Regression of metastatic renal-cell carcinoma after nonmyeloablative allogeneic peripheral-blood stem-cell transplantation

Outcome improvement over time in reduced intensity conditioning hematopoietic transplantation: a 20-year experience

The current study includes all consecutive patients (N = 484) who received a reduced-intensity conditioning regimen (RIC) allogeneic hematopoietic stem cell transplantation in our center from 1999 to 2020. Conditioning regimens were based on fludarabine with melphalan or busulfan, with low-dose thiotepa and pharmacological GVHD prophylaxis consisted of cyclosporine A (CsA)-methotrexate (MTX)/mofetil (MMF) (n = 271), tacrolimus-sirolimus (n = 145), and post-transplantation cyclophosphamide (PTCy)-tacrolimus (n = 68). The median time of overall follow-up in survivors was 8 years (1-22 years) and was at least 3 years in all three GVHD prophylaxis groups. Thirty-three percent had a high or very high disease risk index, 56% ≥ 4 European bone marrow transplantation risk, and 65% ≥ 3 hematopoietic stem cell transplantation comorbidity index score-age score. Neutrophil and platelet engraftment was longer for PTCy-tacro (p 0.0001). Cumulative incidence of grade III-IV aGVHD was 17% at 200 days, and that of moderate-severe cGvHD was 36% at 8 years. GVHD prophylaxis was the only prognostic factor in the multivariable analyses for the development of aGVHD and moderate-severe cGVHD (p 0.0001). NRM and relapse incidences were 29% and 30% at 8 years, while OS and PFS rates were 43% and 39% at 8 years. At 3 years, OS was highest in the PTCy-tacro group (68%) than in the tacro-siro (61%) and CsA-MTX/MMF (49%) cohorts (p < 0.01). In the three groups, respectively, the 200-day incidence of grade III-IV aGvHD (6% vs. 12% vs. 23%) and 3-year moderate-severe cGVHD (8% vs. 40% vs. 38%) were lower in the PTCy cohort. These better outcomes were confirmed in multivariable analyses. Based on our recent results, the PTCy could be considered as a real GvHD prophylaxis in the RIC setting due to improve best 3-year GvHD and survival outcomes.

Harnessing allogeneic CD4+ T cells to reinvigorate host endogenous antitumor immunity

Immune checkpoint blockade (ICB) therapies developed over the past decade have been among the most promising approaches for the treatment of patients with advanced cancers. However, the overall objective response rate of ICB therapy for various cancers remains insufficient. Hence, novel strategies are required to improve the efficacy of immunotherapy for advanced cancers. The graft-versus-tumor (GVT) effect, which reflects strong antitumor immunity, is known to occur after allogeneic hematopoietic stem cell transplantation (HSCT). The GVT effect is mainly caused by transplanted donor lymphocytes that recognize and react to distinct alloantigens on tumor cells. In contrast, transplanted allogeneic cells can, in some instances, induce endogenous antitumor immunity in recipients if the graft has been rejected. Because of this ability, allogeneic cells have also been used to induce endogenous antitumor immunity without HSCT, and their beneficial immune response is referred to as the "allogenic effect." Here, we review the usefulness of allogeneic cells, particularly allogeneic CD4+ T cells, in cancer immunotherapy by highlighting their unique potential to induce host endogenous antitumor immunity.

Novel Immune Therapies for Renal Cell Carcinoma: Looking Beyond the Programmed Cell Death Protein 1 and Cytotoxic T-Lymphocyte-Associated Protein 4 Axes

Immunotherapy has revolutionized treatment for patients with advanced and metastatic renal cell carcinoma. Nevertheless, many patients do not benefit or eventually relapse, highlighting the need for novel immune targets to overcome primary and acquired resistance. This review discusses 2 strategies currently being investigated: disabling inhibitory stimuli that maintain immunosuppression ("brakes") and priming the immune system to target tumoral cells ("gas pedals"). We explore each class of novel immunotherapy, including the rationale behind it, supporting preclinical and clinical evidence, and limitations.

Immunobiology and Metabolic Pathways of Renal Cell Carcinoma

The treatment of advanced renal cell carcinoma (RCC) has changed dramatically with immune checkpoint inhibitors, yet most patients do not have durable responses. There is consequently a tremendous need for novel therapeutic development. RCC, and particularly the most common histology clear cell RCC, is an immunobiologically and metabolically distinct tumor. An improved understanding of RCC-specific biology will be necessary for the successful identification of new treatment targets for this disease. In this review, we discuss the current understanding of RCC immune pathways and metabolic dysregulation, with a focus on topics important for future clinical development.

The Transplantation Ecosystem: A New Concept to Improve Access and Outcomes for Older Allogeneic Hematopoietic Cell Transplantation Patients

Allogeneic hematopoietic cell transplantation (HCT) is increasingly offered to older adults with hematologic malignancies, even though nonrelapse mortality remains a major concern in older patients owing to more comorbidities and greater frailty compared with their younger counterparts. The importance of patient fitness, a well-matched donor, and disease control to the success of allogeneic HCT have been well documented; however, these factors fail to account for the impact of the complex transplantation ecosystem (TE) that older adult HCT candidates must navigate. We propose a definition of the TE modeled after the social determinants of health. Furthermore, we outline a research agenda aimed at increasing understanding of the roles of individual social determinants of transplantation health in the larger ecosystem and how they may benefit or harm older adult HCT candidates. Herein we define the TE and its individual tenets, the social determinants of transplantation health. We review the available literature while incorporating the expertise of the membership of the American Society for Transplantation and Cellular Therapy (ASTCT) Special Interest Group for Aging. The membership of the ASTCT Special Interest Group for Aging identify knowledge gaps and strategies to address them for each of the described social determinants of transplantation health. The ecosystem is an essential but underappreciated pillar for transplant access and success. We put forth this novel research agenda seeking to gain a better understanding of the complexity of HCT in older adults and develop strategies to improve access to HCT, survival, and quality of life.

Direct mapping of kidney function by DCE-MRI urography using a tetrazinanone organic radical contrast agent

Chronic kidney disease (CKD) and acute kidney injury (AKI) are ongoing global health burdens. Glomerular filtration rate (GFR) is the gold standard measure of kidney function, with clinical estimates providing a global assessment of kidney health without spatial information of kidney- or region-specific dysfunction. The addition of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) to the anatomical imaging already performed would yield a 'one-stop-shop' for renal assessment in cases of suspected AKI and CKD. Towards urography by DCE-MRI, we evaluated a class of nitrogen-centered organic radicals known as verdazyls, which are extremely stable even in highly reducing environments. A glucose-modified verdazyl, glucoverdazyl, provided contrast limited to kidney and bladder, affording functional kidney evaluation in mouse models of unilateral ureteral obstruction (UUO) and folic acid-induced nephropathy (FAN). Imaging outcomes correlated with histology and hematology assessing kidney dysfunction, and glucoverdazyl clearance rates were found to be a reliable surrogate measure of GFR.

