Human leukocyte antigen-class II-positive human corneal epithelial cells activate allogeneic T cells

Area of Science:

• Immunology
• Ophthalmology
• Cell Biology

Background:

• Corneal immune diseases, such as allograft rejection, are significant clinical challenges.
• Understanding the immune mechanisms involved is crucial for developing effective treatments.

Purpose of the Study:

• To investigate the capacity of human corneal epithelial (HCE) cells to activate allogeneic T lymphocytes.
• To elucidate the role of HCE cells in initiating immune responses relevant to corneal transplant rejection.

Main Methods:

• A mixed lymphocyte-HCE cell reaction (MLCER) was employed.
• HCE cells, with or without interferon-gamma (IFN-gamma) treatment, were co-cultured with peripheral blood lymphocytes (PBL).
• Lymphocyte proliferation was assessed via 3H-thymidine uptake, and the effect of interleukin-1-alpha (IL-1-alpha) was examined.

Main Results:

• IFN-gamma-treated HCE cells, expressing HLA class II, stimulated allogeneic lymphocytes.
• Non-treated HCE cells, lacking HLA class II, did not induce stimulation.
• Anti-HLA class II antibodies blocked the stimulatory effect, confirming a major histocompatibility complex class II-dependent mechanism.
• Exogenous IL-1-alpha reduced lymphocyte response, an effect inhibited by indomethacin.

Conclusions:

• HLA class II-bearing HCE cells activate allogeneic PBL through a mechanism dependent on the major histocompatibility complex class II.
• HCE cells possess the ability to modulate immune reactions, potentially via IL-1-induced prostaglandin production.