Supported by the International Society for Translational Medicine (ISTM), Wenzhou Medical College and the First Affiliated Hospital of Wenzhou Medical College, the International Conference on Translational Medicine (ICTM) was held on October 22–23, 2011 in Wenzhou, China. Nearly 800 registrants attended the meeting, primarily representing institutes and hospitals in Europe, The United States of America, And Asia, and China. The meeting was chaired and organized by Dr. Xiangdong Wang, Xiaoming Chen, Richard Coico, Jeffrey M. Drazen, Richard Horton, Francesco M. Marincola, Laurentiu M. Popescu, Jia Qu and Aamir Shahzad.
The meeting focused on the communication of the need to foster translational medicine (TM) by building and broadening bridges between basic research and clinical studies at the international level. The meeting included distinguished TM experts from academia, the pharmaceutical and diagnostics industries, government agencies, regulators, and clinicians and provided the opportunity to identify shared interests and efforts for collaborative approaches utilizing cutting edge technologies, innovative approaches and novel therapeutic interventions. The meeting defined the concept of TM in its two-way operational scheme and emphasized the need for bed to bench efforts based directly on clinical observation.
It was the meeting participants’ realization that the shared main goals of TM include breaking the separation between clinic practice and basic research, establishing positive feedback by understanding the basis of expected and unexpected clinical outcomes and accelerating basic research relevant to human suffering. The primary objectives of the meeting were two-fold: to accelerate the two-way translation by informing the participants representing the different disciplines about the state of art activities around TM approaches; and to identify areas that need to be supported by redirecting limited resources as well as identifying new sources of funding. This report summarizes key concepts presented during the meeting representing the state-of-art translational research and salient aspects of the ensuing discussions.
Translational Medicine (TM); International Society for Translational Medicine (ISTM); the International Conference on Translational Medicine (ICTM); Biomarkers; Biobank globalization and networking
Recurrent metastatic melanoma provides a unique opportunity to analyze disease evolution in metastatic cancer. Here, we followed 8 patients with an unusually prolonged history of metastatic melanoma, who developed a total of 26 recurrences over several years. Cell lines derived from each metastasis were analyzed by comparative genomic hybridization and global transcript analysis. We observed that conserved, patient-specific characteristics remain stable in recurrent metastatic melanoma even after years and several recurrences. Differences among individual patients exceeded within-patient lesion variability, both at the DNA copy number (p<0.001) and RNA gene expression level (p<0.001). Conserved patient-specific traits included expression of several cancer/testis antigens and the c-kit proto-oncogene throughout multiple recurrences. Interestingly, subsequent recurrences of different patients did not display consistent or convergent changes toward a more aggressive disease phenotype. Finally, sequential recurrences of the same patient did not descend progressively from each other, as irreversible mutations, such as homozygous deletions were frequently not inherited from previous metastases. This study suggests that the late evolution of metastatic melanoma, which dramatically turns an indolent disease into a lethal phase, is prone to preserve case-specific traits over multiple recurrences and occurs through a series of random events that do not follow a consistent step-wise process.
In multiple forms of cancer, constitutive activation of type I IFN signaling is a critical consequence of immune surveillance against cancer; however, PBMCs isolated from cancer patients exhibit depressed STAT1 phosphorylation in response to IFN-α, suggesting IFN signaling dysfunction. Here, we demonstrated in a coculture system that melanoma cells differentially impairs the IFN-α response in PBMCs and that the inhibitory potential of a particular melanoma cell correlates with NOS1 expression. Comparison of gene transcription and array comparative genomic hybridization (aCGH) between melanoma cells from different patients indicated that suppression of IFN-α signaling correlates with an amplification of the NOS1 locus within segment 12q22-24. Evaluation of NOS1 levels in melanomas and IFN responsiveness of purified PBMCs from patients indicated a negative correlation between NOS1 expression in melanomas and the responsiveness of PBMCs to IFN-α. Furthermore, in an explorative study, NOS1 expression in melanoma metastases was negatively associated with patient response to adoptive T cell therapy. This study provides a link between cancer cell phenotype and IFN signal dysfunction in circulating immune cells.
