Activation of T lymphocytes for the adoptive immunotherapy of cancer

Immune Checkpoint Therapy: Tumor Draining Lymph Nodes in the Spotlights

Tumor-draining lymph nodes play a paradoxical role in cancer. Surgeons often resect these sentinel lymph nodes to determine metastatic spread, thereby enabling prognosis and treatment. However, lymph nodes are vital organs for the orchestration of immune responses, due to the close encounters of dedicated immune cells. In view of the success of immunotherapy, the removal of tumor-draining lymph nodes needs to be re-evaluated and viewed in a different light. Recently, an important role for tumor-draining lymph nodes has been proposed in the immunotherapy of cancer. This new insight can change the use of immune checkpoint therapy, particularly with respect to the use in neoadjuvant settings in which lymph nodes are still operational.

Anti-Cancer Nanomedicines: A Revolution of Tumor Immunotherapy

Immunotherapies have been accelerating the development of anti-cancer clinical treatment, but its low objective responses and severe off-target immune-related adverse events (irAEs) limit the range of application. Strategies to remove these obstacles primarily focus on the combination of different therapies and the exploitation of new immunotherapeutic agents. Nanomedicine potentiates the effects of activating immune cells selectively and reversing tumor induced immune deficiency microenvironment through multiple mechanisms. In the last decade, a variety of nano-enabled tumor immunotherapies was under clinical investigation. As time goes by, the advantages of nanomedicine are increasingly prominent. With the continuous development of nanotechnology, nanomedicine will offer more distinctive perspectives in imaging diagnosis and treatment of tumors. In this Review, we wish to provide an overview of tumor immunotherapy and the mechanisms of nanomaterials that aim to enhance the efficacy of tumor immunotherapy under development or in clinic treatment.

Adoptive T-cell therapy in the treatment of viral and opportunistic fungal infections

Viral infections and opportunistic fungal pathogens represent a major menace for immunocompromised patients. Despite the availability of antifungal and antiviral drugs, mortality in these patients remains high, underlining the need of novel therapeutic options based on completely different strategies. This review describes the potential of several T-cell-based therapeutic approaches in the prophylaxis and treatment of infectious diseases with a particular focus on persistent viral infections and opportunistic fungal infections, as these mostly affect immunocompromised patients.

Adoptive transfer of Mammaglobin-A epitope specific CD8 T cells combined with a single low dose of total body irradiation eradicates breast tumors

Adoptive T cell therapy has proven to be beneficial in a number of tumor systems by targeting the relevant tumor antigen. The tumor antigen targeted in our model is Mammaglobin-A, expressed by approximately 80% of human breast tumors. Here we evaluated the use of adoptively transferred Mammaglobin-A specific CD8 T cells in combination with low dose irradiation to induce breast tumor rejection and prevent relapse. We show Mammaglobin-A specific CD8 T cells generated by DNA vaccination with all epitopes (Mammaglobin-A2.1, A2.2, A2.4 and A2.6) and full-length DNA in vivo resulted in heterogeneous T cell populations consisting of both effector and central memory CD8 T cell subsets. Adoptive transfer of spleen cells from all Mammaglobin-A2 immunized mice into tumor-bearing SCID/beige mice induced tumor regression but this anti-tumor response was not sustained long-term. Additionally, we demonstrate that only the adoptive transfer of Mammaglobin-A2 specific CD8 T cells in combination with a single low dose of irradiation prevents tumors from recurring. More importantly we show that this single dose of irradiation results in the down regulation of the macrophage scavenger receptor 1 on dendritic cells within the tumor and reduces lipid uptake by tumor resident dendritic cells potentially enabling the dendritic cells to present tumor antigen more efficiently and aid in tumor clearance. These data reveal the potential for adoptive transfer combined with a single low dose of total body irradiation as a suitable therapy for the treatment of established breast tumors and the prevention of tumor recurrence.

