Abstract
Allogeneic SCT is being explored as treatment modality for patients with advanced MCL. Complete sustained remissions have been observed after allogeneic SCT illustrating susceptibility of MCL cells to graft-versus-lymphoma (GVL) effect.To potentiate this GVL effect and to reduce graft-versus-host disease (GVHD) reactivity, adoptive transfer of in vitro-selected cytotoxic T cells (CTLs) with specificity for MCL or for hematopoiesis-restricted minor histocompatibility antigens could be an attractive approach. The lack of expression of costimulatory molecules on MCL cells hampers the generation of MCL-reactive T cell-responses. To transform MCL cells into efficient antigen-presenting cells (APCs) we tested the B-lineage specific activating cytokines (IL-4), the unique MCL proliferating cytokine (IL-10) and the ligand of toll like receptor 9, CpG.Furthermore, CD40 triggering using irradiated CD40-L transfected murine fibroblasts (tCD40L) in combination with the cytokines and CpG was examined. The expression of the costimulatory and adhesion molecules CD80, CD86, CD83, CD54 and CD58 of MCL cells of 7 patients, all carrying the t(11;14) translocation, was analyzed by flowcytometry. No upregulation of any of these molecules was observed using the cytokines or CpG. Ligation of CD40 on MCL cells caused a significant upregulation of CD54,CD58, CD80 and CD86 (p<0.01) with maximal expression after 4 days of stimulation. No additional upregulation was induced from IL- 4, IL -10 or CpG. The cumulative production of IL-12 and IL-10 by the MCL cells in response to the various stimuli after 4 days was measured. High amounts of IL-12 (median 1640 pg/mL, range 67–8800 pg/mL) in the absence of IL-10(<100 pg/mL) were synthesized by MCL cells after CD40 activation. Additional stimulation with CpG enhanced the production of IL-12 (1870 pg/mL, range 77–30000 pg/mL) but also the production of IL-10(299 pg/mL, range 0–418 pg/mL). MCL cells were unable to produce IL-12 without CD40 triggering (<5 pg/mL). To analyze the antigen-presenting capacity of primary MCL cells as well as CD40-activated MCL cells (MCL-APC), CD8+ T cells from an unrelated HLA-A and B matched and from a HLA-class I matched donor were stimulated with MCL or MCL-APC cells. Primary MCL cells were not capable of generating T-cell lines. Using a newly developed flowcytometry-based cytotoxicity assay in which the target cells were labeled with CFSE (
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