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PURPOSE Despite unprecedented responses to immune checkpoint inhibitors and targeted therapy in melanoma, a major subset of patients progresses and have few effective salvage options. We have previously demonstrated robust, selective uptake of the peptidomimetic LLP2A labeled with Cu-64 ([64Cu]-LLP2A) for positron emission tomography (PET) imaging in subcutaneous and metastatic models of B16F10 murine melanoma. LLP2A binds with high affinity to very late antigen-4 (VLA-4, integrin α4β1), a transmembrane protein overexpressed in melanoma and other cancers that facilitates tumor growth and metastasis. Yet B16F10 fails to faithfully reflect human melanoma biology, as it lacks certain oncogenic driver mutations, including BRAF mutations found in ≥ 50 % of clinical specimens. Here, we evaluated the PET tracer [64Cu]-CB-TE1A1P-PEG4-LLP2A ([64Cu]-LLP2A) in novel, translational BRAFV600E mutant melanoma models differing in VLA-4 expression-BPR (VLA-4-) and BPRα (VLA-4+). PROCEDURES BPR cells were transduced with α4 (CD49d) to overexpress intact cell surface VLA-4 (BPRα). The binding affinity of [64Cu]-LLP2A to BPR and BPRα cells was determined by saturation binding assays. [64Cu]-LLP2A internalization into B16F10, BPR, and BPRα cells was quantified via a plate-based assay. Tracer biodistribution and PET/CT imaging were evaluated in mice bearing subcutaneous BPR and BPRα tumors. RESULTS [64Cu]-LLP2A demonstrated high binding affinity to BPRα (Kd = 1.4 nM) but indeterminate binding to BPR cells. VLA-4+ BPRα and B16F10 displayed comparable time-dependent [64Cu]-LLP2A internalization, whereas BPR internalization was undetectable. PET/CT showed increased tracer uptake in BPRα tumors vs. BPR tumors in vivo, which was validated by significantly greater (p

The CXCR4 chemokine receptor is an important biomolecular target in cancer diagnostics and therapeutics. In a new multivalent approach, iron oxide nanoparticles were conjugated with multiple binding units of a low affinity azamacrocylic CXCR4 antagonist. The silica coated nanostructure has good suspension stability, a mode size of 72 nm and high affinity for CXCR4, showing >98% inhibition of anti-CXCR4 mAb binding in a receptor binding competition assay on Jurkat cells.

Background Malignant gliomas are deadly tumours with few therapeutic options. Although immunotherapy may be a promising therapeutic strategy for treating gliomas, a significant barrier is the CD11b+ tumour-associated myeloid cells (TAMCs), a heterogeneous glioma infiltrate comprising up to 40% of a glioma's cellular mass that inhibits anti-tumour T-cell function and promotes tumour progression. A theranostic approach uses a single molecule for targeted radiopharmaceutical therapy (TRT) and diagnostic imaging; however, there are few reports of theranostics targeting the tumour microenvironment. Methods Utilizing a newly developed bifunctional chelator, Lumi804, an anti-CD11b antibody (αCD11b) was readily labelled with either Zr-89 or Lu-177, yielding functional radiolabelled conjugates for PET, SPECT, and TRT. Findings 89Zr/177Lu-labeled Lumi804-αCD11b enabled non-invasive imaging of TAMCs in murine gliomas. Additionally, 177Lu-Lumi804-αCD11b treatment reduced TAMC populations in the spleen and tumour and improved the efficacy of checkpoint immunotherapy. Interpretation 89Zr- and 177Lu-labeled Lumi804-αCD11b may be a promising theranostic pair for monitoring and reducing TAMCs in gliomas to improve immunotherapy responses. Funding A full list of funding bodies that contributed to this study can be found in the Acknowledgements section., Graphical abstract Image, graphical abstract

