Generation of T cell effectors using tumor cell-loaded dendritic cells for adoptive T cell therapy

Abstract

Adoptive T cell transfer has been shown to be an effective method used to boost tumor-specific immune responses in several types of malignancies. In this study, we set out to optimize the ACT protocol for the experimental treatment of prostate cancer. The protocol includes a pre-stimulation step whereby T cells were primed with autologous dendritic cells loaded with the high hydrostatic pressure-treated prostate cancer cell line, LNCaP. Primed T cells were further expanded in vitro with anti-CD3/CD28 Dynabeads in the WAVE bioreactor 2/10 system and tested for cytotoxicity. Our data indicates that the combination of pre-stimulation and expansion steps resulted in the induction and enrichment of tumor-responsive CD4 and CD8 T cells at clinically relevant numbers. The majority of both CD4 and CD8 IFN-γ producing cells were CD62L, CCR7 and CD57 negative but CD28 and CD27 positive, indicating an early antigen experienced phenotype in non-terminal differentiation phase. Expanded T cells showed significantly greater cytotoxicity against LNCaP cells compared to the control SKOV-3, an ovarian cancer line. In summary, our results suggest that the ACT approach together with LNCaP-loaded dendritic cells provides a viable way to generate prostate cancer reactive T cell effectors that are capable of mounting efficient and targeted antitumor responses and can be thus considered for further testing in a clinical setting.

HLA-mediated tumor escape mechanisms that may impair immunotherapy clinical outcomes via T-cell activation

“…Cancer immunotherapy strategies to activate T-cell-mediated antitumor responses include the use of antibodies to target inhibitory molecules that impair T-cell cytotoxicity ( 25 ), adoptive cell transfer with tumor infiltrating lymphocytes expanded in vitro ( 96 ), or genetically modified cytotoxic T-cells ( 97 , 98 ). However, CD8 + T-cells have been established to recognize and destroy HLA-I positive tumor cells.…”

Objectives, benefits and challenges of bioreactor systems for the clinical-scale expansion of T lymphocyte cells

“…This combination is reported as a standard "Rapid Expansion Protocol" (REP) (Dudley et al, 2003;Riddell and Greenberg, 1990;Sadeghi et al, 2011;Smith et al, 2015). Methods using co-culture with another cell lineage as a pre-stimulation step were also reported (Vavrova et al, 2016;Vera et al, 2010). How REP can be improved and refined is still investigated today, for instance with additional medium complements (IL-7, IL-15, anti-CD28 antibodies) but also pre-stimulation with a mix of peptides focusing on pp65 protein, leading to higher proliferation rates in the same culture vessel (Grau-Vorster et al, 2020) (G-Rex flask, see section 7.2).…”

“…Proliferation being the ultimate objective, a first approach is the continuous increase of available culture medium volume when cells proliferate to allow them to expand further while maintaining this optimal concentration stable, when suitable with the culture system design (Donia et al, 2014;Jin et al, 2018;Tran et al, 2007;Vavrova et al, 2016). For example, Tran et al doubled culture volume to decrease cell density to 5x10 5 cells/mL as soon as it reached the limit of 1x10 6 cells/mL (Tran et al, 2007).…”

“…More importantly, they showed that the results of cell expansion were better when the process was initiated in a smaller volume. Another approach could therefore be developed by combining an increasing volume with flow perfusion based on cell density or nutrient levels (glutamine and glucose) (Somerville et al, 2012;Tran et al, 2007;Vavrova et al, 2016). Interestingly, besides available volume, all parameters can be adjusted over time while cells are proliferating, such as rocking rate, rocking angle, perfusion flow rate and etc.…”

“…alternative to surgery, radiation or chemotherapy (Piscopo et al, 2018), in particular in the case of melanoma or renal cell carcinoma (Vacchelli et al, 2013) but also others such as prostate cancer (Vavrova et al, 2016) or chronic lymphocytic leukaemia (Hami et al, 2004;Hollyman et al, 2009). Reported as the third most investigated lineage for clinical trials behind hematopoietic and mesenchymal stem cells only 5 years ago (Heathman et al, 2015), T cells are now ranked first in several countries (https://ct.catapult.org.uk/clinical-trials-database and https://clinicaltrials.gov/ as consulted on 16/04/20).…”