Expression of TILs and Patterns of Gene Expression from Paired Samples of Malignant Pleural Mesothelioma (MPM) Patients

MPM is an aggressive disease with an immunosuppressive tumor microenvironment, and interest in exploring immunotherapy in this disease has been increasing. In the first line of treatment, the combination of nivolumab and ipilimumab demonstrated an improvement in survival over chemotherapy. The presence of TILs has been recognized as a marker of antitumor immune response to chemotherapy in solid tumors. The aim of our study is to identify the effect of treatment on immune cells and the immune gene profile in MPM. We investigated the changes in expression of TILs in 10 human MPM paired tumor tissues using immunohistochemistry and gene expression analysis from paired untreated and treated samples. In this small series, we demonstrated that during the evolution of disease without any treatment there was an increase in the inflammatory component in tumor samples. After systemic treatment there was a decrease in the number of TILs. We observed that after systemic treatment or disease progression immune gene signatures were suppressed. Our integrated analysis of paired samples with immune profile and genomic changes on MPM suggested that during the evolution of the disease the immune system tends to switch, turning off with treatment.

T-cell infiltration in matched samples from malignant pleural mesothelioma (MPM) during evolution of disease

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Background: MPM is an aggressive cancer associated with asbestos exposure. Chemotherapy has been a mainstay of therapy and recently immunotherapy has been associated with survival improvements. Chemotherapy and immunotherapy influence the tumor microenvironment and some reports have shown increased of TIL after chemotherapy in MPM. The purpose of this study was to determine dynamic changes in the tumor immune environment during mesothelioma evolution and after systemic therapies in paired samples. Methods: We examined 20 matched formalin-fixed paraffin embedded tissue samples from 10 patients (p) with MPM taken at diagnosis and at disease progression (follow-up), including untreated and treated with chemotherapy or immunotherapy. Tissue densities (number of cells/mm2) of key immune effector cells such as total lymphocytes (CD3), cytotoxic T cells (CD8), regulatory T cells (FOXP3) and monocytes/macrophages (CD163) were quantified by image analysis using multiplexed immunohistochemistry (IHC). PD-L1 expression in both tumor cells and immune cells was analysed by singleplex IHC and quantified using the CPS score. Results: Median age was 62 years (range 53-84), 7 p were male and all p presented epithelioid histology. Three matched samples belong to patients that did not receive any systemic treatment between biopsies and the other 7 pair of samples belong to patients treated with chemotherapy +/- immunotherapy. The median interval between paired biopsies was 12 m (3-33 m). Median overall survival was 27.8 months (1 m-NR). Median densities of T cells and macrophages in diagnostic and matched follow-up samples were: CD3+:982 vs 712; CD8+:422 vs 334, FOXP3+: 22 vs 25 and CD163+: 2086 vs 1706. Median PD-L1 CPS was 2.5 and 4 in diagnostic and follow-up samples, respectively. In p receiving treatment between sample pairs, the median densities in diagnostic and follow-up matched samples were: CD3+:979 vs 407; CD8+:467 vs 225, FOXP3+: 25 vs 15, CD163+: 1583 vs 1508, and PD-L1: 2 and 1. In p without any systemic treatment between sample pairs, the median densities were CD3+:1645 vs 2397; CD8+:376 vs 1605, FOXP3+: 19 vs 121, CD163+: 2102 vs 2377, and PD-L1: 3 vs 25. Conclusions: In our small series with paired samples from MPM p, we observed immune cells infiltration changes during MPM evolution with a trend towards a decrease after systemic therapy. Further investigation in tumor microenvironment in MPM to define the most appropriate time for immunotherapy is needed.

Analysis of chemotherapy efficacy according to histology in malignant pleural mesothelioma (MPM) patients (p)

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Background: MPM is a highly aggressive pleural tumor associated with asbestos exposure and with limited survival despite systemic therapy. Histology is a prognostic factor and recently CheckMate 743 trial demonstrated survival benefit of immunotherapy in first line with some differences in the efficacy of chemotherapy according to histology. However, randomized trials who led to the approval of antifolate in mesothelioma did not include analysis of outcomes by histology. The objective of this study is to characterize the impact of chemotherapy according to histology in p with MPM at our institution. Methods: We review 189 MPM p diagnosed at Vall d´Hebron University Hospital between November 2002 and April 2020. Associations between clinical variables and outcome were assessed with Cox regression models and survival data were calculated by the Kaplan-Meier method. Results: Patient’s characteristics: median age 68 years (y) (45-88 y), males: 70%, performance status (PS)1: 69%, asbestos exposure: 75%, epithelioid subtype: 76%. First line chemotherapy was offered to 85% of p (66% cisplatin-pemetrexed and 27% carboplatin-pemetrexed). Median overall survival (OS) in overall population was 21.3 m (95%CI17.2-24.3). Epithelioid histology, PS 0, neutrophil-lymphocyte ratio <5 and treatment with cisplatin vs carboplatin were associated with significant improvements in OS (p<0.001). When we analyzed the survival of patients who received first line chemotherapy according to histology, we found that patients with epithelioid tumors had better PFS and OS. Median PFS for p with epithelioid tumors treated with chemotherapy in first line was 4.8 m versus 3.6 months non-epithelioid (HR1.5 CI95% 1.1-2.3; p=0.03). OS of epithelioid p treated with first line chemotherapy was 26.7 m versus 15.0 m non-epithelioid patients (HR2.25 CI95% 1.4-3.4; p<0.001). We analyzed if the differences in survival according to histology were due to type of systemic treatment received (Table). Conclusions: In our series, p with non-epithelioid tumors presented worse prognosis. We confirmed histology is a prognostic factor with better OS for p with epithelioid tumors. Moreover, we demonstrated better efficacy of chemotherapy in epithelioid tumors, although histology is not a predictive factor for the platinum agent sensitivity (p of interaction PFS=0.09, p of interaction OS= 0.65).[Table: see text]

