Perspectives in Melanoma: meeting report from the Melanoma Bridge (December 1st-3rd, 2022-Naples, Italy).

Outcomes for patients with melanoma have improved over the past decade with the clinical development and approval of immunotherapies targeting immune checkpoint receptors such as programmed death-1 (PD-1), programmed death ligand 1 (PD-L1) or cytotoxic T lymphocyte antigen-4 (CTLA-4). Combinations of these checkpoint therapies with other agents are now being explored to improve outcomes and enhance benefit-risk profiles of treatment. Alternative inhibitory receptors have been identified that may be targeted for anti-tumor immune therapy, such as lymphocyte-activation gene-3 (LAG-3), as have several potential target oncogenes for molecularly targeted therapy, such as tyrosine kinase inhibitors. Unfortunately, many patients still progress and acquire resistance to immunotherapy and molecularly targeted therapies. To bypass resistance, combination treatment with immunotherapies and single or multiple TKIs have been shown to improve prognosis compared to monotherapy. The number of new combinations treatment under development for melanoma provides options for the number of patients to achieve a therapeutic benefit. Many diagnostic and prognostic assays have begun to show clinical applicability providing additional tools to optimize and individualize treatments. However, the question on the optimal algorithm of first- and later-line therapies and the search for biomarkers to guide these decisions are still under investigation. This year, the Melanoma Bridge Congress (Dec 1st-3rd, 2022, Naples, Italy) addressed the latest advances in melanoma research, focusing on themes of paramount importance for melanoma prevention, diagnosis and treatment. This included sessions dedicated to systems biology on immunotherapy, immunogenicity and gene expression profiling, biomarkers, and combination treatment strategies.

Metabolic Dysregulation Explains the Diverse Impacts of Obesity in Males and Females with Gastrointestinal Cancers.

The prevalence of obesity, defined as the body mass index (BMI) ≥ 30 kg/m2, has reached epidemic levels. Obesity is associated with an increased risk of various cancers, including gastrointestinal ones. Recent evidence has suggested that obesity disproportionately impacts males and females with cancer, resulting in varied transcriptional and metabolic dysregulation. This study aimed to elucidate the differences in the metabolic milieu of adenocarcinomas of the gastrointestinal (GI) tract both related and unrelated to sex in obesity. To demonstrate these obesity and sex-related effects, we utilized three primary data sources: serum metabolomics from obese and non-obese patients assessed via the Biocrates MxP Quant 500 mass spectrometry-based kit, the ORIEN tumor RNA-sequencing data for all adenocarcinoma cases to assess the impacts of obesity, and publicly available TCGA transcriptional analysis to assess GI cancers and sex-related differences in GI cancers specifically. We applied and integrated our unique transcriptional metabolic pipeline in combination with our metabolomics data to reveal how obesity and sex can dictate differential metabolism in patients. Differentially expressed genes (DEG) analysis of ORIEN obese adenocarcinoma as compared to normal-weight adenocarcinoma patients resulted in large-scale transcriptional reprogramming (4029 DEGs, adj. p < 0.05 and |logFC| > 0.58). Gene Set Enrichment and metabolic pipeline analysis showed genes enriched for pathways relating to immunity (inflammation, and CD40 signaling, among others) and metabolism. Specifically, we found alterations to steroid metabolism and tryptophan/kynurenine metabolism in obese patients, both of which are highly associated with disease severity and immune cell dysfunction. These findings were further confirmed using the TCGA colorectal adenocarcinoma (CRC) and esophageal adenocarcinoma (ESCA) data, which showed similar patterns of increased tryptophan catabolism for kynurenine production in obese patients. These patients further showed disparate alterations between males and females when comparing obese to non-obese patient populations. Alterations to immune and metabolic pathways were validated in six patients (two obese and four normal weight) via CD8+/CD4+ peripheral blood mononuclear cell RNA-sequencing and paired serum metabolomics, which showed differential kynurenine and lipid metabolism, which corresponded with altered T-cell transcriptome in obese populations. Overall, obesity is associated with differential transcriptional and metabolic programs in various disease sites. Further, these alterations, such as kynurenine and tryptophan metabolism, which impact both metabolism and immune phenotype, vary with sex and obesity together. This study warrants further in-depth investigation into obesity and sex-related alterations in cancers that may better define biomarkers of response to immunotherapy.