A series of six different 1,8-naphthalimide conjugated dipicolylamine ligands (L1-6) have been synthesised and characterised. The ligands possess a range of different linker units between the napthalimide fluorophore and dipcolylamine chelator which allow the overall lipophilicity to be tuned. A corresponding series of Re(i) complexes have been synthesised of the form fac-[Re(CO)3(L1-6)]BF4. The absorption and luminescence properties of the ligands and Re(i) complexes were dominated by the intramolecular charge transfer character of the substituted fluorophore (typically absorption ca. 425 nm and emission ca. 520 nm). Photophysical assessments show that some of the variants are moderately bright. Radiolabelling experiments using a water soluble ligand variant (L5) were successfully undertaken and optimised with fac-[99mTc(CO)3(H2O)3]+. Confocal fluorescence microscopy showed that fac-[Re(CO)3(L5)]+ localises in the mitochondria of MCF-7 cells. SPECT/CT imaging experiments on naïve mice showed that fac-[99mTc(CO)3(L5)]+ has a relatively high stability in vivo but did not show any cardiac uptake, demonstrating rapid clearance, predominantly via the biliary system along with a moderate amount cleared renally. ispartof: DALTON TRANSACTIONS vol:49 issue:2 pages:511-523 ispartof: location:England status: published

Expression of the chemokine receptor chemokine C-X-C motif receptor 4 (CXCR4) plays an important role in cancer metastasis, in autoimmune diseases, and during stem cell-based repair processes after stroke and myocardial infarction. Previously reported PET imaging agents targeting CXCR4 suffer from either high nonspecific uptake or bind only to the human form of the receptor. The objective of this study was to develop a high-stability 64Cu-labeled small-molecule PET agent for imaging both human and murine CXCR4 chemokine receptors. Methods: Synthesis, radiochemistry, stability and radioligand binding assays were performed for the novel tracer 64Cu-CuCB-bicyclam. In vivo dynamic PET studies were performed on mice bearing U87 (CXCR4 low-expressing) and U87.CXCR4 (human-CXCR4 high-expressing) tumors. Biodistribution and receptor blocking studies were performed on CD1-IGS immunocompetent mice. CXCR4 expression on tumor and liver disaggregates was confirmed using a combination of immunohistochemistry, quantitative polymerase chain reaction, and Western blot. Results:64Cu-CuCB-bicyclam has a high affinity for both the human and the murine variants of the CXCR4 receptor (half-maximal inhibitory concentration, 8 nM [human]/2 nM [murine]) and can be obtained from the parent chelator that has low affinity. In vitro and in vivo studies demonstrate specific uptake in CXCR4-expressing cells that can be blocked by more than 90% using a higher-affinity antagonist, with limited uptake in non-CXCR4-expressing organs and high in vivo stability. The tracer was also able to selectively displace the CXCR4 antagonists AMD3100 and AMD3465 from the liver. Conclusion: The tetraazamacrocyclic small molecule 64Cu-CuCB-bicyclam has been shown to be an imaging agent for the CXCR4 receptor that is likely to be applicable across a range of species. It has high affinity and stability and is suitable for preclinical research in immunocompetent murine models. ispartof: JOURNAL OF NUCLEAR MEDICINE vol:61 issue:1 pages:123-128 ispartof: location:United States status: published

