scholarly journals Antibody-guided in vivo imaging of Aspergillus fumigatus lung infections during antifungal azole treatment

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sophie Henneberg ◽  
Anja Hasenberg ◽  
Andreas Maurer ◽  
Franziska Neumann ◽  
Lea Bornemann ◽  
...  

AbstractInvasive pulmonary aspergillosis (IPA) is a life-threatening lung disease of immunocompromised humans, caused by the opportunistic fungal pathogen Aspergillus fumigatus. Inadequacies in current diagnostic procedures mean that early diagnosis of the disease, critical to patient survival, remains a major clinical challenge, and is leading to the empiric use of antifungal drugs and emergence of azole resistance. A non-invasive procedure that allows both unambiguous detection of IPA and its response to azole treatment is therefore needed. Here, we show that a humanised Aspergillus-specific monoclonal antibody, dual labelled with a radionuclide and fluorophore, can be used in immunoPET/MRI in vivo in a neutropenic mouse model and 3D light sheet fluorescence microscopy ex vivo in the infected mouse lungs to quantify early A. fumigatus lung infections and to monitor the efficacy of azole therapy. Our antibody-guided approach reveals that early drug intervention is critical to prevent complete invasion of the lungs by the fungus, and demonstrates the power of molecular imaging as a non-invasive procedure for tracking IPA in vivo.

Author(s):  
Elena Campione ◽  
Roberta Gaziano ◽  
Elena Doldo ◽  
Daniele Marino ◽  
Mattia Falconi ◽  
...  

AIM: Aspergillus fumigatus is the most common opportunistic fungal pathogen and causes invasive pulmonary aspergillosis (IPA), with high mortality among immunosuppressed patients. Fungistatic activity of all-trans retinoic acid (ATRA) has been recently described in vitro. We evaluated the efficacy of ATRA in vivo and its potential synergistic interaction with other antifungal drugs. MATERIALS AND METHODS: A rat model of IPA and in vitro experiments were performed to assess the efficacy of ATRA against Aspergillus in association with classical antifungal drugs and in silico studies used to clarify its mechanism of action. RESULTS: ATRA (0.5 and 1 mM) displayed a strong fungistatic activity in Aspergillus cultures, while at lower concentrations, synergistically potentiated fungistatic efficacy of sub-inhibitory concentration of Amphotericin B (AmB) and Posaconazole (POS). ATRA also enhanced macrophagic phagocytosis of conidia. In a rat model of IPA, ATRA reduced mortality similarly to Posaconazole. CONCLUSION: Fungistatic efficacy of ATRA alone and synergistically with other antifungal drugs was documented in vitro, likely by inhibiting fungal Hsp90 expression and Hsp90-related genes. ATRA reduced mortality in a model of IPA in vivo. Those findings suggest ATRA as suitable fungistatic agent, also to reduce dosage and adverse reaction of classical antifungal drugs, and new therapeutic strategies against IPA and systemic fungal infections.


2020 ◽  
Vol 56 (4) ◽  
pp. 522-531 ◽  
Author(s):  
D. Basurto ◽  
N. Sananès ◽  
E. Verbeken ◽  
D. Sharma ◽  
E. Corno ◽  
...  

2019 ◽  
Vol 47 (5) ◽  
pp. 1302-1313 ◽  
Author(s):  
Camilla Christensen ◽  
Lotte K. Kristensen ◽  
Maria Z. Alfsen ◽  
Carsten H. Nielsen ◽  
Andreas Kjaer