MEETING HIGHLIGHTS: THE THIRD MARIE SKLODOWSKA-CURIE SYMPOSIUM ON CANCER RESEARCH AND CARE AT ROSWELL PARK COMPREHENSIVE CANCER CENTER, BUFFALO, NY, SEPTEMBER 20-22, 2023.

Marie Sklodowska-Curie Symposia on Cancer Research and Care (MSCS-CRC) promote collaborations between cancer researchers and care providers in the United States, Canada and Central and Eastern European Countries (CEEC), to accelerate the development of new cancer therapies, advance early detection and prevention, increase cancer awareness, and improve cancer care and the quality of life of patients and their families. The third edition of MSCS-CRC, held at Roswell Park Comprehensive Cancer Center, Buffalo, NY, in September 2023, brought together 137 participants from 20 academic institutions in the US, Poland, Ukraine, Lithuania, Croatia and Hungary, together with 16 biotech and pharma entities. The key areas of collaborative opportunity identified during the meeting are a) creating of a database of available collaborative projects in the areas of early-phase clinical trials, preclinical development, and identification of early biomarkers; b) promoting awareness of cancer risks and efforts at cancer prevention; c) laboratory and clinical training; and d) sharing experience in cost-effective delivery of cancer care and improving the quality of life of cancer patients and their families. Examples of ongoing international collaborations in the above areas were discussed. Participation of the representatives of the Warsaw-based Medical Research Agency, National Cancer Institute (NCI) of the United States, National Cancer Research Institutes of Poland and Lithuania, New York State Empire State Development, Ministry of Health of Ukraine and Translational Research Cancer Center Consortium of 13 cancer centers from the US and Canada, facilitated the discussion of available governmental and non-governmental funding initiatives in the above areas.

Improving cancer immunotherapy by rationally combining oncolytic virus with modulators targeting key signaling pathways.

Oncolytic viruses (OVs) represent a new class of multi-modal immunotherapies for cancer, with OV-elicited antitumor immunity being key to their overall therapeutic efficacy. Currently, the clinical effectiveness of OV as monotherapy remains limited, and thus investigators have been exploring various combinations with other anti-cancer agents and demonstrated improved therapeutic efficacy. As cancer cells have evolved to alter key signaling pathways for enhanced cell proliferation, cancer progression and metastasis, these cellular and molecular changes offer promising targets for rational cancer therapy design. In this regard, key molecules in relevant signaling pathways for cancer cells or/and immune cells, such as EGFR-KRAS (e.g., KRASG12C), PI3K-AKT-mTOR, ERK-MEK, JAK-STAT, p53, PD-1-PD-L1, and epigenetic, or immune pathways (e.g., histone deacetylases, cGAS-STING) are currently under investigation and have the potential to synergize with OV to modulate the immune milieu of the tumor microenvironment (TME), thereby improving and sustaining antitumor immunity. As many small molecule modulators of these signaling pathways have been developed and have shown strong therapeutic potential, here we review key findings related to both OV-mediated immunotherapy and the utility of small molecule modulators of signaling pathways in immuno-oncology. Then, we focus on discussion of the rationales and potential strategies for combining OV with selected modulators targeting key cellular signaling pathways in cancer or/and immune cells to modulate the TME and enhance antitumor immunity and therapeutic efficacy. Finally, we provide perspectives and viewpoints on the application of novel experimental systems and technologies that can propel this exciting branch of medicine into a bright future.

Lack of racial differences in clinical outcomes of breast cancer patients receiving neoadjuvant chemotherapy: a single academic center study.

