Project description:The distal lung contains terminal bronchioles and alveoli that facilitate gas exchange. Three-dimensional in vitro human distal lung culture systems would strongly facilitate investigation of pathologies including interstitial lung disease, cancer, and SARS-CoV-2-associated COVID-19 pneumonia. We generated long-term feeder-free, chemically-defined culture of distal lung progenitors as organoids derived from single adult human alveolar epithelial type II (AT2) or KRT5+ basal cells. AT2 organoids exhibited AT1 transdifferentiation potential while basal cell organoids developed lumens lined by differentiated club and ciliated cells. Single cell analysis of basal organoid KRT5+ cells revealed a distinct ITGA6+ITGB4+ mitotic population whose proliferation further segregated to a TNFRSF12Ahi subfraction comprising ~10% of KRT5+ basal cells, residing in clusters within terminal bronchioles and exhibiting enriched clonogenic organoid growth activity. Distal lung organoids were created with apical-out polarity to display ACE2 on the exposed external surface, facilitating SARS-CoV-2 infection of AT2 and basal cultures and identifying club cells as a novel target population. This long-term, feeder-free organoid culture of human distal lung, coupled with single cell analysis, identifies unsuspected basal cell functional heterogeneity and establishes a facile in vitro organoid model for human distal lung infections including COVID-19-associated pneumonia.
Project description:We performed RNA-Seq of SARS-Cov-2 infection in human bronchial epithelium organoids. The organoids were infected with SARS-Cov-2 for 48hours or 72hours respectively, and compared with uninfected mock control.
Project description:We performed RNA-Seq of SARS-Cov-2 infection in human airway epithelium organoids. The organoids were infected with SARS-Cov-2 for 24hours or 48hours respectively, and compared with uninfected mock control.
Project description:Purpose: To identify the diferentially expressed genes in SARS-CoV-2 susceptible and resistant organoids during the ifnection. Method: We selected 3 susceptible (C8, C9, and C10)- and 3 restant (C1, C2, and C7)-organoids lines and infected SARS-CoV-2 at multiplicity of infection (MOI) of 4 for 24 and 72 hrs. The RNAs were collected and then sequenced by CEL-seq2. Sequencing was performed on Illumina NovaSeq 6000. Results: Longitudinal transcriptome analyses identified robust yet late transcriptional changes induced by SARS-CoV-2, the magnitude of which corresponded to the levels of viral infection.
Project description:We performed unbiased transcriptomic profiling on organoids cultures after SARS-CoV-2 infection to gain insights into AT2s response to SARS-CoV-2 infection.
Project description:We investigated the interactions of four distinct betacoronaviruses; HCoV-OC43, SARS-CoV, MERS-CoV, and SARS-CoV-2 within human bronchial epithelial (HBE) organoids using single-cell RNA sequencing (scRNA-seq) to comprehensively understand betacoronaviruses cellular tropism and the intricate interplay between these cells and the host's immune defense mechanisms.
Project description:A critical aspect of the mechanism of SARS-CoV-2 infection is the protease-mediated activation of the viral spike (S) protein. The type II transmembrane serine protease TMPRSS2 is crucial for SARS-CoV-2 infection in lung epithelial Calu-3 cells and murine airways. However, the importance of TMPRSS2 needs to be re-examined because the ability to utilize TMPRSS2 is significantly reduced in the Omicron variants that spread globally. For this purpose, replication profiles of SARS-CoV-2 were analyzed in human respiratory organoids. All tested viruses, including Omicron variants, replicated efficiently in these organoids. Notably, all SARS-CoV-2 strains retained replication ability in TMPRSS2-gene knockout (KO) respiratory organoids, suggesting that TMPRSS2 is not essential for SARS-CoV-2 infection in human respiratory tissues. However, TMPRSS2-gene knockout significantly reduces the inhibitory effect of nafamostat, suggesting the advantage of TMPRSS2-utilizing ability for the SARS-CoV-2 infection in these organoids. Interestingly, Omicron variants regained the TMPRSS2-utilizing ability in recent subvariants. The basal infectivity would be supported mainly by cathepsins because the cathepsin inhibitor, EST, showed a significant inhibitory effect on infection with any SARS-CoV-2 strains, mainly when used with nafamostat. A supplementary contribution of other serine proteases was also suggested because the infection of the Delta variant was still inhibited partially by nafamostat in TMPRSS2 KO organoids. Thus, various proteases, including TMPRSS2, other serine proteases, and cathepsins, co-operatively contribute to SARS-CoV-2 infection significantly in the respiratory organoids. Thus, SARS-CoV-2 infection in the human respiratory tissues would be more complex than observed in cell lines or mice.
Project description:COVID-19 associated acute kidney injury (COVID-AKI) is a common complication of SARS-CoV-2 infection in hospitalized patients. It is unclear how susceptible human kidneys are to direct SARS-CoV-2 infection and whether pharmacologic manipulation of the renin-angiotensin II signaling (RAS) pathway modulates this susceptibility. Using induced pluripotent stem cell derived kidney organoids, SARS-CoV-1, SARS-CoV-2 and MERS-CoV tropism, defined by the paired expression of a host receptor (ACE2, NRP1 or DPP4) and protease (TMPRSS2, TMPRSS4, FURIN, CTSB or CTSL), was identified primarily amongst proximal tubule cells. Losartan, an angiotensin II receptor blocker being tested in COVID-19 patients, inhibited angiotensin II mediated internalization of ACE2, upregulated interferon stimulated genes (IFITM1 and BST2) known to restrict viral entry, and attenuated the infection of proximal tubule cells by SARS-CoV-2. Our work highlights the susceptibility of proximal tubule cells to SARS-CoV-2 and reveals a putative protective role for RAS inhibitors during SARS-CoV-2 infection.