M. Kraft et al., SYNOVIAL FIBROBLASTS AS ACCESSORY CELLS FOR STAPHYLOCOCCAL ENTEROTOXIN-MEDIATED T-CELL ACTIVATION, Immunology, 85(3), 1995, pp. 461-466
Rheumatoid arthritis (RA) is thought to be the result of T-cell-mediat
ed autoimmune phenomena. So far, a critical autoantigen has not been i
dentified. Recently, superantigens have been implied in the pathogenes
is of RA. In the present study it was tested whether major histocompat
ibility complex (MHC) class II-positive synovial fibroblast cells (SFC
) function as superantigen-presenting cells. SFC were stimulated with
interferon-gamma (IFN-gamma) to express class II antigens; then they w
ere cultivated in the presence of T cells with or without staphylococc
al enterotoxins (SE). T-cell activation was measured as proliferation
and interleukin-2 (IL-2) production. Depending on the dose and type of
SE, activation of T-cell clones and also of peripheral T cells was se
en. T-cell activation was inhibited by antibodies to MHC class II anti
gens and also by antibodies to intracellular adhesion molecule type-1
(ICAM-1). The data suggest that class II-positive SFC have the capacit
y to serve as accessory cells for superantigen-mediated T-cell activat
ion. Thus SFC may participate in the propagation of a T-cell dependent
immune response.