Dendritic cells with lymphocyte-stimulating activity differentiate from human CD133 positive precursors

Area of Science:

• Immunology
• Cell Biology
• Hematopoiesis

Background:

• CD133 is a marker for primitive myeloid progenitors.
• CD34+ progenitors are known to differentiate into dendritic cells.
• Langerhans cells are a subset of dendritic cells crucial for immune responses.

Purpose of the Study:

• To investigate if CD133-selected human cord blood cells can generate dendritic cells, specifically Langerhans cells.
• To evaluate the role of transforming growth factor-β1 (TGF-β1) in this differentiation process.

Main Methods:

• Human cord blood cells were selected for CD133 expression.
• Cells were cultured in conditions promoting dendritic cell generation, with and without TGF-β1 or anti-TGF-β1 antibody.
• Immunophenotypic analysis (CD1a, CD54, CD55, CD80, CD83, CD86, langerin) and functional assays (mixed lymphocyte reaction) were performed.

Main Results:

• CD133+ progenitors differentiated into monocytoid cells, then immature dendritic cells, and finally mature dendritic cells expressing CD54, CD80, CD83, and CD86.
• A subset expressed CD1a and langerin, but lacked Birbeck granules.
• TGF-β1 promoted cell growth and the acquisition of mature immunophenotypic and functional features, enhancing lymphocyte stimulation.
• Without TGF-β1, differentiation was limited, and cells poorly stimulated lymphocytes.
• Anti-TGF-β1 inhibited cell growth and key marker expression.

Conclusions:

• CD133+ progenitors can differentiate into mature, immunostimulatory dendritic cells with Langerhans cell molecular features in vitro.
• TGF-β1 is crucial for optimal cell growth and maturation towards an immunostimulatory phenotype.
• Langerin and Birbeck granules are not essential for lymphocyte stimulation by these dendritic cells.