethyl-benzimidazole ring and substitution of the imidazolyl-3-position with a 4-methylbenzyl group were essential for modulating the cytotoxic activity. Compounds 55 and 39, bearing a 4-methylbenzyl substituent at position-3 of 5,6-dimethyl-benzimidazole, were found to be the most potent compounds with IC50 values of 0.52-1.30 µM and 0.56-1.51 µM against four human tumor cell lines investigated. Particularly, compound 57 exhibited inhibitory activity against the MCF-7 cell line with an IC50 value of 0.35 µM and was 56-fold more sensitive than DDP. Moreover, compound 55 inhibited cell proliferation through inducing G0/G1 cell cycle arrest and apoptosis in SMMC-7721 cells.