Study of tumor-infiltrating lymphocytes for adoptive therapy of renal cell carcinoma (RCC) and metastatic melanoma: sequential proliferation of cytotoxic natural killer and noncytotoxic T cells in RCC

Nanomedicine for Combination Urologic Cancer Immunotherapy

Urologic cancers, particularly kidney, bladder, and prostate cancer, have a growing incidence and account for about a million annual deaths worldwide. Treatments, including surgery, chemotherapy, radiotherapy, hormone therapy, and immunotherapy are the main therapeutic options in urologic cancers. Immunotherapy is now a clinical reality with marked success in solid tumors. Immunological checkpoint blockade, non-specific activation of the immune system, adoptive cell therapy, and tumor vaccine are the main modalities of immunotherapy. Immunotherapy has long been used to treat urologic cancers; however, dose-limiting toxicities and low response rates remain major challenges in the clinic. Herein, nanomaterial-based platforms are utilized as the "savior". The combination of nanotechnology with immunotherapy can achieve precision medicine, enhance efficacy, and reduce toxicities. In this review, we highlight the principles of cancer immunotherapy in urology. Meanwhile, we summarize the nano-immune technology and platforms currently used for urologic cancer treatment. The ultimate goal is to help in the rational design of strategies for nanomedicine-based immunotherapy in urologic cancer.

Natural killer cells as a promising tool to tackle cancer-A review of sources, methodologies, and potentials

Immune cell-based therapies are emerging as a promising tool to tackle malignancies, both solid tumors and selected hematological tumors. Vast experiences in literature have documented their safety and added survival benefits when such cell-based therapies are combined with the existing treatment options. Numerous methodologies of processing and in vitro expansion protocols of immune cells, such as the dendritic cells, natural killer (NK) cells, NKT cells, αβ T cells, so-called activated T lymphocytes, γδ T cells, cytotoxic T lymphocytes, and lymphokine-activated killer cells, have been reported for use in cell-based therapies. Among this handful of immune cells of significance, the NK cells stand apart from the rest for not only their direct cytotoxic ability against cancer cells but also their added advantage, which includes their capability of (i) action through both innate and adaptive immune mechanism, (ii) tackling viruses too, giving benefits in conditions where viral infections culminate in cancer, and (iii) destroying cancer stem cells, thereby preventing resistance to chemotherapy and radiotherapy. This review thoroughly analyses the sources of such NK cells, methods for expansion, and the future potentials of taking the in vitro expanded allogeneic NK cells with good cytotoxic ability as a drug for treating cancer and/or viral infection and even as a prophylactic tool for prevention of cancer after initial remission.

Adoptive T cell therapy combined with intralesional administrations of TG1042 (adenovirus expressing interferon-γ) in metastatic melanoma patients

Tumor immune escape has recently been shown to be related to the development of an immune tolerance state of the microenvironment. Cytokines activating the immune system such as IFN-γ can be used to reverse the immune escape and thus to potentiate the efficacy of immunotherapy. A clinical study was conducted in 18 stage IIIc/IV melanoma patients treated with tumor-infiltrating lymphocytes (TILs) in combination with intratumoral TG1042 injection (adenovirus expressing IFN-γ). The primary objective was to investigate the safety of treatment. Secondary objectives were to study the clinical response and translational research. The treatment was well tolerated. Among the 13 patients evaluable for tumor response, 38.5% had an overall objective response (OOR = CR + PR) and disease control rate (DCR = CR + PR + S) of 46%. The clinical response of the 37 targeted lesions led to an OOR of 51% and a DCR of 75%. Translational research on predictive markers did not significantly differ between responder and non-responder patients. However, specifically regarding injected lesions, the clinical response correlated with CD3-/CD56+ NK cells which could be activated by TG1042. Further larger studies of this combined immunotherapy are needed to confirm our findings. Intralesional TG1042 combined with antigen-selected TILs should be discussed.

A pilot clinical trial testing mutant von Hippel-Lindau peptide as a novel immune therapy in metastatic renal cell carcinoma

Background

Due to the lack of specific tumor antigens, the majority of tested cancer vaccines for renal cell carcinoma (RCC) are based on tumor cell lysate. The identification of the von Hippel-Lindau (VHL) gene mutations in RCC patients provided the potential for developing a novel targeted vaccine for RCC. In this pilot study, we tested the feasibility of vaccinating advanced RCC patients with the corresponding mutant VHL peptides.

