The immunogenic properties of plasmid DNA and recombinant adenovirus (Ad) encoding the carcinoembryonic antigen (CEA) were examined in mice by measuring both the amplitude and type of immune response, and the immunogenicity of codon usage optimized cDNA encoding CEA (CEAopt) was assessed both in C57Bl/6 and CEA transgenic mice. Vectors were injected into quadriceps muscle either alone or in combination, and plasmid DNA was electroporated to enhance gene expression efficiency and immunogenicity. Injection of plasmid pVIJ/CEA followed by Ad-CEA boost elicited the highest amplitude of both CD4 1 and CD8 1 T-cell response to the target antigen, measured by both IFNc-ELIspot assay and intracellular staining. Vectors carrying cDNA of CEAopt expressed a greater amount of the CEA protein than their wild-type counterparts, and this enhanced expression was associated with greater immunogenicity. Both CD4 1 and CD8 1 T-cell epitopes were mapped in the C-terminal portion of the protein. In CEA transgenic mice, only immunization based on repeated injections of pVIJ/ CEAopt followed by Ad-CEAopt was able to elicit a CEA-specific CD8 1 T-cell response, whereas the wild-type vectors did not break tolerance to this target antigen. MC38-CEA tumor cells injected s.c. in CEA transgenic mice vaccinated with CEAopt vectors exhibited delayed growth kinetics. These studies demonstrate that this type of genetic vaccine is highly immunogenic and can break tolerance to CEA tumor antigen in CEA transgenic mice. ' 2005 Wiley-Liss, Inc.Key words: CEA; DNA electroporation; adenovirus Despite improvements in prevention, early detection and treatment, the possibility of curing many cancer patients remains elusive. Thus, cancer continues to be a largely unmet medical need for which more efficient therapeutic strategies must be developed. 1 Particular attention has been given to active specific immunotherapy of cancer, whereby patients are immunized against antigens presented by tumor cells. In fact, experimental and clinical evidence have demonstrated the critical role played by the cellular and humoral responses in controlling tumor growth and metastasis. 2 Many of these therapies are specifically targeted to tumorassociated antigens among which carcinoembryonic antigen (CEA) is a frequent example due to its ectopic and deregulated expression in a large percentage of adenocarcinomas. 3 Human CEA is the prototypic member of the human CEA family, a group of highly glycosylated homotypic/heterotypic cell surface intracellular adhesion molecules, and part of the immunoglobulin gene superfamily. CEA is widely used as human tumor marker, is expressed mostly in the gastrointestinal tract and is overexpressed in many human cancers, including epithelial tumors originating from the gastrointestinal tract, lung, thyroid, breast, prostate, cervix and ovaries. 4 CEA has been the focus of extensive preclinical and clinical investigation aimed at developing a CEA-specific vaccine with a therapeutic impact on tumor progression. 5 In this context, genetic vacc...

Myeloid-derived suppressor cells (MDSC) include immature monocytic (M-MDSC) and granulocytic (PMN-MDSC) cells that share the ability to suppress adaptive immunity and hinder the effectiveness of anti-cancer treatments. Of note, in response to interferon-γ (IFNγ) M-MDSC release the tumor-promoting and immunosuppressive molecule nitric oxide (NO), whereas macrophages largely express anti-tumor properties. Investigating these opposing activities, we found that tumor-derived prostaglandin E2 (PGE2) induces nuclear accumulation of p50 NF-κB in M-MDSC, diverting their response to IFNγ towards NO-mediated immunosuppression and reducing TNFα expression. At the genome level, p50 NF-κB promoted binding of STAT1 to regulatory Research.

In this account, we report the development of a series of substituted cinnamic anilides that represents a novel class of mitochondrial permeability transition pore (mPTP) inhibitors. Initial class expansion led to the establishment of the basic structural requirements for activity and to the identification of derivatives with inhibitory potency higher than that of the standard inhibitor cyclosporine-A (CsA). These compounds can inhibit mPTP opening in response to several stimuli including calcium overload, oxidative stress, and thiol cross-linkers. The activity of the cinnamic anilide mPTP inhibitors turned out to be additive with that of CsA, suggesting for these inhibitors a molecular target different from cyclophylin-D. In vitro and in vivo data are presented for (E)-3-(4-fluoro-3-hydroxy-phenyl)-N-naphthalen-1-yl-acrylamide 22, one of the most interesting compounds in this series, able to attenuate opening of the mPTP and limit reperfusion injury in a rabbit model of acute myocardial infarction.

