Meeting Abstract

P1.145  Friday, Jan. 4  Short-term Re-feeding After Calorie Restriction Partially Restores Resistance to Parasite Infection LANG, S.A.*; COLE, M.C.; KRISTAN, D.M.; California State University San Marcos; California State University San Marcos; California State University San Marcos lang014@cougars.csusm.edu

Laboratory mice (Mus musculus) given long-term calorie restriction (CR) have greater susceptibility to infection with the intestinal nematode Heligmosomoides bakeri, despite an adequate immune response. However, it is not known if short-term changes in food intake might influence susceptibility to infection. The goals of our study were to determine (1) if short-term re-feeding (RF) would ameliorate the expected increase in worm numbers seen with CR, (2) if parasite growth and reproduction would be altered after host re-feeding, and (3) if RF mice would have altered immunoglobulin (Ig) production compared to CR mice. MaleC57BL/6 mice were given 40% CR for six months, after which half of the mice were provided ad libitum (AL) food for seven days prior to infection; control mice were fed AL throughout the entire study. All mice were infected for 21d. As expected, CR mice harbored more worms than AL mice; RF mice had an intermediate number of parasites that did not differ significantly from either AL or CR mice. RF mice had intermediate body mass compared to CR and AL mice. There were no differences in parasite size, sex ratio or egg production, and both total circulating IgG1 and parasite-specific IgG1 were similar among mouse treatment groups. Longer infection durations should be assessed to determine if RF mice are able to clear infections at a similar rate as AL mice. Enumeration of CD4+ T cells and associated cytokines related to parasite expulsion, namely interleukin (IL)-4 and IL-13, may help explain observed differences in parasite susceptibility.