A cell line and clones of lymphocytes from a healthy donor, with specificity to S-antigen

Retinal-specific antigens can induce autoimmune diseases in eyes of immunized experimental animals and are thought to be involved in certain uveitic conditions in man. We have recently found that peripheral blood lymphocytes from a large proportion of healthy donors react in culture against the retinal S-antigen (S-Ag), when tested by a modified sensitive assay. The investigation of this responsiveness was extended by isolation and characterization of a cell line and clones specific to S-Ag from the blood of a healthy donor. Characterization of the cell line and clones by flow cytometry showed that these lymphocytes carried antigens specific for helper/inducer T cells (CD3 and CD4). The response of the cell line and clones to S-Ag depended completely on added antigen-presenting cells (APC), and was MHC-restricted; no response was observed in cultures with APC carrying incompatible MHC antigens. The cell line and clones reacted to S-Ag considerably more vigorously than the freshly collected blood lymphocytes from the same donor. These data thus provide additional support to the notion that lymphocytes with reactivity toward retinal specific antigens are present in the circulation of normal donors. The possibility that such cells could be involved in pathogenic autoimmune processes in the eye is discussed.