Clearance of inoculated microfilariae of Brugia malayi by monoclonal antibodies in BALB/c mice.

A stable and long-lasting microfilaremia was developed by intravenous injection with 2 X 10(5) microfilariae (mf) of Brugia malayi into BALB/c mice. Mf density in mice was maintained at least at 30 to 40 mf/20 microliter blood for 4 weeks, then gradually decreased as the same as in the jird. However, mf inoculated were cleared from the blood within 3 weeks in the mice which was immunized with repeated intravenous injections with live mf. The effect of mf clearance was passively transferred into the mice with inoculated microfilaremia by intravenous injection of 0.2 ml serum from the immunized mice. For the analysis of the role of anti-mf antibodies, monoclonal antibodies (MABs) against mf of B. malayi were produced. An IgG1 MAB gave a significant mf reduction in mice and it promoted in vitro adherence of normal mouse spleen cells to mf.