HUMAN LYMPH-NODE LYMPHOCYTES FAIL TO EFFECT LYSIS OF ANTIBODY-COATED TARGET-CELLS

Abstract

Human lymphocytes prepared from peripheral blood, lymph nodes, spleen and thymus were titrated for ability to mediate lysis of human target cells [urinary bladder carcinoma T24 cells and metastatic cutaneous melanoma MEL1 cells] coated with rabbit anti-target antibody. Lymphocytes from blood and spleen produced efficient lysis of targets in the presence of antibody. Lymph node cells and thymocytes were essentially non-reactive in this system. Lymph node preparations from non-cancer patients contained approximately 25% of non-T [thymus-derived] cells with receptors for Fc, C3 [the 3rd complement component] and/or Ig [immunoglobulin]. Regional lymph nodes from patients with primary tumors contained 37-50% non-T cells by the same criteria. Failure of lymph node lymphocytes to effect lysis of antibody-coated targets did not correlate with content of Fc or C3 bearing cells per se. The effector cell in antibody-dependent cytotoxicity in other systems carries Fc and C3 receptors, but not surface Ig. This cell type appears to be absent or non-functional in human lymph nodes.