PURPOSE: Despite unprecedented responses to immune checkpoint inhibitors and targeted therapy in melanoma, a major subset of patients progresses and have few effective salvage options. We have previously demonstrated robust, selective uptake of the peptidomimetic LLP2A labeled with Cu-64 ([(64)Cu]-LLP2A) for positron emission tomography (PET) imaging in subcutaneous and metastatic models of B16F10 murine melanoma. LLP2A binds with high affinity to very late antigen-4 (VLA-4, integrin α(4)β(1)), a transmembrane protein overexpressed in melanoma and other cancers that facilitates tumor growth and metastasis. Yet B16F10 fails to faithfully reflect human melanoma biology, as it lacks certain oncogenic driver mutations, including BRAF mutations found in ≥50% of clinical specimens. Here, we evaluated the PET tracer [(64)Cu]-CB-TE1A1P-PEG(4)-LLP2A ([(64)Cu]-LLP2A) in novel, translational BRAF(V600E) mutant melanoma models differing in VLA-4 expression - BPR (VLA-4(−)) and BPRα (VLA-4(+). PROCEDURES: BPR cells were transduced with α(4) (CD49d) to overexpress intact cell surface VLA-4 (BPRα). The binding affinity of [(64)Cu]-LLP2A to BPR and BPRα cells was determined by saturation binding assays. [(64)Cu]-LLP2A internalization into B16F10, BPR, and BPRα cells was quantified via a plate-based assay. Tracer biodistribution and PET/CT imaging were evaluated in mice bearing subcutaneous BPR and BPRα tumors. RESULTS: [(64)Cu]-LLP2A demonstrated high binding affinity to BPRα (K(d) = 1.4 nM) but indeterminate binding to BPR cells. VLA-4(+) BPRα and B16F10 displayed comparable time-dependent [(64)Cu]-LLP2A internalization, whereas BPR internalization was undetectable. PET/CT showed increased tracer uptake in BPRα tumors vs. BPR tumors in vivo, which was validated by significantly greater (p

Reaction of 5,11,17,23-tetra-tert-butyl-dihydroxy-26,28-bis(2-pentoxy)calix[4]arene (L(OH)2(Opentyl)2) with [TiCl4] afforded the dichlorotitanoacalix[4]arene complex [TiCl2L(O)2(Opentyl)2] (1) in good yield. Hydrolysis of 1 led to the isolation of the complex {[TiL(O)3(Opentyl)]2(μ-OH)(μ-Cl)} (2). Reaction of 5,11,17,23,29,35,41,47-p-tert-butyl-49,50,51,52,53,54,55,56-octapropoxycalix[8]arene (L'(Opropyl)8) with [TiCl4] in refluxing toluene afforded, following work-up, a 35 : 65 mixture (3) of the complex [Ti(NCMe)Cl]2[TiCl(μ-O)]2L' and the silicone grease derived complex [Ti(NCMe)Cl]2[Ti(μ-O)]2[OSi(CH3)2OSi(CH3)2O]L' in which the grease replaces two chloride ligands. The molecular structures of 1·2MeCN, 2·7¼MeCN, and 3·10MeCN have been determined. The complexes were studied using in vitro cell assays and were found to have CC50 values in the range 111-186 μM, i.e. they have low toxicity.

