Organotin compounds decrease in vitro survival, proliferation and differentiation of normal human B lymphocytes

Organotin compounds (OTC) are organometallic compounds with vast industrial and agriculture applications that give rise to ubiquitous environmental co ntamination, OTC are immunotoxic, but most studies have been performed in r odents and almost exclusively focused on T cell immunity. Humans can be exp osed to OTC by inhalation, absorption, and consumption of contaminated food and water. To analyse the effects of OTC in human immune tissue, we isolat ed B cells from tonsils and exposed them to five OTC at various concentrati ons, during in vitro culture, Non-stimulated B cells were killed by 100 nM of all tested OTC after 8 h in vitro culture, under sub-optimal conditions, except TET. OTC also decreased the proliferation of tonsillar B lymphocyte s stimulated with Staphylococcus aureus Cowan 1 (SAC) and IL-2, when presen t at 100 nM and higher concentrations. IgM secretion was reduced in stimula ted cell cultures exposed to 100 nM dibutyltin chloride (DBT), Accordingly, increased phosphatidylserine exposure demonstrated that 100 nM TPT and DBT induced B cells to die by apoptosis, These data indicate that human B cell s are diminished in their capacity to survive, proliferate and differentiat e in the presence of OTC in vitro.