Modulation of leukocytic populations of gilthead sea bream (Sparus aurata) by the intestinal parasite Enteromyxum leei (Myxozoa: Myxosporea).
SUMMARY The cellular mucosal and systemic effectors of gilthead sea bream (GSB) (Sparus aurata) involved in the acute immune response to the intestinal parasite Enteromyxum leei were studied in fish experimentally infected by the anal route. In the intestinal inflammatory infiltrates and in lymphohaematopoietic organs (head kidney and spleen) of parasitized fish, the number of plasma cells, B cells (IgM immunoreactive) and mast cells (histamine immunoreactive) were significantly higher, whereas the number of acidophilic granulocytes (G7 immunoreactive) decreased, compared with non-parasitized and unexposed fish. These differences were stronger at the posterior intestine, the main target of the parasite, and no differences were found in the thymus. In non-parasitized GSB, the percentage of splenic surface occupied by melanomacrophage centres was significantly higher. These results suggest that the cellular response of GSB to E. leei includes proliferation of leukocytes in lymphohaematopoietic organs and recruitment into intestines via blood circulation involving elements of innate and adaptive immunity. Acidophilic granulocytes and mast cells presented opposite patterns of response to the parasite infection, with an overall depletion of the former and an increased amount of the latter. Some differences between both cell types were also detected in regard to their granule density and cell morphology.
Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), 12595 Ribera de Cabanes, Castellón, Spain.
Itziar
I
Estensoro
Department of Cell Biology and Histology, Faculty of Biology, University of Murcia (UM), 30100 Murcia, Spain.
Iván
I
Mulero
Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), 12595 Ribera de Cabanes, Castellón, Spain.
María J
MJ
Redondo
Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), 12595 Ribera de Cabanes, Castellón, Spain.
Pilar
P
Alvarez-Pellitero
Department of Cell Biology and Histology, Faculty of Biology, University of Murcia (UM), 30100 Murcia, Spain.
Victoriano
V
Mulero
Instituto de Acuicultura Torre de la Sal, Consejo Superior de Investigaciones Científicas (IATS-CSIC), 12595 Ribera de Cabanes, Castellón, Spain.
Ariadna
A
Sitjà-Bobadilla
D056704:Adaptive Immunity; D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology*; D049109:Cell Proliferation; D005393:Fish Diseases / Q000276:immunology* / Q000469:parasitology; D006098:Granulocytes / Q000276:immunology; D006790:Host-Parasite Interactions; D007113:Immunity, Innate; D007422:Intestines / Q000469:parasitology; D007962:Leukocytes / Q000276:immunology*; D008407:Mast Cells / Q000276:immunology; D055764:Myxozoa / Q000276:immunology*; D010273:Parasitic Diseases, Animal / Q000276:immunology* / Q000469:parasitology; D021541:Sea Bream / Q000276:immunology* / Q000469:parasitology
D000913:Antibodies, Protozoan