Meeting Abstract
P3.106 Jan. 6 Maintenance of immunological memory is compromised by food restriction in male deer mice NAVARA, KJ*; MARTIN II, LB; WEIL, ZM; NELSON, RJ; The Ohio State University; The Ohio State University; The Ohio State University; The Ohio State University navara.1@osu.edu
After the initial immune response to a pathogen, the immune system produces and maintains an immunological memory of the pathogen to facilitate quicker responses with subsequent exposures. While multiple parts of the initial immune response have demonstrated energetic costs, it is still unclear whether maintenance of immunological memory is also costly. We tested the hypothesis that the maintenance of immunological memory is expensive and thus may be important in terms of trade-offs with other energetically expensive activities. Deer mice (Peromyscus maniculatus) were initially challenged with a novel protein, keyhole limpet hemocyanin (KLH), and primary B-cell mediated antibody (IgG) responses were measured. Immediately after, mice were placed in one of four treatment groups: (1)Food restricted: dietary intake reduced to 70% of normal intake, (2)Ad libitum: provided free access to food, (3)Food restricted/restraint: provided with 70% normal food intake and restrained 6 times for 2 consecutive hours, and (4)Ad libitum/restraint: free access to food and restrained as described above. Treatments lasted for two weeks, during which immunological memory was being maintained. Mice were then re-challenged with KLH and the strength of the secondary antibody response was assessed. As predicted, mice maintained on a restricted diet reduced secondary IgG production to KLH by ~100% relative to mice fed ad lib. Restraint stress had no effect on secondary IgG production and circulating corticosterone (CORT) levels were not different between food restricted and ad lib animals, suggesting that observed changes in immunological memory after food restriction were not mediated by changes in circulating CORT and may instead represent an energetic cost.
