Studies on human dental plaque. 2. Immunochemical characteristics

Area of Science:

• Oral immunology
• Biochemistry
• Immunochemistry

Background:

• Supragingival plaque is a complex microbial biofilm that plays a significant role in oral health and disease.
• The presence and function of immune components within dental plaque are not fully understood.
• Investigating immunoglobulins and other proteins in plaque can provide insights into host-pathogen interactions.

Purpose of the Study:

• To identify and characterize immunoglobulins and other proteins present in supragingival plaque extracts.
• To determine the localization and potential involvement of these proteins in immune complexes within plaque.

Main Methods:

• Preparation of extracts from collected supragingival plaque.
• Immunochemical analyses using fluorescein-labeled antibodies, monospecific and polyvalent antisera.
• Gel filtration for protein fractionation.
• Immunofluorescence microscopy to visualize protein presence in plaque sediment.
• Urea treatment to assess immunoglobulin release.

Main Results:

• Immunoglobulins IgA and IgG, secretory component, C3, alpha2macroglobulin, lactoferrin, and albumin were detected in plaque extracts.
• Gel filtration separated these proteins into distinct fractions, with a nonreactive dialyzable fraction also observed.
• Immunofluorescence confirmed the presence of IgA, IgG, secretory component, and light chains in washed plaque sediment.
• Urea treatment facilitated the release of immunoglobulins, suggesting their association in immune complexes.

Conclusions:

• Supragingival plaque contains a significant array of host-derived immune proteins, including immunoglobulins.
• These immunoglobulins are likely present as immune complexes, potentially influencing the plaque environment.
• Further research is warranted to elucidate the functional role of these immune components in oral health and disease.