Methods

Six patients with advanced RCC and mutated VHL genes were vaccinated with the relevant VHL peptides. Patients were injected with the peptide mixed with Montanide subcutaneously (SQ) every 4 weeks until disease progression or until the utilization of all available peptide stock.

Results

Four out of five evaluable patients (80%) generated specific immune responses against the corresponding mutant VHL peptides. The vaccine was well tolerated. No grade III or IV toxicities occurred. The median overall survival (OS) and median progression-free survival (PFS) were 30.5 and 6.5 months, respectively.

Conclusions

The vaccine demonstrated safety and proved efficacy in generating specific immune response to the mutant VHL peptide. Despite the fact that the preparation of these custom-made vaccines is time consuming, the utilization of VHL as a vaccine target presents a promising approach because of the lack of other specific targets for RCC. Accordingly, developing mutant VHL peptides as vaccines for RCC warrants further investigation in larger trials. Trial registration: 98C0139

Relationship between tumor-infiltrating T lymphocytes and clinical response after reduced-intensity allogeneic hematopoietic stem cell transplantation for advanced renal cell carcinoma: a single center prospective study

OBJECTIVE

Renal cell carcinoma (RCC) is refractory to conventional therapy, including chemotherapy and radiation. However, because RCC is sensitive to cytokine therapy, an immunotherapeutic approach such as hematopoietic stem cell transplantation (HSCT) might lead to a cure. We performed an institutional clinical study of HSCT for refractory RCC patients.

METHODS

RCC patients aged 50 years or over, refractory to therapy, were eligible for the study. HSCT was performed after reduced-intensity conditioning. Primary endpoint was defined as the survival at day 100 after HSCT with complete donor chimerism, and secondary endpoint was the effectiveness of HSCT.

RESULTS

Seven patients, provided with written informed consent, were enrolled in the study. Six of the seven patients achieved complete donor chimera at day 30 after HSCT, but one patient received second HSCT because of graft rejection. Four patients achieved a partial response (PR) and stable disease was observed in another patient, but these responses were temporary. The disease of the other two patients became progressive. Autopsy findings revealed an accumulation of CD8(+) lymphocytes and degenerative changes in the local RCC lesion in three of six patients who responded clinically. An autopsy of a patient who had obtained a PR revealed lymphocyte involvement with a cytotoxic T cell (CTL) phenotype in the metastasis of RCC.

CONCLUSIONS

Our results demonstrate the efficacy of HSCT for RCC and suggest that the graft-versus-tumor effect elicited by CTLs is induced in vivo. HSCT should be further explored as a potential curative treatment for RCC.

Safety profile and anti-tumor effects of adoptive immunotherapy using gamma-delta T cells against advanced renal cell carcinoma: a pilot study

PURPOSE

Although various types of immunotherapy have been used to improve the prognosis of patients with advanced renal cell carcinoma (RCC), adoptive immunotherapy using gamma-delta (gammadelta) T cells has not yet been tried. In this study, we designed a pilot study of adoptive immunotherapy using in vitro activated gammadelta T cells against advanced RCC to evaluate the safety profile and possible anti-tumor effects of this study.

EXPERIMENTAL DESIGN

Patients with advanced RCC after radical nephrectomy were administered via intravenous infusion in vitro-activated autologous gammadelta T cells every week or every 2 weeks, 6-12 times, with 70 JRU of teceleukin. Adverse events, anti-tumor effects and immunomonitoring were assessed. The anti-tumor effects were evaluated according to tumor doubling time (DT) by computed tomography (CT) and immunomonitoring was performed by flow cytometric analysis.

RESULTS

Seven advanced RCC patients were entered in this study. The most common adverse events were fever, general fatigue and elevation of hepatobiliary enzymes, but no severe adverse events were seen. Prolongation of tumor DT was seen in three out of five patients; these three patients showed an increase in the number of gammadelta T cells in peripheral blood and also a high response to the antigen in vitro.

CONCLUSIONS

The results indicated that adoptive immunotherapy using in vitro-activated autologous gammadelta T cells was well tolerated and induced anti-tumor effects.

