scholarly journals Development of [18F]FPy-WL12 as a PD-L1 Specific PET Imaging Peptide

2019 ◽  
Vol 18 ◽  
pp. 153601211985218 ◽  
Author(s):  
Wojciech G. Lesniak ◽  
Ronnie C. Mease ◽  
Samit Chatterjee ◽  
Dhiraj Kumar ◽  
Ala Lisok ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Ex Vivo ◽  
Whole Body ◽  
In Vivo Evaluation ◽  
Positron Emission ◽  
Comprehensive Picture ◽  
Specific Uptake ◽  
Ex Vivo Biodistribution

Expression of programmed cell death ligand 1 (PD-L1) within tumors is an important biomarker for guiding immune checkpoint therapies; however, immunohistochemistry-based methods of detection fail to provide a comprehensive picture of PD-L1 levels in an entire patient. To facilitate quantification of PD-L1 in the whole body, we developed a peptide-based, high-affinity PD-L1 imaging agent labeled with [18F]fluoride for positron emission tomography (PET) imaging. The parent peptide, WL12, and the nonradioactive analog of the radiotracer, 19FPy-WL12, inhibit PD-1/PD-L1 interaction at low nanomolar concentrations (half maximal inhibitory concentration [IC50], 26-32 nM). The radiotracer, [18F]FPy-WL12, was prepared by conjugating 2,3,5,6-tetrafluorophenyl 6-[18F]fluoronicotinate ([18F]FPy-TFP) to WL12 and assessed for specificity in vitro in 6 cancer cell lines with varying PD-L1 expression. The uptake of the radiotracer reflected the PD-L1 expression assessed by flow cytometry. Next, we performed the in vivo evaluation of [18F]FPy-WL12 in mice bearing cancer xenografts by PET imaging, ex vivo biodistribution, and blocking studies. In vivo data demonstrated a PD-L1-specific uptake of [18F]FPy-WL12 in tumors that is reduced in mice receiving a blocking dose. The majority of [18F]FPy-WL12 radioactivity was localized in the tumors, liver, and kidneys indicating the need for optimization of the labeling strategy to improve the in vivo pharmacokinetics of the radiotracer.

scholarly journals A Novel PET Imaging Using64Cu-Labeled Monoclonal Antibody against Mesothelin Commonly Expressed on Cancer Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Kazuko Kobayashi ◽  
Takanori Sasaki ◽  
Fumiaki Takenaka ◽  
Hiromasa Yakushiji ◽  
Yoshihiro Fujii ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Cancer Cells ◽  
Pet Imaging ◽  
Ex Vivo ◽  
Chelating Agent ◽  
Pancreatic Cancer Cells ◽  
Positron Emission ◽  
Wide Range

Mesothelin (MSLN) is a 40-kDa cell differentiation-associated glycoprotein appearing with carcinogenesis and is highly expressed in many human cancers, including the majority of pancreatic adenocarcinomas, ovarian cancers, and mesotheliomas, while its expression in normal tissue is limited to mesothelial cells lining the pleura, pericardium, and peritoneum. Clone 11-25 is a murine hybridoma secreting monoclonal antibody (mAb) against human MSLN. In this study, we applied the 11-25 mAb toin vivoimaging to detect MSLN-expressing tumors. Inin vitroandex vivoimmunochemical studies, we demonstrated specificity of 11-25 mAb to membranous MSLN expressed on several pancreatic cancer cells. We showed the accumulation of Alexa Fluor 750-labeled 11-25 mAb in MSLN-expressing tumor xenografts in athymic nude mice. Then, 11-25 mAb was labeled with64Cu via a chelating agent DOTA and was used in bothin vitrocell binding assay andin vivopositron emission tomography (PET) imaging in the tumor-bearing mice. We confirmed that64Cu-labeled 11-25 mAb highly accumulated in MSLN-expressing tumors as compared to MSLN-negative ones. The64Cu-labeled 11-25 mAb is potentially useful as a PET probe capable of being used for wide range of tumors, rather than18F-FDG that occasionally provides nonspecific accumulation into the inflammatory lesions.

scholarly journals IL-27Rα: A Novel Molecular Imaging Marker for Allograft Rejection

