Functional CD86 (B7-2/B70) on cultured human Langerhans cells

Area of Science:

• Immunology
• Dermatology
• Cell Biology

Background:

• CD86 (B70/B7-2) is an important costimulatory ligand for CD28/CTLA-4, primarily identified on activated B cells.
• Langerhans cells are potent antigen-presenting cells crucial for initiating immune responses in the skin.

Purpose of the Study:

• To investigate the expression and function of CD86 on human Langerhans cells in different states (organ-cultured skin, fresh, and cultured cells).
• To determine the role of CD86 in Langerhans cell-mediated T cell activation.

Main Methods:

• Immunohistochemistry to detect CD86 in situ.
• Flow cytometry (FACS) for CD86 and CD80 expression on isolated Langerhans cells.
• Western blot to confirm CD86 protein.
• RT-PCR to analyze gene expression.
• Allogeneic T cell proliferation assays with anti-CD86 and anti-CD80 antibodies.

Main Results:

• CD86 was expressed on dendritic cells in organ-cultured skin but not fresh skin.
• Freshly isolated Langerhans cells lacked CD80/CD86, while cultured Langerhans cells expressed both.
• Both CD80 and CD86 genes were expressed by Langerhans cells.
• Anti-CD86 antibody significantly inhibited allogeneic CD4 T cell proliferation (81%), more than anti-CD80 (29%).
• Combined anti-CD86 and anti-CD80 antibodies enhanced inhibition to 85.3%.

Conclusions:

• CD86 is predominantly expressed on cultured human Langerhans cells.
• CD86 plays a significant role in transducing costimulatory signals during Langerhans cell-T cell interactions.
• CD86 is a critical costimulatory molecule in initiating immune responses via Langerhans cells.