Reduced L-selectin (CD62LLow) expression identifies tumor-specific type 1 T cells from lymph nodes draining an autologous tumor cell vaccine

Reduced expression of CD62L can identify tumor-specific T cells in lymph nodes draining murine tumors. Here, we examined whether this strategy could isolate tumor-specific T cells from vaccinated patients. Tumor vaccine-draining lymph node (TVDLN) T cells of seven patients were separated into populations with reduced (CD62LLow) or high levels of CD62L (CD62LHigh). Effector T cells generated from CD62LLow cells maintained or enriched the autologous tumor-specific type 1 cytokine response compared to unseparated TVDLN T cells in four of four patients showing tumor-specific cytokine secretion. Interestingly, effector T cells generated from CD62LLow or CD62LHigh TVDLN were polarized towards a dominant type 1 or type 2 cytokine profile, respectively. For CD62LLow T cells the type 1 cytokine profile appeared determined prior to culture. Since a tumor-specific type 1 cytokine profile appears critical for mediating anti-tumor activity in vivo, this approach might be used to isolate T cells for adoptive immunotherapy.

Interleukin-2 Based Therapy for Kidney Cancer

In summary, IL-2 based therapy remains the basis for treatment of metastatic renal cell cancer. Un-answered questions remain in the development of regimens that exceed a mean response rate of 20%. Additionally, there may be differences among the histologic subtypes of renal cell cancer that predispose to response or lack there of to immunotherapy, and this is being further explored. As can be noted from the studies presented in this paper, there are numerous variations on the regimens for IL-2 based therapy. Current recommendations are to use the simplest and most feasible in a given institution. Certainly high dose IL-2 remains the standard regimen to which all others are measured.

Redirecting Effector T Cells Through Their IL-2 Receptors

Fusion proteins constructed of a tumor-specific Ab joined to IL-2 (Ab-IL-2) have been used in the past to deliver cytokine directly to the site of tumor cells in vivo. These molecules mimic the activity of IL-2 and assist in activating and expanding antitumor effector cells. To enhance the cytolytic activity of CTL specific for peptide epitopes of the Her-2/neu tumor Ag presented by HLA-A*0201 molecules, a fusion protein was constructed consisting of a single chain Ab specific for Her-2/neu, linked to IL-2 (neu-Ab-IL-2). When added to a mixture of tumor cells and Her-2/neu-specific CTL, the protein was found to augment lysis of tumor cells. In addition, the hybrid molecule also promoted lysis of Her-2/neu expressing tumors by non-tumor-specific cloned T cell lines, including Th1 CD4 cells. Analysis of the mechanism of cytotoxicity revealed that the fusion protein mediates the formation of stable conjugates between T cells expressing IL-2R and tumor cells expressing Her-2/neu, resulting in lysis through the Fas-Fas ligand pathway. Lysis induction was independent of specific engagement by the TCR. When tested for its ability to enhance tumor cell eradication by Her-2/neu-specific CD8+ T cells in an adoptive transfer model in SCID mice, neu-Ab-IL-2 facilitated the elimination of tumor cells in vivo. Surprisingly, the combination of non-tumor-specific CD8+ T cells and fusion protein also induced a significant delay of tumor growth. This represents a novel approach for redirecting non-tumor-specific T cells to eliminate tumors.

Identification of Her-2/Neu CTL epitopes using double transgenic mice expressing HLA-A2.1 and human CD.8

The Her-2/neu protooncogene is associated with malignant transformation and aggressive disease. Because of its overexpression in tumor cells and because it has been shown to be immunogenic, this protein represents an excellent target for T-cell immunotherapy. By identifying potential HLA-A2.1-binding peptides from the Her-2/neu sequence, peptides were selected as candidate T-cell epitopes. The immunogenicity of each peptide was evaluated by priming double transgenic mice expressing both the human (hu) CD8 and HLA-A2.1 molecules with synthetic peptides corresponding to these sequences. Because of the lack of interaction between murine CD8 and HLA-A2.1, expression of huCD8 on murine cells facilitates recognition of HLA molecules on human tumor cell lines. This led to the identification of two peptides that elicit an A2-restricted CTL response, one of which has not been previously identified. Both peptide-specific CTL populations were able to specifically lyse A2.1 and Her-2/neu expressing human tumor cells originating from a variety of tissues, demonstrating the utility of this murine model in identifying peptides presented by human cells. However, several Her-2/neu peptides previously reported to be immunogenic for human CTL were found not to be immunogenic in transgenic mice. The basis for these discrepancies is discussed.

