Updates on radiotherapy-immunotherapy combinations: Proceedings of 6th annual ImmunoRad conference.

Focal radiation therapy (RT) has attracted considerable attention as a combinatorial partner for immunotherapy (IT), largely reflecting a well-defined, predictable safety profile and at least some potential for immunostimulation. However, only a few RT-IT combinations have been tested successfully in patients with cancer, highlighting the urgent need for an improved understanding of the interaction between RT and IT in both preclinical and clinical scenarios. Every year since 2016, ImmunoRad gathers experts working at the interface between RT and IT to provide a forum for education and discussion, with the ultimate goal of fostering progress in the field at both preclinical and clinical levels. Here, we summarize the key concepts and findings presented at the Sixth Annual ImmunoRad conference

Geometrical, functional, and histomorphometric adaptation of rat carotid artery in induced hypertension

Acute and long-term (up to 56 days) evolution of geometry, structural properties, vascular smooth muscle (VSM) tone and histomorphometric properties of the rat common carotid arteries under induced hypertension were investigated. Hypertension was induced in 8-week old male Wistar rats by total ligation of the aorta between the two kidneys. Rats were sacrificed 2, 4, 8 and 56 days postsurgery. The arterial wall layers thicken non-uniformly during the adaptation process, the inner layers thicken more in the acute phase of hypertension, whereas the outer layers of the wall are thicker than the inner layers at the end of the adaptation phase. Collagen content in the wall media exhibits a non-linear evolution, with a rapid increase in the acute hypertension phase followed by a slower increase at long-term. The elastin content increase is slight and steady, whereas VSM shows a steady but considerable increase which outdoes the collagen increase in long-term phase. VSM tone increases rapidly in the acute phase of remodelling (0-8 days) and this increase in tone contributes to a considerable increase in arterial compliance in the operating pressure range. At long-term (56 days) VSM tone returns to near control level, but compliance is even further increased, which suggests that at long-term the compliance increase is attributed primarily to structural remodelling

Use of quantitative EELS and cathodoluminescence for study of carrier confinement and diffusion in self organized vertical quantum wells

When AxGa1-xAs layers are grown on V-grooved GaAs substrates by metal organic chemical vapour deposition (MOCVD), a Ga rich vertical quantum well (VQW) appears in the V-groove centre. The width and Ga enrichment of this structure depend on the nominal Al concentration and growth temperature. From EELS linescans and spectrum images, concentration profiles and maps of VQWs are obtained, and a subsequent bandstructure calculation shows up to three confined sublevels in the VQW. Carrier confinement in segments of modulated VQWs is demonstrated. In interconnected VQW-quantum wire structures, carrier diffusion channels were assessed by cathodoluminescence. Carrier capture into the VQW and transfer into the QWR was observed

Sec22b regulates phagosomal maturation and antigen crosspresentation by dendritic cells.

International audienceAntigen (Ag) crosspresentation by dendritic cells (DCs) involves the presentation of internalized Ags on MHC class I molecules to initiate CD8+ T cell-mediated immunity in response to certain pathogens and tumor cells. Here, we identify the SNARE Sec22b as a specific regulator of Ag crosspresentation. Sec22b localizes to the ER-Golgi intermediate compartment (ERGIC) and pairs to the plasma membrane SNARE syntaxin 4, which is present in phagosomes (Phgs). Depletion of Sec22b inhibits the recruitment of ER-resident proteins to Phgs and to the vacuole containing the Toxoplasma gondii parasite. In Sec22b-deficient DCs, crosspresentation is compromised after Ag phagocytosis or endocytosis and after invasion by T. gondii. Sec22b silencing inhibited Ag export to the cytosol and increased phagosomal degradation by accelerating lysosomal recruitment. Our findings provide insight into an intracellular traffic pathway required for crosspresentation and show that Sec22b-dependent recruitment of ER proteins to Phgs critically influences phagosomal functions in DCs

Distributed feedback gain-coupled lasers based on InGaAs quantum-wire arrays

Fabrication and characterization of a current-injected InGaAs-GaAs quantum-wire gain-coupled distributed feedback (DFB) laser operating at 77 K at a wavelength of 923 nm are presented, Threshold current densities in broad area lasers were measured to be as low as 160 A/cm(2), The side-mode suppression ratio at twice threshold is 35 dB. A 4-mu m rib waveguide device has a threshold of 14 mA, The patterning process for the second-order DFB grating fabricated with deep UV holography and wet-chemical etching is described

Structural and electrooptical characteristics of quantum dots emitting at 1.3 μm on gallium arsenide

We present a comprehensive study of the structural and emission properties of self-assembled InAs quantum dots emitting at 1.3 μm. The dots are grown by molecular beam epitaxy on gallium arsenide substrates. Room-temperature emission at 1.3 μm is obtained by embedding the dots in an InGaAs layer. Depending on the growth structure, dot densities of 1-6×1010 cm-2 are obtained. High dot densities are associated with large inhomogeneous broadenings, while narrow photoluminescence (PL) linewidths are obtained in low-density samples. From time-resolved PL experiments, a long carrier lifetime of ≈1.8 ns is measured at room temperature, which confirms the excellent structural quality. A fast PL rise (τrise=10±2 ps) is observed at all temperatures, indicating the potential for high-speed modulation. High-efficiency light-emitting diodes (LEDs) based on these dots are demonstrated, with external quantum efficiency of 1% at room temperature. This corresponds to an estimated 13% radiative efficiency. Electroluminescence spectra under high injection allow us to determine the transition energies of excited states in the dots and bidimensional states in the adjacent InGaAs quantum well