The mission of translational research involves difficult tasks to be accomplished for its ultimate goal, i.e. the introduction of novel, effective therapeutic strategies in the clinic to diminish human suffering and cure life-threatening diseases. Translational research (also referred to as translational medicine) facilitates the translation of investment in biomedical research into successful medical treatment. This includes the transfer of diagnostic and therapeutic advances by proving their efficacy in large evidence-based trials. Through the study of humans novel insights about disease are brought back to the laboratory to identify new, observation-based strategies. This “two-way road” (“bench to bedside and bedside to bench”) process includes formulating guidelines for drug development and principles for new therapeutic strategies; initiating clinical investigations that provide the biological basis for new therapies, and related clinical trials; defining therapeutic targets and clinical endpoints. It requires a systematic approach beginning with specimen sampling, patient data collection, laboratory investigations, data analysis, preclinical testing, clinical trials, treatment efficacy monitoring, and finally the evaluation of therapeutic result. The marathon well symbolizes the enormous efforts undertaken by clinicians, scientists, regulators, ethicists, patient advocates, drug developers, and others, coordinately attempting to overcome obstacles along this road toward the final “marathon goal in medicine”.
obstacles; opportunities; therapy; translational medicine; translational research
“Today, owing to strict health and safety issues of vaccine manufacturing, vaccines must meet higher standards of safety and biochemical characterization than they did in the past.”
The identification of tumor antigens (TA) recognized by T cells led to the design of therapeutic strategies aimed at eliciting adaptive-immune responses. The last decade experience has shown that, although active immunization can induce enhancement of anti-cancer T cell precursors (easily detectable in standard assays), most often they are unable to induce tumor regression and, consequently, have scarce impact on overall survival. Moreover, in the few occasions when tumor rejection occurs, the mechanisms determining this phenomenon remain poorly understood, and data derived from in vivo human observations are rare. The advent of high-throughput gene expression analysis (microarrays) has cast new lights on unrecognized mechanisms that are now deemed as central for the development of an efficient immune-mediated tumor rejection. The aim of this article is to review the data about the molecular signature associated with this process. We believe that the description of how the mechanism of immune-mediated tissue destruction occurs would contribute to understand why it happens, thereby allowing to develop more effective immune-therapeutic strategies.
Microarray; microarrays; gene expression; cancer immunotherapy; vaccine therapy; tumor rejection; melanoma; immunologic constant
It is becoming increasingly recognized that experimental animal models, while useful to address monothematic biological questions, bear unpredictable relevance to human disease. Several reasons have been proposed. However, the uncontrollable nature of human genetics and the heterogeneity of disease that with difficulty can be replicated experimentally play a leading role. Comparative immunology is a term that generally refers to the analysis of shared or diverging facets of immunology among species; these comparisons are carried according to the principle that evolutionarily conserved themes outline biologic functions universally relevant for survival. We propose that a similar strategy could be applied searching for themes shared by distinct immune pathologies within our own species. Identification of common patterns may outline pathways necessary for a particular determinism to occur such as tissue-specific rejection or tolerance. This approach is founded on the unproven but sensible presumption that Nature does not require an infinite plethora of redundant mechanisms to reach its purposes. Thus, immune pathologies must follow, at least in part, common means that determine their onset and maintenance. Commonalities among diseases can, in turn, be segregated from disease-specific patterns uncovering essential mechanisms that may represent universal targets for immunotherapy.
Comparative immunology; tumor immunology: vaccines; chronic infection
A cancer immune signature implicating good prognosis and responsiveness to immunotherapy was described that is observed also in other aspects of immune-mediated, tissue-specific destruction (TSD). Its determinism remains, however, elusive. Based on limited but unique clinical observations, we propose a multifactorial genetic model of human cancer immune responsiveness.
cancer genetics; cancer microenvironment; immune responsiveness; immunotherapy; melanoma
In this study, we tested the effectiveness of a melanoma-associated antigen–derived peptide, MART-127–35, in eliciting cellular immune responses in vivo in the context of a phase I active immunization protocol. This peptide (AAGIGILTV) corresponds to residues 27–35 from the nonmutated melanoma-associated antigen MART-1/Melan A and is recognized by most melanoma-specific, HLA-A* 0201–restricted, tumor-infiltrating lymphocytes. To test the in vivo induction of cytotoxic T lymphocyte (CTL) sensitization, we compared CTL reactivity in vitro from peripheral blood mono-nuclear cell (PBMC) pools obtained before and after vaccination.
