tetano
Editor, Senior Moderator
Am J Respir Cell Mol Biol
. 2021 Mar 30.
doi: 10.1165/rcmb.2021-0005OC. Online ahead of print.
A Recombinant Fragment of Human Surfactant Protein D Binds Spike Protein and Inhibits Infectivity and Replication of SARS-CoV-2 in Clinical Samples
Taruna Madan[SUP] 1 [/SUP], Barnali Biswas[SUP] 1 [/SUP], Praveen M Varghese[SUP] 2 [/SUP], Rambhadur Subedi[SUP] 1 [/SUP], Hrishikesh Pandit[SUP] 1 [/SUP], Susan Idicula-Thomas[SUP] 1 [/SUP], Indra Kundu[SUP] 1 [/SUP], Sheetalnath Rooge[SUP] 3 [/SUP], Reshu Agarwal[SUP] 3 [/SUP], Dinesh M Tripathi[SUP] 3 [/SUP], Savneet Kaur[SUP] 3 [/SUP], Ekta Gupta[SUP] 3 [/SUP], Sanjeev K Gupta[SUP] 4 [/SUP], Uday Kishore[SUP] 5 [/SUP]
Affiliations
Abstract
COVID -19 is an acute infectious disease caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Human surfactant protein D (SP-D) is known to interact with spike protein of SARS-CoV, but its immune-surveillance against SARS-CoV-2 is not known. The study aimed to examine the potential of a recombinant fragment of human SP-D (rfhSP-D) as an inhibitor of replication and infection of SARS-CoV-2. The interaction of rfhSP-D with spike protein of SARS-CoV-2 and hACE-2 receptor was predicted via docking analysis. The inhibition of interaction between spike protein and ACE-2 by rfhSP-D was confirmed using direct and indirect ELISA. The effect of rfhSP-D on replication and infectivity of SARS-CoV-2 from clinical samples was studied by measuring the expression of RdRp gene of the virus using qPCR. In-silico interaction studies indicated that three amino acid residues in the RBD of spike of SARS-CoV-2 were commonly involved in interacting with rfhSP-D and ACE-2. Studies using clinical samples of SARS-CoV-2 positive cases (asymptomatic, n=7 and symptomatic, n=8 and negative controls n=15) demonstrated that treatment with 1.67 ?M rfhSP-D inhibited viral replication by ~5.5 fold and was more efficient than Remdesivir (100 ?M). Approximately, a 2-fold reduction in viral infectivity was also observed after treatment with 1.67 ?M rfhSP-D. These results conclusively demonstrate that the calcium independent rfhSP-D mediated inhibition of binding between the receptor binding domain of the S1 subunit of the SARS-CoV-2 spike protein and human ACE-2, its host cell receptor, and a significant reduction in SARS-CoV-2 infection and replication in-vitro. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Keywords: COVID-19; SARS-CoV-2; Spike protein; Surfactant protein D; entry inhibition.
. 2021 Mar 30.
doi: 10.1165/rcmb.2021-0005OC. Online ahead of print.
A Recombinant Fragment of Human Surfactant Protein D Binds Spike Protein and Inhibits Infectivity and Replication of SARS-CoV-2 in Clinical Samples
Taruna Madan[SUP] 1 [/SUP], Barnali Biswas[SUP] 1 [/SUP], Praveen M Varghese[SUP] 2 [/SUP], Rambhadur Subedi[SUP] 1 [/SUP], Hrishikesh Pandit[SUP] 1 [/SUP], Susan Idicula-Thomas[SUP] 1 [/SUP], Indra Kundu[SUP] 1 [/SUP], Sheetalnath Rooge[SUP] 3 [/SUP], Reshu Agarwal[SUP] 3 [/SUP], Dinesh M Tripathi[SUP] 3 [/SUP], Savneet Kaur[SUP] 3 [/SUP], Ekta Gupta[SUP] 3 [/SUP], Sanjeev K Gupta[SUP] 4 [/SUP], Uday Kishore[SUP] 5 [/SUP]
Affiliations
- PMID: 33784482
- DOI: 10.1165/rcmb.2021-0005OC
Abstract
COVID -19 is an acute infectious disease caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Human surfactant protein D (SP-D) is known to interact with spike protein of SARS-CoV, but its immune-surveillance against SARS-CoV-2 is not known. The study aimed to examine the potential of a recombinant fragment of human SP-D (rfhSP-D) as an inhibitor of replication and infection of SARS-CoV-2. The interaction of rfhSP-D with spike protein of SARS-CoV-2 and hACE-2 receptor was predicted via docking analysis. The inhibition of interaction between spike protein and ACE-2 by rfhSP-D was confirmed using direct and indirect ELISA. The effect of rfhSP-D on replication and infectivity of SARS-CoV-2 from clinical samples was studied by measuring the expression of RdRp gene of the virus using qPCR. In-silico interaction studies indicated that three amino acid residues in the RBD of spike of SARS-CoV-2 were commonly involved in interacting with rfhSP-D and ACE-2. Studies using clinical samples of SARS-CoV-2 positive cases (asymptomatic, n=7 and symptomatic, n=8 and negative controls n=15) demonstrated that treatment with 1.67 ?M rfhSP-D inhibited viral replication by ~5.5 fold and was more efficient than Remdesivir (100 ?M). Approximately, a 2-fold reduction in viral infectivity was also observed after treatment with 1.67 ?M rfhSP-D. These results conclusively demonstrate that the calcium independent rfhSP-D mediated inhibition of binding between the receptor binding domain of the S1 subunit of the SARS-CoV-2 spike protein and human ACE-2, its host cell receptor, and a significant reduction in SARS-CoV-2 infection and replication in-vitro. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Keywords: COVID-19; SARS-CoV-2; Spike protein; Surfactant protein D; entry inhibition.