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GFPuv-Expressing Recombinant Rickettsia typhi: a Useful Tool for the Study of Pathogenesis and CD8 + T Cell Immunology in R. typhi Infection.
- Source :
-
Infection and immunity [Infect Immun] 2017 May 23; Vol. 85 (6). Date of Electronic Publication: 2017 May 23 (Print Publication: 2017). - Publication Year :
- 2017
-
Abstract
- Rickettsia typhi is the causative agent of endemic typhus, a disease with increasing incidence worldwide that can be fatal. Because of its obligate intracellular life style, genetic manipulation of the pathogen is difficult. Nonetheless, in recent years, genetic manipulation tools have been successfully applied to rickettsiae. We describe here for the first time the transformation of R. typhi with the pRAM18dRGA plasmid that originally derives from Rickettsia amblyommatis and encodes the expression of GFPuv (green fluorescent protein with maximal fluorescence when excited by UV light). Transformed R. typhi ( R. typhi <superscript>GFPuv</superscript> ) bacteria are viable, replicate with kinetics similar to those of wild-type R. typhi in cell culture, and stably maintain the plasmid and GFPuv expression under antibiotic treatment in vitro and in vivo during infection of mice. CB17 SCID mice infected with R. typhi <superscript>GFPuv</superscript> succumb to the infection with kinetics similar to those for animals infected with wild-type R. typhi and develop comparable pathology and bacterial loads in the organs, demonstrating that the plasmid does not influence pathogenicity. In the spleen and liver of infected CB17 SCID mice, the bacteria are detectable by immunofluorescence microscopy in neutrophils and macrophages by histological staining. Finally, we show for the first time that transformed rickettsiae can be used for the detection of CD8 <superscript>+</superscript> T cell responses. GFP-specific restimulation of spleen cells from R. typhi <superscript>GFPuv</superscript> -infected BALB/c mice elicits gamma interferon (IFN-γ), tumor necrosis factor alpha (TNF-α), and interleukin 2 (IL-2) secretion by CD8 <superscript>+</superscript> T cells. Thus, R. typhi <superscript>GFPuv</superscript> bacteria are a novel, potent tool to study infection with the pathogen in vitro and in vivo and the immune response to these bacteria.<br /> (Copyright © 2017 Hauptmann et al.)
- Subjects :
- Animals
Green Fluorescent Proteins genetics
Liver microbiology
Macrophages microbiology
Mice
Mice, Inbred BALB C
Mice, SCID
Neutrophils microbiology
Plasmids
Rickettsia typhi genetics
Spleen microbiology
Transformation, Bacterial
Typhus, Endemic Flea-Borne microbiology
CD8-Positive T-Lymphocytes immunology
Cytokines immunology
Rickettsia typhi pathogenicity
Typhus, Endemic Flea-Borne immunology
Subjects
Details
- Language :
- English
- ISSN :
- 1098-5522
- Volume :
- 85
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- Infection and immunity
- Publication Type :
- Academic Journal
- Accession number :
- 28289147
- Full Text :
- https://doi.org/10.1128/IAI.00156-17