7 research outputs found
Marine and freshwater micropearls: biomineralization producing strontium-rich amorphous calcium carbonate inclusions is widespread in the genus <i>Tetraselmis</i> (Chlorophyta)
Unicellular algae play important roles in the biogeochemical cycles of
numerous elements, particularly through the biomineralization capacity of
certain species (e.g., coccolithophores greatly contributing to the organic
carbon pump of the oceans), and unidentified actors of these cycles are
still being discovered. This is the case of the unicellular alga
Tetraselmis cordiformis (Chlorophyta) that was recently discovered
to form intracellular mineral inclusions, called micropearls, which had been
previously overlooked. These intracellular inclusions of hydrated amorphous
calcium carbonates (ACCs) were first described in Lake Geneva (Switzerland)
and are the result of a novel biomineralization process. The genus
Tetraselmis includes more than 30 species that have been widely
studied since the description of the type species in 1878.The present study shows that many other Tetraselmis species share
this biomineralization capacity: 10 species out of the 12 tested contained
micropearls, including T. chui, T. convolutae,
T. levis, T. subcordiformis, T. suecica and
T. tetrathele. Our results indicate that micropearls are not
randomly distributed inside the Tetraselmis cells but are located
preferentially under the plasma membrane and seem to form a definite pattern,
which differs among species. In Tetraselmis cells, the
biomineralization process seems to systematically start with a rod-shaped
nucleus and results in an enrichment of the micropearls in Sr over Ca (the
Sr∕Ca ratio is more than 200 times higher in the micropearls than in
the surrounding water or growth medium). This concentrating capacity varies
among species and may be of interest for possible bioremediation techniques
regarding radioactive 90Sr water pollution.The Tetraselmis species forming micropearls live in various habitats, indicating that
this novel biomineralization process takes place in different environments
(marine, brackish and freshwater) and is therefore a widespread phenomenon.</p
Lacustrine freshwater microbialites: a case study from Lake Sevan (Armenia, lesser Caucasus).
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Conserved Interferon-γ Signaling Drives Clinical Response to Immune Checkpoint Blockade Therapy in Melanoma.
We analyze the transcriptome of baseline and on-therapy tumor biopsies from 101 patients with advanced melanoma treated with nivolumab (anti-PD-1) alone or combined with ipilimumab (anti-CTLA-4). We find that T cell infiltration and interferon-γ (IFN-γ) signaling signatures correspond most highly with clinical response to therapy, with a reciprocal decrease in cell-cycle and WNT signaling pathways in responding biopsies. We model the interaction in 58 human cell lines, where IFN-γ in vitro exposure leads to a conserved transcriptome response unless cells have IFN-γ receptor alterations. This conserved IFN-γ transcriptome response in melanoma cells serves to amplify the antitumor immune response. Therefore, the magnitude of the antitumor T cell response and the corresponding downstream IFN-γ signaling are the main drivers of clinical response or resistance to immune checkpoint blockade therapy
Conserved interferon-g signaling drives clinical response to immune checkpoint blockade therapy in melanoma
We analyze the transcriptome of baseline and on-therapy tumor biopsies from 101 patients with advanced melanoma treated with nivolumab (anti-PD-1) alone or combined with ipilimumab (anti-CTLA-4). We find that T cell infiltration and interferon-γ (IFN-γ) signaling signatures correspond most highly with clinical response to therapy, with a reciprocal decrease in cell-cycle and WNT signaling pathways in responding biopsies. We model the interaction in 58 human cell lines, where IFN-γ in vitro exposure leads to a conserved transcriptome response unless cells have IFN-γ receptor alterations. This conserved IFN-γ transcriptome response in melanoma cells serves to amplify the antitumor immune response. Therefore, the magnitude of the antitumor T cell response and the corresponding downstream IFN-γ signaling are the main drivers of clinical response or resistance to immune checkpoint blockade therapy
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Conserved Interferon-γ Signaling Drives Clinical Response to Immune Checkpoint Blockade Therapy in Melanoma.
We analyze the transcriptome of baseline and on-therapy tumor biopsies from 101 patients with advanced melanoma treated with nivolumab (anti-PD-1) alone or combined with ipilimumab (anti-CTLA-4). We find that T cell infiltration and interferon-γ (IFN-γ) signaling signatures correspond most highly with clinical response to therapy, with a reciprocal decrease in cell-cycle and WNT signaling pathways in responding biopsies. We model the interaction in 58 human cell lines, where IFN-γ in vitro exposure leads to a conserved transcriptome response unless cells have IFN-γ receptor alterations. This conserved IFN-γ transcriptome response in melanoma cells serves to amplify the antitumor immune response. Therefore, the magnitude of the antitumor T cell response and the corresponding downstream IFN-γ signaling are the main drivers of clinical response or resistance to immune checkpoint blockade therapy