Corticosterone, inflammation, immune status and telomere length in frigatebird nestlings facing a severe herpesvirus infection

Abstract

In this study, we examined the pathophysiological consequences likely to be attributable to a herpesvirus infection for immune function, corticosterone, telomere length and inflammation. We found that the plasma concentration of haptoglobin was strongly associated with the observable clinical manifestation of disease and could predict probabilities of survival.

Resveratrol supplementation reduces oxidative stress and modulates the immune response in free‐living animals during a viral infection

“…Contrary to our expectation, baseline CORT levels did not differ among the different groups. CORT also did not increase during the progress of the disease, which is in agreement with our previous results (Sebastiano, Eens, Angelier, et al, ). By dividing birds according to the severity of clinical signs and the progress of the disease over the course of the experiment, instead, we found novel findings.…”

“…Supplementation with resveratrol did not affect haemolysis and haemagglutination scores, which might suggest that these particular aspects of the immune system play a minor role in coping with a viral infection in frigatebirds (Sebastiano, Eens, Angelier, et al, 2017). In contrast, nestlings supplemented with resveratrol showed F I G U R E 4 Effect of resveratrol administration on the levels of (left) circulating nonenzymatic antioxidants (μmol Trolox/g of fresh weight), and (right) oxidative damage to lipids (nmol of MDA equivalents/ml) levels.…”

Food supplementation protects Magnificent frigatebird chicks against a fatal viral disease

“…Given that frigatebird chicks experience regularly short periods of fasting during the entire growth period (Osorno, ), it might be that they do not need to upregulate production of CORT to cope with episodes of food shortage. CORT is also not dependent on the time of sampling in our species (Sebastiano et al., ). Blood was collected within three minutes in all birds, thus CORT reflected baseline levels (Romero & Reed, ).…”

“…Significant P-values are shown in bold shortage. CORT is also not dependent on the time of sampling in our species (Sebastiano et al, 2017c). Blood was collected within three minutes in all birds, thus CORT reflected baseline levels (Romero & Reed, 2005).…”

“…In recent years, recurrent episodes of frigatebird chicks' mortality due to disease outbreaks that first appeared in (de Thoisy et al, 2009) have turned into massive mortality episodes (85-95% of chicks) that occur annually (Sebastiano et al, 2017b). The disease is characterized by the appearance of visible clinical signs (i.e., skin crusts) that can rapidly spread all over the chicks' body, giving in most cases no chances of recovery (Sebastiano et al, 2017c;Sebastiano et al, 2018). Microscopic evaluation of skin lesions, attempts of bacterial cultures, viral screening and PCR analyses of skin crusts and cloacal swabs identified the presence of a herpesvirus with up to several million copies of viral DNA in sick individuals (de Thoisy et al, 2009;Sebastiano et al, 2017b).…”