Haploidentical hematopoietic stem cell transplantation as individual treatment option in pediatric patients with very high-risk sarcomas

Background

Prognosis of children with primary disseminated or metastatic relapsed sarcomas remains dismal despite intensification of conventional therapies including high-dose chemotherapy. Since haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is effective in the treatment of hematological malignancies by mediating a graft versus leukemia effect, we evaluated this approach in pediatric sarcomas as well.

Methods

Patients with bone Ewing sarcoma or soft tissue sarcoma who received haplo-HSCT as part of clinical trials using CD3+ or TCRα/β+ and CD19+ depletion respectively were evaluated regarding feasibility of treatment and survival.

Results

We identified 15 patients with primary disseminated disease and 14 with metastatic relapse who were transplanted from a haploidentical donor to improve prognosis. Three-year event-free survival (EFS) was 18,1% and predominantly determined by disease relapse. Survival depended on response to pre-transplant therapy (3y-EFS of patients in complete or very good partial response: 36,4%). However, no patient with metastatic relapse could be rescued.

Conclusion

Haplo-HSCT for consolidation after conventional therapy seems to be of interest for some, but not for the majority of patients with high-risk pediatric sarcomas. Evaluation of its future use as basis for subsequent humoral or cellular immunotherapies is necessary.

A Systematic Review on the Impact of Hypofractionated and Stereotactic Radiotherapy on Immune Cell Subpopulations in Cancer Patients

We investigated how hypofractionated radiotherapy (HFRT) and stereotactic body radiotherapy (SBRT) may impact immune cells in different type of tumors. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The PubMed, Embase and Cochrane databases were searched. Overall, 11 studies met the inclusion criteria and were eligible for the present analysis. Both HFRT and SBRT have different impact on lymphocyte subpopulations, confirming their immunomodulatory effect which may have a crucial role in future combined treatment with new emergent therapies such as immunotherapy. Further studies are needed to shed more light on this emerging topic to ultimately improve patient care, treatment and clinical benefits for cancer patients.

Current State of Cell Therapies for Genitourinary Malignancies

ABSTRACT

Genitourinary (GU) cancers have greatly benefited from immunotherapy treatments, such as immune checkpoint inhibitors. However, the durable clinical response rate for these agents remains relatively low, calling for more innovative immunotherapy approaches. Adoptive cell therapy has shown a significant advancement in the treatment of cancer in recent years and represents a great potential for the treatment of GU cancers. This review summarizes the current advancements in cellular therapy strategies for the treatment of renal cell carcinoma, bladder cancer, and prostate and penile cancers. Further, current and past clinical trials of adoptive cell therapy in GU tumors are reviewed. Finally, a perspective on the future of cell therapy in GU tumors is discussed.

Graft-Versus-Solid-Tumor Effect: From Hematopoietic Stem Cell Transplantation to Adoptive Cell Therapies

After allogeneic hematopoietic stem cell transplantation (HSCT), donor lymphocytes may contribute to the regression of hematological malignancies and select solid tumors, a phenomenon referred to as the graft-versus-tumor effect (GVT). However, this immunologic reaction is frequently limited by either poor specificity resulting in graft-versus-host disease or the frequency of tumor-specific T cells being too low to induce a complete and sustained anti-tumor response. Over the past 2 decades, it has become clear that the driver of GVT following allogeneic HSCT is T-cell-mediated recognition of antigens presented on tumor cells. With that regard, even though the excitement for using HSCT in solid tumors has declined, clinical trials of HSCT in solid tumors provided proof of concept and valuable insights leading to the discovery of tumor antigens and the development of targeted adoptive cell therapies for cancer. In this article, we review the results of clinical trials of allogeneic HSCT in solid tumors. We focus on lessons learned from correlative studies of these trials that hold the potential for the creation of tumor-specific immunotherapies with greater efficacy and safety for the treatment of malignancies.

Interleukin-33 is a Novel Immunosuppressor that Protects Cancer Cells from TIL Killing by a Macrophage-Mediated Shedding Mechanism

Recognition of specific antigens expressed in cancer cells is the initial process of cytolytic T cell-mediated cancer killing. However, this process can be affected by other non-cancerous cellular components in the tumor microenvironment. Here, it is shown that interleukin-33 (IL-33)-activated macrophages protect melanoma cells from tumor-infiltrating lymphocyte-mediated killing. Mechanistically, IL-33 markedly upregulates metalloprotease 9 (MMP-9) expression in macrophages, which acts as a sheddase to trim NKG2D, an activating receptor expressed on the surface of natural killer (NK) cells, CD8+ T cells, subsets of CD4+ T cells, iNKT cells, and γδ T cells. Further, MMP-9 also cleaves the MHC class I molecule, cell surface antigen-presenting complex molecules, expressed in melanoma cells. Consequently, IL-33-induced macrophage MMP-9 robustly mitigates the tumor killing-effect by T cells. Genetic and pharmacological loss-of-function of MMP-9 sheddase restore T cell-mediated cancer killing. Together, these data provide compelling in vitro and in vivo evidence showing novel mechanisms underlying the IL-33-macrophage-MMP-9 axis-mediated immune tolerance against cancer cells. Targeting each of these signaling components, including IL-33 and MMP-9 provides a new therapeutic paradigm for improving anticancer efficacy by immune therapy.

Improvement of abnormal cervical cytology possibly due to a graft-versus-tumor effect: A case report and literature review

The cervical cytology of our patient transformed from squamous cell carcinoma to negative for intraepithelial lesion or malignancy, possibly due to the graft-versus-tumor effect following allogeneic stem cell transplantation.

Long-term Response After Stopping Immunotherapy in a Patient With Metastatic Renal Cancer

BACKGROUND/AIM

Kidney cancers account for about 2% of human malignancies. In recent decades, the incidence of this cancer type has gradually increased, mainly due to advances in imaging. The metastatic potential of these cancers is significant: a quarter of patients will immediately present with metastases and more than one third of patients treated with nephrectomy for a localized disease will develop metastases during their course. In total, more than half of patients will suffer from the consequences of metastasis. The median survival at this stage is only thirteen months, so the therapeutic challenge is immense.

CASE REPORT

The present case report describes a case of left renal clear cell carcinoma with brain, lung, right adrenal, bone and lymph node metastases in a 55-year-old male. The patient received only one line of anticancer treatment with sunitinib, which could not be continued due to haemorrhagic manifestations in brain metastases. The treatment was changed with immunotherapy which showed its effect even if it was stopped due to the patient wishes in the context of the COVID-19 epidemic.

CONCLUSION

Immunotherapy opens the doors to a new era in treatment of metastatic renal cancer and shows efficiency even after it has been stopped.

