Thymus dependency of host resistance to Giardia muris infection: studies in nude mice
Stevens, D.P.; Frank, D.M.; Mahmoud, A.A.
Journal of Immunology 120(2): 680-682
1978
ISSN/ISBN: 0022-1767 PMID: 621403 Document Number: 135017
Nude mice and heterozygous littermates were orally infected with 1,000 cysts of Giardia muris each. Cyst excretion in nude mice rose to peak levels at day 18, persisted at high levels until day 46 and then gradually returned to markedly reduced, but persistent, levels. Cyst excretion in heterozygous mice was at maximum levels from days 7 to 14 and was undetectable by day 42. Challenge of infected nude mice, 12 weeks after the primary infection, with 1,000 cysts resulted in a 2nd peak of cyst excretion, which lasted 28 days, became temporarily undetectable and then returned to persistent low levels. Heterozygous controls, however, showed total resistance to re-infection.