Cancer Immune Therapy Edited by G. Stuhler and P. Walden ...

Glossary
Dendritic cell (DC)
Migratory mononuclear cell found in nearly all tissues and characterized by typical
filiform processes. DCs are highly efficient antigen-presenting cells and particularly
important for the primary induction of immune responses. They are thought to harvest
antigens in the tissues and, upon activation by inflammatory processes, for instance,
migrate to the draining lymph nodes. These mature DCs express high levels
of MHC class I and II molecules, and co-stimulatory molecules, and efficiently activate
T lymphocytes. In man, two types of DCs have been described, the plasmocytoid DCs
and the myeloid DCs. Myeloid DCs are derived from or related to monocytes. Plasmacytoid
DCs, in addition to specific DC markers, express a set of cell surface molecules
that are also found on cells of lymphatic lineage and synthesize type I interferons.
Plasmacytoid and myeloid DCs express different sets of Toll-like receptors, and,
thus, respond differently to pathogenic microorganisms.
Donor lymphocyte infusion (DLI)
Therapeutic strategy of infusing into a patient subsequently to allogeneic bone marrow
transplantation immune-competent T lymphocytes from the same donor. This
therapy aims at induction of a graft-versus-leukemia (GvL) or graft-versus-tumor
(GvT) effect of the donor lymphocytes.
Effector cell
cell with fully developed cytolytic capacity, usually activated CD8 + cytotoxic T lymphocytes
or natural killer cells.
Epitope
Portion of an antigen that is actually bound by the immune receptors, antibodies or
T cell receptors (TCR). For antibodies, epitopes may be continuous stretches of the primary
sequence of a protein antigen (continuous epitopes) or composed of elements
of different parts of the antigen (discontinuous epitopes). In addition to peptides,
any small residue such as a hapten or a hapten in the context of a peptide can form
an epitope for antibodies. Epitopes for T lymphocytes are always peptides derived
from proteins by limited proteolysis that must be bound to MHC molecules for recognition
by the TCR.
Fas (APO-1, CD95)
Cell surface receptor of 43 kDa of the tumor necrosis factor (TNF) receptor superfamily
which is one of the main triggers of receptor-mediated apoptosis. Fas is expressed
in thymus, liver, heart and ovary, and by activated T lymphocytes and some
tumors. It carries an intracellular death domain that, after engagement of Fas with
its ligand (FasL), binds FADD, an intracellular adaptor molecule that initiates caspase-mediated
pathways of apoptosis. FasL (CD95L), also a member of the TNF
superfamily, is expressed predominantly by activated T lymphocytes. However, some
tumors also express FasL and, thus, can induce apoptosis in cytotoxic T lymphocytes
that attack the tumor. The actual role of receptor-mediated apoptosis in the control of
tumors in patients has not yet been clarified.
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