Sex Steroids Modulate Fish Immune Response

Sexual maturation and administration of 17β-estradiol and testosterone induce complex gene expression changes in skin and increase resistance of Atlantic salmon to ectoparasite salmon louse

“…Sex steroids also affect immune responses in birds, but the data often appear contradictory (reviewed by Koutsos and Klasing, 2008). The findings in teleosts also range from stimulatory to suppressive effects for both female and male sex steroids (reviewed by Chaves-Pozo et al, 2012). This can be partly explained by their highly context-dependent action, which is, among other factors, influenced by the presence of the pathogen and its type.…”

“…Differential effects of male and female sex steroid hormones on non-reproductive tissues, including immune cells, could explain some of these differences. It is generally accepted that in mammals, estrogens exert mainly pro-inflammatory effects while androgens are primarily immunosuppressive (see references in Chaves-Pozo et al, 2012). Cook et al (1994) demonstrated that E2 stimulated salmon lymphocyte proliferation in in vitro assays, while T, but not E2, significantly reduced the number of antibody-producing lymphocytes; the magnitude of induced immunosuppression by T was significantly greater in combination with cortisol than when either hormone was administered alone.…”

“…This can be partly explained by their highly context-dependent action, which is, among other factors, influenced by the presence of the pathogen and its type. In sea bream, 11-ketotestosterone increased the expression of IL-1b on acidophilic granulocytes (equivalents of mammalian neutrophils) only upon stimulation with the genomic DNA of Vibrio anguilarium, while T showed stimulatory effects under both conditions (see references in Chaves-Pozo et al, 2012). A study in western fence lizard (Sceloporus occidentalis) revealed that T-implanted males had significantly higher tick (Ixodes pacificus), but lower mite loads in comparison to control males, suggesting that T differentially influences burdens of ectoparasitic acarine species (Pollock et al, 2012).…”

Immune-Specific Expression and Estrogenic Regulation of the Four Estrogen Receptor Isoforms in Female Rainbow Trout (Oncorhynchus mykiss)

“…Despite this difference, estrogens appear to have immunomodulatory actions in teleosts as well. A number of studies could show that immune parameters and immunocompetence of fish are influenced by estrogens, both by endogenous estrogens and by environmental (xeno) estrogens [ 21 , 22 , 23 ]. Moreover, recent research provided evidence that both membrane and nuclear ERs are expressed in immune organs and cells of teleosts [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ].…”

The trenbolone acetate affects the immune system in rainbow trout, Oncorhynchus mykiss

“…In vertebrates, there is an interaction between the endocrine and the immune systems, and changes in the endocrine function may be linked to modifications of endocrine levels. Notably, it is known that both innate and adaptive immunities are altered by androgens (Grossman, 1984;Harris and Bird, 2000;Yada and Nakanishi, 2002;Verburg-Van Kemenade et al, 2009;Chaves-Pozo et al, 2012;Massart et al, 2014). However, the mechanisms leading to the disruption of the immune system remain unclear.…”