Abstract
Immunohistochemistry using whole mount preparations of the murine mesentery revealed twotypes of LYVE-1-immunoreactive cells with dendritic morphology other than F4/80+ typical macrophages.The two types of LYVE-1+ cells were regularly distributed with constant intervalsthroughout the mesentery and appeared to possess their own territory. Both types of LYVE-1+ cells were weakly or moderately immunopositive for F4/80 antibody, a marker of macrophages,while F4/80+ round macrophages were absolutely free from the LYVE-1 immunoreactivity. Only macrophages could ingest latex particles of 20 nm in diameter 3 h after a peritoneal injection.Peritoneal administration of lipopolysaccharide (LPS) induced a rapid reduction of LYVE-1 immunoreactivityin the cells with dendritic morphology followed by an increased immunoreactivityto F4/80 antibody, and simultaneously by dynamic changes in their shape. Under normal conditions,F4/80+ macrophages in various connective tissues expressed LYVE-1, in contrast to lack ofLYVE-1 in F4/80+ macrophages within the parenchyma of visceral organs and macrophages residingin hepatic sinusoids and pulmonary alveoli. LYVE-1 may play a role in cell adhesion and migrationof macrophagic cells within connective tissues rich in hyaluronan, and loss of LYVE-1becomes a reliable sign of activated conditions in inflammation.