PURPOSE: To examine the association between race and clinical outcomes (pathological complete response [pCR]; recurrence-free survival [RFS], and overall survival [OS]) in patients diagnosed with triple-negative (TNBC) or HER2-positive breast cancer treated with neoadjuvant chemotherapy (NAC). METHODS: Patients who self-identified as non-Hispanic white (NHW) or non-Hispanic Black (NHB) and were diagnosed with Stage I-III TNBC (n = 171 including 124 NHW and 47 NHB) and HER2-positive (n = 161 including 136 NHW and 25 NHB) breast cancer who received NAC from 2000 to 2018 at Roswell Park Comprehensive Cancer Center were included. Associations of race with pCR and survival outcomes were evaluated using logistic and Cox regression models, respectively. RESULTS: There was no statistically significant difference in pCR between NHB and NHW patients with TNBC (31.9 vs 29.8%; OR: 1.11, 95% CI 0.54-2.29) or HER2-positive breast cancer (36.0 vs 39.7%; OR: 0.87, 95% CI 0.36-3.11). After controlling for potential confounders, including age, stage, treatment regimens, insurance status, and comorbidities, no statistically significant difference in OS or RFS was observed between NHB and NHW patients within either subtype. CONCLUSION: TNBC or HER2-positive breast cancer patients treated at a single academic center in Buffalo, NY, showed similar outcomes independent of patients' race. Given the known genetic diversity of African American ancestry in the US, further studies investigating the interplay between race, geography, and clinical outcomes are warranted.

The C-terminal peptide of CCL21 drastically augments CCL21 activity through the dendritic cell lymph node homing receptor CCR7 by interaction with the receptor N-terminus.

The endogenous chemokines CCL19 and CCL21 signal via their common receptor CCR7. CCL21 is the main lymph node homing chemokine, but a weak chemo-attractant compared to CCL19. Here we show that the 41-amino acid positively charged peptide, released through C-terminal cleavage of CCL21, C21TP, boosts the immune cell recruiting activity of CCL21 by up to 25-fold and the signaling activity via CCR7 by ~ 100-fold. Such boosting is unprecedented. Despite the presence of multiple basic glycosaminoglycan (GAG) binding motifs, C21TP boosting of CCL21 signaling does not involve interference with GAG mediated cell-surface retention. Instead, boosting is directly dependent on O-glycosylations in the CCR7 N-terminus. As dictated by the two-step binding model, the initial chemokine binding involves interaction of the chemokine fold with the receptor N-terminus, followed by insertion of the chemokine N-terminus deep into the receptor binding pocket. Our data suggest that apart from a role in initial chemokine binding, the receptor N-terminus also partakes in a gating mechanism, which could give rise to a reduced ligand activity, presumably through affecting the ligand positioning. Based on experiments that support a direct interaction of C21TP with the glycosylated CCR7 N-terminus, we propose that electrostatic interactions between the positively charged peptide and sialylated O-glycans in CCR7 N-terminus may create a more accessible version of the receptor and thus guide chemokine docking to generate a more favorable chemokine-receptor interaction, giving rise to the peptide boosting effect.

High intratumoral CD8+ T-cell infiltration is associated with improved survival in prostate cancer patients undergoing radical prostatectomy.

BACKGROUND: A high density of CD8+ tumor infiltrating lymphocytes (TILs) is associated with improved survival in multiple cancers, but its prognostic role in prostate cancer remains controversial. The aim of our study was to evaluate the prognostic value of CD8+ TILs in prostate cancer patients undergoing radical prostatectomy (RP). We hypothesized that elevated density of CD8+ TILs in the RP specimen would correlate with improved clinical outcomes. This information may be helpful for future immunotherapy clinical trial design and treatment selection. METHODS: Tumor microarrays constructed from 230 patients with localized prostate cancers who underwent RP from 2006 to 2012 at Roswell Park Comprehensive Cancer Center were analyzed retrospectively using immunohistochemistry. CD8+ cell density was evaluated using a computerized scoring system. The cohorts were separated by CD8+ TIL density at the 25th percentile (i.e., low 7 or pT3/4). The median follow-up time was 8.4 years. High CD8+ TIL density was associated with improved 5-year overall survival (98% vs. 91%, p = .01) and prostate cancer-specific survival (99% vs. 95%, p = .04) compared with patients with low CD8+ TIL density. There was a trend toward higher 5-year biochemical recurrence-free survival and metastasis-free survival in the cohort of patients with high CD8+ TIL density (52% vs. 38% and 86% vs. 73%, respectively), although the difference did not reach statistical significance (p = .18 and p = .05, respectively). In a multivariate analysis high CD8+ TIL density was an independent favorable prognostic factor for overall survival (hazards ratio = 0.38; 95% confidence interval: 0.17-0.87; p = .02). In contrast to the prognostic value of CD8+ TIL density, the CD8+ cell density in the matched normal prostate tissue was not associated with any clinical outcomes. CONCLUSION: Intratumoral CD8+ T-cell infiltration in the RP specimen is independently associated with improved survival after RP in this high-risk prostate cancer cohort. Pre-RP immunomodulation that promotes intratumoral CD8+ cytotoxic T-cell infiltration may be beneficial for this population.

