D. Piedrafita et al., Anti body-dependent cell-mediated cytotoxicity to newly excysted juvenile Fasciola hepatica in vitro is mediated by reactive nitrogen intermediates, PARASITE IM, 23(9), 2001, pp. 473-482
Passive intraperitoneal transfer of sera from Fasciola hepatica-infected sh
eep, cattle or rats can protect naive rats from F. hepatica infection, sugg
esting a parasite killing mechanism within the peritoneal cavity that is de
pendent on the presence of parasite-specific antibody. We investigated anti
body-dependent cell-mediated cytotoxicity by resident peritoneal lavage cel
l populations, containing large numbers of monocytes/macrophages, as a pote
ntial host resistance mechanism by which juvenile flukes could be killed wi
thin the peritoneal cavity of naive rats. Comparative studies were conducte
d using cell populations containing large numbers of monocytes/macrophages
from sheep. The results demonstrate that monocyte/macrophage-rich lavage ce
ll populations from rat and sheep differ substantially in their ability to
generate nitric oxide. Only resident rat peritoneal lavage cells were able
to mediate antibody-dependent cell-mediated cytotoxicity against newly excy
sted juvenile liver fluke. The mechanism of cytotoxicity was dependent on,
and directly proportional to, the production of nitric oxide and required a
ttachment of effector cells to the newly excysted juvenile liver fluke tegu
ment, which occurred following the addition of sera from F. hepatica-infect
ed animals. This is the first report demonstrating a mechanism of cell-medi
ated cytotoxicity to newly excysted juvenile liver fluke.