Serodiagnosis of toxoplasmosis by using a recombinant form of the 54-kilodalton rhoptry antigen expressed in Escherichia coli.

AUTOR(ES)

van Gelder, P

RESUMO

A 330-residue carboxy-terminal antigenic fragment of the Toxoplasma gondii 54-kDa rhoptry protein (ROP2) was expressed in Escherichia coli as a fusion polypeptide containing a 48-amino-acid sequence derived from phage lambda protein Cro and E. coli protein LacI followed by six consecutive histidyl residues. Metal chelate affinity chromatography provided an easy way to isolate the recombinant product in a highly purified form (> 95%). When this material was used to develop an immunoglobulin G (IgG) enzyme-linked immunosorbent assay for diagnosis of toxoplasmosis, the test reached a sensitivity of 89%. The sensitivity of the assay was similar whether the sera contained T. gondii-specific IgM or were devoid of such IgM. It was also found that ROP2 is a conserved antigen since antibodies against the recombinant antigen could be detected in mice experimentally infected with 11 independent T. gondii isolates originating from infected human tissues tested. Thus, the 54-kDa rhoptry antigen could advantageously complement other previously described T. gondii antigens for the development of more-sensitive and more-informative recombinant antigen-based tests for toxoplasmosis diagnosis.

Documentos Relacionados

• Monoclonal antibodies to a specific 54-kilodalton antigen of Nocardia spp.
• Use of partially purified 54-kilodalton antigen for diagnosis of nocardiosis by Western blot (immunoblot) assay.
• Identification and purification of a recombinant Treponema pallidum basic membrane protein antigen expressed in Escherichia coli.
• Cloning and characterization of a Bacillus subtilis gene encoding a homolog of the 54-kilodalton subunit of mammalian signal recognition particle and Escherichia coli Ffh.
• Purification, characterization, and genetic organization of recombinant Providencia stuartii urease expressed by Escherichia coli.