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

Ratanabanangkoon, K. and Simsiriwong, P. and Pruksaphon, K. and Tan, K.Y. and Eursakun, S. and Tan, C.H. and Chantrathonkul, B. and Wongwadhunyoo, W. and Youngchim, S. and Tan, N.H. (2017) A novel in vitro potency assay of antisera against Thai Naja kaouthia based on nicotinic acetylcholine receptor binding. Scientific Reports, 7 (1). p. 8545. ISSN 2045-2322, DOI https://doi.org/10.1038/s41598-017-08962-3.

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Official URL: http://dx.doi.org/10.1038/s41598-017-08962-3


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 5xIC50 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, ER50s 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.

Item Type: Article
Funders: Chulabhorn Research Institute: a research grant (no. IM 2011-01 to KR), University of Malaya (grant no. UM.C/625/1/HIR/MOE/E00040-20001 to NHT)
Uncontrolled Keywords: In vitro potency assay; Antisera; Thai Naja kaouthia; Nicotinic acetylcholine receptor binding
Subjects: R Medicine
R Medicine > RM Therapeutics. Pharmacology
Divisions: Faculty of Medicine
Depositing User: Ms. Juhaida Abd Rahim
Date Deposited: 30 Aug 2018 08:15
Last Modified: 30 Aug 2018 08:15
URI: http://eprints.um.edu.my/id/eprint/19045

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