Lectin activity from the cattle tick (Boophilus microplus) saliva

The capability of Boophilus microplus saliva (BmS) and lectins to induce immunosuppression in mice and to agglutinate erythrocytes from distinct animal species were compared. CD-1 mice were distributed into groups (two for each substance) of 4-5 animals/group and treated intraperitoneally (i.p.) with 50 mg and 150 mg of BmS; concanavalin A (Con A); potato's lectin (PL), striped bean lectin (SBL) or 0.1 ml of phosphate buffered saline (PBS). All mice were immunized i.p. with 2 x 108 sheep erythrocytes (SE) 48 hours after treatment. Five days after immunization sera was obtained from mice to determine anti-SE antibody titer by direct hemagglutination. The mean antibody titers (Log2) obtained was 5.5 and 4.2 for BmS, 4.4 and 0 for Con A, 5.2 and 4.8 for PL, 4.6 and 0 for SBL and 7.4 for PBS. BmS and lectins were tested to agglutinate mouse (M), rat (Rt), rabbit (Rb), sheep (S) and human A (HA), human B (HB) and human O (HO) erythrocytes. BmS agglutinated Rb, S, HA, HB and HO erythrocytes at titer (Log2) of 1, 1, 6, 1 and 2 respectively. Con A and PL agglutinated erythrocytes from all species tested, while SBL agglutinated M, S and HA erythrocytes. A 50% inhibition of agglutination of HA erythrocytes by BmS was observed when D(+) Galactosamine and D(+) Glucosamine, at 0.2 M, were used. The results obtained indicate that BmS contains a weak nonspecific lectin which is inhibited by aminated sugars, and that induces immunosuppression in mice as other lectins.