Bone marrow toxicity and immune reconstitution in melanoma and non-melanoma solid cancer patients after non-myeloablative conditioning with chemotherapy and checkpoint inhibition

BACKGROUND AIMS

Lymphodepletion with non-myeloablative (NMA) chemotherapy is currently a prerequisite for adoptive cell therapy (ACT). ACT based on tumor-infiltrating lymphocytes has long been used in malignant melanoma (MM), but with the advance of ACT into new cancer diagnoses, the patient predisposition will change. The authors here evaluate the bone marrow (BM) toxicity of NMA in combination with checkpoint inhibition and a priori risk factors in a wide range of cancer diagnoses.

METHODS

Thirty-one non-MM and MM patients were included from two different clinical trials with ACT. The treatment history was extracted from the medical records, together with the hematology data. Immune monitoring with flow cytometry was performed before and at several time points after therapy.

RESULTS

NMA induced reversible myelosuppression in all patients. No significant differences in BM toxicity between MM and non-MM patients were found. The overall hematology counts were reconstituted within 3-6 months but with great individual heterogeneity, including eight patients who developed a second phase of neutropenia after hospital discharge. A performance status >0 was found, and shorter overall survival and sex were statistically associated with longer duration of anemia. By contrast, high expression of co-stimulatory markers CD28+ and CD27+ on T cells at baseline was significantly correlated with shorter duration of neutropenia (P = 0.010 and P = 0.009, respectively), anemia (P = 0.001 and P = 0.001, respectively) and thrombocytopenia (P = 0.017 and P = 0.030, respectively). In addition, following NMA, the authors saw a significant differentiation of T-cell phenotype associated with old age.

CONCLUSIONS

ACT with NMA and checkpoint inhibition is tolerable in patients with multiple cancer diagnoses and therapy backgrounds but comes with substantial transient BM toxicity that is comparable in both non-MM and MM patients. Baseline T-cell CD28/CD27 expression level is predictive of duration of BM toxicity. Furthermore, NMA conditioning induces changes in the immune system that may affect a patient's immunocompetence for many months following therapy.

Arid1a regulates cell cycle exit of transit-amplifying cells by inhibiting the Aurka-Cdk1 axis in mouse incisor

Stem cells self-renew or give rise to transit-amplifying cells (TACs) that differentiate into specific functional cell types. The fate determination of stem cells to TACs and their transition to fully differentiated progeny is precisely regulated to maintain tissue homeostasis. Arid1a, a core component of the switch/sucrose nonfermentable complex, performs epigenetic regulation of stage- and tissue-specific genes that is indispensable for stem cell homeostasis and differentiation. However, the functional mechanism of Arid1a in the fate commitment of mesenchymal stem cells (MSCs) and their progeny is not clear. Using the continuously growing adult mouse incisor model, we show that Arid1a maintains tissue homeostasis through limiting proliferation, promoting cell cycle exit and differentiation of TACs by inhibiting the Aurka-Cdk1 axis. Loss of Arid1a overactivates the Aurka-Cdk1 axis, leading to expansion of the mitotic TAC population but compromising their differentiation ability. Furthermore, the defective homeostasis after loss of Arid1a ultimately leads to reduction of the MSC population. These findings reveal the functional significance of Arid1a in regulating the fate of TACs and their interaction with MSCs to maintain tissue homeostasis.

Beyond conventional immune-checkpoint inhibition - novel immunotherapies for renal cell carcinoma

The management of advanced-stage renal cell carcinoma (RCC) has been transformed by the development of immune-checkpoint inhibitors (ICIs). Nonetheless, most patients do not derive durable clinical benefit from these agents. Importantly, unlike other immunotherapy-responsive solid tumours, most RCCs have only a moderate mutational burden, and paradoxically, high levels of tumour CD8+ T cell infiltration are associated with a worse prognosis in patients with this disease. Building on the successes of antibodies targeting the PD-1 and CTLA4 immune checkpoints, multiple innovative immunotherapies are now in clinical development for the treatment of patients with RCC, including ICIs with novel targets, co-stimulatory pathway agonists, modified cytokines, metabolic pathway modulators, cell therapies and therapeutic vaccines. However, the successful development of such novel immune-based treatments and of immunotherapy-based combinations will require a disease-specific framework that incorporates a deep understanding of RCC immunobiology. In this Review, using the structure provided by the well-described cancer-immunity cycle, we outline the key steps required for a successful antitumour immune response in the context of RCC, and describe the development of promising new immunotherapies within the context of this framework. With this approach, we summarize and analyse the most encouraging targets of novel immune-based therapies within the RCC microenvironment, and review the landscape of emerging antigen-directed therapies for this disease.

Immunologic Clearance of a BK Virus-associated Metastatic Renal Allograft Carcinoma

BACKGROUND

Metastatic carcinoma of a renal allograft is a rare but life threatening event with a difficult clinical management. Recent reports suggested a potential role of BK polyomavirus (BKPyV) in the development of urologic tract malignancies in kidney transplant recipients.

METHODS

We investigated a kidney-pancreas female recipient with an history of BKPyV nephritis who developed a rapidly progressive and widely metastatic donor-derived renal carcinoma 9 years after transplantation.

RESULTS

Histology and fluorescence in situ hybridization analysis revealed a donor-derived (XY tumor cells) collecting (Bellini) duct carcinoma. The presence of BKPyV oncogenic large tumor antigen was identified in large amount within the kidney tumor and the bowel metastases. Whole genome sequencing of the tumor confirmed multiple genome BKPyV integrations. The transplanted kidney was removed, immunosuppression was withdrawn, and recombinant interleukin-2 (IL-2) was administered for 3 months, inducing a complete tumor clearance, with no evidence of disease at 6-year follow-up. The immunological profiling during IL-2 therapy revealed the presence of donor-specific T cells and expanded cytokine-producing bright natural killer cells but no donor-specific antibodies. Finally, we found persistently elevated anti-BK virus IgG titers and a specific anti-BKPyV T cell response.

CONCLUSIONS

This investigation showed evidence for the potential oncogenic role of BKPyV in collecting duct carcinoma in renal allografts and demonstrated that immunosuppression withdrawal and IL-2 therapy can lead to an efficient antitumor cellular mediated rejection possibly via 3 distinct mechanisms including (1) host-versus-graft, (2) host-versus-tumor, and (3) anti-BKPyV responses.

