Synovial cell antigens - differences of antigen compositions between rheumatoid arthritic (RA)- and non-RA-derived synovial cells detected with anti-synovial cell sera.

A number of antisera were produced in rabbits immunized with cultured synovial tissue-derived cells. The synovial cells were injected utilizing a variety of immune manipulations in order to elicit different antibody specificities and to enhance antibodies that may differentiate antigens of rheumatoid arthritic and nonrheumatoid arthritic synovial tissue-derived cells. The major sources of antigens common to both rheumatoid and nonrheumatoid cells were cross-reactive with normal human serum, nonrheumatoid synovial fluids and fetal calf serum components. Adsorptions with the latter antigen sources yielded different antisera with greater differential reactivities to either rheumatoid or nonrheumatoid synovial cells. Crossed immunoelectrophoretic analyses of extracts of the synovial cells using unabsorbed antisera differentiated five electrophoretically distinct antigens with various quantitative differences of the antigens being noted between the rheumatoid and nonrheumatoid extracts. The results suggest that several antigens are quantitatively differentially expressed on rheumatoid-derived synovial cell strains compared to synovial strains of nonrheumatoid origin.