Effects of rearing stress on Atlantic salmon (Salmo salarL.) antibody response to a non-pathogenic antigen

Abstract

This study was carried out to test the effects of acute stress on the primary and the secondary antibody responses in Atlantic salmon (Salmo salar L.). Fish received a primary immunization with sheep red blood cells (SRBC) and received a second immunization 11 weeks later. At priming, a group of fish was stressed by water level reduction for 30 min (moderate stress), and another group was stressed severely by applying the stressor twice, with an interval of 6 h, 3 days in a row (severe stress). At the time of the booster, another two groups of previously unstressed, primed fish were treated likewise. Unstressed fish mounted a primary antibody response to SRBC and a secondary response, which was improved compared with the primary response., The primary antibody response against SRBC was impaired by severe, but not moderate, acute stress at priming, whereas the secondary antibody response was unaffected. Both moderate and severe stress at the time of the booster was immunosuppressive in fish that had been primed under non‐stress conditions. It is concluded that cortisol release as a result of stress exposure is most immunosuppressive at the time of the second immunization.

The effect of allostatic load on hypothalamic–pituitary–interrenal (HPI) axis before and after secondary vaccination in Atlantic salmon postsmolts (Salmo salar L.)

“…After the "boost" injection, the secondary immune response emerged faster and resulted in a greater antibody titre than the primary immune response. This is in accordance with earlier findings involving brown trout (Salmo trutta L.), Atlantic salmon (Salmon salar) and Arctic charr (Salvelinus alpinus), where the initial humoral immune response produced antibody titre to SRBC, and second dose of SRBC produced higher serum agglutinin (titre) compared the initial dose (Einarsdottir et al 2000a;Einarsdottir et al 2000b;Ingram 1985). A secondary immune response ("boost")…”

“…This seemed to be supported by the fact that secondary and tertiary stress responses as plasma chloride, magnesium, fin rot and mortality, were significantly increased in the "stress and vaccine" group compared to the "vaccine and stress" and the control group. Earlier studies have shown that cortisol is often associated with the detrimental effects of stress including: decreased growth rates, reproductive dysfunction (Morgan et al 1999;Schreck et al 2001;Mommsen et al 1999), increased incidence of disease (Barton 2002;Davis et al 2002Davis et al , 2003Einarsdottir et al 2000a;Einarsdottir et al 2000b;Weyts et al 1999), reduced seawater tolerance (Ventura et al 2011;Iversen et al 2009;Mommsen et al 1999;Redding and Schreck 1983;Sandodden et al 2001) and survival (Iversen et al 2005;Portz et al 2006;Finstad et al 2003;Iversen et al 1998;Hasan and Bart 2007). It has also been suggested that if the fish is not permitted enough time to recover completely after stress, a second, normally nonfatal, stressful occurrence could be fatal (Carmichael 1984), as observed in this experiment.…”

“…In this experiment stress prior to vaccination negatively affected the production of antibody titre, while vaccination before applying a daily stressor did not. The "vaccine and stress" group responded with a 2.5 times increase in antibody titre, 245 degrees days after the second vaccination, which is common during a second immunisation (Einarsdottir et al 2000a;Einarsdottir et al 2000b). After the "boost" injection, the secondary immune response emerged faster and resulted in a greater antibody titre than the primary immune response.…”

“…Cortisol is often associated with the detrimental effects of stress, including decreased growth, reproductive dysfunction (Morgan et al 1999;Schreck et al 2001;Schreck 2010;Mommsen et al 1999), increased incidence of disease (Barton 2002;Davis et al 2002Davis et al , 2003Einarsdottir et al 2000a;Einarsdottir et al 2000b;Weyts et al 1999), reduced seawater tolerance (Iversen et al 1998;Liebert and Schreck 2006;Sandodden et al 2001) and survival (Iversen et al 2005;Portz et al 2006;Finstad et al 2003;Iversen et al 1998;Hasan and Bart 2007).…”

Sex and low-level sampling stress modify the impacts of sewage effluent on the rainbow trout (Oncorhynchus mykiss) immune system

“…Effects of stress on immune parameters in fish have been investigated in various studies and e.g. a suppressed antibody response against sheep red blood cells in Atlantic salmon (Salmo salar) (Einarsdottir et al, 2000) and reduced resistance against Trypanoplasma borrelii infection in carp (C. carpio) (Saeij et al, 2003) has been detected after rearing stress due to repeated water level reduction and daily handling, respectively. Acute stress, however, has also been found to enhance specific immune reactions, as has been shown for lysozyme activity in rainbow trout (O. mykiss) after a 10 min handling stress (Demers and Bayne, 1997).…”