SARS-CoV-2's continued global health impact underscores the importance of ongoing pathogenesis research. Insights into the host's first line of defense against severe COVID-19 identify actionable biom Show more
SARS-CoV-2's continued global health impact underscores the importance of ongoing pathogenesis research. Insights into the host's first line of defense against severe COVID-19 identify actionable biomarkers, informing disease management or therapeutics. Yet, the innate immune response, including cytokines, chemokines, adenosine deaminases (ADAs) and Toll-like receptors (TLRs), relevant to COVID-19 remain incompletely characterized. Peripheral blood was longitudinally collected between May 2020 and March 2021 from COVID-19 hospitalized adults (N = 79) and healthy controls (HCs) (N = 14; not tested, assumed COVID-negative, no viral exposure or symptoms). Heparinized blood was fractionated for plasma cryopreservation and in vitro whole blood TLR-stimulation employing TLR-3, -4, and -7/8 agonists. Post-stimulation culture supernatants were analyzed using multiplex and enzymatic assays. Upon hospitalization, plasma concentrations of IFNγ, IL-6, CXCL10, and ADAs were significantly upregulated compared to convalescent time points and HCs. Participants with fatal COVID-19 exhibited higher IL-27, CXCL10, and ADAs concentrations upon admission. Plasma cytokines, chemokines, and ADAs were positively correlated and associated with distinct temporal patterns. TLR-stimulated cell cultures from patients produced reduced IFNα2, IFNγ, IL-12p40, and IL-12p70 compared to HCs or later time points. Higher plasma concentrations of IL-27, CXCL10, and ADAs at admission were associated with severe COVID-19 and mortality. Reduced TLR-mediated IFNα2, IFNγ, and IL-12p70 production suggests COVID dampens Th1-polarizing innate immune responses, providing insight into immunological sequelae of SARS-CoV-2 infection. Show less
Centriole biogenesis and maintenance are crucial for cells to generate cilia and assemble centrosomes that function as microtubule organizing centers (MTOCs). Centriole biogenesis and MTOC function bo Show more
Centriole biogenesis and maintenance are crucial for cells to generate cilia and assemble centrosomes that function as microtubule organizing centers (MTOCs). Centriole biogenesis and MTOC function both require the microtubule nucleator γ-tubulin ring complex (γTuRC). It is widely accepted that γTuRC nucleates microtubules from the pericentriolar material that is associated with the proximal part of centrioles. However, γTuRC also localizes more distally and in the centriole lumen, but the significance of these findings is unclear. Here we identify spatially and functionally distinct subpopulations of centrosomal γTuRC. Luminal localization is mediated by augmin, which is linked to the centriole inner scaffold through POC5. Disruption of luminal localization impairs centriole integrity and interferes with cilium assembly. Defective ciliogenesis is also observed in γTuRC mutant fibroblasts from a patient suffering from microcephaly with chorioretinopathy. These results identify a non-canonical role of augmin-γTuRC in the centriole lumen that is linked to human disease. Show less