The 65 kDa MAG-1 antigen is abundantly located in the bradyzoite’s cyst matrix and it is poorly expressed in tachyzoites. To date no definitive systems are available to detect bradyzoites, responsible of T. gondii reactivation. Home made oligonucleotides deduced from MAG-1 gene and from 35 fold repetitive B1 gene were employed in RT-PCR and Southern blot in detecting relapses of Toxoplasma gondii encephalitis (TE), from nine AIDS patients under anti-TE prophylaxis or treatment. Cerebrospinal fluid (CSF) specimens were checked with both primers and a comparative evaluation was made. The expression of mRNA detected by MAG-1 gene was significantly higher (no. 9/9, 100%) compared to that observed for B1 gene (no. 6/9, 66.6%; p < 0.01), and a specific fragment (212 bp) was confirmed by Southern blot analysis and alignment by GenBank data base (dbEST). The MAG-1 amplified fragment, was internal to 1.2 kb exon, which codifies an antigenic fraction expressed in cystic stage only. Since MAG-1 transcription has been experimentally determined during bradyzoite conversion, our system might be useful in processing clinical specimens especially from patients with TE reactivation.
Expression of Toxoplasmic 65 kDa Cystic mRNA by RT-PCR in Patients with Toxoplasma gondii Relapses
CULTRERA, Rosario;SERACENI, Silva;CONTINI, Carlo
2001
Abstract
The 65 kDa MAG-1 antigen is abundantly located in the bradyzoite’s cyst matrix and it is poorly expressed in tachyzoites. To date no definitive systems are available to detect bradyzoites, responsible of T. gondii reactivation. Home made oligonucleotides deduced from MAG-1 gene and from 35 fold repetitive B1 gene were employed in RT-PCR and Southern blot in detecting relapses of Toxoplasma gondii encephalitis (TE), from nine AIDS patients under anti-TE prophylaxis or treatment. Cerebrospinal fluid (CSF) specimens were checked with both primers and a comparative evaluation was made. The expression of mRNA detected by MAG-1 gene was significantly higher (no. 9/9, 100%) compared to that observed for B1 gene (no. 6/9, 66.6%; p < 0.01), and a specific fragment (212 bp) was confirmed by Southern blot analysis and alignment by GenBank data base (dbEST). The MAG-1 amplified fragment, was internal to 1.2 kb exon, which codifies an antigenic fraction expressed in cystic stage only. Since MAG-1 transcription has been experimentally determined during bradyzoite conversion, our system might be useful in processing clinical specimens especially from patients with TE reactivation.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
