Use of cord blood derived T-cells in cancer immunotherapy: milestones achieved and future perspectives

Generating advanced CAR-based therapy for hematological malignancies in clinical practice: targets to cell sources to combinational strategies

Chimeric antigen receptor T (CAR-T) cell therapy has been a milestone breakthrough in the treatment of hematological malignancies, offering an effective therapeutic option for multi-line therapy-refractory patients. So far, abundant CAR-T products have been approved by the United States Food and Drug Administration or China National Medical Products Administration to treat relapsed or refractory hematological malignancies and exhibited unprecedented clinical efficiency. However, there were still several significant unmet needs to be progressed, such as the life-threatening toxicities, the high cost, the labor-intensive manufacturing process and the poor long-term therapeutic efficacy. According to the demands, many researches, relating to notable technical progress and the replenishment of alternative targets or cells, have been performed with promising results. In this review, we will summarize the current research progress in CAR-T eras from the "targets" to "alternative cells", to "combinational drugs" in preclinical studies and clinical trials.

[The impact of immune cells selection on the therapeutic efficacy of CAR-T cell therapy]

Here we summarized novel Chimeric antigen receptor T-cell immunotherapy (CAR-T) based on the immune material aspect. Young healthy donor T cells, stem cell-like memory T cells, human induced pluripotent stem cells and umbilical cord blood T cells are all potential candidates to enhance CAR-T cell therapy depending on their anti-tumor efficacy. Besides, due to less restricted major histocompatibility complex (MHC) mismatch effect, viral specific T cells, γδT cells, invariant natural killer T cells and macrophages also become idealized T cell sources in terms of Universal CAR-T (UCAR-T) cell therapeutics. In addition, studies demonstrated that more balanced CD4(+)/CD8(+) T cell ratio and eliminating monocytes during leukapheresis have a positive influence on CAR-T cell functioning, whereas T cells with higher exhaustion markers expression hampers anti-tumor ability of CAR-T cells after infusion. To avoid application of such T cells or mitigate the impact using immune checkpoint inhibitors is of great importance.

Sánchez E, Ivanova M, Pastora K, Alcántara-Sánchez C, García-Martínez J, Martín-Antonio B, Ramírez M, González-Murillo Á. Choosing T-cell sources determines CAR-T cell activity in neuroblastoma

Introduction

The clinical success of chimeric antigen receptor-modified T cells (CAR-T cells) for hematological malignancies has not been reproduced for solid tumors, partly due to the lack of cancer-type specific antigens. In this work, we used a novel combinatorial approach consisting of a versatile anti-FITC CAR-T effector cells plus an FITC-conjugated neuroblastoma (NB)-targeting linker, an FITC-conjugated monoclonal antibody (Dinutuximab) that recognizes GD2.

Methods

We compared cord blood (CB), and CD45RA-enriched peripheral blood leukapheresis product (45RA) as allogeneic sources of T cells, using peripheral blood (PB) as a control to choose the best condition for anti-FITC CAR-T production. Cells were manufactured under two cytokine conditions (IL-2 versus IL-7+IL-15+IL-21) with or without CD3/CD28 stimulation. Immune phenotype, vector copy number, and genomic integrity of the final products were determined for cell characterization and quality control assessment. Functionality and antitumor capacity of CB/45RA-derived anti-FITC CAR-T cells were analyzed in co-culture with different anti-GD2-FITC labeled NB cell lines.

Results

The IL-7+IL-15+IL-21 cocktail, in addition to co-stimulation signals, resulted in a favorable cell proliferation rate and maintained less differentiated immune phenotypes in both CB and 45RA T cells. Therefore, it was used for CAR-T cell manufacturing and further characterization. CB and CD45RA-derived anti-FITC CAR-T cells cultured with IL-7+IL-15+IL-21 retained a predominantly naïve phenotype compared with controls. In the presence of the NB-FITC targeting, CD4+ CB-derived anti-FITC CAR-T cells showed the highest values of co-stimulatory receptors OX40 and 4-1BB, and CD8+ CAR-T cells exhibited high levels of PD-1 and 4-1BB and low levels of TIM3 and OX40, compared with CAR-T cells form the other sources studied. CB-derived anti-FITC CAR-T cells released the highest amounts of cytokines (IFN-γ and TNF-α) into co-culture supernatants. The viability of NB target cells decreased to 30% when co-cultured with CB-derived CAR-T cells during 48h.

Conclusion

CB and 45RA-derived T cells may be used as allogeneic sources of T cells to produce CAR-T cells. Moreover, ex vivo culture with IL-7+IL-15+IL-21 could favor CAR-T products with a longer persistence in the host. Our strategy may complement the current use of Dinutuximab in treating NB through its combination with a targeted CAR-T cell approach.

