The third-stage larva (L3) of Brugia: its role in immune modulation and protective immunity.

In this review, we focus on the role of the L3 (third-stage larva) of lymphatic filarial nematodes in immunomodulation and in the development of protective immunity. Studies in the mouse models of Brugia have been fundamental to our understanding of the mechanisms by which infection with L3 results in Th2 responses and the active suppression of Th1 responses. The relevance of these phenomena to the human infection is discussed.