Evidence that radio-sensitive cells are central to skin-phase protective immunity in CBA/Ca mice vaccinated with radiation-attenuated cercariae of Schistosoma mansoni as well as in naive mice protected with vaccine serum.
Naive CBA/Ca mice and CBA/Ca mice vaccinated 4 weeks previously with radiation-attenuated cercariae of Schistosoma mansoni were subjected to 550 rad of whole body (gamma) irradiation and then challenged 3 days later with normal cercariae. The perfusion recovery data showed that this procedure reduced the primary worm burden in naive mice by 22% and the challenge worm burden in vaccinated mice by 82%. Irradiation also ablated the peripheral blood leucocytes of both mouse groups by 90-100% at the time of challenge. Histological data revealed that such treatment caused a dramatic change in number, size and leucocyte composition of cutaneous inflammatory skin reactions that characterize challenged vaccinated mice and are known to entrap invading larvae; cutaneous eosinophils were preferentially abolished by this treatment. Polyvaccine mouse serum that conferred protection passively upon naive recipient mice, failed to protect naive/irradiated mice when administered by the same protocol. Distraction of macrophages by treatment of mice with silica did not affect the establishment of a primary worm burden and reduced the protection exhibited by vaccinated mice by only 16%. These data indicate that radio-sensitive cells are important to both innate and specific acquired resistance in this mouse model and that macrophages contribute only marginally to the expression of vaccine immunity.
Delgado
V S
VS
Division of Parasitology, National Institute for Medical Research, Mill Hill, London.
McLaren
D J
DJ
D000818:Animals; D005260:Female; D007110:Immunity, Active / Q000187:drug effects / Q000528:radiation effects; D007111:Immunity, Cellular / Q000187:drug effects / Q000528:radiation effects; D007116:Immunization, Passive; D007958:Leukocyte Count / Q000528:radiation effects; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D008808:Mice, Inbred CBA; D012550:Schistosoma mansoni / Q000276:immunology* / Q000528:radiation effects; D012555:Schistosomiasis mansoni / Q000276:immunology*; D012822:Silicon Dioxide / Q000494:pharmacology; D014611:Vaccination; D014916:Whole-Body Irradiation
D012822:Silicon Dioxide