Toxins and Antivenoms of Latrodectus tredecimguttatus: Molecular Mechanisms, Antibody Development, and Evidence from Other Latrodectus Species

Latrodectus tredecimguttatus envenomation causes latrodectism, a neurotoxic syndrome driven primarily by α-latrotoxin (α-LTX)-mediated dysregulation of neurotransmitter release. This review examines the development and therapeutic application of specific immunoglobulins against L. tredecimguttatus toxins, integrating toxin diversity, α-LTX mechanisms, antibody production, preclinical neutralization, and clinical use. Eggs and spiderlings also contain bioactive proteins, including Latroeggtoxin-I and Latroeggtoxin-IV, although their relevance to human envenomation and antivenom development remains uncertain. α-LTX acts through receptor engagement, membrane pore formation, Ca2+ influx, and receptor-mediated signaling, providing potential targets for antibody neutralization. Conventional antivenoms rely mainly on animal-derived polyclonal immunoglobulins, whereas phage display and recombinant engineering enable fully human monoclonal antibodies with defined specificity and high affinity. Preclinical studies demonstrate neutralization across cellular, electrophysiological, ex vivo, and in vivo models, but methodological heterogeneity and variable cross-species activity complicate efficacy comparisons. Recombinant human antibodies offer improved molecular definition, reproducibility, and engineering potential, although clinical efficacy remains unestablished. Future development should prioritize standardized neutralization assays, clinically relevant post-exposure models, systematic cross-neutralization studies, and recombinant antibody combinations to achieve broader toxin coverage and safer, more standardized, reproducible, and clinically applicable immunotherapy for L. tredecimguttatus envenomation.