Comparative analysis of CD1a, S-100, CD83, and CD11c human dendritic cells in normal, premalignant, and malignant tissues.

A number of antibodies that recognize human dendritic cells (DC) have been identified. The main aim of this study was to compare and contrast different antigen retrieval techniques using both enzymatic and non-enzymatic treatments in order to determine the expression and distribution of several DC markers on formalin-fixed, paraffin-embedded tissues. Normal human lung, oral epithelial hyperplasia lesions, oral squamous cell carcinoma, and prostate adenocarcinoma tissues were evaluated using a panel of DC specific antibodies. The results of immunohistochemical staining for CD83, CD1a, CD11c, and S-100 DC markers were compared following the different antigen retrieval approaches. The overall best results for the analysis of tumor-associated DC were obtained with the enzymatic methods. Protease XXIV digestion was determined to be essential for detection of S-100 and CD11c positive DC, whereas trypsin and pepsin were required for the recognition of CD1a and CD83 expressing tumor-associated DC. These results could be easily adapted for routine practice and should be useful for characterization of the DC system in cancer patients for both diagnostic and prognostic purposes. In addition, standardized procedures for evaluating different subpopulations of tumor-associated DC should bring new insights in understanding of DC-tumor cell interaction.