| 1990 |
ICAM-1 is a counter-receptor for Mac-1 (CD11b/CD18): purified Mac-1 adsorbed to artificial substrates binds ICAM-1-expressing cells, and COS cells co-transfected with Mac-1 alpha and beta (CD18) chains attach to purified ICAM-1 substrates. This binding is blocked by mAbs to both ICAM-1 and Mac-1, establishing ICAM-1 as a ligand for the CD11b/CD18 heterodimer. |
Purified protein binding assays, cDNA transfection of COS/L cells, reciprocal cell adhesion assays, mAb blocking |
The Journal of cell biology |
High |
1980124
|
| 1989 |
CD18 undergoes stimulus-induced phosphorylation: in resting leukocytes CD18 phosphorylation is minimal, but PMA induces rapid, sustained, high-stoichiometry CD18 phosphorylation predominantly on serine residues (with minor phosphothreonine and phosphotyrosine), while FMLP induces transient CD18 phosphorylation. The CD11 alpha subunits show only minimal changes, indicating CD18 is the primary regulated phosphorylation target in the complex. |
Metabolic radiolabeling with 32P, immunoprecipitation, phosphoamino acid analysis, PMA/FMLP stimulation of human leukocytes |
The Journal of cell biology |
High |
2574726
|
| 1989 |
CD11a/CD18 (LFA-1) and CD11b/CD18 (Mac-1) each contribute approximately equally (~50% each) to PMN adhesion to unstimulated endothelial cells, but through different ligands: CD11a/CD18 binds ICAM-1, while CD11b/CD18 binds a distinct, non-ICAM-1 ligand on endothelial cells. CD11c/CD18 does not participate in this adhesion. |
mAb blocking of individual CD11 chains, anti-ICAM-1 antibody competition, ICAM-1-coated surface down-modulation assays, PMN-endothelial cell adhesion assays |
Journal of immunology |
High |
2809204
|
| 1990 |
Two point mutations in the CD18 coding sequence (Arg593→Cys and Lys196→Thr) each impair CD18 cell-surface expression when introduced into transfected COS cells, identifying conserved residues in the cysteine-rich repeats and another conserved integrin region as critical for normal CD18 surface expression. |
cDNA cloning and sequencing of patient alleles, transfection of mutant CD18 into COS M6 cells, surface expression analysis |
The Journal of clinical investigation |
High |
1968911
|
| 1990 |
Retrovirus-mediated transduction of a functional CD18 gene into LAD patient lymphocytes restores surface expression of CD11a/CD18 (LFA-1) and reconstitutes LFA-1-dependent adhesive function, demonstrating that CD18 is the functional defect in LAD and is sufficient for integrin surface assembly. |
Retrovirus-mediated gene transfer, molecular analysis of proviral integration and CD18 mRNA, flow cytometry for surface CD11a/CD18, functional LFA-1 adhesion assays |
Science |
High |
1972597
|
| 1993 |
CD18 gene targeting in mice produces a hypomorphic allele (2–16% of normal CD18 expression); homozygous mutant mice show mild granulocytosis and impaired inflammatory responses (reduced peritonitis and delayed cardiac allograft rejection), demonstrating that CD18 is required for normal leukocyte integrin-dependent adhesion in vivo. |
Gene targeting (insertional mutation), flow cytometry for CD18 expression, chemical peritonitis model, cardiac transplant rejection model |
Journal of immunology |
High |
8101543
|
| 1998 |
CD18 null mice develop chronic dermatitis, elevated neutrophil counts, and markedly defective T cell proliferation in response to TCR stimulation, demonstrating that CD11/CD18 integrins are required for normal neutrophil tissue migration and T cell activation in vivo. |
CD18 null mouse (gene-targeted), intravital microscopy of cremaster muscle, T cell proliferation assays (staphylococcal enterotoxin A, MHC alloantigens) |
The Journal of experimental medicine |
High |
9653089
|
| 1996 |
Mac-1 (CD11b/CD18) and the urokinase receptor (uPAR/CD87) form a functional unit on monocytic cells: uPAR engagement by urokinase inhibits Mac-1-mediated fibrinogen binding and degradation (up to 91% inhibition) and Factor X binding, while vitronectin-mediated uPAR attachment enhances subsequent Mac-1 fibrinogen degradation 3–4-fold. This co-regulation was reproduced in CHO cells co-transfected with human Mac-1 and uPAR. |
