Meeting Abstract
Glucocorticoids (GC) exhibit varying effects on the immune system at different stages of infection. The relationship appears to be complex, with GCs having both stimulating and inhibitory effects. Numerous studies have found relationships between corticosterone and the immune system’s ability to fight disease. The pathogenic bacterium Mycoplasma gallisepticum (MG) elicits an adaptive immune response in birds, in which B cells produce MG-specific antibodies to fight the infection and prevent reoccurrence. Previously, we found Eastern Bluebirds that produce the most antibodies in response to MG infection also have the highest corticosterone levels. This finding led us to ask whether corticosterone typically stimulates production of antibodies in response to any immune challenge, or if the nature and virulence of the challenge will influence the relationship between corticosterone production and humoral immunity. Here we examine the effects of corticosterone supplementation on Eastern Bluebirds following vaccination against MG. This experiment consisted of a control group that received neither a corticosterone supplement nor a vaccine, and three experimental groups that were either supplemented with corticosterone, injected with the killed vaccine, or given both treatments. We compare results from the current study utilizing a vaccine challenge with those of the previous study where birds were infected with the live pathogen. If both studies generate the same positive relationship, this suggests that corticosterone is stimulating the humoral immune system; if antibody production and corticosterone are negatively related in response to vaccination, this suggests that the nature of the relationship is dependent on factors associated with pathogen virulence.
