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Plasmacytoid dendritic cells (pDC) sense viral RNA through toll-like receptor 7 (TLR7), form self-adhesive pDC–pDC clusters, and produce type I interferons. This cell adhesion enhances type I interferon production, but little is known about the underlying mechanisms. Here we show that MyD88-dependent TLR7 signaling activates CD11a/CD18 integrin to induce microtubule elongation. TLR7+ lysosomes then become linked with these microtubules through the GTPase Arl8b and its effector SKIP/Plekhm2, resulting in perinuclear to peripheral relocalization of TLR7. The type I interferon signaling molecules TRAF3, IKKα, and mTORC1 are constitutively associated in pDCs. TLR7 localizes to mTORC1 and induces association of TRAF3 with the upstream molecule TRAF6. Finally, type I interferons are secreted in the vicinity of cell–cell contacts between clustered pDCs. These results suggest that TLR7 needs to move to the cell periphery to induce robust type I interferon responses in pDCs.

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Abstract. A meteorological balloon-borne cloud sensor called the cloud particle sensor (CPS) has been developed. The CPS is equipped with a diode laser at ∼ 790 nm and two photodetectors, with a polarization plate in front of one of the detectors, to count the number of particles per second and to obtain the cloud-phase information (i.e. liquid, ice, or mixed). The lower detection limit for particle size was evaluated in laboratory experiments as ∼ 2 µm diameter for water droplets. For the current model the output voltage often saturates for water droplets with diameter equal to or greater than ∼ 80 µm. The upper limit of the directly measured particle number concentration is ∼ 2 cm −3 (2×10 3 L −1 ), which is determined by the volume of the detection area of the instrument. In a cloud layer with a number concentration higher than this value, particle signal overlap and multiple scattering of light occur within the detection area, resulting in a counting loss, though a partial correction may be possible using the particle signal width data. The CPS is currently interfaced with either a Meisei RS-06G radiosonde or a Meisei RS-11G radiosonde that measures vertical profiles of temperature, relative humidity, height, pressure, and horizontal winds. Twenty-five test flights have been made between 2012 and 2015 at midlatitude and tropical sites. In this paper, results from four flights are discussed in detail. A simultaneous flight of two CPSs with different instrumental configurations confirmed the robustness of the technique. At a midlatitude site, a profile containing, from low to high altitude, water clouds, mixed-phase clouds, and ice clouds was successfully obtained. In the tropics, vertically thick cloud layers in the middle to upper troposphere and vertically thin cirrus layers in the upper troposphere were successfully detected in two separate flights. The data quality is much better at night, dusk, and dawn than during the daytime because strong sunlight affects the measurements of scattered light.

The syntheses of well-defined polystyrenes functionalized with a definite number (from one to four) of chloromethylphenyl groups at the chain ends or in the chains by means of anionic living polymerization in conjunction with functional group transformation are described. The synthetic method involves the introduction of anion-stable methoxymethylphenyl or tert-butyldimethylsilyloxymethylphenyl groups at the chain ends or in the chains and subsequent transformation reactions of these groups into chloromethylphenyl groups with BCl3. It is also possible to transform the tert-butyldimethylsilyloxymethylphenyl group into bromomethylphenyl and iodomethylphenyl groups by treatment with Me3SiCl−LiBr, and Me3SiCl−NaI, respectively. Furthermore, the synthesis of well-defined polystyrenes having two, four, and six methoxymethylphenyl and six chloromethylphenyl termini via a new iterative approach using 3-(tert-butyldimethylsilyloxy)-1-propyllithium is described. It involves repeated chemical transformations at the chain end from tert-butyldimethylsilyloxybutyl, bromobutyl, and methoxymethylphenyl groups to the chloromethylphenyl group. At each stage in the iteration, the number of chloromethylphenyl groups doubles. The resulting polymers all, after HPLC fractionation in some cases, possessed well-controlled molecular weights and narrow molecular weight distributions. Their functionalities were nearly quantitative in all cases.

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