Perspectives in Melanoma: meeting report from the Melanoma Bridge (December 3rd-5th, 2020, Italy).

Advances in immune checkpoint therapy and targeted therapy have led to improvement in overall survival for patients with advanced melanoma. Single agent checkpoint PD-1 blockade and combination with BRAF/MEK targeted therapy demonstrated benefit in overall survival (OS). Superior response rates have been demonstrated with combined PD-1/CTLA-4 blockade, with a significant OS benefit compared with single-agent PD-1 blockade. Despite the progress in diagnosis of melanocytic lesions, correct classification of patients, selection of appropriate adjuvant and systemic therapies, and prediction of response to therapy remain real challenges in melanoma. Improved understanding of the tumor microenvironment, tumor immunity and response to therapy has prompted extensive translational and clinical research in melanoma. Development of novel biomarker platforms may help to improve diagnostics and predictive accuracy for selection of patients for specific treatment. There is a growing evidence that genomic and immune features of pre-treatment tumor biopsies may correlate with response in patients with melanoma and other cancers but they have yet to be fully characterized and implemented clinically. Overall, the progress in melanoma therapeutics and translational research will help to optimize treatment regimens to overcome resistance and develop robust biomarkers to guide clinical decision-making. During the Melanoma Bridge meeting (December 3rd-5th, 2020, Italy) we reviewed the currently approved systemic and local therapies for advanced melanoma and discussed novel biomarker strategies and advances in precision medicine.

Phase II Trial of Adjuvant Dendritic Cell Vaccine in Combination with Celecoxib, Interferon-α, and Rintatolimod in Patients Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Peritoneal Metastases.

BACKGROUND: Peritoneal metastases portend poor prognosis in the setting of standard chemotherapy. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) improves outcomes, but relapse is common. We report a phase II trial evaluating the safety and efficacy of adjuvant αDC1 vaccination with chemokine modulation (CKM) after CRS/HIPEC. METHODS: Patients undergoing CRS/HIPEC for appendiceal cancer, colorectal cancer, or peritoneal mesothelioma were enrolled. In addition to standard adjuvant chemotherapy, patients received intranodal and intradermal injections of autologous tumor-loaded αDC1 vaccine. After each vaccine booster, patients received CKM over 4 days, consisting of celecoxib, interferon (IFN)-α, and rintatolimod. RESULTS: Forty-six patients underwent CRS/HIPEC followed by αDC1 treatment, including 24 appendiceal primaries, 20 colorectal, and 2 mesotheliomas. DC maturation was successful, with 97% expressing HLA-DR and CD86. Tumor cell recovery from peritoneal tumors was challenging, resulting in only 17% of patients receiving the target dose of αDC1. The αDC1 and CKM regimen was well tolerated. CKM successfully modulated serum inflammatory cytokine and chemokine levels. Median progression-free survival (PFS) for appendiceal primaries was 50.4, 34.2, and 8.9 months for grade 1, 2, and 3 tumors, respectively, while median PFS for colorectal cancer was 20.5 and 8.9 months for moderately and poorly differentiated tumors, respectively. CONCLUSIONS: Adjuvant autologous tumor antigen-loaded αDC1 vaccine and CKM is well tolerated. The mucinous nature of peritoneal metastases limits the feasibility of obtaining adequate autologous tumor cells. The improvement in median PFS did not meet our predefined thresholds, leading us to conclude that αDC1 vaccination is not appropriate for patients undergoing CRS/HIPEC for peritoneal metastases.

