The Antigenic Role of the Excretions and Secretions of Trichinella spiralis in the Production of Immunity in Mice

During the last two decades a great deal of experimental work has been concerned with immunological studies on trichinosis. Owing to the wide host range of Trichinella spiralis, these studies have been performed in a variety of experimental animals. Following one or more immunizing infections, immunity to a challenging infection has been demonstrated in the rat (McCoy, 1931, 1932), rabbit (OliverGonzalez, 1940), and guinea pig (Roth, 1939). Since the work of Culbertson (1942) with mice, attention has been directed toward the use of this host in such studies. Much of the work performed with mice has been reviewed recently by Larsh (1953a). Although the mechanism of the immune response to infection with T. spiralis is not known definitely, present evidence gives strong support to the theory of Taliaferro (1940) that the immune response is due primarily to the action of antibodies with secondary cellular cooperation as described by Taliaferro and Sarles (1939) in their immunity studies of the nematode, Nippostrongylus muris. Recent studies with T. spiralis giving strength to this hypothesis have shown that the immunity in old mice is of a general nature (Larsh, 1953b) and that an inflammatory response in the intestine precedes the loss of adult worms (Larsh and Race, 1954). The latter authors suggest that T. spiralis adults are partially or completely immobilized by antibodies after which phagocytic cells attack the worms and complete their destruction or make conditions in the intestine unfavorable so that they pass rapidly from the host. On the basis of studies with many nematodes, it has become increasingly evident that the excretions and secretions of parasitic worms act as antigens in the stimulation of the immune response(s) in a host. This evidence has consisted largely of the demonstrations that precipitates are formed around the various body openings of worms incubated in homologous antiserum (Taliaferro and Sarles, 1939; OliverGonzalez, 1940, 1943; Otto, 1940; Mauss, 1941; Otto, Schugam, and Groover, 1942; Sadun, 1949; Smith, 1953). The only known study, however, involving the use of excretions and secretions in an attempt to produce artificially acquired immunity is that of Thorson (1953), who found that injections of the excretions and secretions of Nippostrongylus muris stimulated a protective immune response to this parasite in rats.