Generation of functional CLL-specific cord blood CTL using CD40-ligated CLL APC

• Published in: PloS one 2012-12, Vol.7 (12), p.e51390-e51390
• Main Authors: Decker, William K, Shah, Nina, Xing, Dongxia, Lapushin, Ruth, Li, Sufang, Robinson, Simon N, Yang, Hong, Parmar, Simrit, Halpert, Matthew M, Keating, Michael J, Gribben, John G, Molldrem, Jeffrey J, Shpall, Elizabeth J, Wierda, William G
• Format: Article
• Language: English
• Subjects: Adult; Animals; Antigen-Presenting Cells - immunology; Antigen-Presenting Cells - metabolism; Antigens; Antigens, Neoplasm - immunology; Biology; Blood; Cancer; CD40 antigen; CD40 Antigens - immunology; CD40 Antigens - metabolism; Chromium radioisotopes; Chronic illnesses; Chronic lymphatic leukemia; Chronic lymphocytic leukemia; Cord blood; Cytometry; Cytotoxicity; Donors; Enzyme-linked immunosorbent assay; Feasibility Studies; Fetal Blood - immunology; Flow cytometry; Histocompatibility antigen HLA; HLA Antigens - immunology; Humans; Immunological Synapses - immunology; Immunology; Interferon; Killing; Leukemia; Leukemia, Lymphocytic, Chronic, B-Cell - immunology; Lymphocytes; Lymphocytes T; Medicine; Mice; Patients; Stem cell transplantation; Stem cells; String matching; Synapses; T cell receptors; T cells; T-Lymphocytes - immunology; Transplantation; Transplants & implants; Umbilical cord; γ-Interferon
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0051390

Though remissions have been observed following allo-HSCT for the treatment of CLL, many CLL patients are ineligible for transplant due to the lack of HLA-compatible donors. The use of umbilical cord blood (UCB) permits transplantation of many patients who lack HLA-compatible donors due to reduced requirements for stringent HLA matching between graft and recipient; however, disease relapse remains a concern with this modality. The generation of CLL-specific CTL from UCB T-cells, primed and expanded against the leukemic clone, might enhance the GVL effect and improve outcomes with UCB transplantation. Here we report the generation of functional, CLL-specific CTL using CD40-ligated CLL cells to prime partially-HLA matched UCB T-cells. Functionality and specificity were demonstrated by immune synapse assay, IFN-γ ELISpot, multi-parametric intracellular cytokine flow cytometry, and (51)Cr release assay. The use of patient-specific, non-CLL controls demonstrated the generation of both alloantigen and CLL-specific responses. Subsequently, we developed a clinically-applicable procedure permitting separation of alloreactive CTL from leukemia-specific CTL. Leukemia-specific CTL were able to mediate in vivo killing of CLL in humanized mice without concurrent or subsequent development of xenoGVHD. Our results demonstrate that generation of CLL-specific effectors from UCB is feasible and practical, and the results support further exploration of this strategy as a treatment modality for CLL.