Immunotherapy of cancer in 2012.

The immunotherapy of cancer has made significant strides in the past few years due to improved understanding of the underlying principles of tumor biology and immunology. These principles have been critical in the development of immunotherapy in the laboratory and in the implementation of immunotherapy in the clinic. This improved understanding of immunotherapy, enhanced by increased insights into the mechanism of tumor immune response and its evasion by tumors, now permits manipulation of this interaction and elucidates the therapeutic role of immunity in cancer. Also important, this improved understanding of immunotherapy and the mechanisms underlying immunity in cancer has fueled an expanding array of new therapeutic agents for a variety of cancers. Pegylated interferon-α2b as an adjuvant therapy and ipilimumab as therapy for advanced disease, both of which were approved by the United States Food and Drug Administration for melanoma in March 2011, are 2 prime examples of how an increased understanding of the principles of tumor biology and immunology have been translated successfully from the laboratory to the clinical setting. Principles that guide the development and application of immunotherapy include antibodies, cytokines, vaccines, and cellular therapies. The identification and further elucidation of the role of immunotherapy in different tumor types, and the development of strategies for combining immunotherapy with cytotoxic and molecularly targeted agents for future multimodal therapy for cancer will enable even greater progress and ultimately lead to improved outcomes for patients receiving cancer immunotherapy.

Epinephrine promotes COX-2-dependent immune suppression in myeloid cells and cancer tissues.

Activation of the sympathetic nervous system (e.g., due to stress) has been implicated in cancer progression and recurrence, but its cancer-promoting effects have been variable between different studies. Here, we report that although catecholamines, mediators of systemic sympathetic activity, display only weak immunosuppressive impact on their own, their combination with inflammatory signals leads to the induction of COX-2 and multiple COX-2-dependent suppressive factors in human myeloid cells and cancer tissues. Human macrophages exposed to epinephrine and TNFα, or macrophages generated in 6day cultures in the presence of epinephrine, expressed high levels of COX-2, IDO and IL-10, and strongly suppressed both the proliferation and IFNγ production of CD8+ T cells. These suppressive effects of epinephrine were counteracted by celecoxib, a selective inhibitor of COX-2 activity, which inhibited the induction of immunosuppressive factors (including the elevated expression of COX-2 itself) and the ability of epinephrine-exposed macrophages to suppress CD8+ T cell responses. The activation of the COX-2/PGE2 system and COX-2-dependent suppressive events were also observed in ex vivo human breast and colon cancer explant cultures and were similarly counteracted by celecoxib. Our preliminary data also indicate elevated COX-2 expression in mammary tumors of chronic stress-exposed mice. The current demonstration of the interplay between inflammation and the induction of immunosuppressive factors by catecholamines suggest a contextual impact of stress, helping to explain variable results of epidemiologic studies of the link between sympathetic activity and cancer progression, and implicating COX-2 blockade as a potential means to mitigate stress-related immune suppression.

CD40L induces functional tunneling nanotube networks exclusively in dendritic cells programmed by mediators of type 1 immunity.

The ability of dendritic cells (DC) to mediate CD4(+) T cell help for cellular immunity is guided by instructive signals received during DC maturation, as well as the resulting pattern of DC responsiveness to the Th signal, CD40L. Furthermore, the professional transfer of antigenic information from migratory DC to lymph node-residing DC is critical for the effective induction of cellular immune responses. In this study we report that, in addition to their enhanced IL-12p70 producing capacity, human DC matured in the presence of inflammatory mediators of type 1 immunity are uniquely programmed to form networks of tunneling nanotube-like structures in response to CD40L-expressing Th cells or rCD40L. This immunologic process of DC reticulation facilitates intercellular trafficking of endosome-associated vesicles and Ag, but also pathogens such HIV-1, and is regulated by the opposing roles of IFN-γ and IL-4. The initiation of DC reticulation represents a novel helper function of CD40L and a superior mechanism of intercellular communication possessed by type 1 polarized DC, as well as a target for exploitation by pathogens to enhance direct cell-to-cell spread.

