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Junctional adhesion molecule, a novel member of the immunoglobulin superfamily that distributes at intercellular junctions and modulates monocyte transmigration.

ABSTRACT: Tight junctions are the most apical components of endothelial and epithelial intercellular cleft. In the endothelium these structures play an important role in the control of paracellular permeability to circulating cells and solutes. The only known integral membrane protein localized at sites of membrane-membrane interaction of tight junctions is occludin, which is linked inside the cells to a complex network of cytoskeletal and signaling proteins. We report here the identification of a novel protein (junctional adhesion molecule [JAM]) that is selectively concentrated at intercellular junctions of endothelial and epithelial cells of different origins. Confocal and immunoelectron microscopy shows that JAM codistributes with tight junction components at the apical region of the intercellular cleft. A cDNA clone encoding JAM defines a novel immunoglobulin gene superfamily member that consists of two V-type Ig domains. An mAb directed to JAM (BV11) was found to inhibit spontaneous and chemokine-induced monocyte transmigration through an endothelial cell monolayer in vitro. Systemic treatment of mice with BV11 mAb blocked monocyte infiltration upon chemokine administration in subcutaneous air pouches. Thus, JAM is a new component of endothelial and epithelial junctions that play a role in regulating monocyte transmigration.

SUBMITTER: Martin-Padura I

PROVIDER: S-EPMC2133024 | biostudies-literature | 1998 Jul

REPOSITORIES: biostudies-literature

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Junctional adhesion molecule, a novel member of the immunoglobulin superfamily that distributes at intercellular junctions and modulates monocyte transmigration.

Martìn-Padura I I Lostaglio S S Schneemann M M Williams L L Romano M M Fruscella P P Panzeri C C Stoppacciaro A A Ruco L L Villa A A Simmons D D Dejana E E

The Journal of cell biology 19980701 1

Tight junctions are the most apical components of endothelial and epithelial intercellular cleft. In the endothelium these structures play an important role in the control of paracellular permeability to circulating cells and solutes. The only known integral membrane protein localized at sites of membrane-membrane interaction of tight junctions is occludin, which is linked inside the cells to a complex network of cytoskeletal and signaling proteins. We report here the identification of a novel p ...[more]

PMID: 9660867

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Project description:We investigated the hypothesis that transmigration drives monocyte transcriptional changes. Using Agilent Whole Human Genome Microarrays, we identified over 600 differentially expressed genes (2x, p<0.05) in freshly isolated human monocytes following 1.5 h of transmigration across IL1beta-stimulated ECs compared to untreated monocytes. Genes up-regulated by monocyte transmigration belong to a number of overrepresented functional groups including immune response, and inhibition of apoptosis. qRT-PCR confirmed increased expression of monocyte chemotactic proteins 1 and 3 and of NLR family apoptosis inhibitory protein (NAIP) following monocyte transmigration. In addition, quantification of annexin V binding revealed a reduction in apoptosis following monocyte transmigration. Comparison of gene expression in transmigrated monocytes to additional controls (monocytes which failed to transmigrate and monocytes incubated beneath stimulated ECs) revealed 89 differentially expressed genes which were controlled by the physical process of diapedesis. Functional annotation of these genes showed down-regulation of antimicrobial genes (e.g. alpha-defensin down 50x, cathelicidin down 9x, and cathepsin G down 3x). qRT-PCR confirmed down-regulation of these genes. Immunoblots confirmed that monocyte transmigration down-regulates alpha-defensin protein expression. Overall, these data indicate that exposure of monocytes to stimulated ECs promotes further monocyte recruitment and inhibits monocyte apoptosis. Unexpectedly, following transmigration monocytes displayed reduced anti-microbial expression. Monocytes were allowed to transmigrate across IL1b stimulated HUVEC. Monocytes which transmigrated and monocytes which failed to transmigrate were collected after 1.5 hours from 3 experimental replicates of different human donors. Untreated monocytes were collected as a control from 4 human donors. Monocytes incubated beneath stimulated HUVEC for 1.5 hours were also collected from four human donors as a control.

Dataset Information

Junctional adhesion molecule, a novel member of the immunoglobulin superfamily that distributes at intercellular junctions and modulates monocyte transmigration.

Publications

Junctional adhesion molecule, a novel member of the immunoglobulin superfamily that distributes at intercellular junctions and modulates monocyte transmigration.

Similar Datasets

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