Biology subjects

Cardona Gloria, Y.

Publications and source records attributed to Cardona Gloria, Y..

4 recordsLinked to original sources

bioRxiv2024

A cereblon (CRBN) molecular glue degrader of NIMA-related kinase 7 (NEK7) reveals a context-dependent role in NLRP3 inflammasome activation

The NLRP3 (NACHT-, leucine-rich repeat [LRR]- and pyrin domain [PYD]- containing protein 3) inflammasome is a cytoplasmic signaling complex that promotes inflammation in response to signals from infection and cellular damage. Increased activation of the NLRP3 inflammasome is linked to numerous diseases including gout, osteoarthritis, cardiovascular disease, neuroinflammatory diseases and cancer, which has prompted the search for therapeutics that can inhibit the NLRP3 pathway. Recent work suggested that NIMA-related kinase 7 (NEK7) may be required for proper assembly and activation of the NLRP3 inflammasome independent of its kinase activity, and that hence reduction of NEK7 protein levels may block NLRP3 activation. Since NEK7 contains a glycine beta hairpin loop structural degron found in many targets of cereblon (CRBN) molecular glue degraders, we used this strategy to degrade NEK7 and inhibit the NLRP3 inflammasome. We identified NK7-902, a CRBN glue degrader of NEK7. NK7-902 potently and selectively degraded NEK7 in human primary monocytes, peripheral blood mononuclear cells (PBMCs) and whole blood. Unexpectedly, full NEK7 degradation led to only partial blockade of NLRP3-dependent interleukin-1{beta} (IL-1{beta}) release in these cells under different stimulation conditions, with the extent of IL-1{beta} inhibition varying greatly across donors. Unlike most CRBN glue degraders, NK7-902 degraded NEK7 in mouse cells and efficiently inhibited NLRP3-dependent IL-1{beta} release in a mouse cryopyrin-associated syndrome (CAPS) model. By contrast, oral administration of NK7-902 in non-human primates led to profound and long lasting NEK7 degradation but only transiently blocked IL-1{beta} production in blood. Collectively, our data suggest that NEK7 is involved but may not be strictly required for NLRP3 activation in primates and humans. HighlightsO_LIIdentification of NK7-902, a CRBN molecular glue degrader of NEK7 C_LIO_LINK7-902 fully degrades NEK7 in human primary monocytes and whole blood but only partially inhibits NLRP3-dependent IL-1{beta} production C_LIO_LIUnlike most CRBN glue degraders, NK7-902 shows activity in murine systems C_LIO_LIIn vivo oral administration of NK7-902 in non-human primates leads to profound and long-lasting NEK7 degradation but only transiently blocks NLRP3 inflammasome activation C_LI

immunology↗

bioRxiv2022

Chitin oligomers directly promote lymphoid innate and adaptive immune cell activation

BackgroundChitin is a highly abundant N-acetyl-glucosamine (GlcNAc) polysaccharide which has been linked to immune responses in the context of fungal infections and allergic asthma, especially T helper 2 (Th2) immune responses. Unfortunately, due to the frequent use of crude chitin preparations of unknown purity and degree of polymerization there is still great uncertainty how chitin activates different parts of the human immune system. ObjectiveWe recently identified chitin oligomers of six GlcNAc units as the smallest immunologically active chitin motif and the innate immune receptor TLR2 as primary chitin sensor on human and murine myeloid cells, but the response of lymphoid cells to oligomeric chitin has not been investigated and was addressed here. MethodsFlow cytometric analysis of primary human immune cells upon stimulation with oligomeric chitin. For detailed Methods, please see the Methods section in this articles Online Repository at www.jacionline.org. ResultHere we report that chitin oligomers also activate immune responses by both primary lymphoid innate and adaptive immune cells: Notably, chitin oligomers activated Natural Killer (NK) cells and B lymphocytes. Moreover, the maturation of dendritic cells enabled CD8 T cell recall responses. ConclusionsOur results suggest that chitin oligomers not only trigger immediate innate responses in limited range of myeloid cells but exert critical activities across the entire human immune system. Key messagesChitin oligomers are microbe-associated molecular patterns involved in TLR2-dependent fungal recognition by myeloid immune cells. Here we show that lymphoid cells, most notably Natural Killer (NK) cells and B cells, are activated by oligomeric chitin. Oligomeric chitin also promotes antigen-presenting cell (APC) maturation and CD8 T cell recall responses. Capsule summaryOligomeric chitin is a novel microbe-associated molecular patterns involved in TLR2-dependent fungal recognition by myeloid innate immune cells. Here we show that lymphoid innate and adaptive immune responses are also promoted by oligomeric chitin.

immunology↗

bioRxiv2020

The failure of B cells to induce non-canonical MYD88 splice variants correlates with lymphomagenesis via sustained NF-κB signaling

Gain-of-function mutations of the TLR adaptor and oncoprotein MyD88 drive B cell lymphomagenesis via sustained NF-{kappa}B activation. In myeloid cells, sustained TLR activation and NF-{kappa}B activation lead to the induction of inhibitory MYD88 splice variants that restrain prolonged NF-{kappa}B activation. We therefore sought to investigate whether such a negative feedback loop exists in B cells. Analyzing MYD88 splice variants in normal B cells and different primary B cell malignancies, we observed that MYD88 splice variants in transformed B cells are dominated by the canonical, strongly NF-{kappa}B-activating isoform of MYD88 and contain at least three novel, so far uncharacterized signaling-competent splice isoforms. TLR stimulation in B cells unexpectedly reinforces splicing of NF-{kappa}B-promoting, canonical isoforms rather than the MyD88s, a negative regulatory isoform that is typically induced by TLRs in myeloid cells. This suggests that an essential negative feedback loop restricting TLR signaling in myeloid cells at the level of alternative splicing, is missing in B cells, rendering B cells vulnerable to sustained NF-{kappa}B activation and eventual lymphomagenesis. Our results uncover MYD88 alternative splicing as an unappreciated promoter of B cell lymphomagenesis and provide a rationale why oncogenic MYD88 mutations are exclusively found in B cells.

cancer biology↗

bioRxiv2018

The fungal ligand chitin directly binds and signals inflammation dependent on oligomer size and TLR2

Chitin is a highly abundant polysaccharide and linked to fungal infection and asthma. Unfortunately, its polymeric structure has hampered the identification of immune receptors directly binding chitin and signaling immune activation and inflammation, because purity, molecular structure and molarity are not well definable for a polymer typically extracted from biomass. Therefore, by using defined chitin (N-acetyl-glucosamine) oligomers, we identified six subunit long chitin chains as the smallest immunologically active motif and the innate immune receptor Toll-like receptor (TLR) 2 as the primary fungal chitin receptor on human and murine immune cells. Chitin oligomers directly bound TLR2 with nanomolar affinity and showed both overlapping and distinct signaling outcomes compared to known mycobacterial TLR2 ligands. Conversely, chitin oligomers shorter than 6 subunits were inactive or showed antagonistic effects on chitin/TLR2-mediated signaling, hinting to a size-dependent sensing/activation system unexpectedly conserved in plants and humans. Since blocking the chitin-TLR2 interaction effectively prevented chitin-mediated inflammation in vitro and in vivo, our study highlights the chitin TLR2 interaction as a potential target for developing novel therapies in chitin-related pathologies and fungal disease.

immunology↗