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Cancer induces alteration of hematopoiesis to fuel disease progression. We report that in tumor-bearing mice the macrophage colony-stimulating factor elevates the myeloid cell levels of nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in the NAD salvage pathway, which acts as negative regulator of the CXCR4 retention axis of hematopoietic cells in the bone marrow. NAMPT inhibits CXCR4 through a NAD/Sirtuin 1-mediated inactivation of HIF1a-driven CXCR4 gene transcription, leading to mobilization of immature myeloid-derived suppressor cells (MDSC) and enhancing their production of suppressive nitric oxide. Pharmacologic inhibition or myeloid-specific ablation of NAMPT prevented MDSC mobilization, reactivated specific antitumor immunity, and enhanced the antitumor activity of immune checkpoint inhibitors. Our findings identify NAMPT as a metabolic gate of MDSC precursor function, providing new opportunities to reverse tumor immunosuppression and to restore clinical efficacy of immunotherapy in patients with cancer. Significance: These findings identify NAMPT as a metabolic gate of MDSC precursor function, providing new opportunities to reverse tumor immunosuppression and to restore clinical efficacy of immunotherapy in cancer patients.

Hematopoietic stem cells (HSCs) are regulated by signals from the bone marrow (BM) niche, which tune hematopoiesis at steady state and in hematologic disorders. To understand the HSC-niche interactions in altered non-malignant homeostasis, we elected as a paradigm β-thalassemia, a hemoglobin disorder. In this severe congenital anemia, secondary alterations to the primary hemoglobin defect have a potential impact on HSC-niche crosstalk. Here we report that HSCs in thalassemic mice (th3) have an impaired function, caused by the interaction with an altered BM niche. The HSC self-renewal defect is rescued upon transplantation into a normal microenvironment, thus proving the active role of BM stroma. Consistently with the common finding of osteoporosis in patients, we found reduced bone deposition with decreased levels of parathyroid hormone (PTH), which is a key regulator of bone metabolism but also of HSC activity. In vivo activation of PTH signaling through the reestablished Jagged1 and osteopontin levels correlates with the rescue of the functional pool of th3 HSCs by correcting HSC-niche crosstalk. Reduced HSC quiescence is confirmed in thalassemic patients, along with altered features of the BM stromal niche. Our findings uncover a defect of HSCs in β-thalassemia induced by an altered BM microenvironment and provide new relevant insight for improving transplantation and gene therapy approaches.

New evidences indicate that the metabolic instruction of immunity (immune metabolism) results from the integration of cell metabolism and whole-body metabolism, which are both influenced by nutrition, microbiome metabolites and disease-driven metabolism (e.g. cancer metabolism). Cancer metabolism influences the immunological homeostasis and promotes immune alterations that support disease progression, hence influencing the clinical outcome. Cancer cells display increased glucose uptake and fermentation of glucose to lactate, even in the presence of completely functioning mitochondria. A major side effect of this event is immunosuppression, characterized by limited immunogenicity of cancer cells and restriction of the therapeutic efficacy of anticancer immunotherapy. Here, we discuss how the metabolism of myeloid cells associated with cancer contributes to the differentiation of their suppressive phenotype and therefore to cancer immune evasion.

The epithelial cell adhesion molecule, Ep-CAM, has been historically considered a target of passive immunotherapy using monoclonal antibodies, and more recently, of a first Pox-vector-based cancer vaccine Phase I trial in colorectal cancer patients. To shed further light on the use of this antigen, we isolated the mouse and rhesus homologues of human Ep-CAM and explored different genetic vaccination modalities based on the use of adenoviral vectors as well as DNA electroporation (DNA-EP). Immune responses to Ep-CAM were measured by IFN-c ELISPOT and intracellular staining assays using overlapping sets of peptides covering the entire coding regions. We found the most powerful vaccination regimen to be constituted by DNA-EP-prime/Adeno-boost mixedmodality protocols. Vaccination in rhesus macaques resulted in breakage of immunological tolerance in a minority of cases. Similarly, a low frequency of responders was observed with the mouse Ep-CAM vaccine in outbred CD1 mice. When immunized CD1 mice were analyzed for MHC haplotype and TCR expression levels, we observed that immune responders all had the same q/q MHC class I haplotype and showed higher expression levels of the TCRVb4 and TCRVb8 T cell receptors. Our results underscore the current limitations in our capacity to induce efficient cancer vaccines against self antigens like Ep-CAM, but also represent a first effort to identify predictive biomarkers of response.See accompanying commentary: http://dx