A novel in vitro potency assay of antisera against Thai Naja kaouthia based on nicotinic acetylcholine receptor binding

作者:Ratanabanangkoon Kavi*; Simsiriwong Pavinee; Pruksaphon Kritsada; Tan Kae Yi; Eursakun Sukanya; Tan Choo Hock; Chantrathonkul Bunkuea; Wongwadhunyoo Wongsakorn; Youngchim Sirida; Tan Nget Hong
来源:Scientific Reports, 2017, 7(1): 8545.
DOI:10.1038/s41598-017-08962-3

摘要

Snake envenomation is an important medical problem. One of the hurdles in antivenom development is the in vivo assay of antivenom potency which is expensive, gives variable results and kills many animals. We report a novel in vitro assay involving the specific binding of the postsynaptic neurotoxins (PSNTs) of elapid snakes with purified Torpedo californica nicotinic acetylcholine receptor (nAChR). The potency of an antivenom is determined by its antibody ability to bind and neutralize the PSNT, thus preventing it from binding to nAChR. The PSNT of Naja kaouthia (NK3) was immobilized on microtiter wells and nAChR was added to bind with it. The in vitro IC50 of N. kaouthia venom that inhibited 50% of nAChR binding to the immobilized NK3 was determined. Varying concentrations of antisera against N. kaouthia were separately pre-incubated with 5xIC(50) of N. kaouthia venom. The remaining free NK3 were incubated with nAChR before adding to the NK3 coated plates. The in vitro and in vivo median effective ratio, ER(50)s of 12 batches of antisera showed correlation (R-2) of 0.9809 (p < 0.0001). This in vitro assay should be applicable to antisera against other elapid venoms and should reduce the use of live animals and accelerate development of life-saving antivenoms.

  • 出版日期2017-8-17