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Antibodies to various bacterial cell wall peptidoglycans in human and rabbit sera
Abstract:
Sera from patients with verified systemic staphylococcal infection contained antibodies reactive with peptidoglycan (PG) from Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Micrococcus lysodeikticus, Bacillus subtilis, and Escherichia coli. The presence of anti-PG cross-reactive antibodies was verified in patient sera by inhibition studies with the various bacterial PGs. Antibodies to nonstaphylococcal PGs were also elevated in sera from rabbits immunized with S. aureus PG. Antibodies to S. aureus PG were removed with the synthetic peptide analogs of S. aureus PG, the L-Lys-D-Ala-D-Ala, L-Lys-D-Ala, and (Gly)5 determinants, as well as with an S. aureus PG peptide fragment containing the determinants D-Ala-D-Ala and L-Lys-D-Ala. Isolated antibodies to the PG peptides, both synthetic and native, were reactive with S. aureus and S. epidermidis PGs. The antibodies to the D-Ala-D-Ala and the L-Lys-D-Ala determinants were also reactive with S. pyogenes PG, but not with PGs from M. lysodeikticus, B. subtilis, and E. coli.
Insights
Patients with staphylococcal infections have antibodies targeting bacterial peptidoglycan (PG). These antibodies cross-react with PG from various bacteria, including Streptococcus pyogenes, highlighting a broad immune response to staphylococcal PG.
Area of Science:
- Immunology
- Microbiology
- Bacterial Pathogenesis
Background:
- Systemic staphylococcal infections elicit an immune response.
- Peptidoglycan (PG) is a major component of bacterial cell walls and a potential antigen.
Purpose of the Study:
- To investigate the specificity of antibodies against Staphylococcus aureus peptidoglycan (PG).
- To determine the cross-reactivity of anti-PG antibodies with peptidoglycans from other bacterial species.
Main Methods:
- Sera from patients with staphylococcal infections were analyzed for anti-PG antibodies.
- Inhibition studies using various bacterial PGs were performed to assess antibody cross-reactivity.
- Antibodies were characterized using synthetic peptide analogs and native PG fragments.
Main Results:
- Patient sera contained antibodies reactive with peptidoglycan (PG) from multiple bacterial species, including S. aureus, S. epidermidis, and S. pyogenes.
- Antibodies generated against S. aureus PG showed cross-reactivity with PGs from other bacteria.
- Specific antibody responses were observed against synthetic peptide analogs and PG fragments, indicating targeted immune recognition.
Conclusions:
- Antibodies to Staphylococcus aureus peptidoglycan (PG) exhibit significant cross-reactivity with PGs from other Gram-positive bacteria, notably Streptococcus pyogenes.
- The findings suggest that anti-PG antibodies may play a role in the immune response to staphylococcal infections and potentially other Gram-positive bacterial infections.