Use of avian lymphocytes to detect toxicity: effects of a commonly utilized deltamethrin preparation

In building upon the increasing utility of avian immunology as an alternative to the use of mammalian systems for assessing immunotoxic potentials of environmentally and/or occupationally encountered chemicals, in vitro studies were performed to determine if easily obtainable freshly harvested cells from White Leghorn chickens could be used to detect effects on a critical immune cell type by any given toxicant. These studies also sought to determine if these cells could also potentially provide a vehicle to elucidate potential mechanisms underlying effects previously described for the test agent in in vivo investigations. Here, specifically, the toxic effect (and thus, ultimately, the potential to be an immunotoxicant in situ) of a commonly used commercially available form of deltamethrin on Leghorn lymphocytes was examined. The toxicity of this synthetic pyrethroid was evaluated by assaying both lymphoproliferation and apoptosis after exposure. A significant (p < 0.05) inhibitory effect of deltamethrin on mitogen-stimulated lymphocytes was observed at 10(- 5) M. Apoptosis was detected using DNA ladder analyses; annexin-V binding assays incorporating an immunoperoxidase technique were used to identify translocated phosphatidylserine; and, electron microscopy, including both scanning and transmission types, were used to detect ultrastructural changes (e.g., chromatin condensation, membrane blebbing and phagocytosis) in deltamethrin-treated cells. Our results indicated that deltamethrin, even at a very low dose, could give rise to potential immunotoxicities in situ by inducing toxicity (i.e., apoptosis) in immunogenic cells. Our results also show that this particular in vitro system may be used as an alternative to standard laboratory animals for the performance of immunotoxicity experiments involving pesticides.