In vitro assay of biological and chemical toxins using antibodies against lethal toxin neutralizing factor

Lethal Toxin Neutralizing Factor (N-LTNF), MW 63.0 kDa, was isolated from opossum serum. After trypsin digestion, the active domain of N-LTNF was isolated and sequenced. The synthetic peptide consisting of ten amino acids was designated as LT-10. N-LTNF and LT-10 inhibited the lethality of animal, plant and bacteria toxins when tested on mice non-immunologically. The antibodies against N-LTNF and LT-10 only reacted immunologically with toxins and not with non-toxic substances. Anti-LTNF and anti-LT-10 reacted immunologically by ELISA test with toxins that were not detected by mouse test, such as cholera toxin and digoxin. Anti-LTNF and anti-LT-10 failed to react immunologically with non-toxic substances, such as nerve growth factor and collagen. Currently, mouse bioassay is in use for toxin detection and assay. Binding affinity of IgG from anti-LT-10 showed a linear relationship with mouse bioassay by ELISA detection limit to some toxins only. This may be due to the fact that anti-LTNF and anti-LT-10 detected the toxins that were not lethal to mouse. Thus, anti-LTNF and anti-LT-10 can be useful in assaying toxins as an alternative to mouse bioassay.

Sub-lethal injection of honeybee venom decreased the levels of endogenously present substances in organs of mice

Pharmacological substances such as adenosine deaminase (ADA), collagen, histamine, IgE, myoglobin, and nerve growth factor (NGF) are endogenously present in animals. Research from this laboratory reported decreased levels of ADA, histamine, IgE, and NGF in organs of mice injected with sub-lethal doses of cobra venom. The goal of this research is to observe the levels of ADA, collagen, histamine, IgE, myoglobin, and NGF in certain organs of mice injected with venom from the bee Apis mellifera. Adult Balb/c female mice IM injected with half lethal dose of bee venom were sacrificed after 2 and 8 hours for removal of organs. The homogenates of the organs were assayed by ELISA for ADA, collagen, histamine, IgE, myoglobin, and NGF using respective antisera. Organs from mice injected with PBS were used as controls. It was observed that there were decreased levels of ADA, collagen, histamine, IgE, myoglobin, and NGF in certain organs after 2 h and tremendous decrease after 8 h. This is the first report showing the pharmacokinetics of ADA, collagen, histamine, IgE, myoglobin, and NGF as consequence of honeybee envenomation.