Bacterial Lipopolysaccharide Binding Enhances Virion Stability and Promotes Environmental Fitness of an Enteric Virus

Christopher M. Robinson, Palmy R. Jesudhasan, and Julie K. Pfeiffer

Cell Host Microbe. (2014) 15, 36-46.

Speaker: Yi-Pin Tsai (蔡佾頻)                                             Time: 13:10~14:00, Apr. 16, 2014

Commentator: Dr. Guey-Chuen Perng (彭貴春博士)  Place: Room 601

Abstract:

In the last decade, poliovirus transmitted through the fecal-oral route is a major cause of paralysis until the development of vaccines (1). When poliovirus is ingested to the gastrointestinal tract, it encounters a vast of microorganisms. Previous studies showed that intestinal microbiota enhanced poliovirus infectivity (2), but the precise mechanisms are still unclear. In this study, the authors found that bacterial lipopolysaccharide (LPS) increased poliovirus infectivity by enhancing viral stability through elevating the temperature of viral RNA release and by promoting viral attachment to cells. To demonstrate LPS-mediated viral infectivity enhancement, the authors identified a mutant virus, VP1-T99K, with reduced LPS binding. Surprisingly, the authors showed that T99K virus reduced viral stability at physiological temperatures but failed to affect viral attachment when compared to wild-type (WT) virus. Notably, the authors found that viral stability required higher LPS concentrations than viral attachment did, suggesting that LPS-bound T99K virus was sufficient for enhancing attachment but not enough for viral stability. With the same pathogenesis and replication of WT and T99K viruses in mice, the authors used T99K virus as a tool to examine virus viability under environmental pressure by a model mimicking natural transmission. The authors showed that after repeated transmission cycles, LPS enhanced WT viral stability when compared to T99K virus. In conclusion, bacterial LPS enhances poliovirus stability and protects vial particles from inactivation in the environment leading to promote viral transmission in the environment.

References:

1.         Okayasu H1, Sutter RW, Czerkinsky C, Ogra PL. (2011) Mucosal immunity and poliovirus vaccines: impact on wild poliovirus infection and transmission.

Vaccine. 46, 8205-14

2.         Kuss, S.K., Best, G.T., Etheredge, C.A., Pruijssers, A.J., Frierson, J.M.,Hooper, L.V., Dermody, T.S., and Pfeiffer, J.K. (2011) Intestinal microbiota promote enteric virus replication and systemic pathogenesis. Science. 334, 249-252.