Effect of the O-Antigen Chemical Structure in Different Subspecies of Francisella Tularensis on Immunological Reactions
The greatest diagnostic significance for tularemia is played by antibodies against lipopolysaccharide (LPS). Previously, it has been shown that specific antibodies that appear in the blood serum of laboratory animals infected with virulent strains and people who have recovered from tularemia can bind both to LPS Francisella tularensis and to LPS Francisella novicida, while after the vaccination specific antibodies to LPS F. novicida are absent. The aim of this work was to investigate the effect of the structure of the O-antigen of lipopolysaccharide F. tularensis of various subspecies on immunological reactions with specific antibodies. The method to isolate LPS from the various F. tularensis strains according to Westphal with modifications was used, and mild acid hydrolysis, and a method of negative contrast in carrying out electron microscopy were used. The ratio of hydrophilic and hydrophobic components of LPS molecules isolated from strains of various subspecies is determined. Correlation of the size of a capsular substance, determined by electron microscopy, with the ratio of hydrophilic and hydrophobic parts in LPS preparations obtained from the same strains was found. It was shown that in virulent strains of F. tularensis the capsule thickness and the ratio of the hydrophilic and hydrophobic parts were higher than those of the vaccine strain 15 NIIEG. Data indicating the presence of a capsule in F. novicida strain were obtained. A hypothesis is proposed that explains the cross-reacting of the sera of humans and animals infected with virulent strains, and with F. tularensis LPS, and with F. novicida LPS.
1. Cowley S. C., Elkins K. L. Immunity to Francisella. Frontiers in Microbiology, 2011, vol. 2, pp. 1-20.
2. Fulop M., Manchee R., Titball R. Role of lipopolysaccharide and a major outer membrane protein from Francisellatularensis in the induction of immunity against tularemia. Vaccine, 1995, vol. 13, pp. 1220-1225.
3. Apicella M. A., Post D. M., Fowler A. C., Jones B. D., Rasmussen J. A., Hunt J. R., Gibson B. W. Identifi cation, characterization and immunogenicity of an O-antigen capsular polysaccharide of Francisellatularensis. PLoS ONE, 2010, vol. 5 (7), e11060.
4. Rowe H. M., Huntley J. F. From the outside-in: The Francisella tularensis envelope and virulence. Frontiers in Cellular and Infection Microbiology, 2015,vol. 5, pp. 94. DOI: https://doi.org/10.3389/fcimb.2015.00094
5. Vinogradov E. V., Perry M. B., Conlan J. W. Structural analysis of Francisella tularensis lipopolysaccharide. Eur. J. Biochem., 2002, vol. 269, no. 24, pp. 6112-6118. DOI: https://doi.org/10.1046/j.1432-1033.2002.03321.x
6. Vinogradov E. V., Shashkov A. S., Knirel Y. A. Kochetkov N. K., Tochtamysheva N. V., Averin S. F., Goncharova O. V., Khlebnikov V. S. Structure of the O-antigen of Francisella tularensis strain 15. Carbohydr. Res., 1991, vol. 214, pp. 289–297. DOI: https://doi.org/10.1016/0008-6215(91)80036-M
7. Aronova N. V., Pavlovich N. V. Phase variations of lipopolysaccharide tularemia pathogen during human infection and immunization. Journal of Microbiology, Epidemiology and Immunobiology, 2005, iss. 4, pp. 8-12 (in Russian).
8. Westphal O., Jann K. Bacterial lipopolysaccharides. Extraction with phenol-water and further applications of the procedure. Methods in Carbohydrate Chemistry, 1965, vol. 5, pp. 83-91.
9. Galanos C., Luderitz O., Westphal O. A new method for the extraction of R lipopolysaccharides. Eur. J. Biochem., 1969, vol. 9, pp. 245-249.
