Evidence against the existence of specific Schistosoma mansoni subpopulations which are resistant to irradiated vaccine-induced immunity

Journal Article · Tue Jan 01 04:00:00 EST 1985 · Am. J. Trop. Med. Hyg.; (United States)

OSTI ID:5724997

Lewis, F A; Hieny, S; Sher, A

When mice are immunized with irradiated Schistosoma mansoni cercariae a proportion of the subsequent cercarial challenge always escapes killing and matures to egg-laying adults. This report investigates the possibility that incomplete immunity in this system is governed by a genetically-determined insusceptibility of a particular schistosome subpopulation. To do this the authors tested whether more immunoresistant schistosomes would develop following successive passages of progeny of the resistant worms through immunized mice. Mice were immunized with 500 50 Krad-irradiated cercariae, and challenged with normal cercariae when immunity was at its peak. After five successive passages through snails and immune mice, progeny of those parasites which escaped immune killing were no more refractory to vaccine-induced resistance than the original stock maintained in nonimmune mice. Additionally, the passaged isolates did not differ from the original stock in their ability to induce protection following irradiation. The results indicate that with this model of acquired resistance incomplete immunity is unlikely to be due to a subpopulation of the parasites possessing a genetically-determined insusceptibility to killing.

• Research Organization: Biomedical Research Institute, Rockville, MD
• OSTI ID: 5724997
• Journal Information: Am. J. Trop. Med. Hyg.; (United States), Journal Name: Am. J. Trop. Med. Hyg.; (United States) Vol. 34:1; ISSN AJTHA
• Country of Publication: United States
• Language: English

Related Subjects

560134* -- Radiation Effects on Microorganisms-- Vaccine Preparation & Other Applications-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ANIMALS
AQUATIC ORGANISMS
BIOLOGICAL MODELS
HELMINTHS
IMMUNITY
INFECTIVITY
INVERTEBRATES
LARVAE
MAMMALS
MICE
MOLLUSCS
PLATYHELMINTHS
PROGENY
RADIOSENSITIVITY
RODENTS
SCHISTOSOMA
SNAILS
TREMATODES
VACCINES
VERTEBRATES