Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-28T04:30:06.508Z Has data issue: false hasContentIssue false

Acquired immunity to Schistosoma mansoni in the rat: measurement of immunity by the lung recovery technique

Published online by Cambridge University Press:  06 April 2009

Hilda Perez
Affiliation:
Division of Parasitology, National Institute for Medical Research, Mill Hill, London NW7 1AA
J. A. Clegg
Affiliation:
Division of Parasitology, National Institute for Medical Research, Mill Hill, London NW7 1AA
S. R. Smithers
Affiliation:
Division of Parasitology, National Institute for Medical Research, Mill Hill, London NW7 1AA

Extract

Acquired immunity to Schistosoma mansoni in the rat can be assayed by the recovery of a proportion of the schistosomula of a challenge infection from the lungs 5 days after the challenge has been given. The recoveries from immune rats, which are significantly less than those from control animals, demonstrate that a proportion of a challenge infection is killed in the lungs or at an earlier point in the pathway of migration.

Immunity in the Sprague–Dawley rat can first be shown by the lung recovery technique 3 weeks after an immunizing exposure of 500 cercariae. Immunity reaches a peak between weeks 6 and 7 but then declines to zero by week 12. The PVG inbred Hooded rat shows a similar but delayed development and decline of immunity. When the lung recovery technique shows immunity to be declining, hepatic perfusion demonstrates that immunity to reinfection is partially retained, indicating that at this stage the challenge is killed after the first 5 days.

Re-exposure of rats in which immunity has declined induces an anamnestic lung recovery response. There appears to be a relationship between spontaneous cure and the decline of immunity. A factor in the serum of infected rats which kills young schistosomula in culture develops in parallel with immunity, but high titres of this factor are maintained during the decline of immunity.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1974

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Clegg, J. A. & Smithers, S. R. (1968). Death of schistosome cercariae during penetration of the skin. ii. Penetration of mammalian skin by Schistosoma mansoni. Parasitology 58, 111–28.Google Scholar
Clegg, J. A. & Smithers, S. R. (1972). The effects of immune rhesus monkey serum on schistosomula of Schistosoma mansoni. International Journal for Parasitology 2, 7998.Google Scholar
Sher, A., Kusel, J. R., Perez, H. & Clegg, J. A. (1974). Partial isolation of a membrane antigen which induces the formation of antibodies lethal to schistosomes cultured in vitro. Clinical and Experimental Immunology (in the Press).Google Scholar
Smithers, S. R. & Terry, R. J. (1965 a). Acquired resistance to experimental infections of Schistosoma mansoni in the albino rat. Parasitology 55, 711–7.CrossRefGoogle ScholarPubMed
Smithers, S. R. & Terry, R. J. (1965 b). The infection of laboratory hosts with cercariae of Schistosoma mansoni and the recovery of the adult worms. Parasitology 55, 695700.Google Scholar
Smithers, S. R. & Terry, R. J. (1969). The Immunology of Schistosomiasis. In Advances in Parasitology, vol. 7 (ed. Ben, Dawes), pp. 4193. London and New York: Academic Press.Google Scholar