Tumor Immuno-Environment in Cancer Progression and Therapy.

The approvals of Provenge (Sipuleucel-T), Ipilimumab (Yervoy/anti-CTLA-4) and blockers of the PD-1 - PD-L1/PD-L2 pathway, such as nivolumab (Opdivo), pembrolizumab (Keytruda), or atezolizumab (Tecentriq), have established immunotherapy as a key component of comprehensive cancer care. Further, murine mechanistic studies and studies in immunocompromised patients have documented the critical role of immunity in effectiveness of radio- and chemotherapy. However, in addition to the ability of the immune system to control cancer progression, it can also promote tumor growth, via regulatory T cells (Tregs), myeloid-derived dendritic cells (MDSCs) and tumor associated macrophages (TAM), which can enhance survival of cancer cells directly or via the regulation of the tumor stroma.An increasing body of evidence supports a central role for the tumor microenvironment (TME) and the interactions between tumor stroma, infiltrating immune cells and cancer cells during the induction and effector phase of anti-cancer immunity, and the overall effectiveness of immunotherapy and other forms of cancer treatment. In this chapter, we discuss the roles of key TME components during tumor progression, metastatic process and cancer therapy-induced tumor regression, as well as opportunities for their modulation to enhance the overall therapeutic benefit.

Functional reprogramming of human prostate cancer to promote local attraction of effector CD8(+) T cells.

BACKGROUND: Local infiltration of CD8(+) T cells (CTLs) in tumor lesions predicts overall clinical outcomes and the clinical benefit of cancer patients from immune checkpoint blockade. In the current study, we evaluated local production of different classes of chemokines in prostate cancer lesions, and the feasibility of their modulation to promote selective entry of CTLs into prostate tumors. METHODS: Chemokine expression in prostate cancer lesion was analyzed by TaqMan-based quantitative PCR, confocal fluorescence microscopy and ELISA. For ex vivo chemokine modulation analysis, prostate tumor explants from patients undergoing primary prostate cancer resections were cultured for 24 hr, in the absence or presence of the combination of poly-I:C, IFNα, and celecoxib (PAC). The numbers of cells producing defined chemokines in the tissues were analyzed by confocal microscopy. Chemotaxis of effector CD8(+) T cells towards the untreated and PAC-treated tumor explant supernatants were evaluated in a standard in vitro migration assays, using 24 well trans-well plates. The number of effector cells that migrated was enumerated by flow cytometry. Pearson (r) correlation was used for analyzing correlations between chemokines and immune filtrate, while paired two tailed students t-test was used for comparison between treatment groups. RESULTS: Prostate tumors showed uniformly low levels of CTL/NK/Th1-recruiting chemokines (CCL5, CXCL9, CXCL10) but expressed high levels of chemokines implicated in the attraction of myeloid derived suppressor cells (MDSC) and regulatory T cells (Treg ): CCL2, CCL22, and CXCL12. Strong positive correlations were observed between CXCL9 and CXCL10 and local CD8 expression. Tumor expression levels of CCL2, CCL22, and CXCL12 were correlated with intratumoral expression of MDSC/Treg markers: FOXP3, CD33, and NCF2. Treatment with PAC suppressed intratumoral production of the Treg -attractant CCL22 and Treg /MDSC-attractant, CXCL12, while increasing the production of the CTL attractant, CXCL10. These changes in local chemokine production were accompanied by the reduced ability of the ex vivo-treated tumors to attract CD4(+) FOXP3(+) Treg cells, and strongly enhanced attraction of the CD8(+) Granzyme B(+) CTLs. CONCLUSIONS: Our data demonstrate that the chemokine environment in prostate cancer can be reprogrammed to selectively enhance the attraction of type-1 effector immune cells and reduce local attraction of MDSCs and Tregs . Prostate 76:1095-1105, 2016. © 2016 Wiley Periodicals, Inc.

