Antigen-specific induction and regulation of antibody synthesis in cultures of human peripheral blood mononuclear cells.

Culture conditions suitable for specific sensitization of human peripheral blood lymphocytes were established. Production of antibody to sheep erythrocytes and to the 2,4,6-trinitrophenyl group conjugated to burro erythrocytes was investigated in terms of cross-sensitization, feedback control by antibody to the immunogen, and regulation by helper and suppressor T cells. Generation of antigen-specific antibody-forming cells was found to be restricted to a narrow concentration range of cultured peripheral blood lymphocytes. The data suggest that antibody formation is limited by suppressor T cells in high-cell-density cultures and by low frequencies of helper T cells in low-cell-density cultures.