Reorganizing and shaping of embedded near-coalescence silver nanoparticles with off-resonance femtosecond laser pulses

We demonstrate that 2D distributions of non-spherical near-coalescence silver nanoparticles (NPs) embedded in an ultrathin dielectric film can be reorganized, shaped and aligned by exposure to ultrashort laser pulses. As-grown samples prepared by pulsed laser deposition show a broad absorption band with a surface plasmon resonance (SPR) at 650 nm, which can be blue-shifted down to 440 nm and transformed to show polarization anisotropy. In situ white light probing of the spectral sample transmission allows control during irradiation of the position and polarization anisotropy of the SPR, effectively controlling particle reorganization and shaping. Using the high spatial resolution of the optical probe technique (better than 10 μm), the dependence of the nanoparticle shape and distribution on the local fluence can be studied in a single irradiated region. The results inferred from the spectral measurements have been confirmed by TEM studies, showing the formation of nanoparticles with prolate shape, preferential alignment along the polarization axis of the laser and a narrow size distribution. This simple and efficient approach for NP shaping and the straightforward extension to multilayer systems offer excellent perspectives for optical encoding, multidimensional data storage and fabrication of complex, polarization-sensitive spectral masks starting from thin films with near-coalescence distributions of NPs.

Spectral study of the stimulated emission of Nd3+ in fluorotellurite bulk glass

In this work we present, for the first time to our knowledge, laser emission under wavelength selective laser-pulsed pumping in Nd(3+)-doped TeO(2)-ZnO-ZnF(2) bulk glass for two different Nd(3+) concentrations. The fluorescence properties of Nd(3+) ions in this matrix which include, Judd-Ofelt calculation, stimulated emission cross-section of the laser transition and lifetimes are also presented. The site-selective emission and excitation spectra along the (4)I(9/2)→(4)F(3/2) absorption band show the inhomogeneous behaviour of the crystal field felt by Nd(3+) ions in this fluorotellurite glass which allows for spectral tuning of the laser output pulse as a function of the pumping wavelength. The emission cross-section obtained from the Judd-Ofelt analysis and spectral data (4.9x10(-20) cm(2)) is in fairly good agreement with the value obtained from the analysis of the laser threshold data (4x10(-20) cm(2)).

Surface enhanced Raman scattering of silver sensitized cobalt nanoparticles in metal-dielectric nanocomposites

We report the preparation of a new type of nanocomposite containing cobalt and silver nanoparticles organized in parallel layers with a well controlled separation. This arrangement allows the observation of an enhanced low-frequency Raman signal at the vibration frequency of cobalt nanoparticles excited through the surface plasmons of silver nanoparticles. Numerical simulations of the electric field confirm the emergence of hot spots when the separation between silver and cobalt nanoparticles is small enough.

Acoustic vibration modes and electron-lattice coupling in self-assembled silver nanocolumns

Using ultrafast spectroscopy, we investigated electron-lattice coupling and acoustic vibrations in self-assembled silver nanocolumns embedded in an amorphous Al2O3 matrix. The measured electron-lattice energy exchange time is smaller in the nanocolumns than in bulk silver, with a value very close to that of isolated nanospheres with comparable surface to volume ratio. Two vibration modes were detected and ascribed to the breathing and extensional mode of the nanocolumns, in agreement with numerical simulations.

Near-infrared spatial solitons in heavy metal oxide glasses

We demonstrate two-dimensional spatial solitons excited by near-infrared picosecond pulses in Kerr-like heavy metal oxide glasses with a nonlinearity one order of magnitude larger than in fused silica. Solitons were obtained at 820 nm owing to the presence of multiphoton absorption, which prevented catastrophic collapse.

Temporally and spectrally resolved imaging of laser-induced plasmas

We report a hybrid imaging technique capable of performing measurements of the spatial, temporal, and spectral emission characteristics of laser-induced plasmas by use of a single detection system. We apply this technique to study the plasma produced by laser ablation of LiNbO3 and observe phenomena not seen in such detail with standard instruments. These include extreme line broadening up to a few nanometers accompanied by self-absorption near the target surface, and expansion dynamics that differ strongly between the different species. Overall, the wealth of quantitative information provided by this novel technique sheds new light on processes occurring during plasma expansion.

Structural studies of pulsed-laser deposited nanocomposite metal-oxide films

Pulsed laser deposition in vacuum has been used to develop metal-oxide nanocomposite films with well controlled structural quality. Results for the copper-aluminium oxide (Cu:Al2O3) system are used to illustrate the main morphological and structural features of these films. High resolution transmission electron microscopy (TEM) analysis shows that the films consist of Cu nanocrystals with average dimensions that can be controlled between 2 nm and 10 nm embedded in an amorphous Al2O3 matrix. It is observed that the in-plane shape of the nanocrystals evolves from circular to elongated, and the number of nanocrystals per unit area decreases as their size increases. This evolution is explained in terms of nucleation at the substrate surface and coalescence during the later stages of growth. The thermal stability of the films has been studied by in situ TEM annealing and no transformation could be observed up to about 800 degrees C when partial crystallization of the Al2O3 starts.