Granuloma cytokines in murine cysticercosis

Abstract

Taenia solium, is one of the most common causes of seizures worldwide. The symptoms result from granulomatous inflammation associated with dying cyst forms of the parasite. Although the invasive larvae can be killed by immune serum plus complement, immunity to the cyst stage depends on a cellular response. This dichotomous immune response is reminiscent of the extremes of the immune response associated with T helper 1 (Th1) and Th2 cytokine profiles. To characterize the cytokine response in cysticercosis, granulomas were removed from the peritoneal cavity of mice infected with Taenia crassiceps cysts and examined for cytokine message by in situ hybridization using 35 S-labeled RNA probes. The granulomas were staged based on histologic appearance of the degenerating parasite. Message for gamma interferon (IFN-␥) was identified by light microscopy in 11 of the 12 granulomas, and interleukin-2 (IL-2) message was identified in 9 of the 12. By laser scanning confocal microscopy, significantly increased IFN-␥ and IL-2 pixel intensity was identified in nearly all of the granulomas from early histologic stages. Message for IL-4 was seen in 6 of the 12 granulomas. Only granulomas with complete destruction of the parasite architecture displayed more than minimal amounts of IL-4 message by light microscopy, and only 2 of 12 granulomas had IL-4 pixel intensity significantly above background. Only minimal amounts of IL-10 message were detected in 4 of 11 granulomas. Thus, early granulomas in cysticercosis are predominantly associated with a Th1 response, whereas later granulomas, in which parasite destruction is complete, have a mixture of Th1 and IL-4. The Th1 response appears to play an important role both in the pathogenesis of disease as well as in the clearing of the parasites, with IL-4 involved in downregulation of the initial response.

Antigen-specific suppression of cultured lymphocytes from patients with neurocysticercosis

“…3) and to the presence of antibodies. Those in the active phase (type III and mixed type) showed a higher response (mean), probably due to the presence of an active immune process involving the formation of granulomas in response to parasite degeneration [17].…”

Altered cytokine expression in mesenteric lymph nodes in a rat strain (Matsumoto Eosinophilic Shinshu) that spontaneously develops hypereosinophilia

“…It is possible that the granulomas in MES rats at 14 weeks of age are still in the early stages, given that IL-2 expression is increased only at the later stages of granuloma development. 24 In addition to eosinophilopoietic and Th cytokines, the amount of mRNA for the eosinophilic chemokine eotaxin was increased in the MLNs of MES rats. Among the eosinophilic chemokines, including RANTES, eotaxin is the most selective for local eosinophil recruitment into inflammatory lesions.…”

Granulomatous responses in larval taeniid infections

“…Whereas this is obvious for natural infections, it is problematic also in experimental infections: a repeated observation is that within an individual host, individual parasites (and even areas of an individual metacestode) follow different biological courses. 25,55,80,97 This in turn emphasizes the importance of studying these infections at the local scale. 99 Even with the mentioned problems, the data in the previous sections suggest some patterns.…”

“…A very basic summary of the information on local responses in solid tissues is that they have mixed Th1-Th2 profiles with contribution from a Th17 component. 23,33,55,109,110 The central Th1 -4)) phenotypes. 111,112 Macrophage proliferation has also historically been documented in certain granulomatous pathologies.…”