scholarly journals Complement Receptor 3 Forms a Compact High-Affinity Complex with iC3b

2021 ◽  
pp. ji2001208
Author(s):  
Rasmus K. Jensen ◽  
Goran Bajic ◽  
Mehmet Sen ◽  
Timothy A. Springer ◽  
Thomas Vorup-Jensen ◽  
...  
Keyword(s):  
Complement Receptor ◽  
High Affinity ◽  
Complement Receptor 3

scholarly journals Complement receptor 3 forms a compact high affinity complex with iC3b

2020 ◽  
Author(s):  
Rasmus K Jensen ◽  
Goran Bajic ◽  
Mehmet Sen ◽  
Timothy Springer ◽  
Thomas Vorup-Jensen ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Ligand Binding ◽  
Lymphoid Cells ◽  
Complement Receptor ◽  
Ligand Complex ◽  
Receptor Ligand ◽  
X Ray ◽  
High Affinity ◽  
X Ray Scattering ◽  
Complement Receptor 3

Complement receptor 3 (CR3, also known as Mac-1, integrin αMβ2, or CD11b/CD18) is expressed on a subset of myeloid and certain activated lymphoid cells. CR3 is essential for the phagocytosis of complement-opsonized particles such as pathogens and apoptotic or necrotic cells opsonized with the complement fragment iC3b and to a lesser extent C3dg. While the interaction between the iC3b thioester domain and the ligand binding CR3 αM I-domain is structurally and functionally well characterized, the nature of additional CR3-iC3b interactions required for phagocytosis of complement opsonized objects remain obscure. Here we analyzed the interaction between iC3b and the 150 kDa headpiece fragment of the CR3 ectodomain. Surface plasmon resonance experiments demonstrated a 30 nM affinity of CR3 for iC3b compared to 515 nM for the iC3b thioester domain. Small angle x-ray scattering analysis revealed that iC3b adopts an extended but preferred conformation in solution. Upon interaction with CR3, iC3b rearranges to form a compact receptor-ligand complex. Overall, the data suggest that the iC3b-CR3 interaction is of high affinity and relies on minor contacts formed between CR3 and regions outside the iC3b thioester domain. Our results rationalize the more efficient phagocytosis elicited by iC3b than by C3dg and pave the way for development of specific therapeutics for treatment of inflammatory and neurodegenerative diseases that do not interfere with recognition of non-complement CR3 ligands.

scholarly journals β-Glucan enhances complement-mediated hematopoietic recovery after bone marrow injury

Blood ◽  
2006 ◽  
Vol 107 (2) ◽  
pp. 835-840 ◽  
Author(s):  
Daniel E. Cramer ◽  
Daniel J. Allendorf ◽  
Jarek T. Baran ◽  
Richard Hansen ◽  
Jose Marroquin ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Mouse Serum ◽  
Complement Receptor ◽  
Dependent Manner ◽  
Complement Receptor 3 ◽  
Total Body ◽  
Stimulating Factor ◽  
Sublethal Irradiation ◽  
Classic Pathway

AbstractMyelotoxic injury in the bone marrow (BM) as a consequence of total body irradiation (TBI) or granulocyte colony-stimulating factor (G-CSF) mobilization results in the deposition of iC3b on BM stroma (stroma-iC3b). In the present study, we have examined how stroma-iC3b interacts with hematopoietic progenitor cells (HPCs) and the role of complement (C) and complement receptor 3 (CR3) in BM injury/repair. We demonstrate here that stroma-iC3b tethers HPCs via the inserted (I) domain of HPC complement receptor 3 (CR3, CD11b/CD18, Mac-1). Following irradiation, stroma-iC3b was observed in the presence of purified IgM and normal mouse serum (NMS), but not serum from Rag-2-/- mice, implicating a role for antibody (Ab) and the classic pathway of C activation. Furthermore, a novel role for soluble yeast β-glucan, a ligand for the CR3 lectin-like domain (LLD), in the priming of CR3+ HPC is suggested. Soluble yeast β-glucan could enhance the proliferation of tethered HPCs, promote leukocyte recovery following sublethal irradiation, and increase the survival of lethally irradiated animals following allogeneic HPC transplantation in a CR3-dependent manner. Taken together, these observations suggest a novel role for C, CR3, and β-glucan in the restoration of hematopoiesis following injury. (Blood. 2006;107:835-840)

scholarly journals Activated microglia desialylate their surface, stimulating complement receptor 3‐mediated phagocytosis of neurons

Glia ◽  
2019 ◽  
Vol 68 (5) ◽  
pp. 989-998 ◽  
Author(s):  
David H. Allendorf ◽  
Mar Puigdellívol ◽  
Guy C. Brown
Keyword(s):  
Complement Receptor ◽  
Activated Microglia ◽  
Complement Receptor 3

Role of complement and Fcγ receptors in the protective activity of the long pentraxin PTX3 against Aspergillus fumigatus

Blood ◽  
2010 ◽  
Vol 116 (24) ◽  
pp. 5170-5180 ◽  
Author(s):  
Federica Moalli ◽  
Andrea Doni ◽  
Livija Deban ◽  
Teresa Zelante ◽  
Silvia Zagarella ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Alternative Pathway ◽  
Complement Receptor ◽  
Protective Activity ◽  
Opsonic Activity ◽  
Reactive Protein ◽  
Complement Receptor 3 ◽  
Dependent Pathway

AbstractPentraxin 3 (PTX3) is a soluble pattern recognition molecule playing a nonredundant role in resistance against Aspergillus fumigatus. The present study was designed to investigate the molecular pathways involved in the opsonic activity of PTX3. The PTX3 N-terminal domain was responsible for conidia recognition, but the full-length molecule was necessary for opsonic activity. The PTX3-dependent pathway of enhanced neutrophil phagocytic activity involved complement activation via the alternative pathway; Fcγ receptor (FcγR) IIA/CD32 recognition of PTX3-sensitized conidia and complement receptor 3 (CR3) activation; and CR3 and CD32 localization to the phagocytic cup. Gene targeted mice (ptx3, FcR common γ chain, C3, C1q) validated the in vivo relevance of the pathway. In particular, the protective activity of exogenous PTX3 against A fumigatus was abolished in FcR common γ chain-deficient mice. Thus, the opsonic and antifungal activity of PTX3 is at the crossroad between complement, complement receptor 3-, and FcγR-mediated recognition. Because short pentraxins (eg, C-reactive protein) interact with complement and FcγR, the present results may have general significance for the mode of action of these components of the humoral arm of innate immunity.

Factor H facilitates adherence of Neisseria gonorrhoeae to complement receptor 3 on eukaryotic cells

2010 ◽  
Vol 47 (13) ◽  
pp. 2246-2246
Author(s):  
Sarika Agarwal ◽  
Sanjay Ram ◽  
Jutamas Ngampasutadol ◽  
Sunita Gulati ◽  
Peter F. Zipfel ◽  
...  
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Factor H ◽  
Eukaryotic Cells ◽  
Complement Receptor ◽  
Complement Receptor 3

Complement receptor 3-like immunoreactivity in the light green cells and the canopy cells of the pond snail, Lymnaea stagnalis

2000 ◽  
Vol 865 (1) ◽  
pp. 102-106 ◽  
Author(s):  
Dai Hatakeyama ◽  
Iori Ito ◽  
Satoshi Kojima ◽  
Yutaka Fujito ◽  
Etsuro Ito
Keyword(s):  
Lymnaea Stagnalis ◽  
Pond Snail ◽  
Complement Receptor ◽  
Complement Receptor 3 ◽  
Light Green

Neutrophil labeling with [99mTc]-technetium stannous colloid is complement receptor 3-mediated and increases the neutrophil priming response to lipopolysaccharide

2006 ◽  
Vol 33 (3) ◽  
pp. 433-439 ◽  
Author(s):  
Hayley Gallagher ◽  
Stuart C. Ramsay ◽  
Jodie Barnes ◽  
Jacqueline Maggs ◽  
Nathan Cassidy ◽  
...  
Keyword(s):  
Complement Receptor ◽  
Complement Receptor 3 ◽  
Neutrophil Priming
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