2020 ◽  
Vol 21 (4) ◽  
pp. 1315 ◽  
Author(s):  
Shanshan Zhao ◽  
Dai Shi ◽  
Chen Su ◽  
Wen Jiang ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Molecular Imaging ◽  
Graft Rejection ◽  
Ex Vivo ◽  
Inflammatory Diseases ◽  
Whole Body ◽  
Specific Marker ◽  
Post Transplantation ◽  
Ex Vivo Biodistribution

Non-invasively monitoring allogeneic graft rejection with a specific marker is of great importance for prognosis of patients. Recently, data revealed that IL-27Rα was up-regulated in alloreactive CD4+ T cells and participated in inflammatory diseases. Here, we evaluated whether IL-27Rα could be used in monitoring allogeneic graft rejection both in vitro and in vivo. Allogeneic (C57BL/6 donor to BALB/c recipient) and syngeneic (BALB/c both as donor and recipient) skin grafted mouse models were established. The expression of IL-27Rα in grafts was detected. The radio-probe, 125I-anti-IL-27Rα mAb, was prepared. Dynamic whole-body phosphor-autoradiography, ex vivo biodistribution and immunofluorescence staining were performed. The results showed that the highest expression of IL-27Rα was detected in allogeneic grafts on day 10 post transplantation (top period of allorejection). 125I-anti-IL-27Rα mAb was successfully prepared with higher specificity and affinity. Whole-body phosphor-autoradiography showed higher radioactivity accumulation in allogeneic grafts than syngeneic grafts on day 10. The uptake of 125I-anti-IL-27Rα mAb in allogeneic grafts could be almost totally blocked by pre-injection with excess unlabeled anti-IL-27Rα mAb. Interestingly, we found that 125I-anti-IL-27Rα mAb accumulated in allogeneic grafts, along with weaker inflammation earlier on day 6. The high uptake of 125I-anti-IL-27Rα mAb was correlated with the higher infiltrated IL-27Rα positive cells (CD3+/CD68+) in allogeneic grafts. In conclusion, IL-27Rα may be a novel molecular imaging marker to predict allorejection.

scholarly journals Preclinical and Exploratory Clinical Studies of Novel 68Ga-labeled ᴅ-Peptide Antagonist for PET Imaging of TIGIT Expression in Cancers

2021 ◽  
Author(s):  
Xiaobo Wang ◽  
Ming Zhou ◽  
Bei Chen ◽  
Huanhuan Liu ◽  
Jianyang Fang ◽  
...  
Keyword(s):  
Pilot Study ◽  
Pet Imaging ◽  
Ex Vivo ◽  
Ct Imaging ◽  
Whole Body ◽  
Binding Assays ◽  
Pet Ct ◽  
Peptide Antagonist

Abstract Purpose While TIGIT has been propelled under the spotlight as a next-generation target in cancer immunotherapy, anti-TIGIT therapy seems to be promising for a fraction of patients in clinical trials. Therefore, patient stratification is critical for this therapy, which could benefit from a whole-body, non-invasive and quantitative evaluation of TIGIT expression in cancers. In this study, a 68Ga-labeled ᴅ-peptide antagonist, 68Ga-GP12, was developed and validated for PET imaging of TIGIT expression in vitro, in vivo, and first-in-human pilot study. Methods The ᴅ-enantiomer peptide antagonists were modified and radiolabeled with 68Ga. In vitro binding assays were performed in human peripheral blood mononuclear cells (PBMCs) to assess their affinity and specificity. The imaging capacity, biodistribution, pharmacokinetics, and radiation dosimetry were investigated in vivo. Flow cytometry, autoradiography, and immunohistochemical staining were used to confirm the expression of TIGIT ex vivo. The safety and potential of 68Ga-GP12 for PET/CT imaging of TIGIT expression were further evaluated in a first-in-human pilot study with advanced NSCLC. Results 68Ga-labeled ᴅ-peptides were conveniently produced with high radiochemical yields,radiochemical purity and molar activities. In vitro binding assays demonstrated 68Ga-GP12 has favorable affinity and specificity for TIGIT with a KD of 37.28 nM. In vivo and ex vivo studies demonstrated the favorable pharmacokinetics of 68Ga-GP12 for PET imaging of TIGIT expression with high tumor uptake of 4.22 ± 0.68 %ID/g and the tumor-to-muscle ratio of 12.94 ± 2.64 at 60 min post-injection. The primary and metastatic lesions found in the first-in-human studies of 68Ga-GP12 PET/CT imaging were comparable to that in 18F-FDG PET/CT imaging. Moreover, the inhomogenous intra-and-inter-tumoral uptake of 68Ga-GP12 was presented, reflecting the heterogeneity of TIGIT expression levels. Conclusion 68Ga-GP12 is a promising radiotracer for PET imaging of TIGIT expression in cancers, indicating its potential as a potential companion diagnostic for anti-TIGIT therapies.

