Host cell responses of Salmonella typhimurium infected human dendritic cells
Date
2006Author
Kiama, S G
Dreher, Donatus
Cochand, Laurence
Kok, Menno
Obregon, Carolina
Nicod, Laurent
Gehr, Peter
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
Live attenuated Salmonella are attractive vaccine candidates for mucosal application because they
induce both mucosal immune responses and systematic immune responses. After breaking the epithelium barrier,
Salmonella typhimurium is found within dendritic cells (DC) in the Peyer’s patches. Although there are abundant
data on the interaction of S. typhimurium with murine epithelial cells, macrophages and DC, little is known about
its interaction with human DC. Live attenuated S. typhimurium have recently been shown to efficiently infect
human DC in vitro and induce production of cytokines. In this study, we have analysed the morphological consequences of infection of human DC by the attenuated S. typhimurium mutant strains designated PhoPc, AroA and SipB and the wild-type strains of the American Type Culture Collection (Manassas, VA, USA), ATCC 14028 and
ATCC C53, by electron microscopy at 30 min, 3 h and 24 h after exposure. Our results show that genetic background
of the strains profoundly influence DC morphology following infection. The changes included (i) membrane
ruffling; (ii) formation of tight or spacious phagosomes; (iii) apoptosis; and (iv) spherical, pedunculated
membrane-bound microvesicles that project from the plasma membrane. Despite the fact that membrane ruffling
was much more pronounced with the two virulent strains, all mutants were taken up by the DC. The microvesicles
were induced by all the attenuated strains, including SipB, which did not induce apoptosis in the host cell. These
results suggest that Salmonella is internalized by human DC, inducing morphological changes in the DC that could
explain immunogenicity of the attenuated strains.
URI
http://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/14363http://www.nature.com/icb/journal/v84/n5/abs/icb200665a.html
Citation
Immunology and Cell Biology (2006) 84, 475–481Publisher
Department of Genetics and Microbiology, University of Geneva, Geneva, Switzerland Department of Veterinary Anatomy and Physiology, University of Nairobi, Nairobi, Kenya