Please use this identifier to cite or link to this item: https://www.arca.fiocruz.br/handle/icict/12131
Title: Osmotic regulation of expression of two extracellular matrix-binding proteins and a haemolysin of Leptospira interrogans: differential effects on LigA and Sph2 extracellular release
Authors: Matsunaga, James
Medeiros, Marco Alberto
Sanchez, Yolanda
Werneid, Kristian F
Ko, Albert Icksang
Affilliation: VA Greater Los Angeles Healthcare System. Research Service. Los Angeles, CA, USA / UCLA David Geffen School of Medicine. Los Angeles, CA, USA
Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Biomanguinhos. Rio de Janeiro, RJ, Brasil
VA Greater Los Angeles Healthcare System. Research Service. Los Angeles, CA, USA
VA Greater Los Angeles Healthcare System. Research Service. Los Angeles, CA, USA
Weill Medical College of Cornell University. Division of International Medicine and Infectious Diseases. New York, NY, USA / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil
Abstract: The life cycle of the pathogen Leptospira interrogans involves stages outside and inside the host. Entry of L. interrogans from moist environments into the host is likely to be accompanied by the induction of genes encoding virulence determinants and the concomitant repression of genes encoding products required for survival outside of the host. The expression of the adhesin LigA, the haemolysin Sph2 (Lk73.5) and the outer-membrane lipoprotein LipL36 of pathogenic Leptospira species have been reported to be regulated by mammalian host signals. A previous study demonstrated that raising the osmolarity of the leptospiral growth medium to physiological levels encountered in the host by addition of various salts enhanced the levels of cell-associated LigA and LigB and extracellular LigA. In this study, we systematically examined the effects of osmotic upshift with ionic and non-ionic solutes on expression of the known mammalian host-regulated leptospiral genes. The levels of cell-associated LigA, LigB and Sph2 increased at physiological osmolarity, whereas LipL36 levels decreased, corresponding to changes in specific transcript levels. These changes in expression occurred irrespective of whether sodium chloride or sucrose was used as the solute. The increase of cellular LigA, LigB and Sph2 protein levels occurred within hours of adding sodium chloride. Extracellular Sph2 levels increased when either sodium chloride or sucrose was added to achieve physiological osmolarity. In contrast, enhanced levels of extracellular LigA were observed only with an increase in ionic strength. These results indicate that the mechanisms for release of LigA and Sph2 differ during host infection. Thus, osmolarity not only affects leptospiral gene expression by affecting transcript levels of putative virulence determinants but also affects the release of such proteins into the surroundings.
keywords: Leptospira
Leptospira interrogans
Leptospirose
Issue Date: 2007
Publisher: Microbiology Society
Citation: MATSUNAGA, J. et al. Osmotic regulation of expression of two extracellular matrix-binding proteins and a haemolysin of Leptospira interrogans: differential effects on LigA and Sph2 extracellular release. Microbiology, v. 153, p. 3390–3398, 2007.
DOI: 10.1099/mic.0.2007/007948-0
ISSN: 1350-0872
Copyright: open access
Appears in Collections:BA - IGM - Artigos de Periódicos

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