scholarly journals Development of a blood sample detector for multi-tracer positron emission tomography using gamma spectroscopy

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Carlos Velasco ◽  
Adriana Mota-Cobián ◽  
Jesús Mateo ◽  
Samuel España
Keyword(s):  
Positron Emission Tomography ◽  
Blood Sample ◽  
Pet Imaging ◽  
Spectroscopic Analysis ◽  
Gamma Spectroscopy ◽  
Emission Tomography ◽  
Blood Samples ◽  
Positron Emission

Abstract Background Multi-tracer positron emission tomography (PET) imaging can be accomplished by applying multi-tracer compartment modeling. Recently, a method has been proposed in which the arterial input functions (AIFs) of the multi-tracer PET scan are explicitly derived. For that purpose, a gamma spectroscopic analysis is performed on blood samples manually withdrawn from the patient when at least one of the co-injected tracers is based on a non-pure positron emitter. Alternatively, these blood samples required for the spectroscopic analysis may be obtained and analyzed on site by an automated detection device, thus minimizing analysis time and radiation exposure of the operating personnel. In this work, a new automated blood sample detector based on silicon photomultipliers (SiPMs) for single- and multi-tracer PET imaging is presented, characterized, and tested in vitro and in vivo. Results The detector presented in this work stores and analyzes on-the-fly single and coincidence detected events. A sensitivity of 22.6 cps/(kBq/mL) and 1.7 cps/(kBq/mL) was obtained for single and coincidence events respectively. An energy resolution of 35% full-width-half-maximum (FWHM) at 511 keV and a minimum detectable activity of 0.30 ± 0.08 kBq/mL in single mode were obtained. The in vivo AIFs obtained with the detector show an excellent Pearson’s correlation (r = 0.996, p < 0.0001) with the ones obtained from well counter analysis of discrete blood samples. Moreover, in vitro experiments demonstrate the capability of the detector to apply the gamma spectroscopic analysis on a mixture of 68Ga and 18F and separate the individual signal emitted from each one. Conclusions Characterization and in vivo evaluation under realistic experimental conditions showed that the detector proposed in this work offers excellent sensibility and stability. The device also showed to successfully separate individual signals emitted from a mixture of radioisotopes. Therefore, the blood sample detector presented in this study allows fully automatic AIFs measurements during single- and multi-tracer PET studies.

Synthesis and characterization of Chitosan-Catechol conjugates: Development and in vitro, in silico and in vivo evaluation of mucoadhesive pellets of lafutidine

2021 ◽  
pp. 088391152199784
Author(s):  
Loveleen Kaur ◽  
Ajay Kumar Thakur ◽  
Pradeep Kumar ◽  
Inderbir Singh
Keyword(s):  
Drug Release ◽  
In Silico ◽  
Ex Vivo ◽  
Strong Interactions ◽  
Dissolution Time ◽  
Sem Images ◽  
In Vivo Evaluation ◽  
Release Studies