Inflammation plays a central role in the pathogenesis of acute lung injury (ALI) during both the acute pneumonitis stage and progression into the chronic fibroproliferative phase, leading to pulmonary fibrosis. Currently, there is an unmet clinical and research need for noninvasive ways to monitor lung inflammation through targeting of immunoregulatory pathways contributing to ALI pathogenesis. In this study, we evaluated the role of targeted imaging of very late antigen-4 (VLA-4), as a key integrin mediating the adhesion and recruitment of immune cells to inflamed tissues, in quantifying lung inflammation in a mouse model of lipopolysaccharide-induced ALI. Methods: ALI was induced by a single intratracheal administration of lipopolysaccharide (10, 20, or 40 μg per mouse) in C57BL/6J mice. Control mice were intratracheally instilled with sterile phosphate-buffered saline. VLA-4–targeted PET/CT was performed 24 h after intravenous injection of a (64)Cu-labeled high-affinity peptidomimetic ligand referred to as (64)Cu-LLP2A, which is conjugated with the chelator (1,4,8,11-tetraazacyclotetradecane-1-(methane phosphonic acid)-8-(methane carboxylic acid) and a polyethylene glycol 4 linker, at day 2 after the induction of ALI. Ex vivo biodistribution of (64)Cu-LLP2A was determined by γ-counting of harvested organs. The severity of lung inflammation was assessed histologically and by measuring the expression of inflammatory markers in the lung tissue lysates using reverse transcription quantitative polymerase chain reaction. Results: Intratracheal lipopolysaccharide instillation led to an acute inflammatory response in the lungs, characterized by increased expression of multiple inflammatory markers and infiltration of myeloid cells, along with a significant and specific increase in (64)Cu-LLP2A uptake, predominantly in a peribronchial distribution. There was a strong correlation between the lipopolysaccharide dose and (64)Cu-LLP2A uptake, as quantified by in vivo PET (R = 0.69, P < 0.01). Expression levels of both subunits of VLA-4, that is, integrins α(4) and β(1), significantly correlated with the expression of multiple inflammatory markers, including tumor necrosis factor-α, interleukin-1β, and nitric oxide synthase-2, highlighting the potential of VLA-4 as a surrogate marker of acute lung inflammation. Notably, in vivo (64)Cu-LLP2A uptake significantly correlated with the expression of multiple inflammatory markers and VLA-4. Conclusion: Our study demonstrates the feasibility of molecular imaging of VLA-4, as a mechanistically relevant target in ALI, and the accuracy of VLA-4–targeted PET in quantification of ongoing lung inflammation in a murine model.

A series of six different 1,8-naphthalimide conjugated dipicolylamine ligands (L1-6) have been synthesised and characterised. The ligands possess a range of different linker units between the napthalimide fluorophore and dipcolylamine chelator which allow the overall lipophilicity to be tuned. A corresponding series of Re(i) complexes have been synthesised of the form fac-[Re(CO)3(L1-6)]BF4. The absorption and luminescence properties of the ligands and Re(i) complexes were dominated by the intramolecular charge transfer character of the substituted fluorophore (typically absorption ca. 425 nm and emission ca. 520 nm). Photophysical assessments show that some of the variants are moderately bright. Radiolabelling experiments using a water soluble ligand variant (L5) were successfully undertaken and optimised with fac-[99mTc(CO)3(H2O)3]+. Confocal fluorescence microscopy showed that fac-[Re(CO)3(L5)]+ localises in the mitochondria of MCF-7 cells. SPECT/CT imaging experiments on naïve mice showed that fac-[99mTc(CO)3(L5)]+ has a relatively high stability in vivo but did not show any cardiac uptake, demonstrating rapid clearance, predominantly via the biliary system along with a moderate amount cleared renally.

The interaction of [VO(acac)2] with 2,6-bis(hydroxymethyl)-4-methylphenol (L1H3) or 6,6′-methylenebis(4-tert-butyl-2-(hydroxymethyl)phenol) (L2H4) in refluxing toluene afforded, following work-up in ethanol, the complexes [VOL1]2 (1) and {[VO(acac)(HOEt)](VO)L2]}2 (2), respectively. Use of 4-[3,5-bis(2-hydroxyphenyl)-1,2,4-triazol-1-yl]benzoic acid (L3H2) or 4-[3,5-bis(2-hydroxyphenyl)-1,2,4-triazol-1-yl]benzosulfonic acid (L4H2) with [VOCl3] in refluxing acetonitrile, followed by methanol and THF work-up, afforded the complexes [Et3NH][VO(OMe)L3]2 (3) and [Et3NH][VO(OMe)L4]2 (4), respectively. The interaction of [VOSO4] and L3H2 in refluxing acetonitrile afforded, with extraction into methanol, the complex [VO(OMe)L3]2 (5). The molecular structures of 2, 3 and 5 have been determined; the structure of 1 has been reported previously. The complexes in this study have been determined to be of low toxicity using in vitro cell assays with 50% cytotoxicity values (CC50) values in the range 56–126 µM.