T cells expanded from renal cell carcinoma display tumor-specific CD137 expression but lack significant IFN-γ, TNF-α or IL-2 production

Metastatic renal cell carcinoma (RCC) has a poor prognosis. Recent advances have shown beneficial responses to immune checkpoint inhibitors, such as anti-PD-1/PD-L1 antibodies. As only a subset of RCC patients respond, alternative strategies should be explored. Patients refractory to anti-PD-1 therapy may benefit from autologous tumor-infiltrating lymphocyte (TIL) therapy. Even though efficient TIL expansion was reported from RCC lesions, it is not well established how many RCC TIL products are tumor-reactive, how well they produce pro-inflammatory cytokines in response to autologous tumors, and whether their response correlates with the presence of specific immune cells in the tumor lesions. We here compared the immune infiltrate composition of RCC lesions with that of autologous kidney tissue of 18 RCC patients. Tcell infiltrates were increased in the tumor lesions, and CD8⁺ Tcell infiltrates were primarily of effector memory phenotype. Nine out of 16 (56%) tested TIL products we generated were tumor-reactive, as defined by CD137 upregulation after exposure to autologous tumor digest. Tumor reactivity was found in particular in TIL products originating from tumors with ahigh percentage of infiltrated Tcells compared to autologous kidney, and increased CD25 expression on CD8⁺ Tcells. Importantly, although TIL products had the capacity to produce the key effector cytokines IFN-γ, TNF-α or IL-2, they failed to produce significant amounts in response to autologous tumor digests. In conclusion, TIL products from RCC lesions contain tumor-reactive Tcells. Their restricted tumor-specific cytokine production requires further investigation of immunosuppressive factors in RCC and subsequent optimization of RCC-derived TIL culture conditions.

Immune profiling of the bone marrow microenvironment in patients with high-risk localized prostate cancer

Bone marrow (BM) is a primary metastatic site in prostate cancer (PC) and bone invasion is considered incurable. T cell-mediated immune surveillance is essential in controlling both tumorigenesis and initiation of metastases. Beside tropism, dissemination of PC cells to the BM may be facilitated by defects in BM immune homeostasis predisposing this niche to colonization.

To evaluate the BM immune microenvironment in locally advanced, non-metastatic PC, we performed flow cytometry analysis of myeloid and lymphoid subsets in BM aspirates and peripheral blood collected during prostatectomy. Healthy BM aspirates served to establish a reference range for comparison.

We found alterations in BM immune composition of PC patients, including an increased CD4/CD8 ratio, enrichment of CD4⁺ T cells, increased CD56⁺CD3⁺ NKT and CD56⁺CD3^- NK yields compared to healthy controls. The lymphoid phenotype remained comparable regarding T cell activation and chemokine receptor-based polarization patterns. Additionally, we found increased B7H3 expression in the myeloid monocyte/macrophage subset and decreased DC infiltration in BM of PC patients.

These findings suggest that alterations in the immune milieu may limit immune surveillance that compromise the ability of the BM microenvironment to prevent tumor dissemination, and predispose development of bone metastases in a subset of patients with localized PC.

Graft-versus-cancereffect and innovative approaches in thetreatment of refractory solid tumors

Background/aim

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been used for the treatment of various refractory solid tumors during the last two decades. After the demonstration of graft-versus-leukemia (GvL) effect in a leukemic murine model following allo-HSCT from other strains of mice, graft-versus-tumor (GvT) effect in a solid tumor after allo-HSCT has also been reported in a murine model in 1984. Several trials have reported the presence of a GvT effect in patients with various refractory solid tumors, including renal, ovarian and colon cancers, as well as soft tissue sarcomas [1]. The growing data on haploidentical transplants also indicate GvT effect in some pediatric refractory solid tumors. Novel immunotherapy-based treatment modalities aim at inducing an allo-reactivity against the metastatic solid tumor via a GvT effect. Recipient derived immune effector cells (RDICs) in the antitumor reactivity following allo-HSCT have also been considered as an emerging therapy for advanced refractory solid tumors.

Conclusion

This review summarizes the background, rationale, and clinical results of immune-based strategies using GvT effect for the treatment of various metastatic and refractory solid tumors, as well as innovative approaches such as haploidentical HSCT, CAR-T cell therapies and tumor infiltrating lymphocytes (TIL).

Wilms' Tumor 1 (WT1): The Vaccine for Cancer

Vaccines have been used to fight and protect against infectious diseases for centuries. With the emergence of immunotherapy in cancer treatment, researchers began investigating vaccines that could be used against cancer, especially against tumors that are resistant to conservative chemotherapy, surgery, and radiotherapy. The Wilms' tumor 1 (WT1) protein is immunogenic, has been detected in almost all types of malignancies, and has played a significant role in prognosis and disease monitoring. In this article, we review recent developments in the treatment of various types of cancers with the WT1 cancer vaccine; we also discuss theoretic considerations of various therapeutic approaches, which were based on preclinical and clinical data.

Pediatric and young adult renal cell carcinoma

Renal cell carcinoma (RCC) is rare in children but is the most common renal tumor in adults. Pediatric RCC has different clinical characteristics, histopathology, and treatment compared with adult disease. Databases were reviewed from inception to February 2020, identifying 32 publications pertaining to 350 patients under 27 years. Surgery is the cornerstone for cure in localized RCC. Lymph node dissection remains controversial. Conventional radiotherapy has no curative role in RCC; similarly, conventional chemotherapy has not proven to be effective in large cohorts. Pediatric metastatic RCC has a poor outlook. There are no published prospective studies demonstrating which adjuvant therapy could improve outcome. Sunitinib, a tyrosine kinase inhibitor, is recommended in this group despite limited evidence. This review provides an overview for pediatric RCC, including the evolving role of precision medicine.

Checkpoint inhibitor immunotherapy in kidney cancer

Kidney cancer has unique features that make this malignancy attractive for therapeutic approaches that target components of the immune system. Immune checkpoint inhibition is a well-established part of kidney cancer treatment, and rapid advances continue to be made in this field. Initial preclinical studies that elucidated the biology of the programmed cell death 1 (PD-1), programmed cell death 1 ligand 1 (PD-L1) and cytotoxic T lymphocyte antigen 4 (CTLA-4) immune checkpoints led to a series of clinical trials that resulted in regulatory approval of nivolumab and the combination of ipilimumab plus nivolumab for the treatment of advanced renal cell carcinoma. Subsequent data led to approvals of combination strategies of immune checkpoint inhibition plus agents that target the vascular endothelial growth factor receptor and a shift in the current standard of renal cell carcinoma care. However, controversies remain regarding the optimal therapy selection and treatment strategy for individual patients, which might be eventually overcome by current intensive efforts in biomarker research. That work includes evaluation of tumour cell PD-L1 expression, gene expression signatures, CD8⁺ T cell density and others. In the future, further advances in the understanding of immune checkpoint biology might reveal new therapeutic targets beyond PD-1, PD-L1 and CTLA-4, as well as new combination approaches.

