Publications by authors named "Huai-Jie Hao"
Article Synopsis
- The study aimed to create a version of the suilysin protein that does not cause hemolysis (destruction of red blood cells) while still retaining its immune response capabilities.
- Researchers mutated the proline residue at position 353 to three different amino acids (alanine, leucine, and valine) and purified these recombinant proteins to test their hemolytic activity.
- Among the mutants, SLY(P353V) exhibited no hemolytic activity but still demonstrated significant immunogenicity in further tests.
[Expression, purification and activity assay of Streptococcus suis serotype 2 cell wall protein SSU1664].
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi
July 2011
Article Synopsis
- The study aimed to amplify and express the SSU1664 gene from Streptococcus suis in E.coli, and to evaluate the resulting protein's activities.
- The gene was amplified using PCR, cloned into an expression vector, and the protein was purified; its immunogenic properties were assessed using Western blot and ELISA.
- Results indicated that the recombinant protein was immunogenic, with higher levels of anti-SSU1664 antibodies in infected patients, suggesting it could serve as a vaccine candidate and diagnostic marker for early Streptococcus suis infection.
[Purification and biological activities analysis of streptococcus suis Serotype 2 suilysin].
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi
April 2011
Aim: To explore the purification methods of wild-type and recombinant suilysin and to evaluate their biological activities.
Methods: Wild-type suilysin was purified by ammonium sulfate precipitation, anion-exchange chromatography and hydrophobic chromatography in turn, while recombinant suilysin was first refolded and purified by immobilized metal ion affinity chromatography, and further purified by Thiopropyl Sepharose 6B. The biological activities were evaluated by hemolysis test, cytotoxicity assay.
In this study, we evaluated SEA-H61D, a staphylococcal enterotoxin A mutant without emetic activity, as an antitumor agent in vitro and in vivo. It showed that SEA-H61D could significantly inhibit the growth of many cancer cell lines in vitro at very low concentrations by activating human peripheral blood mononuclear cells (PBMCs). CD4+ and CD8+ T lymphocytes could be activated at a dose between 125 and 500 μg/kg.
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- Colloidal gold was created using sodium citrate to develop immunochromatographic strips for detecting Streptococcus suis serotype 2 antigen by coupling it with a specific polyclonal antibody.
- Optimal concentrations for the antibodies and a blocking agent were identified, enhancing the performance of the test strips.
- The final product demonstrated high sensitivity (detecting as low as 10^6 CFU/mL) and specificity, making it an effective tool for rapid and convenient detection of S. suis serotype 2 without cross-reacting with other bacteria.
Hepatocellular carcinoma (HCC), one of the most common and malignant tumors worldwide, is unresponsive to any of the available therapies. Using intact HCC cells as therapeutic targets, we isolated a novel peptide, denoted HCC79 (KSLSRHDHIHHH), from a phage display peptide library. HCC79 can bind to hepatoma cell membranes with high affinity and specificity.
View Article and Find Full Text PDFSince the mid-1980s, there has been a resurgence of severe forms of invasive group A streptococcal (GAS) disease in many countries and regions. However, there has not been any systemic epidemiologic analysis of GAS disease reported in mainland China. To analyse the molecular epidemiology of GAS disease, 86 strains from patients in different regions of mainland China were collected.
View Article and Find Full Text PDFBacterial superantigens (SAg) are the most potent activators of human T lymphocytes and recombinant immunotoxin using bacterial SAg shows promising clinical values. To engineer superantigen for immunotherapy of hepatocellular carcinoma, we genetically fused the superantigen staphylococcus enterotoxin A (SEA(D(227)A)) to the single-chain disulfide-stabilized Fv (scdsFv) of anti-hepatoma monoclonal antibody HAb25 through a short peptide GGGSGGS. We expressed this recombinant protein in Escherichia coli and extract it from inclusion bodies.
View Article and Find Full Text PDFAim: To express, purify, and characterize scdsFv antibody fused with superantigen SEA(D227A).
Methods: The expression plasmid of scdsFv-SEA(D227A) was constructed by standard molecular cloning procedures. The recombinant protein was induced to express in E.