Pisiformis

Early studies with T. taeniaeformis in mice (Miller and Gardiner, 1932 Campbell, 1938b Leid and Williams, 1974 Musoke et al., 1975 Mitchell et al., 1977, 1980), T. pisiformis in rabbits (Campbell, 1938a), T. saginata in cattle (Lloyd and Soulsby, 1976) and T. ovis in sheep (Blundell et al., 1968 Rickard et al., 1977 Heath et al., 1979 Harrison et al., 1993) demonstrated that antibodies in the sera of infected or immunized hosts were capable of transferring passive immunity to na ive hosts. The presence and activities of these protective antibodies were found to be evident in vitro through the demonstration that activated oncospheres were killed if cultured in the presence of serum from infected or vaccinated... 

Campbell, D.H. (1 938a) The specific absorbability of protective antibodies against Cysticercus crassicollis in rats and C. pisiformis in rabbits from infected and artificially immunized animals, journal of Immunology 35, 205-216. 

Heath, D.D. (1 973) Resistance to Taenia pisiformis larvae in rabbits. II. Temporal relationships and the development phase affected. International Journal for Parasitology 3, 491 -498. 

Rajasekariah, G.R., Rickard, M.D. and O Donnell, I.J. (1985) Taenia pisiformis protective immunization of rabbits with solubilized oncospheral antigens. Experimental Parasitology 59, 321-327. 

Fig. 8.22. Jejunal villi of ruminant and non-ruminant showing paths followed by oncospheres of Echinococcus granulosus and Taenia pisiformis (and some other Taenia spp.). The larger diameter of the E. granulosus oncosphere probably enables it to reach the lymphatic before being translocated in a venule. (Reprinted with permission from International Journal of Parasitology, 1, Heath, D. D., The migration of oncospheres of Taenia pisiformis, T. serialis and Echinococcus granulosus within the intermediate host, 1971, Pergamon Journals Ltd.)...

Fig. 8.23. Eight-day (postoncosphere) larva of Taeniapisiformis migrating through the liver of a rabbit, showing the presence of anterior secreting cells. (Reprinted with permission from International Journal for Parasitology, 3, Shield, J. M., Heath, D. D. Smyth, J. D., Light microscope studies on the early development of Taenia pisiformis cysticerci, 1973, Pergamon Journals Ltd.)...

The most successful species cultured to date has been T. pisiformis, using essentially the technique used for E. granulosus (610, 801). Although sexually mature adults with proglottides were obtained, these did not contain infective oncospheres. 

The following species of Taenia have been grown from oncospheres to active larvae with suckers T. hydatigena, T. ovis, T. pisiformis, T. serialis and E. granulosus (308, 314). The techniques of Heath Smyth (314), or modifications of them, have been used widely by other workers for the production and collection of E/S antigens of oncospheres in the preparation of potential vaccines (see Chapter 11, p. 302). Only limited success has been achieved with the culture of larval T. saginata (310, 471) and almost none with T. solium, and the in vitro culture of these important species remains a challenge. 

There is some evidence that some larvae of some species (e.g. T. pisiformis) can release substances which inhibit proteolytic enzymes such as trypsin and chymotrypsin (591) (see Chapter 4). Other host cellular activities reported to be modified by parasite secretions are cell differentiation, macrophage activation, responsiveness to mitogens, cytotoxicity and complement activation (687). 

Early work (796) on T. taeniaeformis and T. pisiformis showed that the high degree of immunity developed against larvae of these species could be transmitted by passive transfer of immune serum. Results with other species, such as E. granulosus and T. solium have not been so successful and not as promising as procedures involving active immunisation (see below). 

Barker, I. K. (1970). The penetration of oncospheres of Taenia pisiformis into the intestine of the rabbit. Canadian Journal of Zoology, 48 1329-32. 

Heath, D. D. (1971). The migration of the oncospheres of Taenia pisiformis, T. serialis, and Echinococcus granulosus within the intermediate host. International Journal for Parasitology, 1 145-52. 

Levels of some trace elements in a canine tapeworm, Taenia pisiformis (Bloch, 1780). Bulletin de I Academie Polonaise des Sciences (Sciences Biologiques), 26 186-6. 

Jenkins, D. J. Rickard, M. D. (1985). Specific antibody responses to Taenia hydatigena, T. pisiformis and Echinococcus granulosus in dogs. Australian Veterinary Journal, 62 72-8. 

Nemeth, I. Juhasz, S. (1980). A trypsin and chymotrypsin inhibitor from the metacestodes of Taenia pisiformis. Parasitology, 80 433-46. 

Properties of a trypsin and chymotrypsin inhibitor secreted by larval Taenia pisiformis. International Journalfor Parasitology, 11 137-44. 

Osuna-Carrillo, A. Mascaro-Lazcano, M. C. (1982). The in vitro cultivation of Taenia pisiformis to sexually mature adults. Zeitschrift fur Parasitenkunde, 67 67-71. 

---