Abstract Purpose Despite remarkable clinical responses and prolonged survival across several cancers, not all patients benefit from PD-1/PD-L1 immune checkpoint blockade. Accordingly, assessment of tumour PD-L1 expression by immunohistochemistry (IHC) is increasingly applied to guide patient selection, therapeutic monitoring, and improve overall response rates. However, tissue-based methods are invasive and prone to sampling error. We therefore developed a PET radiotracer to specifically detect PD-L1 expression in a non-invasive manner, which could be of diagnostic and predictive value. Methods Anti-PD-L1 (clone 6E11, Genentech) was site-specifically conjugated with DIBO-DFO and radiolabelled with 89Zr (89Zr-DFO-6E11). 89Zr-DFO-6E11 was optimized in vivo by longitudinal PET imaging and dose escalation with excess unlabelled 6E11 in HCC827 tumour-bearing mice. Specificity of 89Zr-DFO-6E11 was evaluated in NSCLC xenografts and syngeneic tumour models with different levels of PD-L1 expression. In vivo imaging data was supported by ex vivo biodistribution, flow cytometry, and IHC. To evaluate the predictive value of 89Zr-DFO-6E11 PET imaging, CT26 tumour-bearing mice were subjected to external radiation therapy (XRT) in combination with PD-L1 blockade. Results 89Zr-DFO-6E11 was successfully labelled with a high radiochemical purity. The HCC827 tumours and lymphoid tissue were identified by 89Zr-DFO-6E11 PET imaging, and co-injection with 6E11 increased the relative tumour uptake and decreased the splenic uptake. 89Zr-DFO-6E11 detected the differences in PD-L1 expression among tumour models as evaluated by ex vivo methods. 89Zr-DFO-6E11 quantified the increase in PD-L1 expression in tumours and spleens of irradiated mice. XRT and anti-PD-L1 therapy effectively inhibited tumour growth in CT26 tumour-bearing mice (p < 0.01), and the maximum 89Zr-DFO-6E11 tumour-to-muscle ratio correlated with response to therapy (p = 0.0252). Conclusion PET imaging with 89Zr-DFO-6E11 is an attractive approach for specific, non-invasive, whole-body visualization of PD-L1 expression. PD-L1 expression can be modulated by radiotherapy regimens and 89Zr-DFO-6E11 PET is able to monitor these changes and predict the response to therapy in an immunocompetent tumour model.


Antibiotics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 813
Author(s):  
Chukwuemeka Samson Ahamefule ◽  
Blessing C. Ezeuduji ◽  
James C. Ogbonna ◽  
Anene N. Moneke ◽  
Anthony C. Ike ◽  
...  

With the mortality rate of invasive aspergillosis caused by Aspergillus fumigatus reaching almost 100% among some groups of patients, and with the rapidly increasing resistance of A. fumigatus to available antifungal drugs, new antifungal agents have never been more desirable than now. Numerous bioactive compounds were isolated and characterized from marine resources. However, only a few exhibited a potent activity against A. fumigatus when compared to the multitude that did against some other pathogens. Here, we review the marine bioactive compounds that display a bioactivity against A. fumigatus. The challenges hampering the discovery of antifungal agents from this rich habitat are also critically analyzed. Further, we propose strategies that could speed up an efficient discovery and broaden the dimensions of screening in order to obtain promising in vivo antifungal agents with new modes of action.


2019 ◽  
Vol 29 ◽  
pp. S160-S161
Author(s):  
P. Mantuano ◽  
A. Mele ◽  
O. Cappellari ◽  
A. Fonzino ◽  
F. Sanarica ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Mdx Mice ◽  

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi124-vi124
Author(s):  
Angelie Rivera-Rodriguez ◽  
Lan Hoang-Minh ◽  
Leyda Marrero-Morales ◽  
Duane Mitchell ◽  
Carlos Rinaldi