Present study was aimed to synthesize and characterize Chitosan-Catechol conjugates and to design and develop mucoadhesive pellets loaded with lafutidine. SEM images indicated the presence of fibrous structures responsible for enhanced mucoadhesive potential of Chitosan-Catechol conjugates. Thermodynamic stability and amorphous nature of conjugates was confirmed by DSC and XRD studies respectively. Rheological studies were used to evaluate polymer mucin interactions wherein strong interactions between Chitosan-Catechol conjugate and mucin was observed in comparison to pristine chitosan and mucin. The mucoadhesion potential of Chitosan-Catechol (Cht-C) versus Chitosan (Cht) was assessed in silico using molecular mechanics simulations and the results obtained were compared with the in vitro and ex vivo results. Cht-C/mucin demonstrated much higher energy stabilization (∆E ≈ −65 kcal/mol) as compared to Cht/mucin molecular complex. Lafutidine-loaded pellets were prepared from Chitosan (LPC) and Chitosan-Catechol conjugates (LPCC) and were evaluated for various physical properties viz. flow, circularity, roundness, friability, drug content, particle size and percent mucoadhesion. In vitro drug release studies on LPC and LPCC pellets were performed for computing t50%, t90% and mean dissolution time. The values of release exponent from Korsmeyer-Peppas model was reported to be 0.443 and 0.759 for LPC and LPCC pellets suggesting Fickian and non-Fickian mechanism representing drug release, respectively. In vivo results depicted significant controlled release and enhanced residence of the drug after being released from the chitosan-catechol coated pellets. Chitosan-Catechol conjugates were found to be a promising biooadhesive polymer for the development of various mucoadhesive formulations.

scholarly journals Effect of ethanol and cocaine on [11C]MPC-6827 uptake in SH-SY5Y cells

2021 ◽  
Author(s):  
Naresh Damuka ◽  
Miranda Orr ◽  
Paul W. Czoty ◽  
Jeffrey L. Weiner ◽  
Thomas J. Martin ◽  
...  
Keyword(s):  
Mechanism Of Action ◽  
Ex Vivo ◽  
Neuroblastoma Cells ◽  
Proper Function ◽  
Brain Functions ◽  
Biodistribution Studies ◽  
Positron Emission ◽  
Vitro Binding

AbstractMicrotubules (MTs) are structural units in the cytoskeleton. In brain cells they are responsible for axonal transport, information processing, and signaling mechanisms. Proper function of these processes is critical for healthy brain functions. Alcohol and substance use disorders (AUD/SUDs) affects the function and organization of MTs in the brain, making them a potential neuroimaging marker to study the resulting impairment of overall neurobehavioral and cognitive processes. Our lab reported the first brain-penetrant MT-tracking Positron Emission Tomography (PET) ligand [11C]MPC-6827 and demonstrated its in vivo utility in rodents and non-human primates. To further explore the in vivo imaging potential of [11C]MPC-6827, we need to investigate its mechanism of action. Here, we report preliminary in vitro binding results in SH-SY5Y neuroblastoma cells exposed to ethanol (EtOH) or cocaine in combination with multiple agents that alter MT stability. EtOH and cocaine treatments increased MT stability and decreased free tubulin monomers. Our initial cell-binding assay demonstrated that [11C]MPC-6827 may have high affinity to free/unbound tubulin units. Consistent with this mechanism of action, we observed lower [11C]MPC-6827 uptake in SH-SY5Y cells after EtOH and cocaine treatments (e.g., fewer free tubulin units). We are currently performing in vivo PET imaging and ex vivo biodistribution studies in rodent and nonhuman primate models of AUD and SUDs and Alzheimer's disease.

scholarly journals Effect of Processing on Fish Protein Antigenicity and Allergenicity

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 969
Author(s):  
Xingyi Jiang ◽  
Qinchun Rao
Keyword(s):  
Fish Species ◽  
Protein Denaturation ◽  
Ex Vivo ◽  
Protein Solubility ◽  
Future Research ◽  
Food Protein ◽  
In Vivo Evaluation ◽  
Fish Allergy

Fish allergy is a life-long food allergy whose prevalence is affected by many demographic factors. Currently, there is no cure for fish allergy, which can only be managed by strict avoidance of fish in the diet. According to the WHO/IUIS Allergen Nomenclature Sub-Committee, 12 fish proteins are recognized as allergens. Different processing (thermal and non-thermal) techniques are applied to fish and fishery products to reduce microorganisms, extend shelf life, and alter organoleptic/nutritional properties. In this concise review, the development of a consistent terminology for studying food protein immunogenicity, antigenicity, and allergenicity is proposed. It also summarizes that food processing may lead to a decrease, no change, or even increase in fish antigenicity and allergenicity due to the change of protein solubility, protein denaturation, and the modification of linear or conformational epitopes. Recent studies investigated the effect of processing on fish antigenicity/allergenicity and were mainly conducted on commonly consumed fish species and major fish allergens using in vitro methods. Future research areas such as novel fish species/allergens and ex vivo/in vivo evaluation methods would convey a comprehensive view of the relationship between processing and fish allergy.