Cellular immune response to human renal-cell carcinomas: definition of a common antigen recognized by HLA-A2-restricted cytotoxic T-lymphocyte (CTL) clones

Cytotoxic T lymphocyte (CTL) clones directed against autologous renal-cell carcinoma (RCC) cell lines were generated by mixed lymphocyte/tumor-cell culture (MLTC) using peripheral blood lymphocytes (PBL). A CD8+, CD4- CTL clone MZ1257-CTL 5/30 with high cytolytic activity for the autologous tumor cell line MZ1257-RCC was established. No lysis of the autologous EBV-transformed B lymphocytes (EBV-B) or K562 cells was observed. A panel of HLA-A2-matched allogeneic RCC lines was recognized by CTL 5/30. Further specificity analysis showed a cross-reactivity with HLA-A2-matched allogeneic tumor cells of various origins, especially melanoma. CTL 5/30 was also cross-reactive with several HLA-A2-positive allogeneic normal kidney cells in culture. The restriction element identified for CTL 5/30 was HLA-A2, as shown by blocking of cytotoxicity using an anti-HLA-A2 monoclonal antibody (MAb) and by resistance of an HLA-A2-negative melanoma variant SK29-MEL. 1.22 against lysis by CTL 5/30. In this report we demonstrate HLA-A2-restricted recognition of a T-cell-defined antigen on autologous renal-cancer cells. This antigen is also expressed and recognized in association with HLA-A2 on normal kidney cells in culture and other HLA-A2-positive tumor cells. It may therefore be a normal differentiation antigen to which tolerance is incomplete in the renal-cell cancer system investigated.

Increase in the ability of human cancer cells to induce cytotoxic T lymphocytes by ultraviolet irradiation

The roles of ultraviolet-B (UV) radiation in the immunogenicity of human cancer cells have not been fully studied. We have investigated the effects of UV radiation on metastatic melanoma and renal cell carcinoma cells with regard to MHC antigen expression and the ability to induce cytotoxic T lymphocyte (CTL) activity in peripheral blood mononuclear cells (PBMC) or tumor-infiltrating lymphocytes (TIL) against untreated autologous tumor cells. UV radiation respectively decreased or increased MHC class I expression of freshly isolated tumor cells or cultured tumor cells, and also decreased MHC class I expression of starved cultured tumor cells. It increased the ability of both freshly isolated and cultured tumor cells to induce CTL activity from PBMC against untreated autologous tumor cells. UV-irradiated subclones that were more susceptible to CTL lysis were more potent for CTL induction from TIL than either an untreated parental clone or a UV-irradiated subclone that was resistant to CTL lysis. In summary, UV radiation increased the ability of tumor cells to induce CTL activity without a corresponding effect on MHC antigen expression.

Human renal-cell carcinoma cells are able to activate natural killer cells

We previously reported that natural killer (NK) cells that had infiltrated renal-cell carcinoma (RCC) proliferated vigorously in culture with interleukin-2 (IL-2) and lysed autologous tumor cells. In this study, we investigate the susceptibility of RCC cells to NK-cell lysis and their ability to stimulate proliferation and increase phenotypic expression and function of NK cells. Cells from primary culture of RCC (p-RCC cells) were significantly more susceptible to the lysis mediated by human NK3.3 clones than were cells from primary culture of metastatic melanomas. Both RCC-cell clones and cells from primary culture of non-tumorous kidneys were also susceptible to lysis by NK3.3 clones and IL-2-activated peripheral blood lymphocytes (PBLs). Incubation of NK3.3 clones with p-RCC cells in the absence of IL-2 induced proliferation of NK3.3 clones, whereas incubation with cells from primary culture of metastatic melanomas, K562 cells, or any others tested did not. The p-RCC cells from earlier passages were more potent inducers of NK-cell proliferation than were those from older passages. Cell-free culture supernatants of p-RCC cells with or without NK3.3 clones failed to induce NK-cell proliferation. Incubation of CD16+ NK cells purified from PBLs with p-RCC cells induced higher proliferation of the NK cells only in the presence of IL-2, whereas incubation with cells from primary culture of metastatic melanomas did not. Incubation of NK3.3 clones with p-RCC cells resulted in an increase in CD16, CD25 (IL-2 receptor-alpha), and HLA-DR antigen expression and cytotoxicity in NK3.3 clones. In summary, these results suggest that RCC cells are able to activate NK cells, potentially through cell-to-cell interaction.