Potentials of "stem cell-therapy" in pancreatic cancer: An update

In recent times, cell-therapies like T-activated cells, dendritic cells and natural killer cells have shown increasing promise in treating cancers as evidenced by both animal and human studies in the literature. In addition, stem cells are also being considered as potent anti-cancer agents since they act through multi-pronged approaches (chemokines, cytokines, paracrine action). In this review, we have attempted to discuss the inferences of studies that have used different sub-types of stem cells namely mesenchymal stem cells (MSCs), hematopoietic stem cells (HSCs) and neural stem cells (NSCs) in in-vitro/in-vivo mice and/or human studies as a treatment modality for pancreatic cancer. Pancreatic cancers are diagnosed in late/metastatic stages hence limiting its progress to partial/disease-free status. Recent literature supports evidences of stem cell therapy in pancreatic cancer with promising results; yet their impact remains inconclusive due to limited studies in human subjects. With reference to the treatment options for pancreatic cancer, the most studied sub-type of stem cells was HSCs as evident from the available clinical trials. The suggested mechanism of the HSC-transplantation is presumably via the graft-versus-tumor effect that elicits an anti-tumor immune response activated by the T-cell repertoires. On the other hand, the property of MSCs like tropism, migration to tumor site and activation of host immune cells by its secretome, appear to be able to regulate pancreatic tumor microenvironment. Further, drug delivery potential could be mediated via engineered MSCs to enhance the bioavailability of drug/prodrug at tumor site. Conclusively, stem cells have shown great potentials as next-generation therapeutic options.

Stem Cell Applications for Treatment of Cancer and Autoimmune Diseases: Its Promises, Obstacles, and Future Perspectives

Since the original discovery of stem cells, a new era of promising results has emerged in the clinical application of stem cells for the treatment of several important diseases, including cancer and autoimmune diseases. The plentiful research on stem cells during the past decades has provided significant information on the developmental, morphological, and physiological processes that govern tissue and organ formation, maintenance, and regeneration; cellular differentiation; molecular processes; and tissue homeostasis. In this review, we present the history of the use of stem cells in different clinical applications. Furthermore, we discuss the various therapeutic options for stem cells in cancer, followed by the role of stem cells in the treatment of autoimmune disorders. Additionally, we highlight the risks of and obstacles to the application of stem cells in clinical practice. Ultimately, we show future perspectives in stem cell use, with an aim to improve the clinical usefulness of stem cells.

Transfusion support for matched sibling allogeneic hematopoietic stem cell transplantation (1993-2010): factors that predict intensity and time to transfusion independence

BACKGROUND

Patients undergoing allogeneic hematopoietic stem cell transplant require variable, often extensive transfusion support. Identification of factors that predict urgent, intensive, or special needs should improve management of these patients.

STUDY DESIGN AND METHODS

This is a retrospective study of red blood cell (RBC) and platelet transfusion support provided for sequential matched sibling donor allogeneic transplants conducted at the Clinical Center, National Institutes of Health, from 1993 through 2010. Factors potentially important for predicting quantity of RBC and platelet transfusions, and time to transfusion independence through Day 200 following hematopoietic stem cell transplantation were evaluated.

RESULTS

Subjects (n = 800) received 10,591 RBC and 10,199 platelet transfusions. Multivariable analysis demonstrated that the need for RBC pretransplant, CD34+ dose, transplant year, diagnostic category, and ABO match were significantly independently associated with quantity of RBC transfusions during Days 0 through 30. Only pretransplant need for RBCs, CD34+ dose, and transplant year had significance during Days 0 through 100. Similar analyses for quantity of platelet transfusions demonstrated that for both Days 0 through 30 and 0 through 100 significant factors were need for platelet support before transplant, CD34+ dose, transplant year, and transplant regimen. Of note, long term, during Days 101 through 200, only CD34+ dose remained significant for quantity of RBC and platelet transfusions. Analysis of time to transfusion independence demonstrated that patients with ABO major mismatches required longer to achieve freedom from RBC transfusion support compared to identical matches or those with minor mismatches.

CONCLUSION

Patient-specific factors including CD34+ dose and ABO match of the graft should be given particular consideration by transfusion services when planning support of patients receiving allogeneic hematopoietic stem cell transplant.

Preliminary Study of the Effect of Stereotactic Body Radiotherapy (SBRT) on the Immune System in Lung Cancer Patients Unfit for Surgery: Immunophenotyping Analysis

An immunophenotyping analysis was performed in peripheral blood samples from seven patients with lung cancer unfit for surgery treated with stereotactic body radiotherapy (SBRT). The objective was to characterize the effect of SBRT on the host immune system. Four patients received 60 Gy (7.5 Gy × 8) and three 50 Gy (12.5 Gy × 4). Analyses were performed before SBRT, 72 h after SBRT, and at one, three, and six months after the end of SBRT. Of note, there was a specific increase of the immunoactive component of the immune system, with elevation of CD56^+highCD16+ natural killer (NK) cells (0.95% at baseline to 1.38% at six months), and a decrease of the immunosuppressive component of the immune system, with decreases of CD4+CD25+Foxp3+CDA5RA- regulatory T cells (4.97% at baseline to 4.46% at six months), granulocytic myeloid-derived suppressor cells (G-MDSCs) (from 66.1% at baseline to 62.6% at six months) and monocytic (Mo-MDSCs) (8.2% at baseline to 6.2% at six months). These changes were already apparent at 72 h and persisted over six months. SBRT showed an effect on systemic immune cell populations, which is a relevant finding for supporting future combinations of SBRT with immunotherapy for treating lung cancer patients.

Proceedings From the Fourth Haploidentical Stem Cell Transplantation Symposium (HAPLO2016), San Diego, California, December 1, 2016

The resurgence of haploidentical stem cell transplantation (HaploSCT) over the last decade is one of the most important advances in the field of hematopoietic stem cell transplantation (HSCT). The modified platforms of T cell depletion either ex vivo (CD34+ cell selection, "megadoses" of purified CD34+ cells, or selective depletion of T cells) or newer platforms of in vivo depletion of T cells, with either post-transplantation high-dose cyclophosphamide or intensified immune suppression, have contributed to better outcomes, with survival similar to that in HLA-matched donor transplantation. Further efforts are underway to control viral reactivation using modified T cells, improve immunologic reconstitution, and decrease the relapse rate post-transplantation using donor-derived cellular therapy products, such as genetically modified donor lymphocytes and natural killer cells. Improvements in treatment-related mortality have allowed the extension of haploidentical donor transplants to patients with hemoglobinopathies, such as thalassemia and sickle cell disease, and the possible development of platforms for immunotherapy in solid tumors. Moreover, combining HSCT from a related donor with solid organ transplantation could allow early tapering of immunosuppression in recipients of solid organ transplants and hopefully prevent organ rejection in this setting. This symposium summarizes some of the most important recent advances in HaploSCT and provides a glimpse in the future of fast growing field.

Long-Term Survival in Patients with Metastatic Renal Cell Carcinoma Treated with Continuous Intravenous Infusion of Recombinant Interleukin-2: The Experience of a Single Institution

Aim and background

Metastatic renal cell carcinoma is one of the few tumors for which a clear benefit of immunotherapy has been demonstrated. The aim of this study was to evaluate the long-term survival of patients with metastatic renal cell carcinoma, along with response rate and other prognostic and predictive factors.

