The heparan sulfate proteoglycan form of epithelial CD44v3 serves as a CD11b/CD18 counter-receptor during polymorphonuclear leukocyte transepithelial migration.
Leukocyte beta2-integrin CD11b/CD18 mediates the firm adhesion and subsequent transepithelial migration of polymorphonuclear leukocytes, but the identity of its counter-receptor(s) on epithelia remains elusive. Here we identified a monoclonal antibody, clone C3H7, which strongly bound to the basolateral membranes of epithelial cells and inhibited both the adhesion of epithelial cells to immobilized CD11b/CD8 and the transepithelial migration of PMNs in a physiologically relevant basolateral-to-apical direction. C3H7 antigen expression in epithelial monolayers was significantly increased by treatment with proinflammatory cytokine interferon-gamma or a combination of interferon-gamma and tumor necrosis factor-alpha. Up-regulation of C3H7 antigen was also observed in the epithelium of inflamed human colon tissues. Microsequencing and Western blotting of the purified antigen showed it to be CD44 variant 3 (CD44v3), a approximately 160-kDa membrane glycoprotein. Further studies demonstrated that this epithelial CD44v3 specifically binds to CD11b/CD18 through its heparan sulfate moieties. In summary, our study demonstrates for the first time that the heparan sulfate proteoglycan form of epithelial CD44v3 plays a critical role in facilitating PMN recruitment during inflammatory episodes via directly binding to CD11b/CD18.
Zen
Ke
K
Jiangsu Diabetes Research Center, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210093, China. kzen@nju.edu.cn
Liu
Dan-Qing
DQ
Li
Li-Min
LM
Chen
Celia X-J
CX
Guo
Ya-Lan
YL
Ha
Bihn
B
Chen
Xi
X
Zhang
Chen-Yu
CY
Liu
Yuan
Y
D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology; D039481:CD11b Antigen / Q000276:immunology / Q000378:metabolism*; D018821:CD18 Antigens / Q000276:immunology / Q000378:metabolism*; D018938:Caco-2 Cells; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000276:immunology; D019812:Heparan Sulfate Proteoglycans / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D018960:Hyaluronan Receptors / Q000276:immunology / Q000378:metabolism*; D007371:Interferon-gamma / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology / Q000378:metabolism / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D039481:CD11b Antigen; D018821:CD18 Antigens; C121450:CD44V3,8-10; D019812:Heparan Sulfate Proteoglycans; D018960:Hyaluronan Receptors; C509295:ITGAM protein, human; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma