Immunological Studies on Experimental Infection of Pigs withAscaris suumGoeze, 1782. VI. The Histopathology of the Liver and Lung

Abstract

The histopathology of the livers and lungs of pigs after a primary infection with eggs of A. suum was compared with the lesions and cellular response found in resistant pigs after reinfection.The author's previously published work on experimental infection of guinea pigs, rabbits and pigs is also discussed and summarized.

Immunizing pigs with Ascaris suum haemoglobin increases the inflammatory response in the liver but fails to induce a protective immunity

“…in comparison with control livers. It was originally suggested by Taffs (12) that the development of these white spots in pigs plays an important part in the destruction of invading larvae and in stopping their migration. Eriksen (13) showed that white spots in pigs with acquired resistance against A. suum were significantly larger and more distinct than those in nonresistant pigs.…”

Comparative studies on in vitro cell adherence reactions and delayed hypersensitivity reactions in mice and pigs infected with Ascaris suum

“…MI of sensitized PEC from mice and swine in the presence of ASJ2 extract suggest that PEC from both animals contain sensitized lynphocytes and that migration inhibitory factor (MIF) was released. In addition, it has been reported that the migration and development of ^ suum is identical in mice and swine up to lung-stage juveniles (Douvres and Tronba, 1971) and similar immunological responses to ^ suum infections are induced in both mice and swine (Sprent and Chen, 1949;Bindseil, 1969a andb, 1970b andKelley and Nayak, 1964;Taffs, 1968). Thus, it appears that differences in the amounts of antigen required to induce MI and cytotoxicity might be due to species differences.…”

“…A. suum embryonated eggs are satisfactory immunizing agents, and have been used extensively to study host responses to ^ suum (Sprent and Chen, 1949;Soulsby, 1963;Taffs, 1961bTaffs, , 1963Taffs, , 1964Taffs, , 1965Taffs, , and 1968Kelley and Nayak, 1964;Crandall and Arean, 1965;andBindseil, 1969a and1970b and c. It appears that embryonated eggs induce protective responses in hosts against challenge infections because during the in fections the host is exposed to a series of immunizing antigenic stimuli such as scanatic antigens and metabolic products, consisting of molting fluids and excretory and secretory substances.…”

“…Repeated feeding of infective ^ suum eggs in subclinical doses induced resistance to reinfection in swine Nayak, 1964 andTaffs, 1968). This acquired resistance to reinfection could be due either to failure of infective stages to infect the host, or to the increased host resistance to the migration of juveniles and to the inhibition of juvenile growth.…”

“…Iimnune responses of swine to ^ suum are well documented. Repeated, oral infections of swine with ^ suum-eggs have been reported, to induce acquired resistance to reinfection (Kelley and Nayak, 1964;Taffs, 1968), production of antibodies (Taffs, 1961b(Taffs, , 1963Kelley and Nayak, 1965a), granulona formation (Taffs, 1968;Copanan, 1971) and reduced worm burdens (Kelley and Nayak, 1964;Taffs, 1968). In addition, no antigens similar to swine antigens were found in ASJ2 (Williams and Soulsby, 1970) and helminth juveniles have also been reported to lack host-specificity (Levine, 1968;Sprent, 1969).…”