Significant anti-tumour activity of adoptively transferred T cells elicited by intratumoral dendritic cell vaccine injection through enhancing the ratio of CD8(+) T cell/regulatory T cells in tumour

We have shown that immunization with dendritic cells (DCs) pulsed with hepatitis B virus core antigen virus-like particles (HBc-VLP) packaging with cytosine-guanine dinucleotide (CpG) (HBc-VLP/CpG) alone were able to delay melanoma growth but not able to eradicate the established tumour in mice. We tested whether, by modulating the vaccination approaches and injection times, the anti-tumour activity could be enhanced. We used a B16-HBc melanoma murine model not only to compare the efficacy of DC vaccine immunized via footpads, intravenously or via intratumoral injections in treating melanoma and priming tumour-specific immune responses, but also to observe how DC vaccination could improve the efficacy of adoptively transferred T cells to induce an enhanced anti-tumour immune response. Our results indicate that, although all vaccination approaches were able to protect mice from developing melanoma, only three intratumoral injections of DCs could induce a significant anti-tumour response. Furthermore, the combination of intratumoral DC vaccination and adoptive T cell transfer led to a more robust anti-tumour response than the use of each treatment individually by increasing CD8(+) T cells or the ratio of CD8(+) T cell/regulatory T cells in the tumour site. Moreover, the combination vaccination induced tumour-specific immune responses that led to tumour regression and protected surviving mice from tumour rechallenge, which is attributed to an increase in CD127-expressing and interferon-γ-producing CD8(+) T cells. Taken together, these results indicate that repeated intratumoral DC vaccination not only induces expansion of antigen-specific T cells against tumour-associated antigens in tumour sites, but also leads to elimination of pre-established tumours, supporting this combined approach as a potent strategy for DC-based cancer immunotherapy.

Fate and function of anti-CD3/CD28-activated T cells following adoptive transfer: IL-2 promotes development of anti-tumor memory T cells in vivo

BACKGROUND

Adoptive immunotherapy with T cells activated through CD3 alone requires exogenous IL-2 for T-cell function and survival after transfer, but the in vivo cytokine requirement of T cells activated through CD3 and CD28 is unknown. We hypothesized that CD3/CD28-activated T cells, unlike those activated through CD3 alone, might develop into long-lived memory T cells, either with or without systemic IL-2.

METHODS

We used MHC class I-restricted TCR transgenic T cells from the OT-1 mouse, specific for the surrogate tumor Ag ovalbumin (OVA), to assess the trafficking kinetics, antigenic responsiveness and anti-tumor efficacy of dual-activated T cells in vivo as a function of IL-2 administration. At days 7, 14, and 28 after transfer, lymph node cells and splenocytes were examined for donor cell persistence and antigenic responsiveness by FACS and ELISA, respectively.

RESULTS

In IL-2-treated mice, donor CD8+ T cells persisted and developed a memory phenotype, based on CD44 and Ly6c expression at day 28, while mice given no IL-2 had fewer donor cells at all time points. OVA-specific release of IFN-gamma was higher from lymphocytes of IL-2-treated mice compared with no-IL-2 mice (P<0.02 at all time points). In mice challenged with an OVA-bearing subline of the AML leukemia model C1498, IL-2 did not confer added protection from tumor challenge at 1 or 2 weeks after adoptive transfer, but gave improved survival at 4 weeks post-transfer.

DISCUSSION

We conclude that exogenous IL-2 is not required for anti-tumor activity of CD3/CD28-activated CD8+ cells early after adoptive transfer, but promotes T-cell persistence that confers disease protection at more remote times.

Prolonged Culture of Vaccine-Primed Lymphocytes Results in Decreased Antitumor Killing and Change in Cytokine Secretion

Adoptive transfer of effector T cells has been used successfully to eliminate metastases in animal models. Because antitumor activity depends on the number of effector cells transferred, some human trials have used in vitro-repetitive activation and expansion techniques to increase cell number. We hypothesized that the prolonged culture period might contribute to the lack of human trial success by decreasing the potency of the effector T cells. Lymph nodes draining a progressively growing murine melanoma tumor transduced to secrete granulocyte/macrophage colony-stimulating factor were harvested and activated in vitro with anti-CD3 monoclonal antibody followed by expansion in IL-2 for a total of 5 days in culture. Some lymphocytes were reactivated and further expanded for a total of 9 days in culture. In vivo activity of the effector T cells was measured by the reduction in lung metastases and is shown to be dose dependent. The prolonged culture period resulted in nearly 3-fold more T cells but at least 8-fold less antitumor activity. This was accompanied by decreased secretion of the proinflammatory cytokine, IFN-gamma, and increased secretion of the anti-inflammatory cytokine, IL-10. Thus, although increased cell number is important to maximize the effectiveness of adoptive immunotherapy, some culture conditions may actually be counterproductive in that decreases in cell potency can outweigh the benefits of increased cell numbers. The T-cell cytokine secretion pattern predicts decreased effector cell function and may explain the decreased antitumor effect.

