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Involvement of complement pathways in patients with bacterial septicemia
- Source :
- Molecular Immunology, Molecular Immunology, Elsevier, 2007, 44 (7), pp.1631-8. ⟨10.1016/j.molimm.2006.08.008⟩
- Publication Year :
- 2006
-
Abstract
- The complement system is a major humoral portion of the innate immune system, playing a significant role in host defence against microorganisms. The biological importance of this system is underlined by the fact that at least three different pathways for its activation exist, the classical, the MBL and the alternative pathway. To elucidate the involvement of the classical and/or the MBL pathway during bacterial septicemia, 32 patients with gram-positive and 30 patients with gram-negative bacterial infections were investigated. In patients with gram-positive bacteria, a significant consumption of C1q (p=0.005) but not of mannose-binding lectin (MBL) (p=0.2) was found during the acute phase of infection. In contrast, in patients with gram-negative bacterial infections, a significant reduction of MBL (p=0.002) and only a moderate, less significant reduction of C1q (p=0.03) were observed. As a model for the binding of MBL to gram-negative bacteria, Salmonella strains with defined mutations in their lipopolysaccharide (LPS) structure were used. The comparison of the binding of MBL to these Salmonella strains with that of the corresponding isolated LPS forms bound to microtiter plates revealed a similar binding pattern, supporting the interpretation that LPS on the surface of gram-negative bacteria is the major acceptor molecule for MBL on these bacteria, which according to our results obviously also takes place during gram-negative bacterial septicaemia. Furthermore, we were able to demonstrate that MBL bound to LPS was able to initiate activation of the complement cascade as measured by the occurrence of the cleavage product C4c.
- Subjects :
- MESH: Complement Pathway, Mannose-Binding Lectin
Lipopolysaccharides
Salmonella
MESH: Complement C1q
Lipopolysaccharide
Immunology
chemical and pharmacologic phenomena
Bacteremia
medicine.disease_cause
Gram-Positive Bacteria
Mannose-Binding Lectin
Microbiology
MESH: Gram-Positive Bacteria
03 medical and health sciences
chemistry.chemical_compound
Classical complement pathway
0302 clinical medicine
medicine
Humans
[SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology
Complement Pathway, Classical
MESH: Bacteremia
Molecular Biology
030304 developmental biology
0303 health sciences
Innate immune system
MESH: Humans
biology
Complement C1q
Lectin
Salmonella enterica
Complement Pathway, Mannose-Binding Lectin
MESH: Complement Pathway, Classical
biology.organism_classification
bacterial infections and mycoses
3. Good health
Complement system
MESH: Mannose-Binding Lectin
chemistry
MESH: Salmonella enterica
Alternative complement pathway
biology.protein
MESH: Lipopolysaccharides
Bacteria
030215 immunology
Subjects
Details
- ISSN :
- 01615890
- Volume :
- 44
- Issue :
- 7
- Database :
- OpenAIRE
- Journal :
- Molecular immunology
- Accession number :
- edsair.doi.dedup.....9552752b3f2552da33c8be9f557b5e7e