Biomedical Engineering Reference
In-Depth Information
Definition of Terms
Angiogenesis:
h e physiological process involving the growth of new blood vessels from
pre-existing vessels.
Antigen presenting cells:
Any cell that can process and present antigenic peptides as well as
deliver stimulatory signals necessary to activate T cells.
Chemokines:
A family of small proteins secreted by cells, characterized by the presence of
cysteine residues in conserved locations. h eir name is derived from their ability to
induce directed movement (chemotaxis) in nearby responsive cells.
Dendritic cells:
Leukocytes that specialize in antigen presentation.
Dermis:
h e layer of skin between the epidermis and subcutaneous tissues. h e dermis
contains blood and lymph vessels, hair follicles, and sweat glands. h e dermis also
contains T cells, dendritic cells, macrophages, and mast cells.
Diapedesis:
Passage of cells through the intact wall of a blood vessel to the inside of the
tissue.
Endothelium:
Layer of cells that line the interior surfaces of blood vessels, forming an
interface between circulating blood and the rest of the surrounding tissue.
Epidermis:
Outermost layer of the skin, avascular and nourished by dif usion from the
dermis. Keratinocytes are the major cellular constituent of the epidermis.
Integrins:
A family of heterodimeric cell surface receptors that bind to adhesion molecules
on the endothelium allowing cells to adhere to the endothelium. h ere are many types
of integrin, and many cells have multiple types on their surface.
Junctional adhesion molecules (JAMs):
Proteins expressed at cell junctions in epithelial
and endothelial cells as well as on the surface of leukocytes, platelets, and erythrocytes.
JAMs are important for a variety of cellular processes, including tight junction assembly,
leukocyte transmigration, and angiogenesis.
Selectins:
Single chain transmembrane adhesion molecules bearing a lectin domain that
bind to carbohydrate ligands displayed on leukocytes.
Sialyl Lewis
X
:
Tetrasaccharide carbohydrate, usually attached to O-glycans on the surface of
the cells, and known to play a vital role in cell-cell recognition and attachment.
References
Appay, V. and C. Jandus, V. Voelter, S. Reynard, S.E. Coupland, D. Rimoldi, D. Lienard, P.
Guillaume, A.M. Krieg, J.C. Cerottini, P. Romero, S. Leyvraz, N. Rufer, and D.E. Speiser.
2006. New generation vaccine induces ef ective melanoma-specii c CD8+ T cells in the
circulation but not in the tumor site. J. Immunol. 177(3): 1670-1678.
Campbell, J.J. and D.J. O'Connell, and M.A. Wurbel. 2007. Cutting Edge: Chemokine
receptor CCR4 is necessary for antigen-driven cutaneous accumulation of CD4 T cells
under physiological conditions. J. Immunol. 178(6): 3358-3362.
Chong, B.F. and J.E. Murphy, T.S. Kupper, and R.C. Fuhlbrigge. 2004. E-selectin, thymus-
and activation-regulated chemokine/CCL17, and intercellular adhesion molecule-1
are constitutively coexpressed in dermal microvessels: a foundation for a cutaneous
immunosurveillance system. J. Immunol. 172(3): 1575-1581.