10. Morrison L. J., Parker W. R., Holden D. D., Henderson J. C., Boll J. M., Trent M. S., Brodbelt J. S. UVliPiD: A UVPD-based hierarchical approach for de novo characterization of lipid a structures. Analyt. Chem., 2016, vol. 88, no. 3, pp.1812-1820. DOI: https://doi.org/10.1021/acs.analchem.5b04098
11. Raetz C. R., Guan Z., Ingram B. O., Six D. A., Song F., Wang X., Zha J. Discovery of new biosynthetic pathways: the lipid a story. J. Lipid Res., 2009, vol. 50, pp. 103–108. DOI: https://doi.org/10.1194/jlr.R800060-JLR200
12. Raetz C. R., Reynolds C. M., Trent M. S., Bishop R. E. Lipid A modifi cation systems in gram-negative bacteria. Ann. Rev. Biochem., 2007, vol. 76, pp. 295-329.
13. Raetz C. R., Whitfi eld C. Lipopolysaccharide endotoxins. Ann. Rev. Biochem., 2002, vol. 71, pp. 635–700.
14. Gunn J. S., Ernst R. K. The structure and function of Francisella lipopolysaccharid. Ann. of the New York Academy of Sciences, 2007, vol. 1105, pp. 202-218. DOI: https://doi.org/10.1196/annals.1409.006
15. Tsai C. M., Frash C. E. A sensitive silverstain for detecting lipopolysaccharides in polyacrylamide gels. Anal. Biochem., 1982, vol. 119, pp. 115-119.
16. Aronova N. V., Pavlovich N. V. Use of lipopolysaccharide preparations Francisella tularensis in point solid-state enzyme immunoassay. Journal of Microbiolody, Epidemiology and Immunobiology, 2000, vol. 5, pp. 75-78 (in Russian).
17. Barker J. H., Kaufman J. W., Apicella M. A., Weiss J. P. Evidence suggestingthat Francisella tularensis O-antigen capsule contains a lipid A-like molecule that is structurally distinct from the more abundant free lipid A . PLoS ONE, 2016, vol.11, iss. 6, e0157842. DOI: https://doi.org/10.1371/journal.pone.0157842
18. Olsuf'ev N. G. Taksonomiya, mikrobiologiya I laboratornaya diagnostika vozbuditelya tulyaremii [Taxonomy, microbiology and laboratory diagnosis of the causative agent of tularemia]. Moscow, Meditsina Publ., 1975. 192 p. (in Russian).
19. Olsuf`ev N. G., Rudnev G. P. Tulyaremiya [Tularemia]. Moscow, Medgiz Publ.,1960. 459 p. (in Russian).
20. Soni S., Ernst R. K., Muszynski A., Mohapatra N. P., Perry M. B., Vinogradov E. V., Carlson R. W., Gunn J. S. Francisella tularensis blue-gray phase variation involves structural modifi cations of lipopolysaccharide O-antigen, core and lipid A and affects intramacrophagesurvival and vaccine effi cacy. Frontiers in Microbiology, 2010, vol. 1, pp. 129. DOI: https://doi.org/10.3389/fmicb.2010.00129
21. Sorokin V. M., Pavlovich N. V., Prozorova L. A. Francisella tularensis resistance to bactericidal action of normal human serum . FEMS Immunol. Med. Microbiol., 1996, vol. 13, pp. 249-252.
22. Kingry L. C., Petersen M. Comparative review of Francisella tularensis and Francisella novicida. J. Front Cell Infect. Microbiol., 2014, vol. 4, pp. 35. DOI: https://doi.org/10.3389/fcimb.2014.00035
23. Okan N. A., Kasper D. L. The atypical lipopolysaccharide of Francisella. Carbohydr. Res., 2013, vol. 378, pp. 79-83. DOI: https://doi.org/10.1016/j.carres.2013.06.01
24. Wang X., Ribeiro A. A., Guan Z., McGrath S. C., Cotter R. J., Raetz C. R. Structure and biosynthesis of free lipid A molecules that replace lipopolysaccharide in Francisella tularensis subsp. novicida. Biochemistry, 2006, vol. 45, no. 48, pp. 14427–14440. DOI: https://doi.org/10.1021/bi061767s