PATIENTS AND METHODS
MART-127–35 was administered to HLA-A*0201 melanoma patients subcutaneously in an emulsification with incomplete Freund’s adjuvant. A vaccination course included four inoculations of peptide at 3-week intervals. PBMC collected by leukapheresis and separated by Ficoll-Hypaque gradient before and after vaccination were analyzed in 18 patients by in vitro sensitization with MART-127–35– To induce MART-127–35–specific CTL, PBMC were incubated with 1 μM peptide (on day 0) and interleukin-2 (IL-2) (300 IU/mL, on days 1 and 4 after each stimulation). At weekly intervals, cells were harvested and an aliquot was cryopreserved for later analysis. The remaining cells were replated and restimulated using irradiated autologous PBMC pulsed with 1 μM of relevant peptide. After three restimulations, all samples from one patient were tested simultaneously for HLA-A*0201-restricted anti-MART-127–35 reactivity by microcytotoxicity and cytokine (IFN-γ) release assays.
Toxicities were minimal and consisted of local irritation at the site of vaccine administration. None of the patients sustained a clinical response. The first eight patients were monitored by inducing CTL reactivity from PBMC obtained preimmunization and after two and four vaccinations. Only two prevaccination cultures were reactive to MART-1, compared with five and seven cultures from PBMC obtained after two and four vaccinations, respectively. Thus, an enhancement in cytotoxic activity could be detected in postvaccination CTL cultures, and serial vaccine administrations appeared to boost the detectability of cytotoxicity in vitro. For completeness, the analysis compared prevaccination with postvaccination PBMC cultures. Specific anti–MART-127–35 cytotoxicity (≥ 10 lytic units) could be detected in two prevaccination and 12 postvaccination cultures after two in vitro stimulations. In 15 postvaccination CTL cultures, a more than threefold increase in specific release of IFN-γ was noted, compared with prevaccination.
In vivo administration of a melanoma-associated antigen peptide, emulsified in incomplete Freund’s adjuvant, could safely augment CTL reactivity against epitopes commonly expressed by melanoma cells. Although the enhancement of CTL reactivity did not achieve tumor regression, it is possible that the use of recombinant immunogens with increased immunomodulatory capabilities in future clinical trials could reach the threshold of CTL activation necessary for tumor regression.
MART-1; melanoma; immunization
The functional status of circulating vaccine-induced, tumor-specific T cells has been questioned to explain their paradoxical inability to inhibit tumor growth. We enumerated with HLA-A*0201/peptide tetramers (tHLA) vaccine-elicited CD8+ T cell precursor frequency among PBMC in 13 patients with melanoma undergoing vaccination with the HLA-A*0201-associated gp100: 209–217(210 M) epitope. T cell precursor frequency increased from undetectable to 12,400 ± 3,600 × 106 CD8+ T cells after vaccination and appeared heterogeneous according to previously described functional subtypes: CD45RA+CD27+ (14 ± 2.6% of tHLA-staining T cells), naive; CD45RA−CD27+ (14 ± 3.2%), memory; CD45RA+CD27− (43 ± 6%), effector; and CD45RA−CD27− (30 ± 4.1%), memory/effector. The majority of tHLA+CD8+ T cells displayed an effector, CD27− phenotype (73%). However, few expressed perforin (17%). Epitope-specific in vitro stimulation (IVS) followed by 10-day expansion in IL-2 reversed this phenotype by increasing the number of perforin+ (84 ± 3.6%; by paired t test, p < 0.001) and CD27+ (from 28 to 67%; by paired t test, p = 0.01) tHLA+ T cells. This conversion probably represented a change in the functional status of tHLA+ T cells rather than a preferential expansion of a CD27+ (naive and/or memory) PBMC, because it was reproduced after IVS of a T cell clone bearing a classic effector phenotype (CD45RA+CD27−). These findings suggest that circulating vaccine-elicited T cells are not as functionally active as inferred by characterization of IVS-induced CTL. In addition, CD45RA/CD27 expression may be more informative about the status of activation of circulating T cells than their status of differentiation.
