Lectin activity from the cattle tick (Boophilus microplus) saliva

Area of Science:

• Immunology
• Biochemistry
• Parasitology

Background:

• Boophilus microplus saliva (BmS) is known to possess immunosuppressive properties.
• Lectins are carbohydrate-binding proteins with diverse biological functions, including immune modulation and hemagglutination.

Purpose of the Study:

• To compare the immunosuppressive and hemagglutinating capabilities of BmS with known lectins.
• To characterize the lectin activity in BmS and its inhibition by specific sugars.

Main Methods:

• Mice were treated with BmS or lectins (Concanavalin A, Potato Lectin, Striped Bean Lectin) and immunized with sheep erythrocytes (SE).
• Anti-SE antibody titers were determined by direct hemagglutination.
• BmS and lectins were tested for agglutination of erythrocytes from various animal species and human blood types.
• Inhibition assays were performed using aminated sugars (D(+) Galactosamine, D(+) Glucosamine).

Main Results:

• BmS treatment resulted in reduced anti-SE antibody titers (Log2: 5.5 and 4.2), indicating immunosuppression.
• BmS agglutinated rabbit, sheep, and human erythrocytes (Log2 titers: 1, 1, 6, 1, 2).
• Concanavalin A and Potato Lectin agglutinated erythrocytes from all tested species, while Striped Bean Lectin showed partial agglutination.
• D(+) Galactosamine and D(+) Glucosamine inhibited BmS hemagglutination by 50%.

Conclusions:

• BmS exhibits immunosuppressive effects in mice, comparable to some lectins.
• BmS contains a weak, non-specific lectin inhibited by aminated sugars.
• The findings suggest a role for BmS lectin in tick-host interactions and immune evasion.