"BioReliance, Sterling, UK) (Lamers et al., 2006a). For production of an MC2 TCR vector batch, we generated a stable Phoenix-Ampho packaging cell line, isolated an optimal producer clone, and produced an MC2 TCR vector batch, and stored a series of ready-to-use aliquots at -80°C according to procedures described elsewhere (Schneiders et al., 2012; Lamers et al., 2013b). "
[Show abstract][Hide abstract] ABSTRACT: Therapy with autologous T cells that have been gene-engineered to express chimeric antigen receptors (CAR) or T cell receptors (TCR) provides a feasible and broadly applicable treatment for cancer patients. In a clinical study in advanced renal cell carcinoma (RCC) patients with CAR T cells specific for Carbonic Anhydrase IX (CAIX) we observed toxicities which (most likely) indicated in vivo function of CAR T cells as well as low T cell persistence and clinical response rates. The latter observations were confirmed by later clinical trials in other solid tumor types and other gene-modified T cells. To improve the efficacy of T cell therapy, we have re-defined in vitro conditions to generate T cells with young phenotype, a key correlate with clinical outcome. For their impact on gene modified T cell phenotype and function, we have tested various anti-CD3/CD28 mAb-based T cell activation and expansion conditions as well as several cytokines prior to and/or post gene transfer using two different receptors: CAIX CAR and MAGE-C2(ALK)/HLA-A2 TCR. In a total set of 16 healthy donors, we observed that T cell activation with soluble anti-CD3/CD28 mAbs in the presence of both IL15 and IL21 prior to TCR gene transfer resulted in enhanced proportions of gene-modified T cells with a preferred in vitro phenotype and better function. T cells generated according to these processing methods demonstrated enhanced binding of pMHC, and an enhanced proportion of CD8+,CD27+,CD62L+,CD45RA+ T cells. These new conditions will be translated into a GMP protocol in preparation of a clinical adoptive therapy trial to treat patients with MAGE-C2-positive tumors.
"In particular, their antitumor activity has been well documented in a number of mouse tumor models [4–6], and several clinical observations also indicate their protective role against cancer progression. Furthermore, low numbers and impaired proliferative capacity of iNKT cells were reported in cancer patients compared to normal donors [7, 8], which in some studies were correlated with poor clinical outcome [9, 10]. These preclinical and clinical observations have prompted testing of iNKT cell-directed therapies, mainly through their strong activation by the synthetic glycosphingolipid CD1d ligand, alpha-galactosylceramide (αGC) [11–13]. "
[Show abstract][Hide abstract] ABSTRACT: Despite the well-established antitumor activity of CD1d-restricted invariant natural killer T lymphocytes (iNKT), their use for cancer therapy has remained challenging. This appears to be due to their strong but short-lived activation followed by long-term anergy after a single administration of the CD1d agonist ligand alpha-galactosylceramide (αGC). As a promising alternative, we obtained sustained mouse iNKT cell responses associated with prolonged antitumor effects through repeated administrations of tumor-targeted recombinant sCD1d-antitumor scFv fusion proteins loaded with αGC. Here, we demonstrate that CD1d fusion proteins bound to tumor cells via the antibody fragment specific for a tumor-associated antigen, efficiently activate human iNKT cell lines leading to potent tumor cell lysis. The importance of CD1d tumor targeting was confirmed in tumor-bearing mice in which only the specific tumor-targeted CD1d fusion protein resulted in tumor inhibition of well-established aggressive tumor grafts. The therapeutic efficacy correlated with the repeated activation of iNKT and natural killer cells marked by their release of TH1 cytokines, despite the up-regulation of the co-inhibitory receptor PD-1. Our results demonstrate the superiority of providing the superagonist αGC loaded on recombinant CD1d proteins and support the use of αGC/sCD1d-antitumor fusion proteins to secure a sustained human and mouse iNKT cell activation, while targeting their cytotoxic activity and cytokine release to the tumor site.
Electronic supplementary material
The online version of this article (doi:10.1007/s00262-012-1381-7) contains supplementary material, which is available to authorized users.
Cancer Immunology and Immunotherapy 12/2012; 62(4). DOI:10.1007/s00262-012-1381-7 · 3.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Natural killer (NK) cells and natural killer T (NKT) cells are subsets of lymphocytes that share some phenotypical and functional similarities. Both cell types can rapidly respond to the presence of tumour cells and participate in antitumour immune responses. This has prompted interest in the development of innovative cancer therapies that are based on the manipulation of NK and NKT cells. Recent studies have highlighted how the immune reactivity of NK and NKT cells is shaped by the environment in which they develop. The rational use of these cells in cancer immunotherapies awaits a better understanding of their effector functions, migratory patterns and survival properties in humans.
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