scholarly journals IMMU-31. QUANTITATIVE EVALUATION OF ROUTES OF ADMINISTRATION OF IMMUNOTHERAPEUTIC T CELLS TO ORTHOTOPIC GLIOMA

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii111-ii111
Author(s):  
Lan Hoang-Minh ◽  
Angelie Rivera-Rodriguez ◽  
Fernanda Pohl-Guimarães ◽  
Seth Currlin ◽  
Christina Von Roemeling ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Growth ◽  
Ex Vivo ◽  
Adoptive T Cell Therapy ◽  
Whole Body ◽  
T Cell Therapy ◽  
Clinical Responses

Abstract SIGNIFICANCE Adoptive T cell therapy (ACT) has emerged as the most effective treatment against advanced malignant melanoma, eliciting remarkable objective clinical responses in up to 75% of patients with refractory metastatic disease, including within the central nervous system. Immunologic surrogate endpoints correlating with treatment outcome have been identified in these patients, with clinical responses being dependent on the migration of transferred T cells to sites of tumor growth. OBJECTIVE We investigated the biodistribution of intravenously or intraventricularly administered T cells in a murine model of glioblastoma at whole body, organ, and cellular levels. METHODS gp100-specific T cells were isolated from the spleens of pmel DsRed transgenic C57BL/6 mice and injected intravenously or intraventricularly, after in vitro expansion and activation, in murine KR158B-Luc-gp100 glioma-bearing mice. To determine transferred T cell spatial distribution, the brain, lymph nodes, heart, lungs, spleen, liver, and kidneys of mice were processed for 3D imaging using light-sheet and multiphoton imaging. ACT T cell quantification in various organs was performed ex vivo using flow cytometry, 2D optical imaging (IVIS), and magnetic particle imaging (MPI) after ferucarbotran nanoparticle transfection of T cells. T cell biodistribution was also assessed in vivo using MPI. RESULTS Following T cell intravenous injection, the spleen, liver, and lungs accounted for more than 90% of transferred T cells; the proportion of DsRed T cells in the brains was found to be very low, hovering below 1%. In contrast, most ACT T cells persisted in the tumor-bearing brains following intraventricular injections. ACT T cells mostly concentrated at the periphery of tumor masses and in proximity to blood vessels. CONCLUSIONS The success of ACT immunotherapy for brain tumors requires optimization of delivery route, dosing regimen, and enhancement of tumor-specific lymphocyte trafficking and effector functions to achieve maximal penetration and persistence at sites of invasive tumor growth.

scholarly journals In Vitro and In Vivo Evaluation of Human Adenovirus Type 49 as a Vector for Therapeutic Applications

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1483
Author(s):  
Emily A. Bates ◽  
John R. Counsell ◽  
Sophie Alizert ◽  
Alexander T. Baker ◽  
Natalie Suff ◽  
...  
Keyword(s):  
Viral Vector ◽  
Ex Vivo ◽  
Human Adenovirus ◽  
Adenovirus Type ◽  
Cell Types ◽  
In Vivo Evaluation ◽  
In Vivo Biodistribution ◽  
Adenovirus Type 5

The human adenovirus phylogenetic tree is split across seven species (A–G). Species D adenoviruses offer potential advantages for gene therapy applications, with low rates of pre-existing immunity detected across screened populations. However, many aspects of the basic virology of species D—such as their cellular tropism, receptor usage, and in vivo biodistribution profile—remain unknown. Here, we have characterized human adenovirus type 49 (HAdV-D49)—a relatively understudied species D member. We report that HAdV-D49 does not appear to use a single pathway to gain cell entry, but appears able to interact with various surface molecules for entry. As such, HAdV-D49 can transduce a broad range of cell types in vitro, with variable engagement of blood coagulation FX. Interestingly, when comparing in vivo biodistribution to adenovirus type 5, HAdV-D49 vectors show reduced liver targeting, whilst maintaining transduction of lung and spleen. Overall, this presents HAdV-D49 as a robust viral vector platform for ex vivo manipulation of human cells, and for in vivo applications where the therapeutic goal is to target the lung or gain access to immune cells in the spleen, whilst avoiding liver interactions, such as intravascular vaccine applications.

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