scholarly journals Site-Specific Radiolabeling of a Human PD-L1 Nanobody via Maleimide–Cysteine Chemistry

2021 ◽  
Vol 14 (6) ◽  
pp. 550
Author(s):  
Dora Mugoli Chigoho ◽  
Quentin Lecocq ◽  
Robin Maximilian Awad ◽  
Karine Breckpot ◽  
Nick Devoogdt ◽  
...  
Keyword(s):  
Checkpoint Inhibitors ◽  
Ex Vivo ◽  
Tracer Uptake ◽  
Whole Body ◽  
Cancer Therapies ◽  
Tumor Biopsy ◽  
Efficient Treatment ◽  
Site Specific ◽  
Ex Vivo Biodistribution

Immune checkpoint inhibitors targeting the programmed cell death-1 (PD-1) and its ligand PD-L1 have proven to be efficient cancer therapies in a subset of patients. From all the patients with various cancer types, only 20% have a positive response. Being able to distinguish patients that do express PD-1/PD-L1 from patients that do not allows patients to benefit from a more personalized and efficient treatment of tumor lesion(s). Expression of PD-1 and PD-L1 is typically assessed via immunohistochemical detection in a tumor biopsy. However, this method does not take in account the expression heterogeneity within the lesion, nor the possible metastasis. To visualize whole-body PD-L1 expression by PET imaging, we developed a nanobody-based radio-immunotracer targeting PD-L1 site-specifically labeled with gallium-68. The cysteine-tagged nanobody was site-specifically conjugated with a maleimide (mal)-NOTA chelator and radiolabeling was tested at different nanobody concentrations and temperatures. Affinity and specificity of the tracer, referred to as [68Ga]Ga-NOTA-mal-hPD-L1 Nb, were assayed by surface plasmon resonance and on PD-L1POS or PD-L1NEG 624-MEL cells. Xenografted athymic nude mice bearing 624-MEL PD-L1POS or PD-L1NEG tumors were injected with the tracer and ex vivo biodistribution was performed 1 h 20 min post-injection. Ideal 68Ga-labeling conditions were found at 50 °C for 15 min. [68Ga]Ga-NOTA-mal-hPD-L1 Nb was obtained in 80 ± 5% DC-RCY with a RCP > 99%, and was stable in injection buffer and human serum up to 3 h (>99% RCP). The in vitro characterization showed that the NOTA-functionalized Nb retained its affinity and specificity. Ex vivo biodistribution revealed a tracer uptake of 1.86 ± 0.67% IA/g in the positive tumors compared with 0.42 ± 0.04% IA/g in the negative tumors. Low background uptake was measured in the other organs and tissues, except for the kidneys and bladder, due to the expected excretion route of Nbs. The data obtained show that the site-specific 68Ga-labeled NOTA-mal-hPD-L1 Nb is a promising PET radio-immunotracer due to its ease of production, stability and specificity for PD-L1.

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 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 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.

Detection of allergen-induced airway hyperresponsiveness in isolated mouse lungs

2006 ◽  
Vol 291 (3) ◽  
pp. L466-L472 ◽  
Author(s):  
Martin Witzenrath ◽  
Birgit Ahrens ◽  
Stefanie M. Kube ◽  
Armin Braun ◽  
Heinz G. Hoymann ◽  
...  
Keyword(s):  
Airway Hyperresponsiveness ◽  
Ex Vivo ◽  
Whole Body ◽  
Strongly Correlated ◽  
Ex Vivo Model ◽  
Isolated Lungs ◽  
Spontaneously Breathing

Airway hyperresponsiveness (AHR) is a hallmark of bronchial asthma. Important features of this exaggerated response to bronchoconstrictive stimuli have mostly been investigated in vivo in intact animals or in vitro in isolated tracheal or bronchial tissues. Both approaches have important advantages but also certain limitations. Therefore, the aim of our study was to develop an ex vivo model of isolated lungs from sensitized mice for the investigation of airway responsiveness (AR). BALB/c mice were sensitized by intraperitoneal ovalbumin (Ova) and subsequently challenged by Ova inhalation. In vivo AR was measured in unrestrained animals by whole body plethysmography after stimulation with aerosolized methacholine (MCh) with determination of enhanced pause ( Penh). Twenty-four hours after each Penh measurement, airway resistance was continuously registered in isolated, perfused, and ventilated lungs on stimulation with inhaled or intravascular MCh or nebulized Ova. In a subset of experiments, in vivo AR was additionally measured in orotracheally intubated, spontaneously breathing mice 24 h after Penh measurement, and lungs were isolated further 24 h later. Isolated lungs of allergen-sensitized and -challenged mice showed increased AR after MCh inhalation or infusion as well as after specific provocation with aerosolized allergen. AR was increased on days 2 and 5 after Ova challenge and had returned to baseline on day 9. AHR in isolated lungs after aerosolized or intravascular MCh strongly correlated with in vivo AR. Pretreatment of isolated lungs with the β2-agonist fenoterol diminished AR. In conclusion, this model provides new opportunities to investigate mechanisms of AHR as well as pharmacological interventions on an intact organ level.

scholarly journals Direct anabolic three carbon metabolism via propionate to a six carbon metabolite occurs in human heart and in vivo across mouse tissues

