Co-expression of tetanus toxin fragment C in Escherichia coli with thioredoxin and its evaluation as an effective subunit vaccine candidate.

The receptor-binding domain of tetanus toxin (THc), which mediates the binding of the toxin to the nerve cells, is a candidate subunit vaccine against tetanus. In this study one synthetic gene encoding the THc was constructed and highly expressed in Escherichia coli by co-expression with thioredoxin (Trx). The purified THc-vaccinated mice were completely protected against an active toxin challenge in mouse models of disease and the potency of two doses of THc was comparable to that of three doses of toxoid vaccine.

Development and evaluation of candidate vaccine and antitoxin against botulinum neurotoxin serotype F.

To produce a vaccine suitable for human use, a recombinant non His-tagged isoform of the Hc domain of botulinum neurotoxin serotype F (rFHc) was expressed in Escherichia coli and purified by sequential chromatography. The rFHc was evaluated as a subunit vaccine candidate in mouse model of botulism. A dose-response was observed in both antibody titer and protective efficacy with increasing dosage of rFHc and number of vaccinations.

Development and preclinical evaluation of a new F(ab')₂ antitoxin against botulinum neurotoxin serotype A.

Concern about the malicious applications of botulinum neurotoxin has highlighted the need for a new generation of safe and highly potent antitoxins. In this study, we developed and evaluated the preclinical pharmacology and safety of a new F(ab')₂ antitoxin against botulinum neurotoxin serotype A (BoNT/A). As an alternative to formalin-inactivated toxoid, the recombinant Hc domain of botulinum neurotoxin serotype A (rAHc) was used to immunize horses, and the IgGs from the hyperimmune sera were digested to obtain F(ab')₂ antitoxin.

The recombinant Hc subunit of Clostridium botulinum neurotoxin serotype A is an effective botulism vaccine candidate.

Vaccination with recombinant His-tagged isoforms of the Clostridium botulinum Hc domain of neurotoxin serotype A (rAHc) have effectively protected against challenge with active botulinum neurotoxin serotype A. To establish a formulation suitable for human use, rAHc was expressed in Escherichia coli without a His-tag and purified by sequential chromatography on ion-exchange and hydrophobic-interaction resins. Purified rAHc was used to vaccinate mice and survival was evaluated following challenge with active toxin.

Evaluation of a recombinant Hc of Clostridium botulinum neurotoxin serotype F as an effective subunit vaccine.

A new gene encoding the Hc domain of Clostridium botulinum neurotoxin serotype F (FHc) was designed and completely synthesized with oligonucleotides. A soluble recombinant Hc of C. botulinum neurotoxin serotype F was highly expressed in Escherichia coli with this synthetic FHc gene.

[Cloning NS1 gene of H5N1 avian influenza virus and apoptosis induced by it in human pulmonary carcinoma cell line A549].

The NS1 gene of the H5N1 subtype avian influenza virus was amplified by RT-PCR, and the am-plified product was cloned into the eukaryotic expression vector pCMV-Myc, then it was transfected into A549 cells. After 48 h, the expression of NS1 was detected by Western blot. Fluorescence and electron microscopy and flow cytometry showed that the NS1 gene of H5N1 avian influenza virus could induce apop-tosis in human pulmonary carcinoma cell line A549.

[Screening and identification of antibodies against transferrin receptor].

Aim: To screen the antibodies against transferrin receptor(TfR) from a full humanized phage antibody library.

Methods: Total RNA was extracted from HeLa cells and then the extracellular domain of TfR gene was amplified by RT-PCR in two parts. A full-length gene of extracellular domain was obtained by two rounds of PCR.

[Construction, expression and preliminary pharmacokinetic analysis of IL-1ra mutants].

Interleukin-1 receptor antagonist (IL-1ra), a member of IL-1 family, is a naturally occurring IL-1 inhibitor as "receptor antagonist", which blocks biological responses mediated by IL-1. Recombinant human IL-1ra (rhIL-1ra, Kineret) was introduced in clinical trials involving patients with RA. Between 2001 to approximately 2002, rhIL-1 ra was approved by the US Food and Drug Administration and the European Agency for the Evaluation of Medicine Procedure.

Generation of mouse FANCL antibody and analysis of FANCL protein expression profile in mouse tissues.

Fanconi anemia complementation group L (FANCL) is a novel Fanconi anemia protein, which mono-ubiquitinates FANCD2 as a ubiquitin E3 ligase, and plays a crucial role in DNA damage repair and chromosome stability maintenance. FANCL is involved in the proliferation of primordial germ cells (PGC) in early embryonic stages, and may play a role in the development of germ cells by forming a novel testis-specific network with testis-specific proteins in the adult testis. FancL cDNA sequence was cloned by RT-PCR from mouse testis total RNA, and expressed in E.

[Soluble expression and target study to brain of anti-TfR ScFv].

The single-chain antibody gene (ox26-scFv) to transferrin receptor (TfR) was synthesized and amplified by three-step PCR. After sequencing, the gene was cloned into prokaryotic expression vector pTIG-Trx which carried thioredoxin (Trx) gene and a C-terminal His.tag.