STRUKTURA CHEMICZNA
I AKTYWNOŚĆ BIOLOGICZNA LIPOPOLISACHARYDU
PAŁECZEK Z RODZINY LEGIONELLACEAE
Marta Palusińska-Szysz, Wincenty J. Drożański
Zakład Mikrobiologii Ogólnej, Instytut Mikrobiologii i Biotechnologii,
Uniwersytet Marii Curie-Skłodowskiej, ul. Akademicka 19, 20-033 Lublin,
e-mail: martasz@biotop.umcs.lublin.pl
Wpłynęło w styczniu 2006 r.
1. Wstęp. 2. Struktura i funkcja
lipopolisacharydu. 3. Składniki lipopolisacharydu. 3.1. Łańcuch O-specyficzny. 3.2. Oligosacharyd rdzeniowy. 4. Charakterystyka lipidu A. 4.1. Szkielet lipidu A. 4.2. Kwasy tłuszczowe. 4.2.1. Kwasy tłuszczowe związane amidowo. 4.2.2. Kwasy tłuszczowe związane estrowo. 5. Aktywność biologiczna
LPS-u. 5.1. Antygenowość. 5.2. Endotoksyczność. 6. Podsumowanie
Chemical structure and biological significance of the lipopolisaccharide of Legionellaceae rods Abstract:
Legionellae form a distinct taxonomic unit within the g-2 subdivision of the
Proteobacteria. Members of the family are ubiquitous inhabitants of aquatic environments and moist soil. In natural biotopes the bacteria survives and dissiminate as obligate intracellular parasites of free-living protozoa.
Legionellae are capable of infecting and multiplying also within a variety of mammalian cell lines and has been demonstrated to grow extracellularly only under laboratory conditions. Since 1976 they were recognized as potent pathogens of humans. Currently there are 49 validly described species comprising 70 distinct serogroups, 39 of which are established aetiological agents of the potentially lethal pneumonia commonly known as Legionnaires'disease. The disease, if left untreated, leads to an average mortality rate of 5 to 15%. Approximately 80% of legionellae infection are caused by
Legionella pneumophila serogroups 1 and 6. Other serogroups of
L. pneumophila and another 23 species of Legionellae are associated to a varying degree with human disease. Virulent strains can multiply inside the phagocytes and are able to inhibit the fusion of phagosomes with lysosomes. The differences in the virulence of
Legionellae species or serogroups are associated at least in part with differences of epitopes on the lipopolysaccharide (LPS). LPS's are characteristic components of the envelope of Gram-negative bacteria and represent the O-antigens and endotoxins of bacteria. The role of LPS in
Legionellae virulence and infection, their interaction with humoral and cellular components of the host as well as mechanisms of induction of mediators represent some of the current fields in endotoxin
research. L. pneumophila produces an unusual hydrophobic LPS which may facilitate its intracellular
lifestyle. The O-specific chain of L. pneumophila LPS, the so called repeating units, was found to be homopolimer of
5-acetimidoylamino-7-acetamido-3,5,7,9-tetradeoxy-D-glycero-D-galacto-non-2-ulosonic acid. Lipid A's from legionellae were found to contain the backbone with the rare 2,3-diamino-2,3-dideoxy-glucose. Striking differences also exist in the fatty acids attached to lipid A's from legionellae. The unusal complex fatty acids patterns are known to include a wide range of saturated and methyl-branched (iso and anteiso), cyclopropane-substituted FA as well as monohydroxylated and dihydroxylated
FA. 1. Introduction. 2. Structure and function of
LPS. 3. Lipopolysaccharide components. 3.1. O-specific
chain. 3.2. Core oligosaccharide. 4. Lipid A-components. 4.1. Lipid A
backbone. 4.2. Fatty acids. 4.2.1. Amide bound fatty acids. 4.2.2. Ester bound fatty acids. 5. Biological activity of
LPS. 5.1. Antigenicity. 5.2. Endotoxicity. 6. Conclusion
Słowa kluczowe: antygen somatyczny, endotoksyna, Legionellaceae,
lipopolisacharyd
Key words: somatic antigen, endotoxin, Legionellaceae, lipopolysaccharide
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