Taenia crassiceps surface immunoglobulins: parasite- or host-derived?

Area of Science:

• Parasitology
• Immunology
• Molecular Biology

Background:

• Taeniid cestodes, including Taenia crassiceps, exhibit host proteins, particularly immunoglobulins, on their surface and in cyst fluid.
• Understanding the origin of these immunoglobulins is crucial for comprehending parasite-host interactions and immune evasion strategies.

Purpose of the Study:

• To determine the origin (host vs. parasite) of immunoglobulins found on the tegument of Taenia crassiceps metacestodes.
• To investigate the mechanism of immunoglobulin acquisition and its potential role in parasite survival.

Main Methods:

• Indirect immunofluorescence antibody testing (IFAT) to assess immunoglobulin presence on cultured metacestodes.
• Incubation of cultured metacestodes with normal serum or specific antiserum to observe immunoglobulin reacquisition.
• Immunoprecipitation of in vitro translated and biosynthetically labeled parasite proteins to identify homologous molecules.

Main Results:

• IgG was rapidly lost from metacestode surfaces during in vitro culture but quickly reacquired upon incubation with mouse serum or antiserum.
• No parasite-derived molecules homologous to mammalian immunoglobulins were identified through immunoprecipitation.
• Transplantation experiments showed no significant correlation between immunoglobulin loss during culture and parasite survival in naive hosts.

Conclusions:

• The immunoglobulins on Taenia crassiceps metacestodes are predominantly of host origin, acquired via non-specific binding to surface receptors.
• This acquisition of host immunoglobulins likely serves as a mechanism for immune evasion, masking the parasite from the host's immune system.