Dispersed Cell Cultures of Rheumatoid Synovial Membrane

Macrophage migration and maturation within rheumatoid nodules

In long-established rheumatoid nodules, monocytes continue to be recruited and to migrate from the outer vascular zone toward the palisade and central necrotic area. Maturation of these cells is shown to take place during tissue migration. We found that the great majority of palisade cells express exclusive mononuclear phagocyte phenotypes. Among this mononuclear phagocyte population are many cells that bear the receptor for iC3b (CR3), but few that bear the receptor for C3b (CR1). HLA-D region molecule expression is intense and widespread.

In vitro aggregation of mouse peritoneal exudate cells

(1) Immunological mechanisms which cause macrophage agglutination in vitro have been investigated. (2) Quantitative differences in the agglutinating properties of sero-positive rheumatoid sera and normal sera were found. (3) NZB X W mouse peritoneal macrophages differed from normal (NZCW) mouse peritoneal macrophages in susceptibility to agglutination. These quantitative differences could be explained by NZB X W macrophages carrying a surface immunoglobulin component which increased agglutination by rheumatoid sera. (4) Antimacrophage antibody was more effective in rendering macrophages susceptible to the agglutinating effect of antiglobulins than was heat-aggregated gamma globulin.

Interaction in vitro between synovial cells and autologous lymphocytes and sera from arthritis patients

Synovial cells from patients with rheumatoid arthritis (RA) when grown in vitro in media supplemented with 20% fetal calf serum failed to show any difference in growth rate, life span, uptake of tritiated thymidine or cellular and nuclear characteristics when compared with synovial cells from patients with osteoarthritis or other joint diseases grown similarly in 20% serum enriched medium. There was also no evidence that lymphocytes and/or sera from RA patients were more cytotoxic to autologous synovial cells than sera and/or lymphocytes from OA patients. It is unlikely that antisynovial antibodies or lymphocytes from RA patients act as triggers for synovial damage.