Tumor Ag-specific vaccines used for cancer immunotherapy can generate specific CD8 responses detectable in PBMCs and in tumor-infiltrating lymphocytes. However, human studies have shown that detection of a systemic vaccine-induced response does not necessarily correlate with the occasional instances of tumor rejection. Because this discrepancy might partially be attributable to the genetic heterogeneity of human cancers, as well as to the immunosuppressive effects of previous treatments, we turned to a mouse model in which these variables could be controlled to determine whether a relationship exists between the strength of vaccine-induced immune responses and tumor rejection. We challenged mice with the β-galactosidase (β-gal)-expressing tumor cells, C25.F6, vaccinated them with β-gal-carrying viral vectors, and used quantitative RT-PCR to measure the vaccine-induced immune response of splenocytes directly ex vivo. We found that the strength of the response increased with increasing doses of β-gal-carrying vector and/or upon boosting with a heterologous β-gal-carrying virus. Most importantly, we found that the strength of the detected immune response against this foreign Ag strongly correlated with reduction in the number of lung metastases. The results from this mouse model have major implications for the implementation of tumor vaccines in humans.
The growth of a poorly immunogenic methylcholanthrene (MCA)-induced murine (m) sarcoma genetically engineered to secrete human (h) TNF-α (MCA-102-hTNF) was studied. MCA-102-hTNF tumor cells were implanted in animals bearing three- or 7-day pulmonary metastases established with the parental line MCA-102-WT (wild type). This model approximates the clinical situation in which patients with metastatic cancer would be vaccinated with autologous tumor genetically modified to stimulate the host immune response. Reduction in the number of pulmonary metastases was occasionally seen but was not consistently reproducible. Other cytokine-producing tumors had either no effect on distant pulmonary metastases (mIL-4, IFN-γ) or a mild, inconclusive effect similar to hTNF-α (mTNF-α). Significant growth inhibition of MCA-102-hTNF was noted in animals bearing pulmonary metastases. This inhibition was: 1) tumor specific (regression occurred only in animals bearing pulmonary metastases from the same parental line), 2) TNF specific (it was inhibited by in vivo administration of anti hTNF mAbs), 3) dependent on cellular immunity (immune-depletion with anti-CD4 or CD8 mAbs permitted growth). Tumor-infiltrating lymphocytes (TIL) could not be grown from MCA-102-WT or MCA-102-hTNF tumors nor from MCA-102-WT subcutaneous implants in mice bearing MCA-102-WT pulmonary metastases. However, TIL could be grown from hTNF-secreting tumors implanted in mice bearing MCA-102-WT metastases. These TIL were therapeutic against established lung metastases from the parental tumor in adoptive immunotherapy models. These studies suggest a strategy for using gene modified tumors for the therapy of established cancer.
Stimulating an immune response against cancer with the use of vaccines remains a challenge. We hypothesized that combining a melanoma vaccine with interleukin-2, an immune activating agent, could improve outcomes. In a previous phase 2 study, patients with metastatic melanoma receiving high-dose interleukin-2 plus the gp100:209–217(210M) peptide vaccine had a higher rate of response than the rate that is expected among patients who are treated with interleukin-2 alone.
We conducted a randomized, phase 3 trial involving 185 patients at 21 centers. Eligibility criteria included stage IV or locally advanced stage III cutaneous melanoma, expression of HLA⋆A0201, an absence of brain metastases, and suitability for high-dose interleukin-2 therapy. Patients were randomly assigned to receive interleukin-2 alone (720,000 IU per kilogram of body weight per dose) or gp100:209–217(210M) plus incomplete Freund’s adjuvant (Montanide ISA-51) once per cycle, followed by interleukin-2. The primary end point was clinical response. Secondary end points included toxic effects and progression-free survival.