Patients and methods

Between July 1989 and May 1995, 56 patients with metastatic renal cell carcinoma were treated in a single institution with high-dose recombinant interleukin-2 in continuous infusion. Survival was measured by the Kaplan and Meier method. Prognostic factors were assessed by univariate and multivariate analyses of survival (Cox proportional hazard ratio model).

Results

Of 56 patients, 15 had objective responses (26.8%), 16 stable disease (28.6%), 18 disease progressions (32.1%), and 7 (12.5%) were not valuable for response. Median overall survival was 20 months, and probability of 2- and 5-year survival was 41% and 21%, respectively. At multivariate analysis, the increased risk of death for: performance status ≥2 vs 0 (HR = 6.20), stable disease (HR = 1.87), disease progression (HR = 10.61) vs partial or complete remission, and for hypotension and oliguria toxicity, G3 + G4 vs G1 + G2 (HR = 2.19).

Conclusions

Our study confirms the activity of IL-2 based immunotherapy in renal cell carcinoma. Moreover, ECOG performance status, clinical response, hypotension and oliguria toxicity resulted as independent survival prognostic factors.

Recipient and donor cells in the graft-versus-solid tumor effect: It takes two to tango

Allogeneic hematopoietic stem cell transplantation (alloHSCT) produces -similar to the long-established graft-versus-leukemia effect- graft-versus-solid-tumor effects. Clinical trials reported response rates of up to 53%, occurring mostly but not invariably in association with full donor chimerism and/or graft-versus-host disease. Although donor-derived T cells are considered the principal effectors of anti-tumor immunity after alloHSCT or donor leukocyte infusion (DLI), growing evidence indicate that recipient-derived immune cells may also contribute. Whereas the role of recipient-derived antigen-presenting cells in eliciting graft-versus-host reactions and priming donor T cells following DLI is well known, resulting inflammatory responses may also break tolerance of recipient effector cells towards the tumor. Additionally, mouse studies indicated that post-transplant recipient leukocyte infusion produces anti-leukemia and anti-solid-tumor effects that were exclusively mediated by recipient-type effector cells, without graft-versus-host disease. Here, we review current preclinical and clinical evidence on graft-versus-solid-tumor effects and growing evidence on the effector role of recipient-derived immune cells in the anti-tumor effect of alloHSCT.

Renal Cancer Treatment: A Review of the Literature

Renal carcinoma represents about 3% of all adult tumors, with an estimate of 31,900 new cases diagnosed in 2003 in the United States. In the early phase of its natural history, renal cancer is potentially curable by surgery, but if the disease presents any signs of metastasis, the chances of survival are remote, even though anecdotal cases characterized by long survival have been reported. In fact, the treatment of metastatic renal cancer remains unsatisfactory. Systemic treatment with single agents and with polychemotherapy, with or without cytokine-based immunotherapy, has not been successful, obtaining very low response rates without a significant benefit in overall survival. This review highlights the most interesting issues regarding conventional therapeutic strategies, in localized and in advanced disease. New approaches such as monoclonal antibodies, vaccines, gene therapy, angiogenesis inhibitors and allogeneic cell transplantation and their possible clinical applications are also discussed.

Graft-Versus-Tumor Effect in Adenocarcinoma of the Lung

Donor T cells after allogeneic hematopoietic cell transplantation can give rise to the graft-versus-tumor (GVT) effect in hematologic malignancies. GVT effect has been reported previously to cause regression of some solid tumors. However, none have reported a documented case of GVT effect leading to complete resolution of adenocarcinoma of the lung. Here, we present the case of complete regression of a pathologically proven adenocarcinoma of the lung in a patient undergoing myeloablative-matched unrelated donor peripheral blood stem cell transplantation for the treatment of acute myelogenous leukemia.

Human HLA-A*02:01/CHM1+ allo-restricted T cell receptor transgenic CD8+ T cells specifically inhibit Ewing sarcoma growth in vitro and in vivo

The endochondral bone protein Chondromodulin-I (CHM1) provides oncogene addiction in Ewing sarcoma (ES). We pre-clinically tested the targetability of CHM1 by TCR transgenic, allo-restricted, peptide specific T cells to treat ES. We previously generated allo-restricted wildtype CD8+ T cells directed against the ES specific antigen CHM1319 causing specific responses against ES. However, utilization of these cells in current therapy protocols is hampered due to high complexity in production, relatively low cell numbers, and rapid T cell exhaustion.In order to provide off-the-shelf products in the future, we successfully generated HLA-A*02:01-restricted T cell receptor (TCR) transgenic T cells directed against CHM1319 by retroviral transduction.After short-term expansion a 100% purified CHM1319-TCR-transgenic T cell population expressed a CD62L+/CD45RO and CD62L+/CD45RA+ phenotype. These cells displayed specific in vitro IFNg and granzyme B release in co-culture with HLA-A*02:01+ ES cell lines expressing CHM1. When co-injected with ES cells in Rag2-/-É£c-/- mice, CHM1-specific TCR-transgenic T cells significantly inhibited the formation of lung and liver metastases in contrast to control mice. Lungs and livers of representative mice displayed CD8+ T cell infiltration in the presence (control group treated with unspecific T cells) and in the absence (study group) of metastatic disease, respectively. Furthermore, mice receiving unspecific T cells showed signs of graft-versus-host-disease in contrast to all mice, receiving CHM1319-TCR-transgenic T cells.CHM1319 specific TCR-transgenic T cells were successfully generated causing anti-ES responses in vitro and in vivo. In the future, CHM1319-TCR-transgenic T cells may control minimal residual disease rendering donor lymphocyte infusions more efficacious and less toxic.

Cyclophosphamide-induced tolerance in kidney transplantation avoids long-term immunosuppressive therapy

There has recently been remarkable progress in immunosuppressive agents, such as tacrolimus and cyclosporine. Therefore, the rate of organ establishment has improved in transplantation. However, immunosuppressive agents generally suppress the function of T cells. Thus, opportunistic infections, such as cytomegalovirus infection, are still a major problem in kidney transplantation. Induction of specific tolerance to avoid immunosuppressive drug therapy after kidney transplantation is considered as the ultimate goal of transplantation. Various factors induce tolerance that involves establishment of hematopoietic chimerism and various cell subsets. In particular, we have carried out various studies regarding the cyclophosphamide-induced tolerance system. Tolerance is induced after establishment of hematopoietic chimerism after donor bone marrow transplantation. At the clinical stage, kidney transplantation before administration of cyclophosphamide after transfusion of bone marrow to create hematopoietic chimera is considered to be one of the most successful protocols. Furthermore, recent studies have shown the involvement of multiple populations of immune cells in preserving immunological tolerance and promoting long-term renal grafts. The present review focuses on how cyclophosphamide and other immune factors induce tolerance in kidney transplantation.

