Effect of Human Anti-γ-Globulin Antibodies on Human Lymphocytes.

Addition of rheumatoid factor to cultures of human lymphocytes preincubated with substimulating amounts of rabbit anti-human lymphocyte antibody caused stimulation, while addition to lymphocytes preincubated with anti-HL-A or anti-human γ-chain antiserum had no effect. Neither was there any stimulatory effect on adding pepsin agglutinator, i.e. an antibody to the pepsin site of γG, to lymphocytes preincubated with pepsin-digested γG from anti-lymphocyte or anti-HL-A antiserum. The different results obtained in the various systems may partly be due to differences in the distribution of antigens on the lymphocyte membrane and partly to the lack of heterospecificity of pepsin agglutinator.