[The Lancet Respiratory Medicine] Tropism, replication competence, and innate immune responses of the coronavirus SARS-CoV-2 in human respiratory tract and conjunctiva: an analysis in ex-vivo and in-vitro cultures

07/05/2020

The Lancet Respiratory Medicine, 7 May 2020

Kenrie P Y Hui, Man-Chun Cheung, Ranawaka A P M Perera,Ka-Chun Ng, Christine H T Bui, ohn C W Ho,Mandy M T Ng, Denise I T Kuok, Kendrick C Shih,Sai-Wah Tsao, Leo L M Poon, Malik Peiris, John M Nicholls, Michael C W Chan

Tissue tropism of SARS-CoV-2 and SARS-CoV viruses in ex-vivo cultures of human respiratory tract and conjunctiva

Highlights:

SARS-CoV-2 infected ciliated, mucus-secreting, and club cells of bronchial epithelium, type 1 pneumocytes in the lung, and the conjunctival mucosa.
In the bronchus, SARS-CoV-2 replication competence was similar to MERS-CoV, and higher than SARS-CoV, but lower than H1N1pdm.
In the lung, SARS-CoV-2 replication was similar to SARS-CoV and H1N1pdm, but was lower than MERS-CoV. In conjunctiva (眼結膜), SARS-CoV-2 replication was greater than SARS-CoV.
The conjunctival epithelium and conducting airways appear to be potential portals of infection for SARS-CoV-2. Both SARS-CoV and SARS-CoV-2 replicated similarly in the alveolar epithelium; SARS-CoV-2 replicated more extensively in the bronchus than SARS-CoV.
Findings support the notion that SARS-CoV-2 can transmit between humans via droplets being deposited in the airways or eyes and via fomite transmission when infectious virus is introduced to the eyes via contaminated hands.