Monoclonal antibodies against the major zymosan-induced chemotactic factor in rabbit serum

The major zymosan-induced chemotactic factor in rabbit serum was purified by a two-step ion exchange chromatography procedure. The purified chemoattractant was used as antigen for production of murine monoclonal antibodies against the major chemotactic factor. The primary screening of the hybridoma cultures was an indirect ELISA using purified chemotactic factor as antigen. The final selection among ELISA-positive clones was performed according to the results obtained in a chemotactic inhibition assay. Six monoclonal antibodies were raised. These antibodies completely abrogated or substantially reduced the chemotactic activity in crude zymosan-activated serum. The chemotactic factor(s) could be adsorbed onto an immunosorbent column containing monoclonal antibody and subsequently be specifically eluted with acid. By Western blot analysis the molecular weight of the major chemotactic factor was estimated to be approximately 15 000, and isoelectric focusing indicated a p I of about 9.4.