2019 ◽  
Author(s):  
Mary T. Doan ◽  
Michael D. Neinast ◽  
Erika L Varner ◽  
Kenneth Bedi ◽  
David Bartee ◽  
...  
Keyword(s):  
Human Heart ◽  
Ex Vivo ◽  
Tibialis Anterior Muscle ◽  
Whole Body ◽  
List Type ◽  
Isotope Tracing ◽  
Brown Adipose ◽  
Mouse Tissues

AbstractAnabolic metabolism of carbon in mammals is mediated via the one and two carbon carriers S-adenosyl methionine and acetyl-coenzyme A (acetyl-CoA). In contrast, anabolic metabolism using three carbon units via propionate is not thought to occur. Mammals are primarily thought to oxidize the 3-carbon short chain fatty acid propionate by shunting propionyl-CoA to succinyl-CoA for entry into the TCA cycle. We found that this may not be absolute and that in mammals one non-oxidative fate of two units of propionyl-CoA is to condense to a six-carbon trans-2-methyl-2-pentenoyl-CoA (2M2PE-CoA). We confirmed this pathway using purified protein extracts provided limited substrates and confirmed the product with a synthetic standard. In whole-body in vivo stable isotope tracing with infusion of 13C-labeled valine achieving steady state, 2M2PE-CoA formed via propionyl-CoA in multiple murine tissues including heart, kidney, and to a lesser degree in brown adipose tissue, liver, and tibialis anterior muscle. Using ex vivo isotope tracing, we found that 2M2PE-CoA formed in human myocardial tissue incubated with propionate to a limited extent. While the complete enzymology of this pathway remains to be elucidated, these results confirm the in vivo existence of at least one anabolic three to six carbon reaction conserved in humans and mice that utilizes three carbons via propionate.Highlights- Synthesis and confirmation of structure 2-methyl-2-pentenoyl-CoA- In vivo fate of valine across organs includes formation of a 6-carbon metabolite from propionyl-CoA- Ex vivo metabolism of propionate in the human heart includes direct anabolism to a 6-carbon product- In both cases, this reaction occurred at physiologically relevant concentrations of propionate and valine- In vitro this pathway requires propionyl-CoA and NADH/NADPH as substrates

Whole body PD-1 and PD-L1 PET with 89Zr-nivolumab and 18F- BMS-986192 in pts with NSCLC.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e20047-e20047 ◽  
Author(s):  
Anna-Larissa N. Niemeijer ◽  
Egbert F. Smit ◽  
G.a.M.S. van Dongen ◽  
A.D. Windhorst ◽  
Marc C. Huisman ◽  
...  
Keyword(s):  
Treatment Outcome ◽  
Tracer Uptake ◽  
Whole Body ◽  
Tumor Uptake ◽  
Treatment Results ◽  
Tumor Biopsy ◽  
Small Clinical Trial ◽  
Tissue Contrast ◽  
Substantial Heterogeneity ◽  
Clinical Trial Information

e20047 Background: Tumor PD-L1 IHC relates moderately with treatment outcome following anti-PD-(L)1 monotherapy in pts with NSCLC. Aim: 1. To assess safety of the PET procedures. 2. To quantify PD-1 and PD-L1 expression in tumors with 89Zirconium-labeled nivolumab (89Zr-nivo) and 18F-labeled BMS-986192 (18F-PD-L1) PET. 3. To assess intra- and inter-patient tracer uptake differences in tumors. 4. To correlate PET results with IHC and treatment outcome. Methods: NSCLC pts eligible for treatment with nivolumab were included. Pts received a dynamic and static whole body 18F-PD-L1 and a static 89Zr-nivo PET scan. A baseline tumor biopsy was required and up to two additional biopsies were allowed in case PET showed heterogeneous tumor uptake. SUVpeak was calculated for all delineable tumor lesions and related to PD-(L)1 IHC (28.8 assay) and response after 6 wks of nivolumab treatment. Results: 7 pts (5 ≥1%, 2 ≥50% and 2 negative by PD-L1 IHC) were enrolled and 11 lesions analyzed. No toxicity related to radiotracer administration was identified. Tumor uptake of both tracers was visualized in all pts. There was substantial variability among pts for 18F-PD-L1 (mean SUV 5.4, range 2.2 - 14.4) and 89Zr-nivo (mean SUV 5.0, range 1.6 - 9.7). Intra-patient tracer uptake heterogeneity was also seen: mean 2.5-fold (±0.96) and 2.3-fold (±0.86) differences between lesions for 18F-PD-L1 and 89Zr-nivo SUV, respectively. For lesions with < 50% PD-L1 IHC mean 18F-PD-L1 SUV was 3.4 (±2.9) as compared to 7.1 (±6.0) for lesions with ≥50% PD-L1 IHC (p = 0.22). For lesions with low PD-1 expression mean 89Zr-nivo SUV was 6.9 (±2.7) as compared to 8.1 (±2.0) for lesions with high PD-1 expression (p = 0.44). Five pts were evaluable for response evaluation: 1 PR, 2 SD and 2 PD with 18F-PD-L1 SUV values (most PET avid lesion) of 14.4 (PR), 2.0 and 5.4 (SD) and 6.4 and 6.6 (PD). Conclusion: 1.PET-imaging with both tracers is safe and feasible, with good tumor-to-normal tissue contrast. 2. Tumor uptake demonstrated substantial heterogeneity among pts and among tumors within the same pts. 3. Although higher 18F-PD-L1 tumor uptake was seen in pts with ≥50% tumor PD-L1 IHC and the highest 18F-PD-L1 SUV was measured in the responding pt, the dataset is still very small. Clinical trial information: 2015-004760-11.

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