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Collectin-11, a complement pattern recognition molecule, mediates pulmonary SARS-CoV-2 neutralization and protection
Adrian Sutta1, Anna Offersgaard2,3, Carlos Rene Duarte Hernandez2,3
1Laboratory of Molecular Medicine, Department of Clinical Immunology, Copenhagen University Hospital, Copenhagen, Denmark.
Plos Pathogens
|May 13, 2026
Summary
Collectin-11 (CL-11) binds SARS-CoV-2 variants, activating complement and neutralizing the virus independently of antibodies. This suggests CL-11 plays a key role in controlling early-stage infections.
Area of Science:
- Immunology
- Virology
Background:
- Collectin-11 (CL-11) is a pattern recognition molecule similar to mannose-binding lectin (MBL).
- CL-11 is found in lung epithelium and involved in innate immunity.
- Its potential role in SARS-CoV-2 recognition and complement activation was unexplored.
Purpose of the Study:
- To investigate CL-11's ability to recognize and neutralize SARS-CoV-2.
- To determine if CL-11 activates the complement system upon binding SARS-CoV-2.
- To assess CL-11's effect on SARS-CoV-2 S protein-receptor binding.
Main Methods:
- Produced recombinant CL-11, MBL, and various SARS-CoV-2 Spike (S) proteins.
- Evaluated CL-11 binding to S proteins using ELISA.
- Assessed complement activation and S protein-receptor binding inhibition.
- Performed cell-based neutralization assays for SARS-CoV-2.
Main Results:
- CL-11 demonstrated binding to multiple SARS-CoV-2 S protein variants, similar to MBL.
- CL-11 binding triggered both lectin and alternative complement pathways.
- CL-11 inhibited S protein-receptor binding and neutralized SARS-CoV-2 infection in cell assays.
Conclusions:
- CL-11 effectively binds diverse SARS-CoV-2 variants.
- CL-11 neutralizes SARS-CoV-2 in an antibody-independent manner.
- CL-11 may be crucial for controlling early-stage SARS-CoV-2 infections.
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