Artificial Induction of Concomitant Immunity against Schistosoma mansoni in Mice
Abstract
Before attempting to artificially induce a state of concomitant immunity, the theory why concomitant immunity exists in vivo must be examined. Most likely, due to their common genetic material, the adult worms and schistosomula have some sort of common antigenic determinant on their teguments. An antibody specific for some such common antigeni determinant would therefore direct an immune response against both an adult worm and a schistosomulum. As the adult worm has the abilty to evade host immune responses, it would be only slightly or not at all affected by this immune response. The young schistosomule, however, would be unable to escape the host’s immune action and therefore most likely be killed. Thus, when a host is sufficiently sensitized to an antigen present on the schistosomule’s tegument, it repels the infection. In natural infections, the host’s immune system is not quick enough to respond to such an antigen and mount an immune response directed against the schistosomule before the parasite is able to develop immune evasion capabilities.
Therefore, in order to attempt to artificially induce concomitant immunity, an antigenic determinant from the schistosomule could be isolated and injected into a non-infected "host” in order to attempt to sensitize that individual to the antigen prior to the cercarial attack so that when such an attack occured, the individual’s immune response could easily repel it. Thus, it seems as if the problem could be solved with simple vaccination techniques using cercaria to sensitize individuals against cercaria. However. whole schistosomules that have been either killed or irradiated and then injected into an individual fail to induce proper immunological sensitization against cercaria to prevent infection.
It would therefore seem that in order to evoke the host's immune system to sensitivity, a specific antigen must be used. Also, in order to concur with in vivo models, this specific antigen must also be associated with the adult worm. However, because of the adult worm's evasive abilities and the lack of definitive knowledge of how these abilities work, it is not clear if the host even mounts a successful antibody response against the adult worm. The purpose of this research is to discern whether there are antigens on the worm that the host recognizes as foreign and mounts an antibody response against. Understanding in this area can lead to a more full understanding of concomitant immunity and therefore a greater possibility of artificially inducing it.
Description
Program year: 1983-1984Digitized from print original stored in HDR
Citation
Secor, William Evan (1984). Artificial Induction of Concomitant Immunity against Schistosoma mansoni in Mice. University Undergraduate Fellows. Available electronically from https : / /hdl .handle .net /1969 .1 /CAPSTONE -SecorW _1984.