Ex-vivo culture with γchain cytokines restores defective maturation and activation of tumor infiltrating lymphocytes in indolent non-Hodgkin’s lymphoma

Abstract

9589 This study was aimed at investigating the development of T cell-mediated immune response in B cell tumor patients and at defining the optimal conditions for developing adoptive immunotherapy protocols. The following assessments were carried out utilizing T cells isolated from involved lymph-nodes (LN), peripheral blood or bone marrow of patients with indolent NHL (40 follicular, 32 CLL, 8 MCL): 1. distribution of TCRBV repertoire; 2. analysis of the activation profile; 3. analysis of the differentiation phenotype along the naïve to effector and memory stages by expression of CD45RA, CCR7 and cytolytic factors perforin and granzyme B. The analysis of TCRBV repertoire of CD4+ and CD8+ cells indicated very limited T cell expansions in CD4+ cells in a fraction of patients. This data suggested a reduced effect of neoplastic tissue in shaping the TCRBV repertoire in the LN. Therefore, in most instances, both CD4+ and CD8+ cells were not in a resting condition with high expression of CD69, HLA-DR and CD95 associated to a low expression of CD25 and CD122. Finally, both CD4+ and CD8+ T cells in either periphery, or at tumor site, expressed mainly the early stages of differentiation. The skewed maturation of CD4+ and CD8+ T cells was further confirmed by the low/absent expression of perforin and granzyme B. In contrast, the differentiation phenotype of CD4+ and CD8+ T cells from a panel of 47 healthy donors showed all four T cell maturation stages. T cell culture for 1 to 2 weeks, in the presence of cytokines of the γc family, led to down modulation of CCR7 and expression of perforin and granzyme B in T cells from either peripheral blood and tumor site. Co-culture of T cells isolated from tumor-containing LN with irradiated autologous NHL B cells (n=10) in the presence of IL-2+IL-15 led to an average 45-fold increase of number of CD3+ T-lymphocytes and to activation of tumor-specific T cells as assessed by IFN-γ release and tumor lysis assays. Thus, cytokine-driven functional maturation of tumor-specific T cells from B cell tumor patients could represent an option for reversal of impaired differentiation/activation and for development of adoptive immunotherapy strategies. No significant financial relationships to disclose.