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Abstract Bladder mechanical properties are critical for organ function and tissue homeostasis. Therefore, alterations of tissue mechanics are linked to disease onset and progression. This study aims to characterize the tissue elasticity of the murine bladder wall considering its different anatomical components, both in healthy conditions and in actinic cystitis, a state characterized by tissue fibrosis. Here, we exploit Brillouin microscopy, an emerging technique in the mechanobiology field that allows mapping tissue mechanics at the microscale, in non-contact mode and free of labeling. We show that Brillouin imaging of bladder tissues is able to recognize the different anatomical components of the bladder wall, confirmed by histopathological analysis, showing different tissue mechanical properties of the physiological bladder, as well as a significant alteration in the presence of tissue fibrosis. Our results point out the potential use of Brillouin imaging on clinically relevant samples as a complementary technique to histopathological analysis, deciphering complex mechanical alteration of each tissue layer of an organ that strongly relies on mechanical properties to perform its function.

BackgroundIn adoptive T cell therapy, the long term therapeutic benefits in patients treated with engineered tumor specific T cells are limited by the lack of long term persistence of the infused cellular products and by the immunosuppressive mechanisms active in the tumor microenvironment. Exhausted T cells infiltrating the tumor are characterized by loss of effector functions triggered by multiple inhibitory receptors (IRs). In patients, IR blockade reverts T cell exhaustion but has low selectivity, potentially unleashing autoreactive clones and resulting in clinical autoimmune side effects. Furthermore, loss of long term protective immunity in cell therapy has been ascribed to the effector memory phenotype of the infused cells.MethodsWe simultaneously redirected T cell specificity towards the NY-ESO-1 antigen via TCR gene editing (TCRED) and permanently disrupted LAG3, TIM-3 or 2B4 genes (IRKO) via CRISPR/Cas9 in a protocol to expand early differentiated long-living memory stem T cells. The effector functions of the TCRED-IRKO and IR competent (TCRED-IRCOMP) cells were tested in short-term co-culture assays and under a chronic stimulation setting in vitro. Finally, the therapeutic efficacy of the developed cellular products were evaluated in multiple myeloma xenograft models.ResultsWe show that upon chronic stimulation, TCRED-IRKO cells are superior to TCRED-IRCOMP cells in resisting functional exhaustion through different mechanisms and efficiently eliminate cancer cells upon tumor re-challenge in vivo. Our data indicate that TIM-3 and 2B4-disruption preserve T-cell degranulation capacity, while LAG-3 disruption prevents the upregulation of additional inhibitory receptors in T cells.ConclusionThese results highlight that TIM-3, LAG-3, and 2B4 disruptions increase the therapeutic benefit of tumor specific cellular products and suggest distinct, non-redundant roles for IRs in anti-tumor responses.

Abstract Background Malignant mesothelioma (MM) is an aggressive tumor, with a poor prognosis, usually unresectable due to late diagnosis, mainly treated with chemotherapy. BoxA, a truncated form of “high mobility group box 1” (HMGB1), acting as an HMGB1 antagonist, might exert a defensive action against MM. We investigated the potential of BoxA for MM treatment using experimental 40-MHz ultrasound and optical imaging (OI) in a murine model. Methods Murine MM cells infected with a lentiviral vector expressing the luciferase gene were injected into the peritoneum of 14 BALB/c mice (7 × 104 AB1-B/c-LUC cells). These mice were randomized to treatment with BoxA (n = 7) or phosphate-buffered saline (controls, n = 7). The experiment was repeated with 40 mice divided into two groups (n = 20 + 20) and treated as above to confirm the result and achieve greater statistical power. Tumor presence was investigated by experimental ultrasound and OI; suspected peritoneal masses underwent histopathology and immunohistochemistry examination. Results In the first experiment, none of the 7 controls survived beyond day 27, whereas 4/7 BoxA-treated mice (57.1%) survived up to day 70. In the second experiment, 6/20 controls (30.0%) and 16/20 BoxA-treated mice (80.0%) were still alive at day 34 (p = 0.004). In both experiments, histology confirmed the malignant nature of masses detected using experimental ultrasound and OI. Conclusion In our preclinical experience on a murine model, BoxA seems to exert a protective role toward MM. Both experimental ultrasound and OI proved to be reliable techniques for detecting MM peritoneal masses.

Abstract Defective functionality of thymic epithelial cells (TECs), due to genetic mutations or injuring causes, results in altered T‐cell development, leading to immunodeficiency or autoimmunity. These defects cannot be corrected by hematopoietic stem cell transplantation (HSCT), and thymus transplantation has not yet been demonstrated to be fully curative. Here, we provide proof of principle of a novel approach toward thymic regeneration, involving the generation of thymic organoids obtained by seeding gene‐modified postnatal murine TECs into three‐dimensional (3D) collagen type I scaffolds mimicking the thymic ultrastructure. To this end, freshly isolated TECs were transduced with a lentiviral vector system, allowing for doxycycline‐induced Oct4 expression. Transient Oct4 expression promoted TECs expansion without drastically changing the cell lineage identity of adult TECs, which retain the expression of important molecules for thymus functionality such as Foxn1, Dll4, Dll1, and AIRE. Oct4‐expressing TECs (iOCT4 TEC) were able to grow into 3D collagen type I scaffolds both in vitro and in vivo, demonstrating that the collagen structure reproduced a 3D environment similar to the thymic extracellular matrix, perfectly recognized by TECs. In vivo results showed that thymic organoids transplanted subcutaneously in athymic nude mice were vascularized but failed to support thymopoiesis because of their limited in vivo persistence. These findings provide evidence that gene modification, in combination with the usage of 3D biomimetic scaffolds, may represent a novel approach allowing the use of postnatal TECs for thymic regeneration. Stem Cells Translational Medicine 2019;8:1107–1122

