TY - JOUR
T1 - Human keratinocyte adhesion and phagocytosis promoted by fibronectin
AU - Takashima, A.
AU - Grinnell, F.
N1 - Funding Information:
It has been reported that following incisional skin wounding, migrating keratinocytes can phagocytose extracellular debris including fibrin fragments [1]. In addition, keratinocytes have been observed to phagocytose parts of Langerhans cells after epidermal tape-stripping [2]. Keratinocytes also have been observed to phagocytose latex beads injected into blister cavities [3]. Despite the possible importance of phagocytosis in the wound healing response of keratinocytes, the phagocytic properties of these cells have not been characterized further. Neither Manuscript received March 13, 1984; accepted for publication May 21, 1984. This work was supported by N.J.H. Grant GM31321. Reprint requests to: Frederick Grinnell, Ph.D., Department of Cell Biology, The University of Texas Health Science Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75235. Abbreviations: BSA: bovine serum albumin DMEM: Dulbecco's modified Eagle's medium pFN: plasma fibroneclin PS: phosphate saline 'l'CA: trichloroacetic acid the cell surface receptors nor the opsonins involved in keratinocyte phagocytosis have been identified.
PY - 1984
Y1 - 1984
N2 - Epidermal cells from human foreskin or cadaver skin were found to bind and phagocytose fibronectin-coated latex beads but not serum albumin-coated beads. Three lines of evidence suggested that the beads actually were internalized by the cells and not bound only at the cell surfaces. First, the fibronectin coat on internalized beads could be detected with antifibronectin antibodies only if the cells were permeabilized prior to indirect immunofluorescence staining. Second, the internalized beads were not released from the cells by trypsin treatment. Finally, electron microscopic observations showed that the internalized beads were packaged individually and in clusters inside endocytic vesicles in the perinuclear region of the cells. These vesicles had the typical appearance of lysosomes, and, based on the release of trichloroacetic acid-soluble radioactive fragments of fibronectin into the incubation medium, it was concluded that degradation of the fibronection on the bead surfaces occurred. The epidermal cells that phagocytosed the fibronectin-coated beads were confirmed as keratinocytes according to their electron microscopic appearance and prominent immunofluorescence staining with antikeratin but not anti-plasma fibronectin antibodies. Fibronectin also was found to promote the attachment and spreading of keratinocytes on culture dishes, although the concentration of fibronectin required for half-maximal activity (~5 μg/ml) was severalfold higher than the concentration of fibronectin required for spreading of human fibroblasts (~1 μg/ml). The results suggest the possible importance of fibronectin in mediating adhesion and phagocytosis by keratinocytes, which may be important for the migration of these cells during wound repair.
AB - Epidermal cells from human foreskin or cadaver skin were found to bind and phagocytose fibronectin-coated latex beads but not serum albumin-coated beads. Three lines of evidence suggested that the beads actually were internalized by the cells and not bound only at the cell surfaces. First, the fibronectin coat on internalized beads could be detected with antifibronectin antibodies only if the cells were permeabilized prior to indirect immunofluorescence staining. Second, the internalized beads were not released from the cells by trypsin treatment. Finally, electron microscopic observations showed that the internalized beads were packaged individually and in clusters inside endocytic vesicles in the perinuclear region of the cells. These vesicles had the typical appearance of lysosomes, and, based on the release of trichloroacetic acid-soluble radioactive fragments of fibronectin into the incubation medium, it was concluded that degradation of the fibronection on the bead surfaces occurred. The epidermal cells that phagocytosed the fibronectin-coated beads were confirmed as keratinocytes according to their electron microscopic appearance and prominent immunofluorescence staining with antikeratin but not anti-plasma fibronectin antibodies. Fibronectin also was found to promote the attachment and spreading of keratinocytes on culture dishes, although the concentration of fibronectin required for half-maximal activity (~5 μg/ml) was severalfold higher than the concentration of fibronectin required for spreading of human fibroblasts (~1 μg/ml). The results suggest the possible importance of fibronectin in mediating adhesion and phagocytosis by keratinocytes, which may be important for the migration of these cells during wound repair.
UR - http://www.scopus.com/inward/record.url?scp=0021186615&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0021186615&partnerID=8YFLogxK
U2 - 10.1111/1523-1747.ep12264522
DO - 10.1111/1523-1747.ep12264522
M3 - Article
C2 - 6208292
AN - SCOPUS:0021186615
SN - 0022-202X
VL - 83
SP - 352
EP - 358
JO - Journal of Investigative Dermatology
JF - Journal of Investigative Dermatology
IS - 5
ER -