Treating breast cancer with cell-based approaches: an overview

INTRODUCTION

Breast cancer is the most common malignancy in women. Despite there being considerable progress in the treatment of this disease, metastatic dissemination is still considered an incurable condition at the present time, causing 500,000 deaths worldwide every year. Although most of the research efforts have been focused on pharmacological approaches, over the last three decades, the use of bone marrow and peripheral blood-derived cell therapy approaches have been attempted and developed. Areas covered: This review will briefly address cell therapy for breast cancer, including autologous stem cell transplantations for overcoming the myelosuppressive effects of high-dose chemotherapy, allogeneic stem cell transplants and adoptive immunotherapy using bone-marrow derived T-cells. Expert opinion: The treatment of breast cancer using bone marrow or peripheral-blood derived cells has evolved from a supportive care approach to allow dose escalation of conventional chemotherapy to a therapeutic strategy aimed at eliciting immune cell mediated anticancer immunity. This latter principle has led to the development of adoptive immunotherapies, either with 'natural' or genetically engineered effectors, which are being intensively investigated for their great potential against several solid tumors, including breast cancer.

Hematopoietic progenitor cell mobilization is more robust in healthy African American compared to Caucasian donors and is not affected by the presence of sickle cell trait

BACKGROUND

Granulocyte-colony-stimulating factor (G-CSF)-stimulated hematopoietic progenitor cells (HPCs) collected by apheresis have become the predominant graft source for HPC transplantation in adults. Among healthy allogeneic donors, demographic characteristics (age, sex, body mass index [BMI]) and baseline hematologic counts affect HPC mobilization, leading to variability in CD34+ apheresis yields. Racial differences in HPC mobilization are less well characterized.

STUDY DESIGN AND METHODS

We retrospectively analyzed data from 1096 consecutive G-CSF-stimulated leukapheresis procedures in healthy allogeneic African American (AA) or Caucasian donors.

RESULTS

In a multivariate analysis, after adjusting for age, sex, BMI, baseline platelet and mononuclear cell counts, and daily G-CSF dose, peak CD34+ cell mobilization was significantly higher among AAs (n = 215) than Caucasians (n = 881; 123 ± 87 × 10(6) cells/L vs. 75 ± 47 × 10(6) cells/L; p < 0.0001). A ceiling effect was observed with increasing G-CSF dose (10 µg/kg/day vs. 16 µg/kg/day) in AAs (123 ± 88 × 10(6) cells/L vs. 123 ± 87 × 10(6) cells/L) but not in Caucasians (74 ± 46 × 10(6) cells/L vs. 93 ± 53 × 10(6) cells/L; p < 0.001). In AA donors, the presence of sickle cell trait (SCT; n = 41) did not affect CD34+ mobilization (peak CD34+ 123 ± 91 × 10(6) cells/L vs. 107 ± 72 × 10(6) cells/L, HbAS vs. HbAA; p = 0.34). Adverse events were minimal and similar across race.

CONCLUSIONS

AAs demonstrated significantly better CD34 mobilization responses to G-CSF than Caucasians. This was independent of other demographic and hematologic variables. Studying race-associated pharmacogenomics in relation to G-CSF may improve dosing strategies. Adverse event profile and CD34 mobilization were similar in AA donors with and without SCT. Our findings suggest that it would be safe to include healthy AA donors with SCT in unrelated donor registries.

A Preliminary Report: Radical Surgery and Stem Cell Transplantation for the Treatment of Patients With Pancreatic Cancer

We examined the immunologic effects of allogeneic hematopoietic stem cell transplantation (HSCT) in the treatment of pancreatic ductal adenocarcinoma, a deadly disease with a median survival of 24 months for resected tumors and a 5-year survival rate of 6%. After adjuvant chemotherapy, 2 patients with resected pancreatic ductal adenocarcinoma underwent HSCT with HLA-identical sibling donors. Comparable patients who underwent radical surgery, but did not have a donor, served as controls (n=6). Both patients developed humoral and cellular (ie, HLA-A*01:01-restricted) immune responses directed against 2 novel tumor-associated antigens (TAAs), INO80E and UCLH3 after HSCT. Both TAAs were highly expressed in the original tumor tissue suggesting that HSCT promoted a clinically relevant, long-lasting cellular immune response. In contrast to untreated controls, who succumbed to progressive disease, both patients are tumor-free 9 years after diagnosis. Radical surgery combined with HSCT may cure pancreatic adenocarcinoma and change the cellular immune repertoire capable of responding to clinically and biologically relevant TAAs.

Risk Factors for Subsequent Central Nervous System Tumors in Pediatric Allogeneic Hematopoietic Cell Transplant: A Study from the Center for International Blood and Marrow Transplant Research (CIBMTR)

Survivors of hematopoietic cell transplantation (HCT) are at risk of subsequent solid tumors, including central nervous system (CNS) tumors. The risk of CNS tumors after HCT in pediatric HCT recipients is not known. We evaluated the incidence and risk factors for CNS tumors in pediatric recipients of allogeneic HCT reported to the Center for International Blood and Marrow Transplant Research between 1976 and 2008. A case control design was used. There were no CNS tumors in the nonmalignant cohort (n = 4543) or in those undergoing HCT for solid tumors (n = 26). There were 59 CNS tumors in 8720 patients transplanted for hematologic malignancies. In comparison with the general population, pediatric HCT recipients with hematologic malignancies had a 33 times higher than expected rate of CNS tumors (95% confidence interval, 22.98 to 45.77; P < .0001). The cumulative incidence of subsequent CNS tumors was 1.29% (95% confidence interval .87 to 1.87) at 20 years after HCT. Significant risk factors in the entire cohort were having an unrelated donor (HR, 3.35; P = .0002) and CNS disease before HCT for both acute lymphoblastic leukemia (HR, 8.21; P = .0003) and acute myeloid leukemia (HR, 6.21; P = .0174). Analysis of the matched cohort showed having an unrelated donor transplant (HR, 4.79; P = .0037), CNS disease before HCT (HR, 7.67; P = .0064), and radiotherapy exposure before conditioning (HR, 3.7; P = .0234) to be significant risk factors. Chronic graft-versus-host disease was associated with a lower risk (HR, .29; P = .0143). Survivors of HCT for nonmalignant diseases did not show an increased incidence of CNS tumors, whereas survivors of hematologic malignancies have a markedly increased incidence of CNS tumors that warrants lifelong surveillance.