Summary: Lymph nodes (LNs) are secondary lymphoid tissues that play a critical role in filtering the lymph and promoting adaptive immune responses. Surgical resection of LNs, radiation therapy, or infections may damage lymphatic vasculature and compromise immune functions. Here, we describe the generation of functional synthetic lympho-organoids (LOs) using LN stromal progenitors and decellularized extracellular matrix-based scaffolds, two basic constituents of secondary lymphoid tissues. We show that upon transplantation at the site of resected LNs, LOs become integrated into the endogenous lymphatic vasculature and efficiently restore lymphatic drainage and perfusion. Upon immunization, LOs support the activation of antigen-specific immune responses, thus acquiring properties of native lymphoid tissues. These findings provide a proof-of-concept strategy for the development of functional lympho-organoids suitable for restoring lymphatic and immune cell functions. : In this article, Lenti and colleagues show the generation of functional lympho-organoids using basic constituents of the lymph node. Their findings indicate that transplantation of lympho-organoids may represent a therapeutic approach to restore lymphatic and immune cell functions in lymphedema and other diseases in which lymph nodes have been removed or are dysfunctional. Keywords: lymphoid tissue development, stromal cell biology, tissue engineering, preclinical mouse models, tissue regeneration, lymphatic system, lympho-organoids

Abstract Background The increasing use of gold nanoparticles (AuNPs) in the field of neuroscience instilled hope for their rapid translation to the clinical practice. AuNPs can be engineered to carry therapeutics or diagnostics in the diseased brain, possibly providing greater cell specificity and low toxicity. Although there is a general enthusiasm for these tools, we are in early stages of their development. Overall, their brain penetrance, stability and cell specificity are critical issues that must be addressed to drive AuNPs to the clinic. Results We studied the kinetic, distribution and stability of PEG-coated AuNPs in mice receiving a single injection into the cisterna magna of the 4th ventricle. AuNPs were conjugated with the fluorescent tag Cy5.5 (Cy5.5-AuNPs) to track their in vivo distribution. Fluorescence levels from such particles were detected in mice for weeks. In situ analysis of brains by immunofluorescence and electron microscopy revealed that Cy5.5-AuNPs penetrated the brain parenchyma, spreading in the CNS parenchyma beneath the 4th ventricle. Cy5.5-AuNPs were preferentially found in neurons, although a subset of resting microglia also entrapped these particles. Conclusions Our results suggest that the ICM route for delivering gold particles allows the targeting of neurons. This approach might be pursued to carry therapeutics or diagnostics inside a diseased brain with a surgical procedure that is largely used in gene therapy approaches. Furthermore, this approach could be used for radiotherapy, enhancing the agent’s efficacy to kill brain cancer cells.

Glucose transport and consumption are increased in tumors, and this is considered a diagnostic index of malignancy. However, there is recent evidence that carcinoma-associated stromal cells are capable of aerobic metabolism with low glucose consumption, at least partly because of their efficient vascular supply. In the present study, using dynamic contrast-enhanced magnetic resonance imaging and [F-18]fluorodeoxyglucose (FDG) positron emission tomography (PET), we mapped in vivo the vascular supply and glucose metabolism in syngeneic experimental models of carcinoma and mesenchymal tumor. We found that in both tumor histotypes, regions with high vascular perfusion exhibited a significantly lower FDG uptake. This reciprocity was more conspicuous in carcinomas than in mesenchymal tumors, and regions with a high-vascular/low-FDG uptake pattern roughly overlapped with a stromal capsule and intratumoral large connectival septa. Accordingly, mesenchymal tumors exhibited a higher vascular perfusion and a lower FDG uptake than carcinomas. Thus, we provide in vivo evidence of vascular/metabolic reciprocity between epithelial and mesenchymal histotypes in tumors, suggesting a new intriguing aspect of epithelial-stromal interaction. Our results suggests that FDG-PET-based clinical analysis can underestimate the malignity or tumor extension of carcinomas exhibiting any trait of “mesenchymalization” such as desmoplasia or epithelial-mesenchymal transition.

The whole-body dose (WBD) is routinely calculated for targeted radionuclide therapy (TRT). The aim of this work was to investigate the feasibility of using spectral analysis (SA) for the automatic delineation of decay phases, and consequently, the calculation of the WBD given a whole-body (WB) time-activity curve (TAC). SA characterizes the TAC as an arbitrary sum of exponential functions determined by fitting the data with a non-negative least-squares (NNLS) algorithm. The cumulated activity (CA) is calculated analytically as the integral of the fitted curve while the number of phases describing the kinetics of the radiopharmaceutical and the half-lives of the phases can be determined from the spectrum. The uncertainty associated with the estimation of the WBD can be obtained using bootstrap techniques. SA was applied to WB TACs from 186Re-HEDP and 131I-mIBG therapies. The results were compared to results obtained using a semiempirical method and showed good agreement in the calculated WBDs. Bootstrapping with resampling on a subset of patients from the two therapies showed much larger coefficient-ofvariation (CV) for the 186Re-HEDP TACs than for the 131I-mIBG therapies. We concluded that SA provides a fast, accurate, and reproducible method to obtain WBDs and accurate estimates of the parameters describing the radiotracer kinetics. The method could be extended to other dosimetric applications. [ABSTRACT FROM AUTHOR]