Generation of monoclonal antibodies against a nematode peptide extract: another approach for identifying unknown neuropeptides.

Monoclonal antibodies that cross-react with Ascaris neural antigens were generated in mice immunized with a conjugate made with keyhole limpet hemocyanin (KLH) linked to a crude peptide extract from Caenorhabditis elegans. The response to KLH was suppressed by injection of cyclophosphamide 3 days after immunization with a gamma-aminobutyric acid (GABA)-KLH conjugate. Screening of hybridomas was carried out by enzyme-linked immunosorbent assay and whole mount immunocytochemistry. Two similar clones produced antibodies that recognized a small subset of Ascaris neurons. This result suggests that the monoclonal antibody technique might be useful for identifying new neuropeptides since the antibodies can be used for localization of the neuropeptidelike substances and, potentially, for immunoaffinity chromatography. As a by-product of this experiment, monoclonal antibodies that recognize GABA-like immunoreactivity in whole mounts and plastic sections were also obtained.