title: Multiple acute temperature stress affects leucocyte populations and antibody responses in common carp, Cyprinus carpio L.
abstract: Stress is a potential factor causing increased susceptibility of fish to pathogens. In this study, stress-induced immunological changes that may contribute to a decreased immune status were investigated. A 3 h drop in ambient water temperature of 9 degrees C was used as a relative mild and acute stress model for carp. Effects of this stressor on the dynamics of leucocyte populations were determined with specific monoclonal antibodies. The relative number of circulating B-lymphocytes in the total leucocyte population decreased significantly within 4 h after the onset of single or multiple cold shocks. This decrease was reversible, as B-lymphocyte numbers were restored within 24 h. Most probably, a redistribution of B-lymphocytes contributed to this phenomenon. In head kidney, an increase was measured in the relative number of B-lymphocytes. Granulocyte numbers showed opposite reactions: the percentage of granulocytes in the total leucocyte population nearly doubled in circulation and decreased significantly in the head kidney. This demonstrates that in vivo, a mild stressor differentially alters the distribution of leucocytes. In stressed carp, the percentage of apoptotic lymphocytes in blood is significantly higher compared with the unstressed animals. B-lymphocytes as well as Ig- lymphoid cells contributed to this increased apoptosis. Labelling of blood lymphocytes with a polyclonal antiserum against the glucocorticoid receptor also showed, besides B-lymphocytes, part of the Ig- lymphoid cell population to be glucocorticoid receptor positive. As the distribution of B-lymphocytes was substantially affected, the effect of temperature stress on T-lymphocyte-independent (trinitrophenyl-lipopolysaccharide) and T-lymphocyte-dependent (dinitrophenyl-keyhole limpet hemocyanin) humoral antibody responses was determined. Kinetics of the primary antibody response to the T-lymphocyte-independent antigen showed lower antibody titres in stressed carp during the onset of the immune response, implying a slower development of the antibody response against the T-lymphocyte-independent antigen.
authors.affiliation: Cell Biology and Immunology Group, Wageningen Institute of Animal Sciences, Wageningen University, P.O. Box 338, 6700 AH Wageningen, The Netherlands.
authors.forename: Marc Y
authors.initials: MY
authors.lastname: Engelsma
authors.forename: Sander
authors.initials: S
authors.lastname: Hougee
authors.forename: Dagmar
authors.initials: D
authors.lastname: Nap
authors.forename: Marloes
authors.initials: M
authors.lastname: Hofenk
authors.forename: Jan H W M
authors.initials: JH
authors.lastname: Rombout
authors.forename: Willem B
authors.initials: WB
authors.lastname: van Muiswinkel
authors.forename: B M
authors.initials: BM
authors.lastname: Lidy Verburg-van Kemenade
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000906:Antibodies / Q000276:immunology*; D017756:Aquaculture; D002347:Carps / Q000276:immunology*; D004136:Dinitrobenzenes / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D007150:Immunohistochemistry; D007668:Kidney / Q000276:immunology; D007962:Leukocytes / Q000276:immunology*; D008070:Lipopolysaccharides / Q000276:immunology; D011965:Receptors, Glucocorticoid / Q000276:immunology; D013696:Temperature
chemical_list: D000906:Antibodies; D004136:Dinitrobenzenes; D008070:Lipopolysaccharides; D011965:Receptors, Glucocorticoid; C048761:trinitrophenyl-lipopolysaccharide