Cord blood-derived CD19-specific chimeric antigen receptor T cells: an off-the-shelf promising therapeutic option for treatment of diffuse large B-cell lymphoma

Purpose

Autologous chimeric antigen receptor (CAR) T cell therapy is one of the most significant breakthroughs in hematological malignancies. However, a three-week manufacturing cycle and ineffective T cell dysfunction in some patients hinder the widespread application of auto-CAR T cell therapy. Studies suggest that cord blood (CB), with its unique biological properties, could be an optimal source for CAR T cells, providing a product with 'off-the-shelf' availability. Therefore, exploring the potential of CB as an immunotherapeutic agent is essential for understanding and promoting the further use of CAR T cell therapy.

Experimental design

We used CB to generate CB-derived CD19-targeting CAR T (CB CD19-CAR T) cells. We assessed the anti-tumor capacity of CB CD19-CAR T cells to kill diffuse large B cell lymphoma (DLBCL) in vitro and in vivo.

Results

CB CD19-CAR T cells showed the target-specific killing of CD19+ T cell lymphoma cell line BV173 and CD19+ DLBCL cell line SUDHL-4, activated various effector functions, and inhibited tumor progression in a mouse (BALB/c nude) model. However, some exhaustion-associated genes were involved in off-tumor cytotoxicity towards activated lymphocytes. Gene expression profiles confirmed increased chemokines/chemokine receptors and exhaustion genes in CB CD19-CAR T cells upon tumor stimulation compared to CB T cells. They indicated inherent changes in the associated signaling pathways in the constructed CB CAR T cells and targeted tumor processes.

Conclusion

CB CD19-CAR T cells represent a promising therapeutic strategy for treating DLBCL. The unique biological properties and high availability of CB CD19-CAR T cells make this approach feasible.

Umbilical Cord Blood as a Source of Less Differentiated T Cells to Produce CD123 CAR-T Cells

Simple Summary

We used fresh or thawed Umbilical Cord Blood (UCB) to produce CAR-T cells directed against CD123, and we compared their functionality to Peripheral Blood (PB) CAR-T cells. T cells expressing CD123 CAR, derived from UCB, was exhibited through a high transduction rate, activation status, and cytotoxic potential in vitro as PB derived CAR-T cells. Moreover, we obtained T cells that had a less differentiated profile than the PB-derived T cells. UCB derived CAR-T can significantly control tumor progression in mice models. CAR-T obtained from thawed or fresh UCB gives the same results.

Abstract

Chimeric Antigen Receptor (CAR) therapy has led to great successes in patients with leukemia and lymphoma. Umbilical Cord Blood (UCB), stored in UCB banks, is an attractive source of T cells for CAR-T production. We used a third generation CD123 CAR-T (CD28/4-1BB), which was previously developed using an adult’s Peripheral Blood (PB), to test the ability of obtaining CD123 CAR-T from fresh or cryopreserved UCB. We obtained a cell product with a high and stable transduction efficacy, and a poorly differentiated phenotype of CAR-T cells, while retaining high cytotoxic functions in vitro and in vivo. Moreover, CAR-T produced from cryopreserved UCB are as functional as CAR-T produced from fresh UCB. Overall, these data pave the way for the clinical development of UCB-derived CAR-T. UCB CAR-T could be transferred in an autologous manner (after an UCB transplant) to reduce post-transplant relapses, or in an allogeneic setting, thanks to fewer HLA restrictions which ease the requirements for a match between the donor and recipient.

Efficient lentiviral transduction method to gene modify cord blood CD8+ T cells for cancer therapy applications

Adoptive T cell therapy utilizing tumor-specific autologous T cells has shown promising results for cancer treatment. However, the limited numbers of autologous tumor-associated antigen (TAA)-specific T cells and the functional aberrancies, due to disease progression or treatment, remain factors that may significantly limit the success of the therapy. The use of allogeneic T cells, such as umbilical cord blood (CB) derived, overcomes these issues but requires gene modification to induce a robust and specific anti-tumor effect. CB T cells are readily available in CB banks and show low toxicity, high proliferation rates, and increased anti-leukemic effect upon transfer. However, the combination of anti-tumor gene modification and preservation of advantageous immunological traits of CB T cells represent major challenges for the harmonized production of T cell therapy products. In this manuscript, we optimized a protocol for expansion and lentiviral vector (LV) transduction of CB CD8⁺ T cells, achieving a transduction efficiency up to 83%. Timing of LV treatment, selection of culture media, and the use of different promoters were optimized in the transduction protocol. LentiBOOST was confirmed as a non-toxic transduction enhancer of CB CD8⁺ T cells, with minor effects on the proliferation capacity and cell viability of the T cells. Positively, the use of LentiBOOST does not affect the functionality of the cells, in the context of tumor cell recognition. Finally, CB CD8⁺ T cells were more amenable to LV transduction than peripheral blood (PB) CD8+ T cells and maintained a more naive phenotype. In conclusion, we show an efficient method to genetically modify CB CD8⁺ T cells using LV, which is especially useful for off-the-shelf adoptive cell therapy products for cancer treatment.