Expression of the intercellular adhesion molecule-3 (ICAM-3) in human renal tissue with relation to kidney transplants and various inflammatory diseases

Integral Roles for Integrins in γδ T Cell Function

Integrins are adhesion receptors on the cell surface that enable cells to respond to their environment. Most integrins are heterodimers, comprising α and β type I transmembrane glycoprotein chains with large extracellular domains and short cytoplasmic tails. Integrins deliver signals through multiprotein complexes at the cell surface, which interact with cytoskeletal and signaling proteins to influence gene expression, cell proliferation, morphology, and migration. Integrin expression on γδ T cells (γδTc) has not been systematically investigated; however, reports in the literature dating back to the early 1990s reveal an understated role for integrins in γδTc function. Over the years, integrins have been investigated on resting and/or activated peripheral blood-derived polyclonal γδTc, γδTc clones, as well as γδ T intraepithelial lymphocytes. Differences in integrin expression have been found between αβ T cells (αβTc) and γδTc, as well as between Vδ1 and Vδ2 γδTc. While most studies have focused on human γδTc, research has also been carried out in mouse and bovine models. Roles attributed to γδTc integrins include adhesion, signaling, activation, migration, tissue localization, tissue retention, cell spreading, cytokine secretion, tumor infiltration, and involvement in tumor cell killing. This review attempts to encompass all reports of integrins expressed on γδTc published prior to December 2017, highlights areas warranting further investigation, and discusses the relevance of integrin expression for γδTc function.

Induction of adhesion molecule expression in co-culture of human bronchial epithelial cells and neutrophils suppressed by puerarin via down-regulating p38 mitogen-activated protein kinase and nuclear factor κB pathways

OBJECTIVE

In this study, we aimed to investigate the expressions of adhesion molecules on human bronchial epithelial cells and neutrophils in co-culture system, assess the effects of puerarin on suppressing these adhesion molecules expressions, and explore the roles of two crucial signal-transduction elements p38 mitogen-activated protein kinase (p38 MAPK) and nuclear factor kappa B (NF-κB) in modulating adhesion molecules expressions.

METHODS

Neutrophils and BEAS-2B cells (one human bronchial epithelial cell line) were co-cultured, and adhesion molecules expressions on cell surface were detected using flow cytometry. The mRNA levels of adhesion molecules were assessed by real-time quantitative polymerase chain reaction (real-time qPCR). Phosphorylated p38 MAPK and inhibitor κB were analyzed by Western blot.

RESULTS

In co-culture system, adhesion molecules expressions on BEAS-2B cells and neutrophils were enhanced significantly (P<0.05). Correspondingly, the mRNA levels of adhesion molecules were also increased greatly. Moreover, the pretreatment of peurarin obviously suppressed adhesion molecules expressions on cell surface. Furthermore, phosphorylated p38 MAPK and inhibitor κB in BEAS-2B cells and neutrophils were elevated in co-culture system, but decreased significantly after upon the treatment of peurarin (P<0.05).

CONCLUSIONS

Coculture boosted the interactions between human bronchial epithelial cells and neutrophils mimicking airway inflflammation, whereas peurarin decreased the expression of adhesion molecules on cell surface by suppressing the activities of p38 MAPK and NF-κB pathways, and exhibiting its anti-inflflammation activity.

Requirements for αd in IgG Immune Complex-Induced Rat Lung Injury

αd is a newly cloned adhesion molecule that forms a heterodimer with CD18. The requirement for αd in IgG immune complex-induced lung injury in rats has been evaluated by the use of blocking polyclonal and monoclonal antibodies to rat αd. Using whole lung extracts, Northern and Western blot analyses have revealed up-regulation of mRNA and αd protein in inflamed lungs. Immunostaining has revealed the presence of αd in lung tissue and in alveolar macrophages as early as 1 h after initiation of the inflammatory reaction. When polyclonal rabbit Ab to rat αd was coinstilled into lung together with Ab to BSA, lung injury (as determined by leakage of [125I]albumin into lung parenchyma) was significantly diminished. In parallel, there was reduced accumulation of neutrophils recoverable in bronchoalveolar lavage (BAL) fluids. These findings were associated with reduced levels of TNF-α as well as NO2−/NO3− in BAL fluids. A hamster mAb to rat αd was also protective in this lung injury model. Anti-αd inhibited in vitro production of NO2−/NO3− by rat alveolar macrophages (stimulated with LPS and IFN-γ) by approximately 60%. These data suggest that, in the lung inflammatory model employed, αd up-regulation occurs in lung macrophages and is necessary for expression of TNF-α, recruitment of neutrophils, and full development of lung injury.