[Protein interaction site of Toxoplasma gondii microneme protein 6 and aldolase determined by site-directed mutagenesis].

Objective: To identify the protein interaction site of Toxoplasma gondii microneme protein 6 (MIC6) and aldolase by using site-directed mutagenesis.

Methods: Based on Toxoplasma gondii MIC6 gene sequence (GenBank Accession No. AF110270), the specific primers were designed.

Genotyping of Pneumocystis jirovecii isolates from Chinese HIV-infected patients based on nucleotide sequence variations in the internal transcribed spacer regions of rRNA genes.

Genetic diversity of Pneumocystis jirovecii isolates based on internal transcribed spacer (ITS) of the nuclear rRNA locus has previously been reported. The information about ITS genotype and epidemiology of this organism in Chinese human immunodeficiency virus-infected patients has not been available. In this study, 12 bronchoalveolar lavage fluid specimens obtained from HIV-infected patients were analyzed by PCR followed by cloning, sequencing and typing.

Molecular cloning and characterization of a matrix metalloproteinase, from Caenorhabditis elegans: employed to identify homologous protein from Angiostrongylus cantonensis.

Matrix metalloproteinases (MMPs) are a class of zinc-binding endopeptidases mainly responsible for degrading extracellular matrix constituent components, which also serve as effectors of leukocyte recruitment, cytotoxicity, cytokine and chemokine processing, and defensin activation involved in multiple mechanisms of immunomodulation. MMPs are a conserved proteolytic enzyme family participating in normal physiological function. In the present study, we have cloned a gene named CEMMP62 from Caenorhabditis elegans, the putative 62-kDa protein that contained 579 residues with MMP-conserved catalytic domain known as ZnMc_MMP and showed high identities with MMPs from other nematodes, and demonstrated that the recombinant CEMMP62 (rCEMMP62) expressed and purified from Escherichia coli could have weak proteolytic activity on swine gelatin; Western blot analysis revealed that sera from BALB/c mice immunized by recombinant protein could recognize excretory-secretary antigens from Angiostrongylus cantonensis third-stage larvae (L3).

[Protein interaction between aldolase and actin of Toxoplasma gondii by GST pull-down].

Objective: To identify the protein-protein interaction between aldolase and actin of Toxoplasma gondii by GST pull-down.

Methods: The aldolase and actin genes were obtained from cDNA library by PCR amplification, and subcloned respectively into pGEX-4T-1 and pET30a. The fusion protein GST-Aldolase and Actin-His6 were expressed in E.

Specific detection of Angiostrongylus cantonensis in the snail Achatina fulica using a loop-mediated isothermal amplification (LAMP) assay.

Angiostrongylus cantonensis, a rat lungworm, can cause eosinophilic meningitis and angiostrongyliasis in humans following ingestion of contaminated foods or intermediate/paratenic hosts with infective larvae. The snail Achatina fulica is one of the important intermediate hosts of A. cantonensis and is commonly eaten by humans in some countries.

[Epidemiological investigation of Angiostrongylus cantonensis in Jiangmen of Guangdong Province].

Objective: To make an epidemiological survey on Angiostrongylus cantonensis in Jiangmen City of Guangdong Province.

Methods: From October 2006 to November 2007, the characteristics of A. cantonensis infection were investigated in Jiangmen district in various hosts, including the third stage larva infection in the snails Achatina fulica and Pomacea canaliculata by digestion method, and the adult A.

[Pathological change in the brain of mice infected with Angiostrongylus cantonensis].

Objective: To observe the pathological change in the brain of Angiostrongylus cantonensis-infected mouse.

Methods: Forty-eight mice were orally infected each with 40 third stage larvae of A. cantonensis, 3 mice were sacrificed at 7, 10, 13, 16, 19, 22, 25, 28 days postinfection respectively for worm recovery, and another 3 mice were for observing the histopathological change in tissue sections of the brain.

Absence of Pneumocystis jirovecii dihydropteroate synthase gene mutations among samples from a group of AIDS patients in China.

Pneumocystis jirovecii dihydropteroate synthase (DHPS) gene mutations are associated with failure of sulfur prophylaxis of Pneumocystis pneumonia. Here the P. jirovecii DHPS gene was amplified from bronchoalveolar fluid of 10 AIDS patients in China.

[Construction of the life cycle of Angiostrongylus cantonensis in laboratory].

Objective: To construct the life cycle of Angiostrongylus cantonensis (A.cantonensis) in laboratory condition.

Methods: SD rats were infected orally with the third-stage larvae of A.

[Identification and tissue localization of intermediate filament protein in Angiostrongylus cantonensis].

Objective: To identify the type of the intermediate filament (IF) protein of Angiostrongylus cantonensis and analyze its tissue localization.

Methods: Recombinant pET-IF of antigen IF was expressed in E.coli with IPTG induction, and the expression products were purified by His.

[Sequence analysis and expression of GRA7 gene of Toxoplasma gondii isolates in Escherichia coli].

Objective: To analyze the difference of GRA7 gene of Toxoplasma gondii different isolated strains and express GRA7 in Escherichia coli.

Methods: The GRA7 gene was amplified from genomes of T. gondii isolates by PCR and was cloned into pGEX-4T-1.

Schistosoma japonicum: construction of phage display antibody library and its application in the immunodiagnosis of infection.

Background: A monoclonal antibody would be an effective tool for the detection of circulating antigens in the serum of patients with schistosomiasis, but the traditional way of producing monoclonal antibodies is not cost-effective. The objective of this study was to find a new method for the large-scale production of monoclonal antibodies against Schistosoma japonicum (Sj).

Methods: A phage display antibody library for Sj was constructed.

[Expression of proteinase cathepsin L1 gene of Schistosoma japonicum in Escherichia coli].

Objective: To express the proteinase cathepsin L1 gene of Schistosoma japonicum (SjCL1) in Escherichia coli JM109 cells.

Methods: The SjCL1 gene was amplified from the recombinant plasmid pcDNA3-SjCL1 by PCR. The gene was cloned into a prokaryotic expression vector pGEX4T-1 to construct a recombinant plasmid pGEX-SjCL1.

[Screening and identification of phage antibodies from phage display library against Schistosoma japonicum].

Objective: To obtain single chain variable fragment(ScFv) against the circulating antigen(CAg) from Schistosoma japonicum(Sj).

Methods: Metabolic antigen of adult worm of Sj (Sj-MAg) was used in the panning of phage library against Schistosoma japonicum. The activity of Sj-MAg-binding phage clones was assayed by ELISA.