Co-expression in CHO cells (transfection), fibrinogen binding and degradation assays, Factor X binding assays, monocytic cell lines, fresh monocytes |
Blood |
High |
8874219
|
| 1997 |
Mac-1 (CD11b/CD18) is an oligodeoxynucleotide-binding protein: binding of thymidine homopolymer occurs on both the CD11b alpha subunit and the CD18 beta subunit; soluble fibrinogen competes for this binding; anti-Mac-1 mAbs inhibit binding; increased surface Mac-1 expression correlates with increased ODN internalization by PMNs. |
Binding assays with phosphodiester and phosphorothioate ODNs, competition with fibrinogen, anti-Mac-1 mAb inhibition, upregulation by TNF-alpha, internalization quantification |
Nature medicine |
Medium |
9095175
|
| 1999 |
CD18-expressing phagocytes transport Salmonella from the gastrointestinal tract to the bloodstream: CD18-deficient mice are resistant to extraintestinal dissemination of SPI1-deficient S. typhimurium to liver and spleen after oral administration, establishing a CD18-dependent pathway for systemic bacterial dissemination. |
CD18-deficient mouse model, oral Salmonella challenge, organ bacterial burden quantification |
Nature |
High |
10548107
|
| 1998 |
CD18 deficiency significantly reduces myocardial infarct size and PMN infiltration after ischemia-reperfusion: CD18-/- mice show ~57% reduction in infarct area and 54% reduction in PMN infiltration compared to wild-type, demonstrating that CD18-mediated neutrophil-endothelial adhesion is required for PMN-driven myocardial reperfusion injury. |
CD18-/- and ICAM-1-/- mouse models, surgical myocardial ischemia-reperfusion, infarct size measurement, PMN infiltration histology |
The American journal of physiology |
High |
9843832
|
| 1999 |
A missense mutation (Cys36Ser) in canine ITGB2 disrupts a conserved cysteine (likely a disulfide bond) and causes canine leukocyte adhesion deficiency (CLAD): mutant CD18 fails to support CD11/CD18 surface expression, confirmed by retroviral transduction of mutant vs. normal canine CD18 into human LAD EBV B-cells. |
Sequence analysis, retroviral vector transduction of LAD B-cells, flow cytometry for CD11/CD18 surface expression |
Genomics |
High |
10512685
|
| 2003 |
CD18 deficiency (gene knockout) inhibits choroidal neovascularization (CNV): CD18-/- mice show significantly fewer CNV lesions with fluorescein leakage and significantly smaller CNV volumes after laser photocoagulation compared to wild-type, demonstrating a nonredundant role for CD18-mediated leukocyte adhesion in CNV development. |
CD18-/- mouse laser photocoagulation CNV model, confocal volumetric CNV measurement, fluorescein angiography |
Investigative ophthalmology & visual science |
High |
12766082
|
| 2008 |
The CD18 (beta2 integrin) subunit is the T-lymphocyte receptor for Helicobacter pylori vacuolating cytotoxin VacA: VacA enters activated T lymphocytes by binding CD18 and exploiting LFA-1 recycling. LFA-1-deficient Jurkat cells are resistant to VacA-induced vacuolation and IL-2 modulation; genetic complementation with LFA-1 or Mac-1 (containing human CD18) restores sensitivity. VacA targets human but not murine CD18. |
LFA-1-deficient Jurkat T cells, genetic complementation with human CD18-containing integrins, vacuolation assays, IL-2 secretion assays, species-specificity analysis |
Cell host & microbe |
High |
18191791
|
| 2007 |
Human CD18 is the functional receptor for Aggregatibacter actinomycetemcomitans leukotoxin (LtxA): chimeric beta2-integrins expressed in LtxA-resistant cells confer susceptibility, and the cysteine-rich tandem repeats encompassing integrin-EGF-like domains 2, 3, and 4 of the CD18 extracellular region are critical for species-specific LtxA-induced cytotoxicity. |
Chimeric beta2-integrin expression in resistant cell lines, domain-deletion analysis, cytotoxicity assays |
Infection and immunity |
High |
17635865
|
| 2002 |
