Variation in lipid A structure in the pathogenic yersiniae.
Important pathogens in the genus Yersinia include the plague bacillus Yersinia pestis and two enteropathogenic species, Yersinia pseudotuberculosis and Yersinia enterocolitica. A shift in growth temperature induced changes in the number and type of acyl groups on the lipid A of all three species. After growth at 37 degrees C, Y. pestis lipopolysaccharide (LPS) contained the tetra-acylated lipid IV(A) and smaller amounts of lipid IV(A) modified with C10 or C12 acyl groups, Y. pseudotuberculosis contained the same forms as part of a more heterogeneous population in which lipid IV(A) modified with C16:0 predominated, and Y. enterocolitica produced a unique tetra-acylated lipid A. When grown at 21 degrees C, however, the three yersiniae synthesized LPS containing predominantly hexa-acylated lipid A. This more complex lipid A stimulated human monocytes to secrete tumour necrosis factor-alpha, whereas the lipid A synthesized by the three species at 37 degrees C did not. The Y. pestis phoP gene was required for aminoarabinose modification of lipid A, but not for the temperature-dependent acylation changes. The results suggest that the production of a less immunostimulatory form of LPS upon entry into the mammalian host is a conserved pathogenesis mechanism in the genus Yersinia, and that species-specific lipid A forms may be important for life cycle and pathogenicity differences.
Rebeil
Roberto
R
Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 S. 4th St., Hamilton, MT 59840, USA.
Ernst
Robert K
RK
Gowen
Brian B
BB
Miller
Samuel I
SI
Hinnebusch
B Joseph
BJ
D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D006801:Humans; D008050:Lipid A / Q000737:chemistry* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000737:chemistry* / Q000494:pharmacology; D015394:Molecular Structure; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013696:Temperature; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015007:Yersinia / Q000737:chemistry* / Q000378:metabolism / Q000472:pathogenicity*
D023181:Antimicrobial Cationic Peptides; D001426:Bacterial Proteins; D008050:Lipid A; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; C061064:PhoP protein, Bacteria