Summary: Parasite Immunology, 2001: 23: 345±352
Divergent roles for macrophages in lymphatic filariasis
JUDITH E.ALLEN & P'NG LOKE
Institute of Cell, Animal and Population Biology, University of Edinburgh, Edinburgh, UK
Macrophages have long been recognized as important cells
associated with filarial infection but their function as
effectors and/or suppressors has not been elucidated.
Recent advances in our understanding of the role that
macrophages may play in lymphatic filariasis have come
from in vitro studies and mouse models of filarial infection.
Based on these new findings, we hypothesize that while
dead or dying worms induce the `classical' activation of
macrophages and a subsequent pro-inflammatory response,
live and healthy worms secrete products that induce type 2
cytokines and the differentiation of `alternatively' activated
macrophages that downregulate an inflammatory response.
Thus, the balance between the `classical' and `alternative'
activation pathways of macrophages could be an important
factor in inflammatory pathology associated with filariasis.