CD11b/CD18-dependent PMN interactions with intestinal epithelium are mediated by fucosylated proteoglycans: fucoidin directly binds CD11b/CD18 in a divalent cation- and sulfation-dependent manner blocked by anti-CD11b mAbs; fucosidase treatment of T84 epithelial cells reduces adhesion to purified CD11b/CD18; proteoglycan synthesis inhibition blocks T84 adhesion to CD11b/CD18. |
Purified CD11b/CD18 adhesion assays, fucoidin direct binding, anti-CD11b mAb blocking, fucosidase and neuraminidase treatment, proteoglycan synthesis inhibition, ligand blotting |
Journal of immunology |
High |
12391246
|
| 2001 |
CD18 undergoes conformational change upon leukocyte activation: mAbs recognizing activation-induced neoepitopes on CD18 reveal a subpopulation of LFA-1 with altered conformation that correlates with cell adhesion, requires divalent cations, is sensitive to cellular signaling, is absent in LAD-1 variant cells defective in LFA-1 activation, and co-occurs with high-affinity ICAM-1 binding. Function-blocking CD18 mAbs suppress this conformational change. |
Novel activation-epitope mAb panel, flow cytometry on T lymphocytes and LAD-1 variant cell lines, correlation with ICAM-1 binding affinity, recombinant LFA-1 |
Journal of immunology |
High |
11714770
|
| 2003 |
Fluid shear stress causes cleavage of the extracellular domain of CD18 from neutrophil surfaces via cysteine protease (cathepsin B) activity: shear (5 dyn/cm²) cleaves the extracellular but not cytoplasmic CD18 domain, is abolished by extracellular Ca²⁺ chelation and cathepsin B inhibitors (but not cathepsin L, calpain, elastase, or metalloprotease inhibitors), and results in CD18 redistribution rather than cytoplasmic internalization. |
Confocal microscopy of single adherent neutrophils, flow cytometry, protease inhibitor panel, Ca²⁺ chelation, domain-specific antibody epitope mapping |
Proceedings of the National Academy of Sciences of the United States of America |
High |
14595007
|
| 2002 |
Lck tyrosine kinase is required for CD11a/CD18 surface expression and activation in T cells: Lck-deficient Jurkat cells (JCaM1.6) show dramatically reduced CD3- and phorbol ester-induced adhesion to ICAM-1 and lower CD11a/CD18 surface expression, with CD18 predominantly in an immature, unassociated form; retransfection of Lck restores adhesion. |
Lck-deficient Jurkat cell line (JCaM1.6), Src-kinase inhibitor PP2, flow cytometry, cell surface labeling, Lck retransfection rescue |
European journal of immunology |
High |
12115650
|
| 1999 |
Redox signaling via oxidative S-thiolation is required for CD11b/CD18 activation: H₂O₂ induces CD11b/CD18-dependent neutrophil adhesion and activation neoepitope expression; this is inhibited by tyrosine kinase inhibitors and sulfhydryl-complexing agents. Physiological agonists (TNF-alpha)-induced integrin activation is blocked by flavoprotein oxidoreductase inhibitor (DPI), free radical scavengers, tyrosine kinase inhibitors, and PAO, but not by integrin-activating KIM185 mAb. |
H₂O₂ treatment of neutrophils, activation neoepitope mAb (clone 24), tyrosine kinase inhibitors, PAO, DPI, free radical scavengers, chronic granulomatous disease patient neutrophils |
European journal of immunology |
Medium |
10556796
|
| 1996 |
CD63 associates physically with CD11/CD18 on neutrophil surfaces and crosslinking of CD63 upregulates CD11/CD18 expression and increases neutrophil adhesion to endothelium via a CD18-dependent mechanism. CD63-associated protein kinase activity is predominantly tyrosine kinase activity (Lyn, Hck), linking CD63-CD18 complexes to intracellular signaling. |
Co-immunoprecipitation, flow cytometry for CD11/CD18 expression, neutrophil-HUVEC adhesion assays, mAb blocking, kinase activity assay, Src family kinase identification |
Journal of immunology |
Medium |
8871662
|
| 1992 |
CD18 expression is transcriptionally regulated during myeloid differentiation via a defined promoter: the CD18 promoter contains AP-1 elements mediating PMA transcriptional response and a PU.1 binding site; a CD18 promoter-luciferase construct increases expression after PMA in U937 cells, and nuclear run-on studies confirm transcriptional regulation during TPA-induced HL-60 monocytic differentiation. |