First-in-man study of western reserve strain oncolytic vaccinia virus: safety, systemic spread, and antitumor activity.

Oncolytic viral therapy utilizes a tumor-selective replicating virus which preferentially infects and destroys cancer cells and triggers antitumor immunity. The Western Reserve strain of vaccinia virus (VV) is the most virulent strain of VV in animal models and has been engineered for tumor selectivity through two targeted gene deletions (vvDD). We performed the first-in-human phase 1, intratumoral dose escalation clinical trial of vvDD in 16 patients with advanced solid tumors. In addition to safety, we evaluated signs of vvDD replication and spread to distant tumors, pharmacokinetics and pharmacodynamics, clinical and immune responses to vvDD. Dose escalation proceeded without dose-limiting toxicities to a maximum feasible dose of 3 × 10(9) pfu. vvDD replication in tumors was reproducible. vvDD genomes and/or infectious particles were recovered from injected (n = 5 patients) and noninjected (n = 2 patients) tumors. At the two highest doses, vvDD genomes were detected acutely in blood in all patients while delayed re-emergence of vvDD genomes in blood was detected in two patients. Fifteen of 16 patients exhibited late symptoms, consistent with ongoing vvDD replication. In summary, intratumoral injection of the oncolytic vaccinia vvDD was well-tolerated in patients and resulted in selective infection of injected and noninjected tumors and antitumor activity.

Consensual immunity: success-driven development of T-helper-1 and T-helper-2 responses.

Non-germline-encoded T- and B-cell receptors allow humans to effectively deal with rapidly mutating pathogens. Here, we argue that, in addition to determining the antigenic specificity of immune responses, the same receptor systems can also regulate the T-helper-1/T-helper-2 profile of immunity. Such a mechanism--based on feedback from distinct effector cells to dendritic cells, rather than on instruction from pathogens--uses the effectiveness of particular effector cells at targeting and destroying a pathogen as a reliable, experience-based criterion to induce and maintain the appropriately polarized response.

P2RX7 purinoceptor: a therapeutic target for ameliorating the symptoms of duchenne muscular dystrophy.

BACKGROUND: Duchenne muscular dystrophy (DMD) is the most common inherited muscle disease, leading to severe disability and death in young men. Death is caused by the progressive degeneration of striated muscles aggravated by sterile inflammation. The pleiotropic effects of the mutant gene also include cognitive and behavioral impairments and low bone density. Current interventions in DMD are palliative only as no treatment improves the long-term outcome. Therefore, approaches with a translational potential should be investigated, and key abnormalities downstream from the absence of the DMD product, dystrophin, appear to be strong therapeutic targets. We and others have demonstrated that DMD mutations alter ATP signaling and have identified P2RX7 purinoceptor up-regulation as being responsible for the death of muscles in the mdx mouse model of DMD and human DMD lymphoblasts. Moreover, the ATP-P2RX7 axis, being a crucial activator of innate immune responses, can contribute to DMD pathology by stimulating chronic inflammation. We investigated whether ablation of P2RX7 attenuates the DMD model mouse phenotype to assess receptor suitability as a therapeutic target. METHODS AND FINDINGS: Using a combination of molecular, histological, and biochemical methods and behavioral analyses in vivo we demonstrate, to our knowledge for the first time, that genetic ablation of P2RX7 in the DMD model mouse produces a widespread functional attenuation of both muscle and non-muscle symptoms. In dystrophic muscles at 4 wk there was an evident recovery in key functional and molecular parameters such as improved muscle structure (minimum Feret diameter, p < 0.001), increased muscle strength in vitro (p < 0.001) and in vivo (p = 0.012), and pro-fibrotic molecular signatures. Serum creatine kinase (CK) levels were lower (p = 0.025), and reduced cognitive impairment (p = 0.006) and bone structure alterations (p < 0.001) were also apparent. Reduction of inflammation and fibrosis persisted at 20 mo in leg (p = 0.038), diaphragm (p = 0.042), and heart muscles (p < 0.001). We show that the amelioration of symptoms was proportional to the extent of receptor depletion and that improvements were observed following administration of two P2RX7 antagonists (CK, p = 0.030 and p = 0.050) without any detectable side effects. However, approaches successful in animal models still need to be proved effective in clinical practice. CONCLUSIONS: These results are, to our knowledge, the first to establish that a single treatment can improve muscle function both short and long term and also correct cognitive impairment and bone loss in DMD model mice. The wide-ranging improvements reflect the convergence of P2RX7 ablation on multiple disease mechanisms affecting skeletal and cardiac muscles, inflammatory cells, brain, and bone. Given the impact of P2RX7 blockade in the DMD mouse model, this receptor is an attractive target for translational research: existing drugs with established safety records could potentially be repurposed for treatment of this lethal disease.