Ex vivo expansion of the highly cytotoxic human natural killer-92 cell-line under current good manufacturing practice conditions for clinical adoptive cellular immunotherapy

BACKGROUND

Adoptive transfer of ex vivo expanded cytotoxic immune cells has become a viable strategy for treatment of malignant disease. Natural killer (NK)-92, a highly cytotoxic, IL2-dependent human NK cell-line, is an excellent candidate as an immunotherapeutic agent, being active for prolonged periods following irradiation and IL2 deprivation, non-toxic and non-immunogenic, and easily expanded. A number of clinical trials using NK-92 for different indications are currently underway. The aim of this study was to develop current good manufacturing practice (cGMP)-compliant expansion methodology for NK-92.

METHODS

The ability to expand NK-92 ex vivo was evaluated. Serum-free culture media, as well as media supplements (IL2, serum/plasma/albumin), culture containers and feeding regimens were compared for their ability to support expansion, viability and cytotoxicity of NK-92 cells.

RESULTS

NK-92 cells can be expanded in X-Vivo 10 serum-free media with 500 U/mL of rhIL2 (Proleukin), and 2.5% human serum/plasma to achieve concentrations sufficient to treat patients with >5210(10) cells. The protocol involves cultures initiated at 2.5210(5) cells/mL in 25 mL in 1 L Vuelife culture bags, with addition of fresh media plus IL2 every 3 days to maintain an optimal density of NK-92 cells for expansion. Daily disruption of cell aggregates enhances NK-92 cells expansion and viability during the culture period. Final yields of approximately 1.1-1.3210(6) cells/mL in a 1.2 L volume (1.36-1.56210(9) cells; 218-250 fold expansion) over 15-17 days is achievable under cGMP-compliant conditions with >85% viability. The feasibility of this approach has been shown in ongoing clinical trial with NK-92.

DISCUSSION

We describe a protocol that allows for >200-fold expansion of NK-92 cells within a 2-2.5 week period under GMP standards, in quality and quantity suitable for clinical adoptive immunotherapy.

Adoptive immunotherapy in patients with recurrent malignant glioma: preliminary results of using autologous whole-tumor vaccine plus granulocyte-macrophage colony–stimulating factor and adoptive transfer of anti-CD3–activated lymphocytes

Object

This trial was designed to determine the ability of autologous whole–tumor cell vaccines to induce cell-mediated immune responses in patients with recurrent malignant glioma, as well as to determine whether combining such vaccination with adoptive transfer of in vitro activated T lymphocytes prolongs patient survival.

Methods

Nineteen patients with recurrent malignant glioma, in whom previous external beam radiotherapy and at least one course of chemotherapy had failed were vaccinated twice with irradiated autologous whole tumor cells by using granulocyte-marcrophage colony–stimulating factor as an adjuvant. Patients then underwent leukapheresis followed by adoptive transfer of peripheral blood lymphocytes activated in vitro with anti-CD3 and interleukin-2. In vivo immune response, radiological response, clinical outcome, and survival were monitored.

Seventeen patients developed a delayed-type hypersensitivity (DTH) response to vaccination that appeared to be directed against the autologous tumor. In eight patients there was radiological evidence of a response and in five there was evidence of clinical improvement. Median survival was 12 months (range 6–28 months), and both the presence of a DTH response and the radiological response correlated with survival (p < 0.02 and p < 0.04, respectively).

Conclusions

These preliminary results suggest that autologous whole–tumor cell vaccines induce a cell-mediated immune response, which appears to be tumor specific in most patients. Furthermore, vaccination combined with adoptive immunotherapy with in vitro activated cells may induce a radiologically demonstrated tumor response and improved survival despite a condition of advanced disease and immunosuppression resulting from previous treatment or tumor burden. Further studies of immunotherapy are warranted.

Persistence, immune specificity, and functional ability of murine mutant ras epitope-specific CD4(+) and CD8(+) T lymphocytes following in vivo adoptive transfer