Promoter cloning, primer extension, RNase protection, DNA sequencing, luciferase reporter assay, nuclear run-on transcription |
Blood |
High |
1350225
|
| 2005 |
CD18 (LFA-1) is required for optimal development and function of CD4+CD25+ T regulatory cells: CD18-/- mice have reduced Treg numbers, defective thymic and peripheral Treg development, and LFA-1-deficient Tregs fail to suppress conventional T cells in vitro or prevent colitis in lymphopenic hosts following adoptive transfer. |
CD18-/- mouse (NOD background), Treg enumeration, in vitro suppression assays, T cell adoptive transfer colitis model |
Journal of immunology |
High |
16339524
|
| 2009 |
Genetic deficiency of Itgb2 completely prevents autoimmune diabetes and insulitis in NOD/LtJ mice, and abolishes T-cell adhesion to islet microvascular endothelial cells under hydrodynamic flow conditions, demonstrating that CD18 (beta2 integrin) mediates diabetogenic T-cell adhesion to islet endothelium. |
Itgb2 gene-targeted NOD/LtJ mice, diabetes incidence monitoring, insulitis scoring, in vitro hydrodynamic flow T-cell adhesion assays, adoptive transfer studies |
Diabetes |
High |
19223596
|
| 2017 |
Cathepsin B cleaves CD18 from the leukocyte surface to regulate extravasation from angiogenic vessels: CtsB-deficient leukocytes accumulate more in angiogenic vessels, extravasate less, and retain higher CD18 surface expression. CD18-deficient leukocytes extravasate later but migrate faster once outside vessels, revealing that CD18-ECM interactions slow interstitial transmigration velocity. |
In vivo corneal angiogenesis/cytokine implant model, CtsB-/- and CD18-/- leukocyte tracking, CD18 surface expression measurement |
FASEB journal |
Medium |
28904019
|
| 2019 |
Crystal/SAXS structures of staphylococcal leukocidin GH (LukGH) in complex with the alpha-I domain of CD11b (CD11b-I domain of CD18 heterodimer) reveal two binding interfaces on LukG and LukH protomers; human CD11b-I induces LukGH oligomerization in solution (required for cytolytic pore formation), while murine CD11b-I binds weakly and does not support oligomerization, explaining species specificity. |
Crystal structure and SAXS of LukGH-CD11b-I complex, LukGH variant engineering, murine vs. human CD11b-I binding assays, oligomerization assays, cytolysis assays with murine neutrophils |
Proceedings of the National Academy of Sciences of the United States of America |
High |
31852826
|
| 2016 |
Mac-1 (CD11b/CD18) plays a dominant role in macrophage fusion to form multinucleated giant cells: IL-4-induced fusion of Mac-1-deficient macrophages is strongly reduced in vitro, and fewer giant cells form in the inflamed peritoneum of Mac-1-/- mice compared to wild-type. Mac-1 deficiency reduces macrophage spreading but not adhesion or migration. Integrin αDβ2 (CD11d/CD18) also contributes to fusion, but less prominently. ICAM-1 deficiency does not alter fusion rate, suggesting a novel counter-receptor. |
Mac-1-/- and αDβ2-/- mice, IL-4-induced macrophage fusion assay, peritoneal inflammation model, spreading/adhesion/migration assays |
The American journal of pathology |
High |
27315778
|
| 2018 |
Integrin ITGAM-ITGB2 (Mac-1/CR3) is the phagocytic receptor that initiates LC3-associated phagocytosis (LAP) of Listeria monocytogenes in tissue macrophages: LAP is required for bacterial killing and anti-listerial immunity in vivo, whereas canonical autophagy is dispensable. |
In vivo mouse infection model, genetic identification of Mac-1 as LAP-initiating receptor, macrophage killing assays |
Autophagy |
Medium |
29923444
|
| 2013 |
LA1 (leukadherin-1), a small molecule CD11b/CD18 agonist, enhances CD11b/CD18:ICAM-1 binding primarily by increasing membrane tether formation rather than cytoskeleton-anchored bonds. In contrast, Mn²⁺ additionally promotes CSK-anchored bond formation, demonstrating two mechanistically distinct modes of CD11b/CD18 activation. |