The receptor for advanced glycation end products promotes pancreatic carcinogenesis and accumulation of myeloid-derived suppressor cells.

Pancreatic ductal adenocarcinoma (PDA) has an aggressive natural history and is resistant to therapy. The receptor for advanced glycation end products (RAGE) is a pattern recognition receptor for many damage-associated molecular pattern molecules. RAGE is overexpressed in both human and murine models of PDA as well as most advanced epithelial neoplasms. The immunosuppressive nature of the PDA microenvironment is facilitated, in part, by the accumulation of regulatory immune cell infiltrates such as myeloid-derived suppressor cells (MDSCs). To study the role of RAGE expression in the setting of mutant Ras-promoted pancreatic carcinogenesis (KC), a triple-transgenic model of spontaneous murine PDA in a RAGE-null background (KCR) was generated. KCR mice had markedly delayed pancreatic carcinogenesis and a significant diminution of MDSCs compared with KC mice at comparable time points postweaning. Although RAGE was not required for the development or suppressor activity of MDSCs, its absence was associated with temporally limited pancreatic neoplasia and altered phenotype and function of the myeloid cells. In lieu of MDSCs, KCR animals at comparable time points exhibited mature CD11b(+)Gr1(-)F4/80(+) cells that were not immunosuppressive in vitro. KCR mice also maintained a significantly less suppressive milieu evidenced by marked decreases in CCL22 in relation to CXCL10 and diminished serum levels of IL-6.

Regulation of immune responses by prostaglandin E2.

PGE(2), an essential homeostatic factor, is also a key mediator of immunopathology in chronic infections and cancer. The impact of PGE(2) reflects the balance between its cyclooxygenase 2-regulated synthesis and 15-hydroxyprostaglandin dehydrogenase-driven degradation and the pattern of expression of PGE(2) receptors. PGE(2) enhances its own production but suppresses acute inflammatory mediators, resulting in its predominance at late/chronic stages of immunity. PGE(2) supports activation of dendritic cells but suppresses their ability to attract naive, memory, and effector T cells. PGE(2) selectively suppresses effector functions of macrophages and neutrophils and the Th1-, CTL-, and NK cell-mediated type 1 immunity, but it promotes Th2, Th17, and regulatory T cell responses. PGE(2) modulates chemokine production, inhibiting the attraction of proinflammatory cells while enhancing local accumulation of regulatory T cells cells and myeloid-derived suppressor cells. Targeting the production, degradation, and responsiveness to PGE(2) provides tools to modulate the patterns of immunity in a wide range of diseases, from autoimmunity to cancer.

Polarized dendritic cells as cancer vaccines: directing effector-type T cells to tumors.

Ex vivo generation and antigen loading of dendritic cells (DCs) from cancer patients helps to bypass the dysfunction of endogenous DCs. It also allows to control the process of DC maturation and to imprint in maturing DCs several functions essential for induction of effective forms of cancer immunity. Recent reports from several groups including ours demonstrate that distinct conditions of DC generation and maturation can prime DCs for preferential interaction with different (effector versus regulatory) subsets of immune cells. Moreover, differentially-generated DCs have been shown to imprint different effector mechanisms in CD4(+) and CD8(+) T cells (delivery of "signal three") and to induce their different homing properties (delivery of "signal four"). These developments allow for selective induction of tumor-specific T cells with desirable effector functions and tumor-relevant homing properties and to direct the desirable types of immune cells to tumors.