Regulation Of CD4~+T Cells By Pleural Mesothelial Cells Via Adhesion Molecule-dependent Mechanisms In Tuberculous Pleurisy

Objectives Intercellular adhesion molecule-1(ICAM-1) and vascular celladhesion molecule-1(VCAM-1) have been demonstrated to be expressed on pleuralmesothelial cells (PMCs) and to mediate leukocyte adhesion and migration, however,little is known about regulation of CD4~+T cells by PMCs via adhesionmolecule-dependent mechanisms in tuberculous pleural effusion (TPE).Methods Expressions on ICAM-1and VCAM-1on PMCs, as well asexpressions of CD11a and CD29, the counter-receptors for ICAM-1and VCAM-1,respectively, expressed on CD4~+T cells in TPE were determined using flow cytometry.The immune regulations on adhesion, proliferation, activation, selective expansion ofCD4~+helper T cell subgroups exerted by PMCs via adhesion molecule-dependentmechanisms were explored.Result Percentages of ICAM-1-positive and VCAM-1-positive PMCs inTPE were increased compared with PMC line. Interferon-γ enhanced fluorescenceintensity of ICAM-1, and IL-4promoted VCAM-1expression. Prestimulation of PMCs with anti-ICAM-1or anti-VCAM-1mAb significantly inhibited CD4~+T celladhesion, activation, as well as regulatory T cell expansion induced by PMCs.Conclusions Our current data showed that adhesion molecule pathways onPMCs regulated adhesion and activation of CD4~+T cells, and selectively promotedthe expansion of regulatory T cells.