DIPG is an incurable brain tumor with median overall survival times of less than 10 months, with current treatment. Immunotherapy is an attractive approach for some DIPG patients based on promising clinical and preclinical studies. However, due to surgical inaccessibility, intratumoral heterogeneity, and lack of biomarkers, patient stratification and real-time monitoring of immunotherapy is challenging. Furthermore, radiologic enlargement of tumors, due to immune cell infiltration (pseudoprogression) may result in premature removal from effective clinical trials. Molecular imaging of immunologic markers may allow for non-invasive quantification of tumor antigen levels, activated T-cells within tumors, and differentiation of tumor progression from pseudoprogression. Based on our previous experience, receptor densities/cell, cell type specificity, and analysis of publicly available gene expression data we selected EphA2, CD69, and CD45, for development of antibodies radiolabeled with Zr-89 to quantify receptor levels by positron emission tomography (PET). EphA2, a tumor antigen, could be used to stratify patients for therapy. CD69, a marker on activated lymphocytes, could be used to quantify activated NK and T-cells within the tumor. Finally, quantification of CD45, a highly expressed marker on immune cells, could be used to measure immune infiltrates to distinguish tumor growth from pseudoprogression. We have developed an immunotherapy sensitive syngeneic orthotopic cell injection DIPG model (SB-DIPG-11), using tumor cells isolated from de novo tumors induced by sleeping beauty transposon-mediated integration of DIPG-relevant oncogenic genes. Intravenous injection of radiotracers into SB-DIPG-11 tumor-bearing mice demonstrated standard uptake values (SUVs) of 3.9, 2.5, and 2.2 for Zr-89-labeled anti-EphA2, anti-CD69, and anti-CD45, in the tumors, respectively. All SUVs were dramatically reduced by pre-blocking of targets with unlabeled antibody. Biodistribution analysis and flow cytometry validated the SUVs. Overall, our data suggest that immunoPET quantification of tumor antigen and immune cell markers may be promising for stratification and monitoring of DIPG patients for immunotherapy.

A number of p-sulfonatocalix[4]arene complexes of the lanthanides (Tb, Gd, and Eu) have been prepared, some in the presence of tetraazamacrocycle 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (DO3A), and fully characterised. Crystal structure determinations reveal lanthanide coordination at the sulfonate group, bridging several calixarene units, giving coordination polymers. All complexes in this study have been determined to be relatively non-toxic using in vitro cell assays with CC50 values in the range 30–170 μM.