Single-molecule force spectroscopy (AFM), K562 cells expressing CD11b/CD18, LFA-1-/- neutrophils, ICAM-1-coated AFM tips |
Biophysical journal |
High |
24314082
|
| 2013 |
CD11c alpha-chain phosphorylation at Ser-1158 is required for CD11c/CD18 (CR4) function: alanine substitution at this site impairs adherence and phagocytosis, establishing that alpha-chain phosphorylation is functionally critical for this beta2 integrin. |
Phosphorylation site mapping, site-directed mutagenesis (Ser1158Ala), adherence and phagocytosis functional assays |
The Journal of biological chemistry |
High |
24129562
|
| 2020 |
CD18 expression is dispensable for initial bacterial attachment but required for phagocytic internalization of Pseudomonas aeruginosa: CRISPR-generated CD18-deficient human monocytes and murine neutrophils fail to internalize both motile and nonmotile P. aeruginosa, while ectopic CR3 expression in CD18-negative CHO cells does not rescue initial binding. Surface N-linked glycans facilitate initial bacterial attachment; talin-1 and kindlin-3 promote CD18-dependent internalization. |
CRISPR/Cas9 CD18-deficient human monocytes and murine neutrophils, ectopic CR3 expression in CHO cells, phagocytosis assays with motile/nonmotile isogenic mutants, talin-1 and kindlin-3 manipulation |
Infection and immunity |
High |
32041787
|
| 2016 |
Folate receptor beta (FRβ) physically interacts with the CD11b/CD18 (Mac-1) beta2 integrin heterodimer in the plasma membrane of FRβ+ macrophages and impedes CD11b/CD18-mediated adhesion to collagen. This was identified by affinity purification and mass spectrometry of the FRβ membrane microenvironment. |
Affinity purification of FRβ membrane microenvironment, mass spectrometry, adhesion assays to collagen, FRβ-transduced THP-1 monocytic cells, primary FRβ+ macrophages |
Journal of immunology |
Medium |
27534550
|
| 2023 |
ITGAM and ITGB2 expressed on extracellular vesicles (EVs) from severe acute pancreatitis (SAP) mediate pulmonary accumulation and acute lung injury (ALI): EVs engineered to overexpress ITGAM and ITGB2 compete with SAP-EVs for pulmonary accumulation and attenuate pulmonary inflammation and endothelial barrier disruption in vivo. |
EV integrin overexpression engineering, integrin antagonist peptide (HYD-1) preincubation, in vivo SAP mouse model, pulmonary inflammation and endothelial barrier assays |
ACS nano |
Medium |
37022097
|
| 2023 |
Alpha2-3-linked sialic acid on CD11b/CD18 regulates PMN transepithelial migration and integrin activation: inhibiting sialidase-mediated desialylation of CD11b/CD18 inhibits PMN migration across intestinal epithelium in vitro and in vivo, reduces degranulation and superoxide release, and blocks bacterial peptide-mediated CD11b/CD18 activation and downstream Syk/p38 MAPK signaling. |
Sialidase inhibitors, in vitro transepithelial migration assays, in vivo intestinal inflammation model, CD11b/CD18 activation assays, Syk and p38 MAPK signaling readouts |
JCI insight |
Medium |
36719745
|
| 2021 |
CD18 knockout in zebrafish (CRISPR/Cas9) causes key LAD-I symptoms: increased circulating neutrophils and reduced neutrophil trafficking to sterile inflammation sites. Sequence analysis shows conservation of the I-like domain and cytoplasmic NXXF motifs between zebrafish and human CD18, supporting functional orthology. |
CRISPR/Cas9 CD18 KO in zebrafish larvae, sequence alignment, intravital neutrophil trafficking assays |
Frontiers in immunology |
Medium |
34557186
|
| 2019 |
LFA-1 (CD11a/CD18) and Mac-1 (CD11b/CD18) distinctly regulate neutrophil extravasation at two sequential hotspots: LFA-1 FRET (CD11a-YFP/CD18-CFP) mice and Mac-1 FRET (CD11b-YFP/CD18-CFP) mice show that LFA-1 and Mac-1 operate at different stages (hotspot I through endothelium, hotspot II through basement membrane/pericyte sheath), as visualized by two-photon intravital imaging. |
Two-photon intravital imaging, transmission electron microscopy, LFA-1 FRET and Mac-1 FRET knock-in mice |
Experimental & molecular medicine |
High |
30967528
|