ABSTRACT
Objective To analyze the RNA binding protein of Toxoplasma gondii (TgDDX39) using bioinformatics technology, and to evaluate the immunogenicity of TgDDX39, so as to provide insights into development of toxoplasmosis vaccines. Methods The amino acid sequences of TgDDX39 were retrieved from the ToxoDB database, and the physicochemical properties, transmembrane structure domain, signal peptide sites, post-translational modification sites, coils, secondary and tertiary structures, hydrophobicity, and antigenic epitopes of the TgDDX39 protein were predicted using online bioinformatics tools, incluiding ProtParam, TMHMM 2.0, SignalP 5.0, NetPhos 3.1, COILS, SOPMA, Phyre2, ProtScale, ABCpred, SYFPEITHI and DNA-STAR. Results TgDDX39 protein was predicted to be an unstable hydrophilic protein with the molecular formula of C2173H3458N598O661S18, which contained 434 amino acids and had an estimated molecular weight of 49.1 kDa and a theoretical isoelectric point of 5.55. The protein was predicted to have an extremely low possibility of signal peptides, without transmembrane regions, and contain 27 phosphorylation sites. The β turn and random coils accounted for 39.63% of the secondary structure of the TgDDX39 protein, and a coiled helix tended to produce in one site. In addition, the TgDDX39 protein contained multiple B and T cell antigenic epitopes. Conclusions Bioinformatics analyses predict that TgDDX39 protein has high immunogenicity and contains multiple antigenic epitopes. TgDDX39 protein is a potential candidate antigen for vaccine development.
ABSTRACT
Precisely delivering combinational therapeutic agents has become a crucial challenge for anti-tumor treatment. In this study, a novel redox-responsive polymeric prodrug (molecular weight, MW: 93.5 kDa) was produced by reversible addition-fragmentation chain transfer (RAFT) polymerization. The amphiphilic block polymer-doxorubicin (DOX) prodrug was employed to deliver a hydrophobic photosensitizer (PS), chlorin e6 (Ce6), and the as-prepared nanoscale system [NPs(Ce6)] was investigated as a chemo-photodynamic anti-cancer agent. The glutathione (GSH)-cleavable disulfide bond was inserted into the backbone of the polymer for biodegradation inside tumor cells, and DOX conjugated onto the polymer with a disulfide bond was successfully released intracellularly. NPs(Ce6) released DOX and Ce6 with their original molecular structures and degraded into segments with low MWs of 41.2 kDa in the presence of GSH. NPs(Ce6) showed a chemo-photodynamic therapeutic effect to kill 4T1 murine breast cancer cells, which was confirmed from a collapsed cell morphology, a lifted level in the intracellular reactive oxygen species, a reduced viability and induced apoptosis. Moreover, ex vivo fluorescence images indicated that NPs(Ce6) retained in the tumor, and exhibited a remarkable in vivo anticancer efficacy. The combinational therapy showed a significantly increased tumor growth inhibition (TGI, 58.53%). Therefore, the redox-responsive, amphiphilic block polymeric prodrug could have a great potential as a chemo-photodynamic anti-cancer agent.
ABSTRACT
Objective@#To evaluate the value of non-invasive prenatal testing (NIPT) in pregnancies with anomaly in prenatal screening. @*Methods@#This was a retrospective study of 2 837 singleton pregnancies who performed NIPT indicated by isolated anomaly in prenatal screening at Guangdong Women and Children Hospital between November 2014 and August 2016. All pregnancies were divided into 3 groups by single indication: advanced maternal age ( AMA, ≥35), abnormal multiples of the median (MoM) in standard screening, increased nuchal translucency thickness (NT, 2.5-3.0 mm). High risk results were verified by prenatal diagnosis. Low risk cases were followed by a 22-26 week anatomical ultrasound examination. All of the cases were followed up and the performance of NIPT for every single indication was evaluated. @*Results@#There were total of 2 837 pregnant women who underwent NIPT. Twenty-five of 2 448 pregnancies indicated by AMA had high risk results, among which 17 were confirmed by invasive genetic testing, except 1 case rejecting prenatal diagnosis. In 351 pregnant women with abnormal MoM, NIPT found 3 cases of sex chromosome aneuploidies (SCA) and 2 of them were validated by invasive prenatal diagnosis. Increased NT group included 38 cases, NIPT found 1 case of trisomy 21 which was consistent with karyotype analysis. For common aneuploidies and SCA, the performance of NIPT in the pregnant women who indicated by AMA, abnormal MoM and increased NT were as the follows: the sensitivity were 17/17, 2/2 and 1/1 respectively, the specificity were 99.7% (2 423/2 431), 99.7% (348/349) and 100%(37/37), the positive predictive value were 68% (17/25), 2/3 and 1/1, the negative predictive value were 100% (2 423/2 423), 100% (348/348) and 100% (38/38), respectively. By follow-up survey, a total of 8 cases of abnormal fetus were recorded in NIPT low-risk women, including 5 cases of termination of pregnancy due to abnormal ultrasound findings, 2 cases of abortion as a result of severe obstetric complications and 1 case of stillbirth. @*Conclusions@#To the pregnant women who indicated by advanced maternal age, abnormal MoM and increased NT (2.5-3.0 mm), NIPT had satisfactory performance for common aneuploidies, and also had potential value for SCA, resulting in a significant reduction in diagnostic procedures. However, for NIPT low-risk pregnancies, routine antenatal examination and anatomical ultrasound detection would be highly necessary to avoid missing abnormal fetuses.(Chin J Lab Med, 2018, 41: 509-513)