| Autor: |
Schaeffer, Lyndsay M., McCormack, Francis X., Wu, Huixing, Weiss, Alison A. |
| Zdroj: |
Infection and Immunity; December 2004, Vol. 72 Issue: 12 p7124-7130, 7p |
| Abstrakt: |
ABSTRACTSurfactant proteins A (SP-A) and D (SP-D) play an important role in the innate immune defenses of the respiratory tract. SP-A binds to the lipid A region of lipopolysaccharide (LPS), and SP-D binds to the core oligosaccharide region. Both proteins induce aggregation, act as opsonins for neutrophils and macrophages, and have direct antimicrobial activity. Bordetella pertussisLPS has a branched core structure and a nonrepeating terminal trisaccharide. Bordetella bronchisepticaLPS has the same structure, but lipid A is palmitoylated and there is a repeating O-antigen polysaccharide. The ability of SP-A and SP-D to agglutinate and permeabilize wild-type and LPS mutants of B. pertussisand B. bronchisepticawas examined. Previously, wild-type B. pertussiswas shown to resist the effects of SP-A; however, LPS mutants lacking the terminal trisaccharide were susceptible to SP-A. In this study, SP-A was found to aggregate and permeabilize a B. bronchisepticamutant lacking the terminal trisaccharide, while wild-type B. bronchisepticaand mutants lacking only the palmitoyl transferase or O antigen were resistant to SP-A. Wild-type B. pertussisand B. bronchisepticawere both resistant to SP-D; however, LPS mutants of either strain lacking the terminal trisaccharide were aggregated and permeabilized by SP-D. We conclude that the terminal trisaccharide protects Bordetellaspecies from the bactericidal functions of SP-A and SP-D. The O antigen and palmitoylated lipid A of B. bronchisepticaplay no role in this resistance. |
| Databáze: |
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