Abstract BACKGROUND Adoptive cell therapies (ACT) are strategies being explored to boost the immune response against cancer. ACT cancer immunotherapies are effective against metastatic melanoma, leukemia, and lymphoma, but face challenges in treating other solid tumors, such as in the brain. A critical step for the success of ACT in solid cancers is achieving trafficking and persistence of T-cells at tumor sites. Glioblastoma (GBM) is the most common and aggressive cancer of the central nervous system in adults, with a prognosis of 15-18-month average patient survival after diagnosis. Biomedical imaging is often used to track cell therapies. Magnetic Particle Imaging (MPI) is a novel biomedical imaging modality enabling non-invasive visualization of the distribution of biocompatible superparamagnetic iron oxide (SPIO) tracers. OBJECTIVE Label T-cells with SPIO to non-invasively track adoptive T cell transfer immunotherapy with MPI in the context of brain cancer. METHODS Murine pmel-DsRed T-cells were isolated from the spleen of a transgenic C57BL/6 mouse, and were exposed to different SPIO concentrations ex vivo. Cell viability, phenotype, and cytotoxic function were analyzed to determine if T-cells were affected by the SPIO labeling. Moreover, in vivo experiments were performed in a murine GBM model, and labeled T-cells were injected intravenously and tracked using MPI. RESULTS The SPIO-labeling of T-cells did not affected cell viability, phenotype, or cell cytotoxic function at all tested incubation conditions. The internalized SPIO can be quantified and spatially detected using MPI both in vitro and in vivo. In addition, MPI in vivo tracking shows T-cells accumulation in liver and lungs, as well in the spleen and brain, as showed ex vivo. CONCLUSIONS SPIO-labeling of T-cells did not affected its cytotoxic function and MPI allows for in vivo tracking of adoptively T-cell transfer. MPI will provide better understanding of ACT dynamics to accelerate development of novel treatments.


2020 ◽  
Author(s):  
Fabian C. Herbert ◽  
Olivia Brohlin ◽  
Tyler Galbraith ◽  
Candace Benjamin ◽  
Cesar A. Reyes ◽  
...  

<div> <div> <div> <p>Icosahedral virus-like particles (VLPs) derived from bacteriophages Qβ and PP7 encapsulating small-ultra red fluorescent protein (smURFP) were produced using a versatile supramolecualr capsid dissassemble-reassemble approach. The generated fluorescent VLPs display identical structural properties to their non-fluorescent analogs. Encapsulated smURFP shows indistinguishable photochemical properties to its unencapsulated counterpart, exhibits outstanding stability towards pH, and produces bright in vitro images following phagocytosis by macrophages. In vivo imaging allows biodistribution to be imaged at different time points. Ex vivo imaging of intravenously administered encapsulated smURFP reveleas localization in the liver and </p> </div> </div> <div> <div> <p>kidneys after 2 h blood circulation and substantial elimination constructs as non-invasive in vivo imaging agents. </p> </div> </div> </div>


2017 ◽  
Author(s):  
Brett S. Klosterhoff ◽  
Keat Ghee Ong ◽  
Laxminarayanan Krishnan ◽  
Kevin M. Hetzendorfer ◽  
Young-Hui Chang ◽  
...  

AbstractBone development, maintenance, and regeneration are remarkably sensitive to mechanical cues. Consequently, mechanical stimulation has long been sought as a putative target to promote endogenous healing after fracture. Given the transient nature of bone repair, tissue-level mechanical cues evolve rapidly over time after injury and are challenging to measure non-invasively. The objective of this work was to develop and characterize an implantable strain sensor for non-invasive monitoring of axial strain across a rodent femoral defect during functional activity. Herein, we present the design, characterization, and in vivo demonstration of the device’s capabilities for quantitatively interrogating physiological dynamic strains during bone regeneration. Ex vivo experimental characterization of the device showed that it exceeded the technical requirements for sensitivity, signal resolution, and electromechanical stability. The digital telemetry minimized power consumption, enabling long-term intermittent data collection. Devices were implanted in a rat 6 mm femoral segmental defect model and after three days, data were acquired wirelessly during ambulation and synchronized to corresponding radiographic videos, validating the ability of the sensor to non-invasively measure strain in real-time. Lastly, in vivo strain measurements were utilized in a finite element model to estimate the strain distribution within the defect region. Together, these data indicate the sensor is a promising technology to quantify local tissue mechanics in a specimen specific manner, facilitating more detailed investigations into the role of the mechanical environment in dynamic skeletal healing and remodeling.


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