International audience; Objectives: Delocalized lipophilic cations, such as triphenylphosphonium (TPP), are able to cross cell membranes and are known to accumulate in the mitochondria in a membrane potential (MMP) dependent manner. MMP is a reliable indicator of mitochondrial and, consequently, cell and tissue function, hence MMP dependent uptake radiotracers are of interest in cardiac and tumour imaging. Conventional C-18F radiofluorination methods require strict aprotic conditions and heating, moreover, C-18F fluorinated tracers may suffer from metabolic defluorination reducing the quality of the images. The objective of this study was to investigate a suitability of o-B[18F]F3-phosphonium pincer moiety, easily accessible via radiofluorination of boronic ester precursors in aqueous mixtures to give high stability, for use as MMP dependent tracers.Methods: Required boronic ester precursors and cold 19F-fluorine labelled reference compounds 1-4 (Fig. 1) were prepared and purified following modified published synthetic protocols. Radiofluorination was carried out in a 0.2 mg scale with carrier added 18F-fluoride at 55oC in 30 min in 20% acetonitrile / water mixture acidified by addition of concentrated hydrochloric acid. LogD7.4 values were determined via the shake flask method. Stability in human serum was assessed using radio-HPLC analysis. The isolated mitochondria uptake assay was performed on freshly isolated mitochondria from Sprague-Dawley rat heart tissue. Cell uptake of the tracer was measured in normal H9c2 cardiac and U87 tumour cells in presence and absence of a membrane depolarizing agent 2-[2-(3-chlorophenyl)hydrazineylyidene]propanedinitrile (CCCP). PET/CT imaging and biodistribution studies were performed in CD-1 nude mice bearing U87 tumour xenografts. Overall charge distributions were calculated using fully optimised geometries at TPSS-D3/def2-TZVPP theory level. 18FHTP (6-18F-fluorohexyltriphenylphosphonium) was prepared in an original one step radiolabelling procedure from an iodinated precursor and was used to validate all assays and as a benchmark for the novel tracers.Results: 18FHTP and 18F-1-4 were obtained in 20-25% decay corrected radiochemical yields within 60 min from the end of bombardment. The LogD7.4 values ranged between 1.78±0.06 (18FHTP and 18F-2) and 0.52±0.01 (18F-1), with 0.88±0.09 and 1.11±0.08 for 18F-3 and 18F-4, respectively. All radiotracers showed 蠅 95% stability in human serum for 3 h. Tracers 18FHTP and 18F-2 showed a comparable MMP dependent uptake in isolated mitochondria (~8%), with the uptake of 18F-3 and 18F-4 below 4% and MMP independent, indicating the importance of the lipophilicity. U87 cell uptake of all tracers was low and MMP independent (~ 0.1% and 1% for 18FHTP and 18F-1-4 respectively). 18F-2 showed the highest and the only MMP dependent cell uptake from the series of new compounds(~ 4% vs ~7% observed for 18FHTP). None of BF3 group containing tracers showed any cardiac or tumour uptake in vivo. Overall charge distribution analysis in a computational study revealed a localised positive charge at the boron atom with partial negative charges carried by fluorine atoms or an ipso carbon of one of the unsubstituted phenyl rings.Conclusion: A series of o-BF3 substituted triphenylphosphonium tracers were successfully synthesized and radiolabelled with fluorine-18. A preliminary in vitro investigation confirmed the importance of the lipophilicity for mitochondrial uptake of the tracer, however, this was not sufficient to ensure cell membrane transport and consequent in vivo localization. The comparison of overall charge distribution maps suggests that addition of a BF3 group introduces a localized charge which is not compensated for by the charge of phosphonium and cannot be delocalised into the phenyl rings.

Glioblastoma is a lethal brain tumor, heavily infiltrated by tumor-associated myeloid cells (TAMCs). As up to 30% of a glioma cellular mass may be attributed to immunosuppressive myeloid cells, including myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs). TAMCs impede natural and immunotherapy-driven anti-tumor responses, they are a high-priority and promising therapeutic target currently being evaluated in clinical trials. Multiple preclinical and clinical trials have attempted to target these cells, however monitoring of biologic responses to therapy remains a challenge. Quantifying real time status of MDSCs and TAMs at the tumor site using non-invasive immunoPET could improve therapeutic response and allow for better patient stratification and monitoring of targeted treatment responses. TAMCs highly expressed the cell surface marker, integrin CD11b (Mac-1, αMβ2) and may be a highly effective imaging target for immunoPET strategies. The human/mouse cross-reactive anti-CD11b antibody (clone M1/70) was radiolabeled with 89Zr for PET imaging. PET/CT imaging, with or without a blocking dose of anti-CD11b Ab, was performed in mice bearing established orthotopic syngeneic GL261 gliomas. Flow cytometry and histology in tissues collected from post-imaging biodistribution validated targeting of CD11b+ MDSCs and TAMs. There was significant Zr-89-anti-CD11b Ab uptake in the tumor ipsilateral right brain (SUVmean = 2.6 ± 0.24) compared to contralateral left brain (SUVmean = 0.6 ± 0.11). Blocking with 10-fold lower specific activity 89Zr-anti-CD11b Ab reduced the SUV in right brain with (SUVmean = 0.11 ± 0.06). Immune rich organs spleen and lymph nodes showed high uptake. These results correlated with biodistribution analysis. CD11b expression in the right and left brain were validated using flow cytometry, H&E and IHC, showing high CD11b expression in the right brain. Imaging TAMs and MDSCs with 89Zr-labeled anti-CD11b Ab targeting was validated in a mouse model of malignant gliomas, demonstrating the feasibility of monitoring immune response during immunotherapy.