Review of allogeneic hematopoietic stem cell transplantation with reduced intensity conditioning in solid tumors excluding breast cancer

Solid tumors in adults constitute a heterogeneous group of malignancy originating from various organ systems. Solid tumors are not completely curable by chemotherapy, even though some subgroups are very chemo-sensitive. Recently, oncologists have focused on the use of allogeneic hematopoietic stem cell transplantation (allo-HSCT) with reduced intensity conditioning (RIC) for the treatment of some refractory solid tumors. After the demonstration of allogeneic graft-versus-leukemia effect in patients with hematological malignancies who received allo-HSCT, investigators evaluated this effect in patients with refractory metastatic solid tumors. According to data from experimental animal models and preliminary clinical trials, a graft-versus-tumor (GvT) effect may also be observed in the treatment of some solid tumors (e.g., renal cell cancer, colorectal cancer, etc.) after allo-HSCT with RIC. The use of RIC regimens offers an opportunity of achieving full-donor engraftment with GvT effect, as well as, a reduced transplant-related mortality. Current literature suggests that allo-HSCT with RIC might become a choice for elderly and medically fragile patients with refractory metastatic solid tumors.

First Attempt of Sequential Living Donor Liver and Hematopoietic Stem Cell Transplantation in a Child With Advanced Hepatocellular Carcinoma: Case Report

Effective therapeutic options for advanced hepatocellular carcinoma are limited. Hematopoietic stem cell transplantation may offer a graft-versus-tumor effect. Combined liver and hematopoietic stem cell transplantation from the same donor with preparatory conditioning may promote tolerogenicity to the liver allograft and offers the potential for immunosuppression withdrawal. We report our experience with the use of this approach in a pediatric patient with invasive hepatocellular carcinoma and pulmonary metastases who underwent a living-donor liver transplantation followed by reduced-toxicity myeloablative conditioning and hematopoietic stem cell transplant from the same parental donor. Neutrophil engraftment and full donor chimerism was achieved without liver allograft dysfunction. Despite normal liver function and marrow engraftment, the patient succumbed to multisystem organ failure from disseminated toxoplasmosis. At autopsy, there was no histologic evidence of tumor recurrence. No pulmonary nodules were found. Regardless of the unfortunate overall result, this case demonstrates preliminary feasibility of sequential living-donor liver transplantation and hematopoietic stem cell transplantation for unresectable and metastasized hepatic tumors. Future studies in select pediatric patients require evaluation of the optimal conditioning regimen and prevention strategies for opportunistic infections to determine both graft-versus-tumor effect on hepatic tumors and durability of tolerogenicity and possible immunosuppression withdrawal.

Systemic Therapy in Metastatic Renal Cell Carcinoma

During the last two decades considerable advances have been made in the understanding of the biology of RCC. Although the best therapeutic options for patients with metastatic RCC have not been defined, it is apparent that use of immunomodulating cytokines like interferon-alpha and interleukin-2 either alone or combined with chemotherapeutic agents provides the best available results in routine clinical practice. Numerous studies have confirmed that objective tumour responses are seen only in a small fraction of patients (averagely in 15–20%). In spite of a lot of evidence that these treatments prolong survival, expectations of only 5–10% long-term survivals with complete and durable regression of tumours are realistic. Recently, some new promising investigational approaches have been reported. These may already in near future further improve overall treatment results.

Safety and Efficacy of Transplantation with Allogeneic Skin Tumors to Treat Chemically-Induced Skin Tumors in Mice

Background

Transplantation with allogeneic cells has become a promising modality for cancer therapy, which can induce graft-versus-tumor (GVT) effect. This study was aimed at assessing the safety, efficacy, and tissue type GVT (tGVT) response of transplantation with allogeneic skin tumors to treat chemically-induced skin tumors in mice.

Material/Methods

FVB/N and ICR mice were exposed topically to chemicals to induce skin tumors. Healthy ICR mice were transplanted with allogeneic skin tumors from FVB/N mice to test the safety. The tumor-bearing ICR mice were transplanted with, or without, allogeneic skin tumors to test the efficacy. The body weights (BW), body condition scores (BCS), tumor volumes in situ, metastasis tumors, overall survival, and serum cytokines were measured longitudinally.

Results

Transplantation with no more than 0.03 g allogeneic skin tumors from FVB/N mice to healthy ICR mice was safe. After transplantation with allogeneic skin tumors to treat tumor-bearing mice, it inhibited the growth of tumors slightly at early stage, accompanied by fewer metastatic tumors at 24 days after transplantation (21.05% vs. 47.37%), while there were no statistically significant differences in the values of BW, BCS, tumor volumes in situ, metastasis tumors, and overall survival between the transplanted and non-transplanted groups. The levels of serum interleukin (IL)-2 were significantly reduced in the controls (P<0.05), but not in the recipients, which may be associated with the tGVT response.

Conclusions

Our results suggest that transplantation with allogeneic skin tumors is a safe treatment in mice, which can induce short-term tGVT response mediated by IL-2.

Lysosome-associated membrane glycoprotein 1 predicts fratricide amongst T cell receptor transgenic CD8+ T cells directed against tumor-associated antigens

AIM

Autologous as well as allogeneic CD8+ T cells transduced with tumor antigen specific T cell receptors (TCR) may cause significant tumor lysis upon adoptive transfer. Besides unpredictable life-threatening off-target effects, these TCRs may unexpectedly commit fratricide. We hypothesized lysosome-associated membrane glycoprotein 1 (LAMP1, CD107a) to be a marker for fratricide in TCR transgenic CD8+ T cells.

METHODS

We identified HLA-A*02:01/peptide-restricted T cells directed against ADRB3295. After TCR identification, we generated HLA-A*02:01/peptide restricted TCR transgenic T cells by retroviral transduction and tested T cell expansion rates as well as A*02:01/peptide recognition and ES killing in ELISpot and xCELLigence assays. Expansion arrest was analyzed via Annexin and CD107a staining. Results were compared to CHM1319-TCR transgenic T cells.

RESULTS

Beta-3-adrenergic receptor (ADRB3) as well as chondromodulin-1 (CHM1) are over-expressed in Ewing Sarcoma (ES) but not on T cells. TCR transgenic T cells demonstrated HLA-A*02:01/ADRB3295 mediated ES recognition and killing in ELISpot and xCELLigence assays. 24h after TCR transduction, CD107a expression correlated with low expansion rates due to apoptosis of ADRB3 specific T cells in contrast to CHM1 specific transgenic T cells. Amino-acid exchange scans clearly indicated the cross-reactive potential of HLA-A*02:01/ADRB3295- and HLA-A*02:01/CHM1319-TCR transgenic T cells. Comparison of peptide motive binding affinities revealed extended fratricide among ADRB3295 specific TCR transgenic T cells in contrast to CHM1319.

CONCLUSION

Amino-acid exchange scans alone predict TCR cross-reactivity with little specificity and thus require additional assessment of potentially cross-reactive HLA-A*02:01 binding candidates. CD107a positivity is a marker for fratricide of CD8+ TCR transgenic T cells.