Fish immune response to Myxozoan parasites

Abstract

Summary :Myxozoan parasites are responsible for important economic losses among fisheries and aquaculture industries, and hence the high interest in studying the immune response of fish against them. The most important data available concerning the immune response of fish against myxosporeans are reviewed, with emphasis on the different innate and adaptive immune mechanisms, their relationship with natural and acquired resistance and the strategies to control and prevent myxosporoses. Cellular effectors (lymphocytes, granulocytes, phagocytes, non-specific cytotoxic cells, rodlet cells) and humoral factors (lysozyme, peroxidades, antiproteases, complement, specific antibodies) have been examined for several myxosporoses, and some immune relevant genes have been studied. This information will be crucial for the future development of vaccines and other preventive strategies such as immunomodulation and selection of disease-resistant strains

Complex interaction between proliferative kidney disease, water temperature and concurrent nematode infection in brown trout

“…Therefore, the recovery process following a PKD infection seemed to be influenced by the concurrent parasitic disease. The fish immune response against myxozoan infections in general consists of cellular components, like macrophages, lymphocytes, and granulocytes, and of humoral components, like lysozyme, peroxidases, complement pathways and specific antibodies (Sitjà-Bobadilla 2008). It is possible that this immune response is influenced and possibly retarded by the concurrent infection.…”

Modulation of the IgM gene expression and IgM immunoreactive cell distribution by the nutritional background in gilthead sea bream (Sparus aurata) challenged with Enteromyxum leei (Myxozoa)

“…In an effort to understand the possible underlying mechanisms involved in the greater progression of the infection in 66VO fish, we undertook a series of detailed studies of gut immunology and fish immune response in fish fed such diets and confronted with this myxosporean. Production of specific antibodies has been described for several myxosporean infections [17] and circulating antibodies against Enteromyxum scophthalmi produced by turbot [18] are involved in resistance to re-infection to survivor fish [19]. Furthermore, in E. scophthalmi-experimentally infected turbot, an increase of Igþ cells occurred in the intestine, whereas a decrease was observed in lymphohaematopoietic tissues [20].…”

Quantitative and qualitative evaluation of iNOS expression in turbot (Psetta maxima) infected with Enteromyxum scophthalmi

“…Several humoral and cellular factors are activated in case of infection. Cytotoxic effector molecules, such as reactive nitrogen species, are mainly produced by activated phagocytes [6], and have been demonstrated in infections caused by other myxosporeans, as in Enteromyxum leei-infected sharp snout sea bream [7].…”