The Generation and Expression of Immunity to Trichinella spiralis in Laboratory Rodents

Two emerging concepts in the study of intestinal nematode rejection include the view that there are multiple independent mechanisms of rejection and that the primary rodent species—mice and rats—may differ in their final effector mechanisms against individual parasite species. It is noted that immunoparasitology has gained independence and recognition as it is realized that helminthic infections can help explain the basic immunological paradigm then dominating research endeavor—the Th1 and Th2 model of CD4 cell function. This seemed an opportune point at which the strengths and weaknesses of past approaches can be examined to develop new and more direct means of investigating host responsiveness in the future. A key element of this view is that nematode parasites are the ancient adversaries of the immune system, which has evolved specific strategies for dealing with them that owe little to other infectious agents, such as bacteria and viruses. Moreover, there is little novelty in host adaptive mechanisms of defense and these have probably all been defined —antibody and activated cells of several lineages. The novelty is the way they are brought together for different parasitic organisms.