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Arjomandi, M.

Publications and source records attributed to Arjomandi, M..

2 recordsLinked to original sources

NF-κB inhibitor alpha has a cross-variant role during SARS-CoV-2 infection in ACE2-overexpressing human airway organoids

As SARS-CoV-2 continues to spread worldwide, tractable primary airway cell models that accurately recapitulate the cell-intrinsic response to arising viral variants are needed. Here we describe an adult stem cell-derived human airway organoid model overexpressing the ACE2 receptor that supports robust viral replication while maintaining 3D architecture and cellular diversity of the airway epithelium. ACE2-OE organoids were infected with SARS-CoV-2 variants and subjected to single-cell RNA-sequencing. NF-{kappa}B inhibitor alpha was consistently upregulated in infected epithelial cells, and its mRNA expression positively correlated with infection levels. Confocal microscopy showed more I{kappa}B expression in infected than bystander cells, but found concurrent nuclear translocation of NF-{kappa}B that I{kappa}B usually prevents. Overexpressing a nondegradable I{kappa}B mutant reduced NF-{kappa}B translocation and increased viral infection. These data demonstrate the functionality of ACE2-OE organoids in SARS-CoV-2 research and identify an incomplete NF-{kappa}B feedback loop as a rheostat of viral infection that may promote inflammation and severe disease.

microbiology↗

Lung Immune Tone Regulation by the Gut-Lung Immune Axis: Short-chain Fatty Acid Receptors FFAR2 and FFAR3, and IL-1β Expression Profiling in Mouse and Human Lung

Microbial metabolites produced by the gut microbiome, such as short-chain fatty acids (SCFA), can influence both local intestinal and distant lung physiology and response to injury. However, how lung immune activity is regulated by SCFAs is unknown. We examined fresh human lung tissue and observed the presence of SCFAs with large inter-individual and even intra-lobe variability. In vitro, SCFAs were capable of modifying the metabolic programming in both resting and LPS-exposed alveolar macrophages (AM). Additionally, since we hypothesized that lung immune tone could be defined through priming of the inflammasome (aka signal 1), we interrogated naive mouse lungs for pro-IL-1{beta} message and localized its presence within the alveolar space in situ, specifically in AM subsets, and in close proximity to alveolar type 2 epithelial (AT2) cells. We established that metabolically active gut microbiota, that produce SCFAs, can transmit LPS and SCFAs to the lung (potential sources of signal 1), and thereby could regulate lung immune tone and metabolic programming. To understand how murine lung cells sensed and upregulated IL-1{beta} in response to gut-microbiome factors, we determined that in vitro, AM and AT2 cells expressed SCFA receptors, FFAR2, FFAR3, and IL-1{beta} but with different expression patterns and LPS-inducibility. Finally, we observed that IL-1{beta}, FFAR2 and FFAR3 were expressed both in isolated human AM and AT2 cells ex-vivo, but in fresh human lung sections in situ, only AM expressed IL-1{beta} at rest and after LPS challenge. Together, this translational study using mouse and human lung tissue and cells supports an important role for the gut microbiome and SCFAs in regulating lung immune tone.

immunology↗