Antigenicity and specificity of very low molecular weight Onchocerca volvulus polypeptides in the range 2.2-12.5 kD.
Onchocerca volvulus polypeptides in the molecular mass range of 2.2 to 12.5 kD were separated by Tricine-SDS-PAGE and the serological recognition of these very low molecular weight antigens (VLMW-OvAg) was then investigated by immuno-blotting. Sera from 21 onchocerciasis patients as well as from 53 individuals with other filariases were used to determine the sensitivity and specificity of detection of individual VLMW-OvAg. In onchocerciasis patients, up to 16 VLMW-OvAg were recognized predominantly by IgG1 and IgG4, while only few antigens were recognized by IgG2 and IgG3. The antigen recognition pattern varied individually, but 4 VLMW-OvAg of 8.6, 6.2, 5.4, and 5.1 kD, respectively, were bound by IgG4 from more than 90% of the onchocerciasis patients. Six VLMW-OvAg of 7.3, 5.8, 5.4, 4.0, 3.8, and 3.6 kD were recognized exclusively by IgG1 from onchocerciasis patients. In amicrofilaraemic filariasis patients with lymphatic pathology, a strong reactivity of IgG3 to an OvAg of 2.2 kD was observed, indicating a possible contribution of this antigen to the pathogenesis. In the molecular mass range below 13 kD, no specific carbohydrate residues or phosphorylcholine-containing (PC) determinants could be identified by lectin-blotting or PC-specific immunoblotting, respectively. Two-dimensional separation and immunoblotting distinctly resolved more than 40 antigenic polypeptides, the majority focusing at acidic isoelectric points. In O. volvulus-infected chimpanzees the IgG1- and IgG4-reactivity against OvAg below 13 kD appeared concurrently with onset of patent infection. These data suggest that some of these VLMW-OvAg might be associated with the production and release of microfilariae from gravid female worms as well as be involved in immune-mediated pathogenesis during filarial infections.
Hoffmann
W H
WH
Institute of Tropical Medicine, University of Tübingen, Germany.
Blanke
C H
CH
Maier
J M
JM
Lüder
C G
CG
Schulz-Key
H
H
Soboslay
P T
PT
D000293:Adolescent; D000328:Adult; D000818:Animals; D000947:Antigens, Helminth / Q000097:blood* / Q000302:isolation & purification; D018420:Ape Diseases / Q000175:diagnosis; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D000939:Epitopes; D006801:Humans; D015151:Immunoblotting / Q000379:methods; D008875:Middle Aged; D008970:Molecular Weight; D017181:Onchocerca volvulus / Q000276:immunology*; D009855:Onchocerciasis / Q000175:diagnosis / Q000662:veterinary; D002679:Pan troglodytes; D010455:Peptides / Q000097:blood* / Q000302:isolation & purification; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods / Q000662:veterinary; D014037:Togo
D000947:Antigens, Helminth; D000939:Epitopes; D010455:Peptides