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A possible CD1a Langerhans cell-mast cell interaction in chronic hyperplastic candidosis
Ahmed Ali1, Riina Rautemaa, Jarkko Hietanen
1Department of Anatomy/Biomedicum, University of Helsinki, Helsinki, Finland.
Insights
In chronic hyperplastic candidosis (CHC), CD1a-positive Langerhans cells and RANKL-positive mast cells show altered distribution and activity. This suggests enhanced dendritic cell recruitment and interaction with T lymphocytes, impacting oral immunity.
Area of Science:
- Immunology
- Oral Pathology
- Dermatology
Background:
- T lymphocyte-antigen-presenting cell (APC) interaction is crucial for immune responses.
- Langerhans cells (LCs) are key APCs in oral mucosa.
- Chronic hyperplastic candidosis (CHC) involves persistent Candida infection and immune dysregulation.
Purpose of the Study:
- To investigate the distribution and characteristics of CD1a-positive Langerhans cells (LCs) in CHC.
- To examine the presence and localization of receptor activator of nuclear factor kappa B ligand (RANKL)-positive cells in CHC.
- To understand the role of LCs and RANKL in the pathogenesis of CHC.
Main Methods:
- Tissue sections of CHC, leukoplakia, and healthy oral mucosa were analyzed.
- Immunohistochemistry using CD1a and RANKL monoclonal antibodies was performed.
- Two antigen-retrieval protocols (pepsin and Tris-EDTA heat treatment) were employed.
Main Results:
- CD1a-positive LCs were found in all epithelial layers, at the basement membrane, and in the lamina propria in CHC, unlike in healthy or leukoplakia tissues.
- Pepsin digestion revealed mast cell degranulation, indicating RANKL release.
- LCs exhibited numerical, morphological, and topographical variations in CHC.
Conclusions:
- Dendritic cell (DC) recruitment into the epithelium contributes to the altered LC profile in CHC.
- RANK-positive and RANKL-sensitive DCs in CHC have increased opportunities for T lymphocyte interaction.
- Mast cells are a source of soluble RANKL, suggesting active mast cell involvement in CHC pathogenesis.
Aims:
T lymphocyte-antigen-presenting cell (APC) interaction plays a central role in T lymphocyte activation and APC maturation. We therefore studied the CD1a-positive Langerhans cells with respect to receptor activator of nuclear factor kappa B ligand (RANKL)-positive cells in chronic hyperplastic candidosis (CHC).
Materials And Methods:
Tissue sections of CHC were compared with leukoplakia and healthy oral mucosa using RANKL and CD1a monoclonal antibodies in an avidin-biotin peroxidase complex protocol. Two different antigen-retrieval protocols, pepsin preincubation and Tris-EDTA heat treatment, were used.
Results:
CD1a-positive Langerhans cells were in healthy and leukoplakia epithelium found in the middle layer, but in CHC in all layers of the epithelium, at the basement membrane and as mononuclear round cells in the lamina propria. Use of pepsin digestion enabled studies of mast cells and their activation in the form of degranulation of RANKL.
Conclusions:
The numerical, morphological and topographical versatility of the CD1a-positive Langerhans cells in CHC can be clarified by dendritic cell (DC) recruitment into the epithelium. RANK-positive and RANKL-sensitive DCs have ample opportunity to interact with local T lymphocytes. Use of an optimized antigen-retrieval protocol enabled demonstration of an active engagement (degranulation) of mast cells, which represent a rapidly available source of soluble RANKL.
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