Adoptive T-cell transfer has been shown to be a potentially effective strategy for cellular immunotherapy in some murine models of disease. However, several issues remain unresolved regarding some of the basic features involved in effective adoptive transfer, such as the influence of specific peptide antigen (Ag) boost after T-cell transfer, the addition of IL-2 post-T-cell transfer, the trafficking of transferred T cells to lymphoid and nonlymphoid tissues, and the functional stability of recoverable CD4(+) and CD8(+) T cells. We investigated several of these parameters, particularly as they relate to the persistence and maintenance of effector functions of murine CD4(+) and/or CD8(+) T lymphocytes after adoptive cellular transfer into partially gamma-irradiated syngeneic hosts. Our laboratory previously identified murine (H-2(d)) immunogenic CD4(+) and CD8(+) T-cell peptide epitopes reflecting codon 12 ras mutations as tumor-specific Ag. Therefore, the model system chosen here employed epitope-specific MHC class II-restricted CD4(+) T cells and MHC class I-restricted CD8(+) T cells produced from previously immunized BALB/c mice. Between 2 and 7 days after T-cell transfer, recipient mice received various combinations of peptide boosts and/or IL-2 treatments. At different times after the T-cell transfer, spleen and lung tissues were analyzed phenotypically to monitor the persistence of the immune T cells and functionally (via proliferation or cytotoxicity assays) to assess the maintenance of peptide specificity. The results showed that immune donor T lymphocytes (uncultured immune T cells or cloned T cells) were recoverable from the spleens and lungs of recipient mice after transfer. The recovery of Ag-specific T-cell responses was greatest from recipient mice that received peptide boosts and IL-2 treatment. However, mice that received a peptide boost without IL-2 treatment responded nearly as well, which suggested that including a peptide boost after T-cell transfer was more obligatory than exogenous IL-2 treatment to sustain adoptively transferred T cells in vivo. Ag-specific T-cell responses were weak in mice that either received IL-2 alone or did not receive the cognate peptide boost after T-cell transfer. The T-cell clones were also monitored by flow cytometry or RT-PCR based on expression of the T-cell receptor Vbeta-chain, which was previously characterized. Ag-specific T cells were recovered from both spleens and lungs of recipient mice, demonstrating that the T-cell clones could localize to both lymphoid and nonlymphoid tissues. This study demonstrates that both uncultured and in vitro-cloned T lymphocytes can migrate to lymphoid tissues and nonlymphoid (e.g., lung) tissues in recipient hosts and that their functional activities can be maintained at these sites after transfer, if they are exposed to peptide Ag in vivo.

Systemic T cell adoptive immunotherapy of malignant gliomas

OBJECT

To determine the feasibility, toxicity, and potential therapeutic benefits of systemic adoptive immunotherapy, 10 patients with progressive primary or recurrent malignant glioma received this treatment. Adoptive immunotherapy, the transfer of immune T lymphocytes, is capable of mediating the regression of experimental brain tumors in animal models. In animal models, lymph nodes (LNs) that drain the tumor vaccine site are a rich source of tumor-immune T cells.

METHODS

In this clinical study, patients were inoculated intradermally with irradiated autologous tumor cells and granulocyte macrophage-colony stimulating factor as an adjuvant. Cells from draining inguinal LNs, surgically resected 7 days after vaccination, were stimulated sequentially with staphylococcal enterotoxin A and anti-CD3, and a low dose of interleukin-2 (60 IU/ml) was used to expand the stimulated cells. The maximum cell proliferation was 350-fold over 10 days of culture. The activated cells were virtually all T cells consisting of various proportions of CD4 and CD8 cells. These cells were given to patients by intravenous infusion at doses ranging from 9 x 10(8) to 1.5 x 10(11). There were no Grade 3 or 4 toxicities associated with the treatment. Following T-cell transfer therapy, radiographic regression that lasted at least 6 months was demonstrated in two patients with recurrent tumors. One patient demonstrated stable disease that has lasted for more than 17 months. The remaining patients had progressive disease; however, four of the eight patients with recurrent tumor remain alive more than 1 year after surgery for recurrence. Three patients required intervention with corticosteroid agents or additional surgery approximately 1 month following cell transfer.

CONCLUSIONS

These intriguing clinical observations warrant further trials to determine whether this approach can provide therapeutic benefits and improve survival.