The treatment groups were well balanced with respect to baseline characteristics and received a similar amount of interleukin-2 per cycle. The toxic effects were consistent with those expected with interleukin-2 therapy. The vaccine–interleukin-2 group, as compared with the interleukin-2–only group, had a significant improvement in centrally verified overall clinical response (16% vs. 6%, P = 0.03), as well as longer progression-free survival (2.2 months; 95% confidence interval [CI], 1.7 to 3.9 vs. 1.6 months; 95% CI, 1.5 to 1.8; P = 0.008). The median overall survival was also longer in the vaccine–interleukin-2 group than in the interleukin-2–only group (17.8 months; 95% CI, 11.9 to 25.8 vs. 11.1 months; 95% CI, 8.7 to 16.3; P = 0.06).
In patients with advanced melanoma, the response rate was higher and progression-free survival longer with vaccine and interleukin-2 than with interleukin-2 alone. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT00019682.)
The fourth “Melanoma Bridge Meeting” took place in Naples, December 5 to 8th, 2013. The four topics discussed at this meeting were: Diagnosis and New Procedures, Molecular Advances and Combination Therapies, News in Immunotherapy, and Tumor Microenvironment and Biomarkers.
Until recently systemic therapy for metastatic melanoma patients was ineffective, but recent research in tumor biology and immunology has led to the development of new targeted and immunotherapeutic agents that prolong progression-free survival (PFS) and overall survival (OS). New therapies, such as mitogen-activated protein kinase (MAPK) pathway inhibitors, like BRAF and MEK inhibitors, as well as other signaling pathways inhibitors, are being tested in metastatic melanoma either as monotherapy or in combination, and have yielded promising results.
Improved survival rates have also been observed with immune therapy for patients with metastatic melanoma. Immune-modulating antibodies came to the forefront with anti-CTLA-4, programmed cell death-1 (PD-1) and PD-1 ligand 1 (PD-L1) pathway blocking antibodies that result in durable responses in a subset of melanoma patients. Agents targeting other immune inhibitory (e.g., Tim-3) or immune stimulating (e.g., CD137) receptors and other approaches such as adoptive cell transfer demonstrate clinical benefit in melanoma as well.
This meeting’s specific focus was on advances in targeted therapy and immunotherapy. Both combination targeted therapy approaches and different immunotherapies were discussed. Similarly to the previous meetings, the importance of biomarkers for clinical application as markers for diagnosis, prognosis and prediction of treatment response was an integral part of the meeting. Significant consideration was given to issues surrounding the development of novel therapeutic targets as further study of patterns of resistance to both immunologic and targeted drugs are paramount to future drug development to guide existing and future therapies. The overall emphasis on biomarkers supports novel concepts toward integrating biomarkers into contemporary clinical management of patients with melanoma across the entire spectrum of disease stage. Translation of the knowledge gained from the biology of tumor microenvironment across different tumors represents a bridge to impact on prognosis and response to therapy in melanoma.
Early changes in transcriptional profiles of circulating mononuclear cells were compared with those occurring within the microenvironment of melanoma metastases following systemic IL-2 administration. The results suggest that the immediate effects of IL-2 administration on the tumor microenvironment is transcriptional activation of genes predominantly associated with monocyte cell function.
lnterleukin-2 (IL-2) has direct pluripotent effects on cells with immune and inflammatory function. Which of these effects has a critical role in mediating tumor regression remains enigmatic. In this study, we compared early changes in transcriptional profiles of circulating mononuclear cells with those occurring within the microenvironment of melanoma metastases following systemic IL-2 administration.
The results suggest that the immediate effects of IL-2 administration on the tumor microenvironment is transcriptional activation of genes predominantly associated with monocyte cell function; minimal effects were noted on migration, activation and proliferation of T cells. However, production of chemokines and markers of adhesion and migration within few hours of IL-2 administration may be responsible for a secondary recruitment of immune cells to the tumor site later.
