Stimulation of organ specific and non-organ specific antigens on the surface of thyroid cells by phytohaemagglutinin P

Cellular immunity to possible synovial antigens in rheumatoid arthritis

A reaction has been demonstrated between extracts of synovial cells removed from intact rheumatoid knee joints and autologous leucocytes. The cell mediated immunity test system used was leucocyte migration inhibition. Variable reactions were found with a spectrum of allogeneic extracts when donor leucocytes came from married or transfused females or transfused males. Leucocytes from healthy (nontransfused) males showed no reaction with any of the extracts. As a period of cell culture was used prior to preparation of this extract to remove nonspecific inhibitory substances, native immunoglobulins, and complexes, the data are best explained by the presence of a foreign pathogen or altered cell component in the synovial cells of these rheumatoid patients.

Susceptibility of rheumatoid and nonrheumatoid synovial cells to antibody-dependent cell-mediated cytotoxicity

Fibroblastic cells derived from rheumatoid (RA) and nonrheumatoid (N-RA) synovial tissue (synovial cells) were used as targets in assays of antibody-dependent cell-mediated cytotoxicity (ADCC). Synovial cells that had been pretreated with human alloantisera were rapidly lysed by normal human blood mononuclear cells. RA and N-RA synovial cells were equally susceptible to ADCC under these assay conditions. Antibody to autologous synovial cells was not detected in sera from 10 patients with RA by this method of assay.

Cytotoxic activity of rheumatoid and normal lymphocytes against allogeneic and autologous synovial cells in vitro

The possibility that lymphocytes from patients with rheumatoid arthritis (RA) might be sensitized to RA synovial cell antigens was investigated with a 51Cr release cytotoxicity assay. Peripheral blood lymphocytes from rheumatoid and normal donors were tested for cytotoxic activity against their own synovial cells and against allogeneic rheumatoid and nonrhemuatoid synovial cells. In the allogeneic studies, the degree of cytotoxicity was significantly influenced by the age in culture (passage number) of the synovial target cells (P less than 0.001). When the passage number of the target cells was considered in the analysis, rheumatoid lymphocytes were found to have greater cytotoxic activity than normal lymphocytes against young cultures (low passage number) of both RA and non-RA synovial cells (P = 0.0042). Differences in susceptibility to lysis between RA and non-RA synovial cells were more susceptible to both RA and normal lymphocyte-induced lysis than were non-RA synovial cells (P = 0.0048). No evidence of cytotoxicity was detected when lymphocytes from nine RA patients and two osteoarthritis patients were reacted against their own synovial cells. Although the data demonstrated an increased cytotoxic activity of peripheral blood lymphocytes from some RA patients against allogeneic synovial cells, the fact that this reactivity was seen against both non-RA and RA synovial cells and was not demonstrated against autologous synovial cells argues against the presence of an immunospecific response of RA lymphocytes to RA synovial cell antigens.