[Anti-idiotypic monoclonal antibodies against latrotoxin interact with rat brain synaptosomes and modify latrotoxin-induced calcium entry into synaptosomes].

Hybridoma lines producing anti-idiotypic monoclonal antibodies (AImAbs) were prepared by fusing splenocytes of mice immunized with alpha-latrotoxin (LT) and P3-X63Ag8.653 myeloma line cells. AImAbs (1) bind to the rat brain synaptosomes, (2) do not affect the LT binding to the high-affinity receptor, and (3) do not react with LT in solution. The effect of AImAbs on the LT-induced 45Ca2+ influx into rat brain synaptosomes was studied. Some antibodies (6.6D11 and 11.7B7) were found to strongly inhibit this process. The result obtained indicate that the presynaptic membrane contains unidentified components interacting with LT. The distortion of the interaction of LT with these unknown components affects the LT-induced calcium influx into synaptosomes.