Pathogenic Leptospires Modulate Protein Expression and Post-translational Modifications in Response to Mammalian Host Signals

Frontiers in Cellular and Infection Microbiology

Grassmann, Andre A.¹  McBride, Alan J.¹  Seshu, Janakiram²  Planchon, Sé³  Renaut, Jenny⁴  bastien⁴  Sergeant, Kjell⁴  Nally, Jarlath E.⁵ 

[1] Biotechnology Unit, Technological Development Center, Federal University of Pelotas, Pelotas, Brazil;Department of Biology, University of Texas San Antonia, San Antonia, TX, United States;Departments of Medicine, Pediatrics, and Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, United States;Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Belvaux, Luxembourg;Infectious Bacterial Diseases Research, National Animal Disease Center, United States Department of Agriculture, Agricultural Research Service, Ames, IA, United States

关键词: Leptospira;    spirochetes;    Proteomics;    DIGE;    Post-Translational Modifications.;   

DOI  :  10.3389/fcimb.2017.00362

学科分类：生物科学（综合）

来源: Frontiers

【 摘 要 】

Pathogenic species of Leptospira cause leptospirosis, a bacterial zoonotic disease with a global distribution affecting over one million people annually. Reservoir hosts of leptospirosis, including rodents, dogs and cattle, exhibit little to no signs of disease but shed large numbers of organisms in their urine. Transmission occurs when mucosal surfaces or abraded skin come into contact with infected urine or urine-contaminated water or soil. Whilst little is known about how Leptospira adapt to and persist within a reservoir host, in vitro studies suggest that leptospires alter their transcriptomic and proteomic profiles in response to environmental signals encountered during mammalian infection. We applied the dialysis membrane chamber (DMC) peritoneal implant model to compare the whole cell proteome of in vivo derived leptospires with that of leptospires cultivated in vitro at 30oC and 37oC by 2-dimensional difference in gel electrophoresis (2-D DIGE). Of 1735 protein spots aligned across 9 2-D DIGE gels, 202 protein spots were differentially expressed (p1.25 or <-1.25) across all three conditions. Differentially expressed proteins were excised for identification by mass spectrometry. Data are available via ProteomeXchange with identifier PXD006995. The greatest differences were detected when DMC-cultivated leptospires were compared with IV30- or IV37-cultivated leptospires, including the increased expression of multiple isoforms of Loa22, a known virulence factor. Unexpectedly, 20 protein isoforms of LipL32 and 7 isoforms of LipL41 were uniformly identified by DIGE as differentially expressed, suggesting that unique post-translational modifications are operative in response to mammalian host conditions. To test this hypothesis, a rat model of persistent renal colonization was used to isolate leptospires directly from the urine of experimentally infected rats. Comparison of urinary derived leptospires to IV30 leptospires by 2-D immunoblotting confirmed that modification of proteins with trimethyllysine and acetyllysine occurs to a different degree in response to mammalian host signals encountered during persistent renal colonization. These results provide novel insights into differential protein and post-translational modifications present in response to mammalian host signals which can be used to further define the unique equilibrium that exists between pathogenic leptospires and their reservoir host of infection.

【 授权许可】

CC BY