Cord blood transplantation (CBT) is an increasingly effective treatment for patients with hematological malignancies for whom suitable HLA-matched donors are not available. If T cells that mediate graft verus leukemia (GVL) could be distinguished from those that mediate graft versus host disease (GVHD), more effective immunotherapy strategies could be developed. Our long-term goal is to improve the outcome of CBT for patients with AML by engineering donor T cells to increase GVL without increasing GVHD. We hypothesize that donor T-cells targeting leukemia-associated antigens (LAA), such as the HLA-A2-restricted PR1 peptide on AML, preferentially mediate GVL activity over GVHD and that cord blood (CB) donor-derived PR1-specific cytotoxic T lymphocytes (PR1-CTL) can be elicited and expanded ex vivo for clinical use to selectively induce GVL in CBT recipients. Thus, we have cloned high- and low-affinity PR1-specific T cell receptor-alphaBeta (TCR) heterodimers from PR1 vaccine clinical responders, which can be transduced into polyclonal T-cells to redirect antigen specificity and mediate antileukemic effects. We have also produced a monoclonal antibody with high affinity for a specific conformational epitope of PR1/HLA-A2 (8F4) that mediates potent and specific cytotoxicity against acute myeloid leukemia (AML), and a single chain Fv of 8F4 fused with CD3zeta + CD28 as a chimeric antigen receptor (CAR) will be used to gene modify T-cells to study GVL effects. In addition, the number of precursor PR1-CTL is ~1000-fold higher in CB compared to adult peripheral blood and CB PRI-CTL can be activated and expanded more than 5-fold in vitro. On the strength of these advances, we propose to (1) identify an optimal method to elicit and expand potent CB-derived PR1-CTL ex vivo by comparing (a) cell expansion from single CB units, (b) cell purification from multiple donors, (c) PR1-TCR-alphaBeta gene modification, and (d) 8F4-CAR gene modification;(2) use a xenogeneic mouse model to validate the potency of PR1-CTL against human AML in vivo to study the persistence and possible tolerance induction of PR1-CTL by AML, and to determine the spatial and temporal GVL effects, persistence, and possible tolerance of CB-derived PR1-CTL using bioluminescence and PET/CT imaging. Finally, based on the method identified to optimally obtain PR1-CTL, we will (3) test the clinical feasibility and safety of CB-derived PR1-CTL as adoptive cell therapy for AML patients after CBT.
While CBT is potentially an effective treatment alternative for leukemia, poor immune reconstitution, GVHD, and disease relapse continue to be significant obstacles to successful outcomes. We will determine methods to improve the GVL effect, decrease the risk of relapse, and mitigate GVHD by adoptively transferring donor-derived antigen-specific T-cells to CBT recipients. Thus, combining targeted T-cell therapy with CBT may provide an effective alternative to leukemia patients at high risk for treatment failure.
|Kellner, Joshua; Li, Sufang; Zweidler-McKay, Patrick A et al. (2015) Phenotypic and functional comparison of mobilized peripheral blood versus umbilical cord blood megakaryocyte populations. Cytotherapy 17:418-27|
|Deniger, Drew C; Maiti, Sourindra N; Mi, Tiejuan et al. (2014) Activating and propagating polyclonal gamma delta T cells with broad specificity for malignancies. Clin Cancer Res 20:5708-19|
|Parmar, Simrit; Liu, Xiaoying; Tung, Shawndeep S et al. (2014) Third-party umbilical cord blood-derived regulatory T cells prevent xenogenic graft-versus-host disease. Cytotherapy 16:90-100|
|Kumaresan, Pappanaicken R; Manuri, Pallavi R; Albert, Nathaniel D et al. (2014) Bioengineering T cells to target carbohydrate to treat opportunistic fungal infection. Proc Natl Acad Sci U S A 111:10660-5|
|Hildebrandt, Martin; Peggs, Karl; Uharek, Lutz et al. (2014) Immunotherapy: opportunities, risks and future perspectives. Cytotherapy 16:S120-9|
|Mehta, Rohtesh S; Di Stasi, Antonio; Andersson, Borje S et al. (2014) The development of a myeloablative, reduced-toxicity, conditioning regimen for cord blood transplantation. Clin Lymphoma Myeloma Leuk 14:e1-5|
|Hanley, Patrick J; Bollard, Catherine M (2014) Controlling cytomegalovirus: helping the immune system take the lead. Viruses 6:2242-58|
|Bear, Adham S; Hanley, Patrick J; Bosque, Doyle M et al. (2014) Low rate of infusional toxicity after expanded cord blood transplantation. Cytotherapy 16:1153-7|
|Saglio, Francesco; Hanley, Patrick J; Bollard, Catherine M (2014) The time is now: moving toward virus-specific T cells after allogeneic hematopoietic stem cell transplantation as the standard of care. Cytotherapy 16:149-59|
|Robinson, Simon N; Thomas, Michael W; Simmons, Paul J et al. (2014) Fucosylation with fucosyltransferase VI or fucosyltransferase VII improves cord blood engraftment. Cytotherapy 16:84-9|
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