Detection of human Toxoplasma-specific immunoglobulins A, M, and G with a recombinant Toxoplasma gondii rop2 protein.
The Toxoplasma gondii rhoptry protein Rop2 was expressed in Escherichia coli as a fusion protein containing 44 kDa of the 55-kDa mature Rop2, supplied with six histidyl residues at the N-terminal end (Rop2196-561). Humoral response during Toxoplasma infection of humans was analyzed by immunoglobulin G (IgG), IgA, and IgM enzyme-linked immunosorbent assay with Rop2196-561 as the antigen substrate. The analyzed sera were divided according to T. gondii-specific serological tests (IgG, IgA, or IgM indirect immunofluorescence and IgA or IgM immunosorbent agglutination assay) as group A (IgG+ IgA- IgM-; n = 35), group B (IgG+ IgA+ IgM+; n = 21), group C (IgG+ IgA+ IgM-; n = 5), and group D (IgG+ IgA- IgM+; n = 16). Twenty-six T. gondii-seronegative sera from individuals with other infections were also included (group E). Anti-Rop2 IgG antibodies were detected in 82.8% of group A sera and in 97.6% of the sera with acute-phase marker immunoglobulins (groups B, C, and D). The percentage of IgA antibody reactivity against Rop2196-561 was 17.1% in group A, 50% in group D, and 80.8% in groups B and C. The percentage of IgM antibody reactivity was 0% in groups A and C and 62% in groups B and D. Sera from group E failed to show IgA, IgM, or IgG antibody reactivity. Since T. gondii Rop2 elicits a strong humoral response from an early stage of infection, it is suggested that recombinant Rop2196-561 would be suitable for use in diagnostic systems, in combination with other T. gondii antigens, to detect specific IgG, IgA, and IgM antibodies.
Martin
V
V
Departamento de Parasitología, ANLIS Dr. Carlos G. Malbran, Buenos Aires, Argentina.
Arcavi
M
M
Santillan
G
G
Amendoeira
M R
MR
De Souza Neves
E
E
Griemberg
G
G
Guarnera
E
E
Garberi
J C
JC
Angel
S O
SO
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000918:Antibody Specificity; D000953:Antigens, Protozoan / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007114:Immunization; D015151:Immunoblotting; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007136:Immunoglobulins / Q000097:blood*; D008297:Male; D051379:Mice; D010957:Plasmids / Q000235:genetics; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000175:diagnosis / Q000276:immunology; D015800:Protozoan Proteins / Q000235:genetics* / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology*; D014122:Toxoplasma / Q000254:growth & development / Q000276:immunology*; D014123:Toxoplasmosis / Q000175:diagnosis* / Q000276:immunology; D014125:Toxoplasmosis, Congenital / Q000175:diagnosis / Q000276:immunology
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins