Soluble collectin-12 mediates C3-independent docking of properdin that activates the alternative pathway of complement

  1. Jie Zhang
  2. Lihong Song
  3. Dennis V Pedersen
  4. Anna Li
  5. John D Lambris
  6. Gregers Rom Andersen
  7. Tom Eirik Mollnes
  8. Ying Jie Ma  Is a corresponding author
  9. Peter Garred  Is a corresponding author
  1. Rigshospitalet/Copenhagen University, Denmark
  2. Aarhus University, Denmark
  3. University of Pennsylvania, United States
  4. University of Oslo, Norway

Abstract

Properdin stabilizes the alternative C3 convertase (C3bBb), whereas its role as pattern recognition molecule mediating complement activation is disputed for decades. Previously, we have found that soluble collectin-12 (sCL-12) synergizes complement alternative pathway (AP) activation. However, whether this observation is C3 dependent is unknown. By application of the C3-inhibitor Cp40, we found that properdin in normal human serum bound to Aspergillus fumigatus solely in a C3b-dependent manner. Cp40 also prevented properdin binding when properdin-depleted serum reconstituted with purified properdin was applied, in analogy with the findings achieved by C3-depleted serum. However, when opsonized with sCL-12, properdin bound in a C3-independent manner exclusively via its tetrameric structure and directed in situ C3bBb assembly. In conclusion, a prerequisite for properdin binding and in situ C3bBb assembly was the initial docking of sCL-12. This implies a new important function of properdin in host defence bridging pattern recognition and specific AP activation.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files.

Article and author information

Author details

  1. Jie Zhang

    Department of Clinical Immunology, Rigshospitalet/Copenhagen University, Copenhagen, Denmark
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4472-3468
  2. Lihong Song

    Department of Clinical Immunology, Rigshospitalet/Copenhagen University, Copenhagen, Denmark
    Competing interests
    No competing interests declared.
  3. Dennis V Pedersen

    Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
    Competing interests
    No competing interests declared.
  4. Anna Li

    Department of Clinical Immunology, Rigshospitalet/Copenhagen University, Copenhagen, Denmark
    Competing interests
    No competing interests declared.
  5. John D Lambris

    Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, United States
    Competing interests
    John D Lambris, inventor of patents (Patent Number: 9630992) and/or patent applications 426 (Application Number: 15/126,937) that describe the use of complement inhibitors for therapeutic purposes, the founder of Amyndas Pharmaceuticals, which is developing complement inhibitors (i.e., third-generation compstatins) for clinical applications, and the inventor of the compstatin technology licensed to Apellis Pharmaceuticals (i.e., 4[1MeW]7W/POT-4/APL-1 and PEGylated derivatives)..
  6. Gregers Rom Andersen

    Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-6292-3319
  7. Tom Eirik Mollnes

    Department of Immunology, University of Oslo, Oslo, Norway
    Competing interests
    No competing interests declared.
  8. Ying Jie Ma

    Department of Clinical Immunology, Rigshospitalet/Copenhagen University, Copenhagen, Denmark
    For correspondence
    mayingjie606@hotmail.com
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4003-2579
  9. Peter Garred

    Department of Clinical Immunology, Rigshospitalet/Copenhagen University, Copenhagen, Denmark
    For correspondence
    peter.garred@regionh.dk
    Competing interests
    No competing interests declared.

Funding

Kirsten og Freddy Johansens Fond (Research fund)

  • Ying Jie Ma

Novo Nordisk (Research fund)

  • Peter Garred

Købmand I Odense Johan og Hanne Weimann Født Seedorffs Legat (Research fund)

  • Ying Jie Ma

Alfred Benzon Foundation (Research fund)

  • Ying Jie Ma
  • Peter Garred

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Frank L van de Veerdonk, Radboud University Medical Center, Netherlands

Version history

  1. Received: July 9, 2020
  2. Accepted: September 9, 2020
  3. Accepted Manuscript published: September 10, 2020 (version 1)
  4. Accepted Manuscript updated: September 14, 2020 (version 2)
  5. Version of Record published: September 23, 2020 (version 3)

Copyright

© 2020, Zhang et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 1,095
    views
  • 151
    downloads
  • 14
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Jie Zhang
  2. Lihong Song
  3. Dennis V Pedersen
  4. Anna Li
  5. John D Lambris
  6. Gregers Rom Andersen
  7. Tom Eirik Mollnes
  8. Ying Jie Ma
  9. Peter Garred
(2020)
Soluble collectin-12 mediates C3-independent docking of properdin that activates the alternative pathway of complement
eLife 9:e60908.
https://doi.org/10.7554/eLife.60908

Share this article

https://doi.org/10.7554/eLife.60908

Further reading

    1. Immunology and Inflammation
    Zhixin Jing, Phillip Galbo ... David Fooksman
    Research Article

    Durable serological memory following vaccination is critically dependent on the production and survival of long-lived plasma cells (LLPCs). Yet, the factors that control LLPC specification and survival remain poorly resolved. Using intravital two-photon imaging, we find that in contrast to most plasma cells (PCs) in the bone marrow (BM), LLPCs are uniquely sessile and organized into clusters that are dependent on APRIL, an important survival factor. Using deep, bulk RNA sequencing, and surface protein flow-based phenotyping, we find that LLPCs express a unique transcriptome and phenotype compared to bulk PCs, fine-tuning expression of key cell surface molecules, CD93, CD81, CXCR4, CD326, CD44, and CD48, important for adhesion and homing. Conditional deletion of Cxcr4 in PCs following immunization leads to rapid mobilization from the BM, reduced survival of antigen-specific PCs, and ultimately accelerated decay of antibody titer. In naïve mice, the endogenous LLPCs BCR repertoire exhibits reduced diversity, reduced somatic mutations, and increased public clones and IgM isotypes, particularly in young mice, suggesting LLPC specification is non-random. As mice age, the BM PC compartment becomes enriched in LLPCs, which may outcompete and limit entry of new PCs into the LLPC niche and pool.

    1. Immunology and Inflammation
    2. Microbiology and Infectious Disease
    Ffion R Hammond, Amy Lewis ... Philip M Elks
    Research Article

    Tuberculosis is a major global health problem and is one of the top 10 causes of death worldwide. There is a pressing need for new treatments that circumvent emerging antibiotic resistance. Mycobacterium tuberculosis parasitises macrophages, reprogramming them to establish a niche in which to proliferate, therefore macrophage manipulation is a potential host-directed therapy if druggable molecular targets could be identified. The pseudokinase Tribbles1 (Trib1) regulates multiple innate immune processes and inflammatory profiles making it a potential drug target in infections. Trib1 controls macrophage function, cytokine production, and macrophage polarisation. Despite wide-ranging effects on leukocyte biology, data exploring the roles of Tribbles in infection in vivo are limited. Here, we identify that human Tribbles1 is expressed in monocytes and is upregulated at the transcript level after stimulation with mycobacterial antigen. To investigate the mechanistic roles of Tribbles in the host response to mycobacteria in vivo, we used a zebrafish Mycobacterium marinum (Mm) infection tuberculosis model. Zebrafish Tribbles family members were characterised and shown to have substantial mRNA and protein sequence homology to their human orthologues. trib1 overexpression was host-protective against Mm infection, reducing burden by approximately 50%. Conversely, trib1 knockdown/knockout exhibited increased infection. Mechanistically, trib1 overexpression significantly increased the levels of proinflammatory factors il-1β and nitric oxide. The host-protective effect of trib1 was found to be dependent on the E3 ubiquitin kinase Cop1. These findings highlight the importance of Trib1 and Cop1 as immune regulators during infection in vivo and suggest that enhancing macrophage TRIB1 levels may provide a tractable therapeutic intervention to improve bacterial infection outcomes in tuberculosis.