A panel of four recombinantly produced immunodominant proteins of filarial nematodes (tropomyosin, chitinase, 33kD protein and cystatin) are studied. These proteins predominantly induce IgG1 production in mouse and IgG4 in humans. All these proteins have been cloned and expressed from the human pathogenic filariae Onchocerca volvulus and the rodent filariae Acanthocheilonema viteae. Within the project we comparatively study the role of antibody subclasses generated against these proteins, and of ICs in sera of rodents and humans after nematode infection or immunizations.