Adoptive transfer of mast cells does not enhance the impaired survival of KitW/KitW−v mice in a model of low dose intraperitoneal infection with bioluminescent Salmonella typhimurium

Mast cells are important effector cells in IgE-associated immune responses, but also can contribute to host defense in certain examples of bacterial infection. We found that genetically mast cell-deficient WBB6F1-KitW/KitW−v mice exhibited more bacterial CFUs per spleen by 6 days after intraperitoneal injection of bioluminescent Salmonella typhimurium, and died more rapidly after infection, than did the congenic WBB6F1-Kit+/+ wild type mice. Adoptive transfer of bone marrow-derived cultured mast cells of Kit+/+ origin to the peritoneal cavity of KitW/KitW−v mice resulted in engraftment of mast cells in the peritoneal cavity and mesentery of the recipient mice, and the development of large numbers of mast cells in the spleen. However, such mast cell-engrafted KitW/KitW−v mice appeared sicker after intraperitoneal injection with S. typhimurium than did mast cell-deficient KitW/KitW−v mice, and exhibited numbers of CFUs of bacteria per spleen, and a survival curve, that were not significantly different than those of KitW/KitW−v mice. These results, when taken together with prior studies investigating the roles of mast cells in innate immunity, strongly suggest that whether mast cells can be shown to have a significant role in enhancing survival during bacterial infections may depend critically on the details of the particular experimental systems examined.