Flow cytometric analysis of surface major histocompatibility complex class II expression on human epithelial cells...

Area of Science:

• Gastroenterology
• Immunology
• Cell Biology

Background:

• Single cell suspensions are crucial for analyzing the epithelial layer of the small intestine.
• Current methods may not yield sufficient viable cells for detailed analysis, particularly for flow cytometry.
• Endoscopic biopsies offer a minimally invasive source of small intestinal tissue.

Purpose of the Study:

• To develop and validate a technique for preparing viable single-cell suspensions from endoscopic small intestinal biopsies.
• To assess the yield and purity of epithelial cells obtained using the described method.
• To evaluate the suitability of the prepared cells for flow cytometric analysis of surface molecule expression.

Main Methods:

• Processing of four endoscopic small intestinal biopsies with constant agitation for 60 minutes.
• Use of chelating and reducing agents to facilitate cell dissociation.
• Filtration through a nylon wool column to remove dead cells and debris.
• Flow cytometric analysis of cell surface markers, specifically MHC class II molecules.

Main Results:

• The technique yielded 1.2-6.7 x 10^6 cells per sample, with 11-30% being intraepithelial lymphocytes (IEL).
• Nylon wool filtration effectively removed dead cells, improving sample quality.
• Epithelial cells (EC) demonstrated strong surface expression of HLA-DR, moderate DP, and minimal DQ, indicating suitability for flow cytometry.
• The method proved effective for analyzing epithelial cells from routine endoscopic biopsies.

Conclusions:

• A reliable technique for generating viable single-cell suspensions from small intestinal endoscopic biopsies has been established.
• The prepared cells are suitable for advanced analyses such as flow cytometry.
• This method facilitates the study of epithelial cell immunophenotypes, including MHC class II expression, in a clinical setting.