Screening Of High Immunogenic Antigen Of T. Gondii And Its Preliminary Application

Toxoplasmosis is an important apicomplexan disease with medical and veterinarysignificance. There is still no effective drug for its control. At present, parts of the worldpopulation infected with Toxoplasma gondii is quite common, there are around2billionpeople are infected. In China, since1964the first case about toxoplasmosis was reported,have been discovered more and more cases of toxoplasmosis, fetal malformations incongenital toxoplasmosis in the first place[2].Toxoplasmosis may cause severe complicationsin pregnant women and immunocompromised patients. If infection occurs during pregnancy,the parasite can cross the placental barrier and cause severe damage to the fetus. Inimmunocompromised patients, toxoplasmic encephalitis can be life-threatening.In recent years, many toxoplasma genes have been cloned,and several genes or genefragments have been expressed in heterologous systems. Until now, only a limited number ofrecombinant antigens have been tested in an ELISA. In this study, we got positive gene oftoxoplasma gondii cDNA libraries, then,amplification sequences can choose express strongeffects of GRA7protein.gene of GRA7was expressed and purified. recombinant antigenand natural antigen were analyzed by ELISA.Firstly, PCR amplified46positive cloning ofcDNA library screening results, sequencing appraisal results were compared in NCBI(http://blast.ncbi.nlm.nih.gov/Blast.) and the Genebank, we obtained two cDNA molecules,respectively ME49strains coding toxoplasma gondii dense granules protein7(GRA7) androd body protein2(ROP2) part of the pieces. GRA7genes was cloned andexpressed.through the nickel column purification of soluble recombinant protein.cultured T.gondii ME49strain, collection, purification of Toxoplasma gondii soluble antigens.GRA7recombinant proteins and Toxoplasma gondii natural antigens were tested in an ELISAformat for the serum of200pregnant women of T. gondii infection.17cases of therecombinant antigens GRA7serum positive. Natural antiges test200serum of19casespositive. The positive rates were8.5%and9.5%. Compared with the natural antigen,recombinant antigen of GRA7the detection sensitivity of89.5%, expected to replace thenatural antigen as a diagnostic antigen. The immunoreactivity of the recombinant antigenshas potential application in the serodiagnosis of T. gondii infection.