Anti-tumor effects of local irradiation in combination with peritumoral administration of low doses of recombinant interleukin-2 (rIL-2)

The aim of this work was to improve radiotherapy results by immune stimulation. We tested the effects of a combination of radio- and immunotherapy, i.e., local low dose recombinant interleukin-2 (rIL-2) treatment, in two murine tumor models. Syngeneic tumors (SL2 lymphoma or M8013 mammary carcinoma) were induced subcutaneously on one or both flanks of mice. Irradiation was given either as a single dose (20 Gy) or fractionated (25 Gy) in 2 weeks. One or two cycles of rIL-2 were given concurrent with or subsequent to radiotherapy. One cycle of rIL-2 consisted of peritumoral injections administered on 5 consecutive days. Treatment effects were measured in terms of local tumor response and disease-free survival (DFS). The combined treatment modality was significantly better than treatment with either irradiation alone or rIL-2 alone. When tumors were inoculated on both flanks of the mice, combined radioimmunotherapy of one of the tumors also resulted in regression of the contralateral untreated tumor, indicating that a systemic anti-tumor immune reaction was induced. Additional rIL-2 injections did not enhance radiation toxicity. In conclusion supplementing irradiation with locally administered low doses of rIL-2 results in better local anti-tumor responses and DFS rates than either treatment alone without enhanced treatment toxicity. Furthermore, the local treatment induces a systemic anti-tumor reaction, influencing the growth patterns of a second, untreated tumor.

Therapy with cultured T cells: principles revisited

In animals and in humans, T-cell therapy can cure advanced disseminated leukemia that would otherwise be fatal. The therapeutic effect of immune T cells is quantitative. As the dose of effector T cells is increased, survival is proportionately increased. Therefore, effective T-cell therapy is predicated on the ability to procure large numbers of immune effector T cells. By using cultured T cells, the number of immune T cells can be increased in vivo substantially above the level achievable by vaccination. The survival of cultured T cells in vivo is dependent upon both the culture conditions used and the therapeutic regimens employed. Under appropriate conditions, cultured T cells can proliferate in vivo in response to stimulation by antigen, distribute widely and survive long term to provide effector function and immunologic memory. Given that T cells recognize peptides, the need for immunization with tumor can be circumvented by immunization with peptide. Peptide-specific T cells and the progeny of single T-cell clones can provide the necessary cellular functions to eradicate disseminated murine leukemia. The ability of cloned T cells to similarly provide substantial measurable immunity in humans has been validated in clinical trials. By priming with peptides and by using established culture conditions, T-cell therapy can now be directed against virtually any antigen within the host T-cell repertoire. The major remaining question to be answered is which proteins and which peptides are the most suitable targets for T-cell therapy trials.

The fucosyltransferase FucT-VII regulates E-selectin ligand synthesis in human T cells

Selectin-ligands on T cells contribute to the recruitment of circulating cells into chronic inflammatory lesions in the skin and elsewhere. This report provides the first evidence that a single fucosyltransferase, termed FucT-VII, controls the synthesis of E-selectin ligands in human T-lymphoblasts. The FucT-IV transferase (the ELFT enzyme), in contrast constructs lower avidity E-selectin ligands and requires enzyme levels found only in myeloid cells. Treatment of Jurkat cells with phorbol myristate acetate increased the expression of sialylated Lewis(x)-related sLe(x)related epitopes and induced the synthesis of E-selectin ligands functional at physiologic levels of linear shear-stress. Northern analysis revealed a parallel increase in the steady-state levels FucT-VII mRNA, but there were no increases in the two other leukocyte-associated fucosyltransferases (FucT-IV and VI). The stable transfection of the FucT-VII gene into Jurkat cells induced high levels of the sLe(x)-related epitopes and the synthesis of E-selectin ligands which equal or exceeded the avidity of those on circulating lymphocytes. The growth of T-lymphoblasts under conditions which induced expression of the sLe(x,a) epitopes increased the level of FucT-VII mRNA, the synthesis of sialylated-Lewis(x) structures by cell-free extracts and the synthesis of E-selectin ligands equal in avidity to those on FucT-VII transfectants. In contrast, neither the mRNA levels nor activities of the FucT-IV and VI enzymes increased in association with E-selectin ligand synthesis in T-lymphoblasts. Myeloid cell lines, unlike lymphoblasts, expressed high levels of both the FucT-VII and IV enzymes in conjunction with E-selectin ligands raising the possibility that both enzymes contributed to ligand synthesis. FucT-IV transfected Jurkat cells synthesized low avidity ligands for E-selectin but only in association with CDw65 (VIM-2) carbohydrate epitope. Only blood neutrophils and myeloid cell lines expressed this epitope at the levels associated with E-ligand synthesis in the transfectants. In contrast, native Jurkat cells, blood monocytes, blood lymphocytes, and cultured T-lymphoblasts expressed low levels or none. We conclude that FucT-VII is a principal regulator of E-selectin ligand synthesis in human T-lymphoblasts while both FucT-VII and FucT-IV may direct ligand synthesis in some myeloid cells.