Monoclonal antibodies as investigative tools in onchocerciasis

The development of monoclonal antibodies against parasites can facilitate analysis of host-parasite interactions and can lead to the identification and characterization of antigens that induce protective responses in the immunized host. As diagnostic reagents for human and bovine onchocerciasis, monoclonal antibodies have been used to detect circulating antigens. So far only complex antigens have been used to generate monoclonal antibodies against filarial parasites. The use of such heterogeneous immunogens may result in interference or even in inhibition of the response to the desired parasite antigen(s). Epitopes that are similar or identical to determinants on host molecules or that are components of other infectious agents serve to complicate the generation and selection of monoclonal antibodies against Onchocerca volvulus antigens, and cross-reactivity can be due to monoclonal antibodies reacting with phosphorylcholine, which is present in many preparations of helminth antigens. Because of the host-dependent immunogenicity of filarial agents, reagents should be screened carefully for species specificity by use of a set of different helminth antigens. It is hoped that active collaboration among all investigators engaged in filariasis research will facilitate resolution of such difficulties.