Our results suggest that IL-2 induces inflammation at tumor sites with three predominant secondary effects: activation of antigen-presenting monocytes; massive production of chemoattractants that may recruit other immune cells to the tumor (including MIG and PARC, which are specific for T cells); and activation of cytolytic mechanisms in monocytes (calgranulin, grancalcin) and NK cells (NKG5, NK4).
Single-cell network profiling (SCNP) is a multiparametric flow cytometry-based approach that simultaneously measures evoked signaling in multiple cell subsets. Previously, using the SCNP approach, age-associated immune signaling responses were identified in a cohort of 60 healthy donors.
In the current study, a high-dimensional analysis of intracellular signaling was performed by measuring 24 signaling nodes in 7 distinct immune cell subsets within PBMCs in an independent cohort of 174 healthy donors [144 elderly (>65 yrs); 30 young (25–40 yrs)].
Associations between age and 9 immune signaling responses identified in the previously published 60 donor cohort were confirmed in the current study. Furthermore, within the current study cohort, 48 additional immune signaling responses differed significantly between young and elderly donors. These associations spanned all profiled modulators and immune cell subsets.
These results demonstrate that SCNP, a systems-based approach, can capture the complexity of the cellular mechanisms underlying immunological aging. Further, the confirmation of age associations in an independent donor cohort supports the use of SCNP as a tool for identifying reproducible predictive biomarkers in areas such as vaccine response and response to cancer immunotherapies.
Multi-parameter flow cytometry; Systems immunology; Aging; Immune signaling
Until recently, most immunotherapeutic approaches used to fight cancer were ineffective, counteracted by the tumour’s ability to evade immune attack. However, extensive research has improved our understanding of tumour immunology and enabled the development of novel treatments that can harness the patient’s immune system and prevent immune escape. Over the last few years, through numerous clinical trials and real-world experience, we have accumulated a large amount of evidence regarding the potential for long-term survival with immunotherapy agents in various types of malignancy. The results of these studies have also highlighted a number of recurring observations with immuno-oncology agents, including their potential for clinical application across a broad patient population and for both conventional and unconventional response patterns. Furthermore, given the numerous immune checkpoints that exist and the multiple mechanisms used by tumours to escape the immune system, targeting distinct checkpoint pathways using combination approaches is an attractive therapeutic strategy with the potential to further enhance the antitumour immune response.
Immunotherapy; Melanoma; Efficacy; Survival; Sequencing
It has been recently proposed that nanomaterials, alone or in concert with their specific biomolecular conjugates, can be used to directly modulate the immune system, therefore offering a new tool for the enhancement of immune-based therapies against infectious disease and cancer. Here, we revised the publications on the impact of functionalized carbon nanotubes (f-CNTs), graphene and carbon nanohorns on immune cells. Whereas f-CNTs are the nanomaterial most widely investigated, we noticed a progressive increase of studies focusing on graphene in the last couple of years. The majority of the works (56%) have been carried out on macrophages, following by lymphocytes (30% of the studies). In the case of lymphocytes, T cells were the most investigated (22%) followed by monocytes and dendritic cells (7%), mixed cell populations (peripheral blood mononuclear cells, 6%), and B and natural killer (NK) cells (1%). Most of the studies focused on toxicity and biocompatibility, while mechanistic insights on the effect of carbon nanotubes on immune cells are generally lacking. Only very recently high-throughput gene-expression analyses have shed new lights on unrecognized effects of carbon nanomaterials on the immune system. These investigations have demonstrated that some f-CNTs can directly elicitate specific inflammatory pathways. The interaction of graphene with the immune system is still at a very early stage of investigation. This comprehensive state of the art on biocompatible f-CNTs and graphene on immune cells provides a useful compass to guide future researches on immunological applications of carbon nanomaterials in medicine.
Carbon nanotubes; Graphene; Graphene oxide; Nanomedicine; Immune system; Cells; Therapy; Diagnosis