Depressed T-cell proliferation associated with susceptibility to experimental Taenia crassiceps infection

Abstract

Peritoneal infection with Taenia crassiceps cysticerci of naturally resistant (C57BL/10J and C57BL/6J) and susceptible (BALB/cAnN) mice induces a cellular immune depression. T-cell proliferation in response to concanavalin A (ConA) or anti-CD3 was significantly depressed in infected mice of all strains tested. However, in resistant mice, the diminished response to ConA was transient and animals recovered normal responsiveness at day 40, whereas susceptible mice remained suppressed throughout the 40 days of the experiment. In contrast, the proliferative response to anti-CD3 was lower in infected mice than in noninfected controls regardless of differences in natural susceptibility of the strains. Intraperitoneal injection of mice with a parasite extract also induced a depression of the response to ConA, although not as strong as that produced by the parasite itself. This depression is not due to direct effects by parasite antigens over host lymphocytes, as proliferation is not affected by the presence of cysticercal antigens added in vitro. Diminished interleukin-2 production during the parasitosis accounts at least in part for the diminished responses to ConA. A primary infection favors parasite establishment after a second challenge, pointing to the relevance of the immunodepression in generating a host environment favorable to the parasite.

Antigen-specific suppression of cultured lymphocytes from patients with neurocysticercosis

“…On the other hand, several experimental animal studies have attempted to determine the causes of immunosuppression observed in cysticercosis, with different conclusions, such as: release of antigenic products [14] that form circulating immunocomplexes [11], suppressing lymphocyte cytokine production or inducing chromosome instability [15]; increase and/or decrease in CD8+ cells depending on the evolutive phase of the disease [19]; genetic instability and chromosome alterations in circulating lymphocytes induced by infection [20,21]. Furthermore, other investigators have shown that CD4+ T cells (Th1 and/or Th2) and the cytokines produced by these cells are involved in the suppression caused in the experimental model of T. crassiceps [17,22–26].…”

Profound suppression of cellular proliferation mediated by the secretions of nematodes

“…Studies with cestode E/S have demonstrated a similar pattern of proliferative suppression (Rakha et al 1991, Sciutto et al 1995. This led us to question if the generation of a non-specific anti-proliferative host cell is a general phenomenon associated with helminth infection.…”

Analysis of cells in cerebrospinal fluid from patients with neurocysticercosis by means of flow cytometry

“…These cells may be involved in parasite elimination by cytotoxicity mechanisms. Events of suppression possibly determined by cysticercus antigens have been described in experimental cysticercosis in mice (22).…”