Diffuse intrinsic pontine glioma (DIPG) is one of the most lethal pediatric brain tumors. DIPG is insensitive to chemotherapy and surgically inaccessible, creating an urgent need for novel therapeutic approaches. We have been evaluating peptide vaccine immunotherapies that target glioma-associated antigens (GAAs). Enhancing the expression of these immunogenic GAAs and MHC I on tumor cells may promote immune-mediated tumor recognition and killing following peptide vaccine immunotherapy. DNA methyltransferase (DNMT) inhibitors have been shown to augment the expression of MHC, tumor antigens, and other immunosensitizing molecules. Guadecitabine (SGI-110), a next-generation DNMT inhibitor, has been developed to prolong tumor cell exposure to its active metabolite, decitabine. In this study, we investigated whether SGI-110 can immunosensitize glioma cells to peptide vaccine immunotherapy by enhancing their surface expression of MHC I and a GAA, EphA2. We developed a novel C57BL/6-syngeneic DIPG model by culturing cells from a Sleeping Beauty de novo DIPG induced in a neonatal mouse using a K27M-mutated histone 3.3 plasmid and other oncogenic plasmids (SB-DIPG-11). Flow cytometry analysis showed that SB-DIPG-11 cells express both MHC I (H-2Kb/H-2Db) and EphA2 on their surface. In vitro, treatment of SB-DIPG-11 or C57BL/6-syngeneic GL261 cells with SGI-110 resulted in a dose-dependent increase of MHC I and EphA2 surface expression. In vivo, subcutaneous administration of SGI-110 in combination with an EphA2-targeted peptide vaccine significantly prolonged the survival of mice bearing orthotopic DIPG-like tumors compared with the control treatment. Analysis of dissociated tumor tissue by flow cytometry showed elevated levels of MHC I and EphA2 in mice receiving SGI-110 or SGI-110 and peptide vaccine. Based on these data, we have begun evaluating SGI-110 with peptide vaccine in a distinct highly immunogenic syngeneic glioma model and whether subcutaneous or intracerebroventricular administration of the drug is more effective. Overall, SGI-110 may sensitize children with DIPG to peptide vaccine immunotherapy.

The structural features required for mitochondrial uptake of BODIPY-based optical imaging agents have been explored and are the first derivatives of this class of dyes shown to have mitochondrial membrane potential-dependent uptake in both cancer and heart cells have been developed.

International audience; The commercial availability of combined magnetic resonance imaging (MRI)/positron emission tomography (PET) scanners for clinical use has increased demand for easily prepared agents which offer signal or contrast in both modalities. Herein we describe a new class of silica coated iron–oxide nanorods (NRs) coated with polyethylene glycol (PEG) and/or a tetraazamacrocyclic chelator (DO3A). Studies of the coated NRs validate their composition and confirm their properties as in vivo T2 MRI contrast agents. Radiolabelling studies with the positron emitting radioisotope gallium-68 (t1/2 = 68 min) demonstrate that, in the presence of the silica coating, the macrocyclic chelator was not required for preparation of highly stable radiometal-NR constructs. In vivo PET-CT and MR imaging studies show the expected high liver uptake of gallium-68 radiolabelled nanorods with no significant release of gallium-68 metal ions, validating our innovation to provide a novel simple method for labelling of iron oxide NRs with a radiometal in the absence of a chelating unit that can be used for high sensitivity liver imaging.

