Expansion of cytotoxic CD3(+)CD56(+) cells from peripheral blood progenitor cells of patients undergoing autologous hematopoietic cell transplantation

Immunotherapy may potentially improve the outcome of autologous hematopoietic cell transplantation (HCT). Poor effector cell proliferation and marginal antitumor activity limit attempts to use immunotherapy. We have characterized the ex vivo expansion, up to 1000-fold, of CD3(+)CD56(+) lymphocytes from the peripheral blood lymphocytes (PBL) of healthy donors. Expanded cells termed cytokine-induced killer (CIK) cells induce non-major histocompatibility complex-restricted lysis of tumor cells and demonstrate cytolytic activity superior to lymphokine-activated killer cells without the requirement of interleukin (IL)-2 treatment in vivo. To determine whether cytolytic cells could be expanded from patient material, we evaluated samples of peripheral blood progenitor cells (PBPCs) from 25 patients undergoing autologous HCT. The PBPCs were expanded by priming with interferon-gamma followed by anti-CD3 monoclonal antibody and IL-2 the next day. Fluorescence-activated cell sorting analysis was performed on days 0, 15, 21, and 28 of cell culture. The median T-cell content rose from 15.3% (range, 1.1% to 89.7%) on day 0 to 97.2% (range, 83.6% to 99.5%) by day 15. By day 21, T cells expanded 21.8-fold (range, 1.7- to 420.0-fold) and CD3(+)CD56(+) cells expanded 44.8-fold (range, 5.1- to 747.0-fold). CIK cells were used as effector cells against B-cell lymphoma targets (OCI-Ly8) with a median of 24% (range, 3% to 67%) and 42% (range, 6% to 96%) specific lysis of target cells on days 21 and 28, respectively. CIK cells derived from PBL of 2 additional patients with acute myelogenous leukemia demonstrated 39% and 78% specific lysis of OCI-Ly8 and 26% and 58% specific lysis of autologous leukemic blasts at an effector:target ratio of 40:1. CIK cells may be expanded from granulocyte colony-stimulating factor-mobilized PBPCs of patients undergoing posttransplantation adoptive immunotherapy.