ANTIGEN HANDLING IN THE SPLEEN OF THE YELLOW-BELLIED TOAD, BOMBINA-VARIEGATA

The primitive anuran amphibian, the yellow-bellied toad, Bombina varie gata, possesses the spleen with a large white pulp, containing the imm une-complex-trapping-cells (ICTCs). The handling of immunologically di fferent substancess in the spleen of B. variegata was investigated. Ad ult toads were injected into dorsal lymph sacs with a mixture of rabbi t peroxidase-antiperoxidase, FITC-Ficoll and latex beads. Two hours af ter injection antigens were found in the blood vessels of the spleen w here some cells had also PAP on their surface. At that time antigens a lso reached the white and the red pulps. Finally PAP was trapped on th e surface of ICTCs in the white pulp and was phagocytized by the white and red pulp macrophages. FITC-Ficoll was detected in the red pulp ma crophages while latex beads in macrophages of both compartments. The p resent study suggests that ICTCs are specialized in trapping only immu ne complexes.