CXCR4 is a chemokine receptor overexpressed in numerous cancer types that plays a key role in invasion and metastases. For this reason, CXCR4 appears as an interesting biomarker for the field of diagnostic oncology and in the past few years it has gained interest for application in molecular imaging. Both peptide-based and small molecules have been developed as CXCR4 inhibitors. Among all existing organic molecules, cyclam derivatives AMD3100 and AMD3465 were described as strong CXCR4 inhibitors. To image CXCR4 expression in tumor models, macromolecular agents such as 111In- and 18F-labeled peptides and 125 I-labeled monoclonal antibodies have been investigated using either SPECT or PET. Recently, AMD3100 and AMD3465 were directly radiolabeled with 99mTc and 64Cu, but these complexes have a low in vivo stability leading to the decomplexation of the metal. In this context, we decided to use the high affinity of these molecules for CXCR4 and to attach to these systems an optimized chelating agent in order to image CXCR4 by SPECT/PET imaging or MRI using different metals such as 111In, 64Cu, 68Ga or Gd. AMD3100 and AMD3465 were modified in order to introduce an adapted chelator. Our new analogues were then metalated with Gd, cold Ga, In, and Cu, but also 68Ga and 64Cu. Biological experiments on Jurkat and MCF-7 cell lines were performed to determine the affinity of our new imaging agents toward the CXCR4 receptor. We will present the synthetic pathway toward our new AMD analogues together with flow cytometry and radiolabelling experiments. Two compounds show promising results and will be used for in-vivo experiments. We report here new imaging agents targeting the chemokine receptor CXCR4 that could be use either for PET/SPECT and MRI. Our concept also offers the possibility of attaching a fluorescent tag for optical imaging or bimodal systems.

The milk loss due to Fasciolosis in dairy animals has been assessed in four major agro-ecological regions, viz. High-hills, Mid-hills, Bhabar, and Tarai area of Uttarakhand state. The prevalence rate of Fasciolosis has been found lower in the High-hills than in Mid-hills, Bhabar, and Tarai regions. A comparison of prevalence rates of Fasciolosis across different species and breeds has revealed a higher prevalence rate of Fasciolosis in buffaloes than in crossbred and indigenous cows. In buffaloes, the adverse effect of Fasciolosis, in terms of reduction in milk yield, becomes more prominent during the latter stages of lactation. The milk loss in the state due to Fasciolosis has been observed highest for buffaloes, followed distantly by crossbred and indigenous cows. The annual milk loss in the state of Uttarakhand due to Fasciolosis has been estimated to be of 90.41 crore. The milk loss has been found highest in buffaloes and since the adult female buffaloes constitute 66 per cent of the total bovine population in the state, Fasciolosis seems to be an important parasitic problem which needs to be tackled adequately to prevent substantial milk losses.

Common variants of fat mass and obesity-associated gene (FTO, fat mass- and obesity-associated gene) have been shown to be associated with obesity and type 2 diabetes in population of European and non-European ethnicity. However, studies in Indian population have provided inconsistent results. Here, we examined association of eight FTO variants (rs1421085, rs8050136, rs9939609, rs9930506, rs1861867, rs9926180, rs2540769 and rs708277) with obesity and type 2 diabetes in 5364 North Indians (2474 type 2 diabetes patients and 2890 non-diabetic controls) in two stages. None of the variants including previously reported intron 1 variants (rs1421085, rs8050136, rs9939609 and rs9930506) showed body mass index (BMI)-dependent/independent association with type 2 diabetes. However, rs1421085, rs8050136 and rs9939609 were associated with obesity status and measures of obesity (BMI, waist circumference and waist-to-hip ratio) in stage 2 and combined study population. Meta-analysis of the two study population results also revealed that rs1421085, rs8050136 and rs9939609 were significantly associated with BMI both under the random- and fixed-effect models (P (random/fixed)=0.02/0.0001, 0.004/0.0006 and 0.01/0.01, respectively). In conclusion, common variants of FTO were associated with obesity, but not with type 2 diabetes in North Indian population.