Folia Parasitologica 46[1] 1-9 (1999)

Immune mechanisms in fish skin against monogeneans - a model

Kurt Buchmann

Department of Veterinary Microbiology, Section of Fish Diseases, Royal Veterinary and Agricultural University, 13 Bülowsvej, DK-1870 Frederiksberg C, Denmark

Host responses against skin inhabiting monogeneans are commonly observed but the responsible immune mechanisms in the fish skin are insufficiently described. Based on recent knowledge of fish immunity and skin response mechanisms in mammals a model for the skin immunity in fish to monogenean infections is proposed. Important cellular components of the model are the epithelial cells, the mucous cells and leucocytes. The release of cytokines, e.g. IL-1, following mechanical or chemical injury of the epithelial cells, initiates a series of events leading to decrease of the ectoparasite population. Cytokines (e.g. IL-1, TNF, INF) are suggested to affect secretions from mucous cell and attract neutrophils and macrophages. Leukotrienes are probably involved in the inflammatory reactions. The subsequent production of humoral substances (among others complement factors and peptides) could be responsible for the antiparasitic response in the later stages of infection. Although non-specific factors dominate the response, the involvement of specific antibodies and lymphocytes cannot be excluded.

Keywords: Monogenea, fish immunity, skin immune system, cytokines, complement, humoral factors, cellular responses

Received: December 23, 1997; Accepted: July 28, 1998; Published: March 1, 1999  Show citation