Elicitation of Xenopus laevis Tadpole and Adult Frog Peritoneal Leukocytes.

Peritoneal lavage of Xenopus laevis tadpoles and adult frogs is a reliable way of isolating resident and/or recruited innate immune populations. This protocol details the isolation of tadpole and adult amphibian (Xenopus laevis) peritoneal leukocytes. The isolated cells are comprised predominantly of innate immune populations and chiefly of mononuclear and polymorphonuclear granulocytes. As described here, these cells are typically elicited by peritoneal injections of animals with heat-killed Escherichia coli, causing peritoneal accumulation of inflammatory cell populations, which are then isolated from the stimulated animals by lavage. E. coli-mediated elicitation of tadpole and adult peritoneal leukocytes greatly enhances the total numbers of recovered cells, at the cost of their inflammatory activation. Conversely, lavage may be performed on naïve, unstimulated animals to isolate nonactivated cells with much lower yield. This protocol represents a reliable means of deriving tadpole and adult frog innate immune cell populations, and the conditions of the stimulation may be amended to suit the specifics of a given experimental design.