Objective:To express,purify,prepare antibodies,and analyze the subcellular localization of Toxoplasma gondii thioredoxin 20(Trx20),and to provide the reference for the development of Toxoplasma gondii vaccine.Methods:Bioinformatics-related websites and software were used to perform bioinformatics analysis of the Trx20 protein;specific primers were designed to amplify the target fragment and construct the prokaryotic expression vector;the protein was expressed in vitro and purified;experimental animals were immunized to prepare antibodies;enzyme-linked immunosorbent assay(ELISA)method was used to detect the titer of the polyclonal antibodies;Western blotting method was used to verify the specificity and sensitivity of the antibodies and to determine the natural expression of the protein;immunofluorescence assay(IFA)was used to analyze the subcellular localization of the protein.Results:The bioinformatics analysis results showed that Trx20 protein was a relatively stable hydrophilic protein with a molecular formula of C2172H3412N548O616S20,containing 424 amino acids,a predicted relative molecular mass of 47 700,and a theoretical isoelectric point of 8.55;it was predicted that the protein had one signal peptide,no transmembrane region,contained one domain named"Thioredoxin like Superfamily",and had 35 phosphorylation sites,one N-glycosylation site,and 17 antigenic determinants;in the secondary structure,alpha-helices accounted for 41.51％of the total amino acids,and random coils accounted for 39.86％;the recombinant plasmids pET-28a-Trx20 and pGEX-4T-1-Trx20 were successfully constructed,and the soluble recombinant protein was expressed and purified;polyclonal antibodies were successfully prepared with a titer as high as 1:64 000,and they specifically recognized the endogenous Trx20 protein in Toxoplasma gondii;the subcellular localization results showed that Trx20 protein was widely distributed in the cytoplasm of the parasite.Conclusion:Toxoplasma gondii Trx20 protein is a secretory protein containing phosphorylation/glycosylation modification sites and a thioredoxin domain,and it is localized in the cytoplasm of the parasite.

Pleomorphic adenoma (PA) is the most common benign tumour in the salivary gland and has high morphological complexity. However, the origin and intratumoral heterogeneity of PA are largely unknown. Here, we constructed a comprehensive atlas of PA at single-cell resolution and showed that PA exhibited five tumour subpopulations, three recapitulating the epithelial states of the normal parotid gland, and two PA-specific epithelial cell (PASE) populations unique to tumours. Then, six subgroups of PASE cells were identified, which varied in epithelium, bone, immune, metabolism, stemness and cell cycle signatures. Moreover, we revealed that CD36⁺ myoepithelial cells were the tumour-initiating cells (TICs) in PA, and were dominated by the PI3K-AKT pathway. Targeting the PI3K-AKT pathway significantly inhibited CD36⁺ myoepithelial cell-derived tumour spheres and the growth of PA organoids. Our results provide new insights into the diversity and origin of PA, offering an important clinical implication for targeting the PI3K-AKT signalling pathway in PA treatment.
Humans ; Adenoma, Pleomorphic/genetics* ; Phosphatidylinositol 3-Kinases ; Proto-Oncogene Proteins c-akt ; Transcriptome ; Myoepithelioma