Taenia crassicepssurface immunoglobulins: parasite- or host-derived?

Abstract

In common with other taeniid cestodes, host or host-like proteins, especially immunoglobulins, occur on the surface and in the cyst fluid of Taenia crassiceps metacestodes. Here, several approaches have been used to determine the origin of the immunoglobulins present on the tegument. Indirect IFAT showed that IgG was almost totally lost from the surface of bladders after 6 days culture in vitro. There was a rapid reacquisition of immunoglobulins following incubation of the cultured metacestodes with either normal mouse serum or mouse anti-T. crassiceps antiserum. Immunoprecipitation of in vitro translation products and biosynthetically labelled T. crassiceps proteins with a panel of anti-IgG antisera failed to positively identify any molecule with homology to mammalian immunoglobulins. These results suggest strongly that the immunoglobulins located on the surface of T. crassiceps are of host rather than parasite origin. The occurrence of a relatively low abundance receptor in the surface of the bladders, which binds non-specific host immunoglobulin, together with surface-bound specific anti-T. crassiceps antibodies can account for the presence of these host proteins. Freshly obtained bladders and metacestodes cultured in vitro for 6 days were transplanted into naive mice and the survival and development of the resulting parasites compared. In some individual mice there was a decrease in the number and volume of metacestodes and an increase in encapsulated parasites arising from cultured bladders. This was probably not related to the loss of host immunoglobulins from the parasite surface during culture as the reacquisition of these proteins after transplantation is likely to be far more rapid than any immune response could evoke in a naive host.

Granuloma cytokines in murine cysticercosis

“…The parasite surface and cyst fluid contain host immunoglobulin. Some of the immunoglobulin binds to parasite antigens, but most of it is not specific for the parasite (27). Host immunoglobulins are known to be slowly degraded, perhaps serving as a source of amino acids (4,6).…”

Regulatory T Cells as an Escape Mechanism to the Immune Response in Taenia crassiceps Infection

“…Cysticerci also secrete a metallo-aminopeptidase that degrades cytokines and cysteineproteases to degrade antibodies (White et al, 1992;White et al, 1997;Baig et al, 2005). Other strategies include antibody-coating (McManus and Lamsam, 1990;Flores-Bautista et al, 2018) and a suppression of the specific proliferative immune response by limiting IL-2, a growth factor of proliferating effector cells (Sciutto et al, 1995;Tato et al, 1995;Hernańdez-Mendoza et al, 2005;Peoń et al, 2013). T regulatory cells (Tregs) may play a critical role in this specific suppression of immunity.…”