Detection of serum IgG antibodies specific for Wolbachia surface protein in rhesus monkeys infected with Brugia malayi

The mechanism of lymphedema development in individuals with lymphatic filar iasis is presently poorly understood. To investigate whether Wolbachia, sym biotic bacteria living within filarial nematodes, may be involved in diseas e progression, Wolbachia-specific immune responses were assayed in a group of Brugia malayi-infected rhesus monkeys. Serum IgG antibodies specific for a major Wolbachia surface protein (WSP) were detected in 2 of 12 infected monkeys. It is interesting that both of these monkeys developed lymphedema after becoming amicrofilaremic. WSP-specific antibody responses were tempor ally associated with increases in antifilarial IgG1 antibodies as well as l ymphedema development. These findings suggest that Wolbachia may be importa nt in understanding disease caused by filarial worms.