Pathogen-Mediated Inhibition of Anorexia Promotes Host Survival and Transmission

Sheila Rao,
Alexandria M. Palaferri Schieber, Carolyn P. O’Connor, Mathias Leblanc, Daniela Michel, Janelle S. Ayres

Cell 168, 503–516, January 26, 2017

Speaker: Yu-Shan Lin (林鈺珊)                                    Time: 15:00~16:00, May. 3, 2017

Commentator: Ching-Hao Teng (鄧景浩 老師)          Place: Room 601

Abstract:

Bacterial infection can trigger behavioral changes in the host, including anorexia, fever, and sleep disturbances. These behavior changings are referred as ‘‘sickness-behaviors’’. In previous studies, the authors found out using a mice model that systemic infection with Listeria monocytogenescan trigger anorexia and this response is protective [1] ; however, the anorexic response lead to an opposite result in Drosophila model[2] . In this study the authors aimed to better understand the mechanism of anorexia, and further confirm whether the anorexic response is beneficial to the host. Using Salmonella Typhimurium (ST) as a model, the authors found out after a series of animal experiments that ST effector protein, Slrp, could negatively regulate virulence and inhibit inflammasome activation. Furthermore, Slrp can block IL-1-mediated anorexia via the vagus nerve-hypothalamus pathway. Animal experiments also showed that the pathogen-mediated inhibition of anorexia could increase host survival rate and ST transmission to a second host. The findings of this study suggest that microbes can develope a mechanism to modulate sickness-behaviors to promote health of the host as well as their own transmission through negatively regulating virulence factors.

References：

1. Murray, M.J., and Murray, A.B. (1979). Anorexia of infection as a mechanism of host defense. Am. J. Clin. Nutr. 32, 593–596.

2. Ayres, J.S., and Schneider, D.S. (2009). The role of anorexia in resistance and tolerance to infections in Drosophila. PLoS Biol. 7, e1000150.