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  • Ex vivo SARS-CoV-2 infection of human lung reveals heterogeneous host defense and therapeutic responses.

Ex vivo SARS-CoV-2 infection of human lung reveals heterogeneous host defense and therapeutic responses.

JCI insight (2021-08-07)
Matthew A Schaller, Yamini Sharma, Zadia Dupee, Duy Nguyen, Juan Urueña, Ryan Smolchek, Julia C Loeb, Tiago N Machuca, John A Lednicky, David J Odde, Robert F Campbell, W Gregory Sawyer, Borna Mehrad
ABSTRACT

Cell lines are the mainstay in understanding the biology of COVID-19 infection but do not recapitulate many of the complexities of human infection. The use of human lung tissue is one solution for the study of such novel respiratory pathogens. We hypothesized that a cryopreserved bank of human lung tissue would allow for the ex vivo study of the interindividual heterogeneity of host response to SARS-CoV-2, thus providing a bridge between studies with cell lines and studies in animal models. We generated a cryobank of tissues from 21 donors, many of whom had clinical risk factors for severe COVID-19. Cryopreserved tissues preserved 90% cell viability and contained heterogenous populations of metabolically active epithelial, endothelial, and immune cell subsets of the human lung. Samples were readily infected with HCoV-OC43 and SARS-CoV-2 and demonstrated comparable susceptibility to infection. In contrast, we observed a marked donor-dependent heterogeneity in the expression of IL6, CXCL8, and IFNB1 in response to SARS-CoV-2. Treatment of tissues with dexamethasone and the experimental drug N-hydroxycytidine suppressed viral growth in all samples, whereas chloroquine and remdesivir had no detectable effect. Metformin and sirolimus, molecules with predicted but unproven antiviral activity, each suppressed viral replication in tissues from a subset of donors. In summary, we developed a system for the ex vivo study of human SARS-CoV-2 infection using primary human lung tissue from a library of donor tissues. This model may be useful for drug screening and for understanding basic mechanisms of COVID-19 pathogenesis.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Chloroquine diphosphate salt, powder or crystals, 98.5-101.0% (EP)
Sigma-Aldrich
Anti-Coronavirus Group Antigen Antibody, nucleoprotein of OC-43, clone 542-7D, clone 542-7D, Chemicon®, from mouse
Roche
Liberase TM Research Grade, medium Thermolysin concentration
Sigma-Aldrich
Ertapenem sodium, ≥90% (HPLC)
Sigma-Aldrich
CryoSOfree DMSO-free Cryopreservation Medium
Sigma-Aldrich
Deoxyribonuclease I from bovine pancreas, Type IV, lyophilized powder, ≥2,000 Kunitz units/mg protein
Sigma-Aldrich
Dexamethasone-Water Soluble, suitable for cell culture, BioReagent