The immune response to and immunomodulation byHymenolepis diminuta

Abstract

Analyses of laboratory-based helminth-rodent model systems have been immensely useful in delineating the workings of the mammalian immune system. Investigations in the 1970s-1980s on the fate of the rat tapeworm, Hymenolepis diminuta, in rats and mice and the systemic and local responses evoked following infection have contributed directly to our knowledge of how permissive and non-permissive hosts respond to the challenge of infection with a helminth parasite. This convenient laboratory model system has, in the authors' opinion, regrettably received considerably less attention in recent years. With the goal of highlighting the utility of this model system, data is presented on: (1) the immune and enteric responses of rats and mice to infection with H. diminuta; (2) the ability of excretory or secretory products derived from H. diminuta to significantly reduce T cell and macrophage activation in vitro; and (3) how assessment of H. diminuta-rodent models can be used to identify immune effector or regulatory mechanisms that can be translated into novel treatments for inflammatory and autoimmune disorders.

Enteric epithelial cells support growth of Hymenolepis diminuta in vitro and trigger TH2-promoting events in a species-specific manner

“…1D). These data are consistent with the absence of any obvious damage in the small intestine of H. diminuta-infected rats or mice (McKay, 2010). Similarly, analysis of murine colonic permeability was not altered (assessed by ion conductance) 3 or Fig.…”

“…Analyses to date reveal that rats mount immune responses to infection that are quantitatively and qualitatively of lesser magnitude than those observed in infected mice (McKay, 2010). Unlike many nematode and trematode parasites, H. diminuta does not migrate through the host's tissues causing damage; rather the infective cysticercoid stage enters the small intestine where the developing adult seeks to establish itself.…”

Splenic B Cells fromHymenolepis diminuta–Infected Mice Ameliorate Colitis Independent of T Cells and via Cooperation with Macrophages

“…Infection with H. diminuta results in a TH2-dominated immune response (19), and enumeration revealed an ∼25% increase in CD19 + /CD45R(B220) + splenic B cells 7 d postinfection: 48.8 6 2.8 versus 38.5 6 1.6 3 10 6 (n = 5; p , 0.01). Splenic B cell purified with magnetic beads yielded a population composed of 90-92% CD19 + cells, with the remainder being predominantly …”

“…Hymenolepis diminuta is a largely innocuous cestode that is expelled from mice within 12-14 d of a primary infection (19). Infection with H. diminuta significantly reduces the severity of dinitrobenzene sulfonic acid (DNBS)-induced colitis in mice, an effect that involved IL-10 likely from CD4 + T cells.…”

Biology and Diseases of Rats

“…Research Complications Experimentally, H. diminuta has been shown to elicit a host Th2 type immune response (McKay, 2010;Starke and Oaks, 2001;Webb et al, 2007) that may modulate models of intestinal and extraintestinal disease (Graepel et al, 2013;Hunter et al, 2005Hunter et al, , 2007aReardon et al, 2001). However, inadvertent interference of research has been not been reported likely because of the rarity of hymenolepiasis in rat research colonies.…”