Masayuki Miyata

Influences of heat aggregated human IgG on the proliferation of mononuclear cells

It is believed that circulating immune complexes (IC) play pathogenic roles by affecting lymphocyte and/or monocyte function in type III allergy. We studied the influences of heat aggregated human IgG (AHG), as a model of IC, on the proliferation of mononuclear cells in respect of difference in the involved IgG subclasses. IgG 1 and IgG 2 subclass of AHG (AHG1, AHG 2) suppressed significantly the proliferation of mononuclear cells without mitogens. Proliferation of mononuclear cells stimulated by concanavalin A (Con A) was significantly suppressed not only by AHG 1 and AHG 2 but also by AHG 4. Flow cytometric analysis indicated that unstimulated lymphocytes or monocytes could bind more AHG 1 and AHG 2 than AHG 3 and AHG 4. Since results coincided with the results mentioned above, unstimulated mononuclear cell proliferation was suppressed through the binding of AHG on the surface of mononuclear cells. AHG suppression of mononuclear cells stimulated by Con A was effectively inhibited by an addition of indomethacin and/or catalase.These results indicated that prostaglandin and/or H2O2 might play an important role in inhibition of proliferation of mononuclear cells by AHG. Taken together, IC play a different role in immune network by affecting lymphocytes or monocytes according to difference in IgG subclasses.

Cytotoxicity of synovial lymphocytes of patients with rheumatoid arthritis.

The lymphocytes in the synovial tissues of patients with rheumatoid arthritis (RA) showed a cytotoxic activity against synovial cultured cells taken from patients with RA, in a similar extent to that of normal peripheral lymphocytes. However, the activity was weaker than that of polymorphonuclear leukocytes in synovial fluids of RA patients. In addition, the synovial lymphocytes of RA patients showed the natural killer activity against K 562 cells which were higher than that of normal peripheral lymphocytes and also ADCC activity which was similar to that of normal peripheral lymphocytes.

Studies on subsets, NK and ADCC activity of lymphocytes in synovial fluids of patients with rheumatoid arthritis

Subsets of lymphocytes in synovial fluids of patients with rheumatoid arthritis (RASF-Ly) along with lymphocytes in peripheral bloods of normal subjects (Healthy-Ly) were studied.Percent of OKT-3+cells (P<0.01), OKT-4+cells (P<0.01), OKT-8+cells (P<0.05) and OK-Ial+cells (P<0.01) of RASF-Ly were significantly higher than those of Healthy-Ly. Therefore, we examined the correlation these percentage of subsets. Positive correlation were observed in RASF-Ly between percentage of OKT-8+cells (P<0.01) or Leu-7+cells (p<0.01) and that of OK-Ial+cells and also between percentage of OKT-8+cells and that of Leu-7+cells of RAST-Ly (p<0.01) . Since OK-Ial represents a marker of activated T cells, both OKT-8+cells and Leu-7+cells in RASF-Ly seemed to be activated and Leu-7+cells seemed also to be immature. NK activity of RASF-Ly was significantly lower than that of Healthy-Ly (p<0.01), whereas ADCC activity of RASF-Ly was similar to that of Healthy-Ly.