Specific and sensitive IgG4 immunodiagnosis of onchocerciasis with a recombinant 33 kD Onchocerca volvulus protein (Ov33)

Abstract

The full length cDNA of the immunodominant Ov33 protein of Onchocerca volvulus was expressed in E. coli using various vector constructs. Expression was best with the vectors pGEX2T and pCG808fx, yielding fusion protein Ov33-GST and Ov33-MBP, respectively. Purified fusion protein Ov33-GST and O. volvulus antigen extracts (OvAg) were used to compare antibody responses (IgM and IgG-subclasses) of patients infected with O. volvulus, Brugia malayi, Wuchereria bancrofti, Mansonella perstans/Loa loa and of Sudanese control sera. Sera of all groups contained IgM reacting with Ov33-GST and with OvAg. There was no IgG1 response to Ov33-GST. IgG1 responses to OvAg were only detected in filariasis sera...