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

390 Glossary
cytes and addressing leukocytes. There are now, however, reports of ILs produced by
other cells as well, such as IL-10 by keratinocytes, of ILs having a broad range of effects
on non-leukocytes and of cell surface variants of some of the ILs, such as IL-1.
Among the ILs which are particularly important in the context of tumor immunology
and cancer immunotherapy are IL-2 as a growth and differentiation factor for
T lymphocytes, IL-4 and IL-6 as factors regulating B lymphocyte differentiation, IL-10
as an immune-suppressive factor, and IL-12 which is thought to be particularly potent
in supporting immune responses by CD8 + effector T lymphocytes.
Lymphokine-activated killer (LAK) cell
Lymphocytic cell generated in the absence of antigen by exposure to high doses of cytokines
such as interleukin-2 exhibiting a high cytolytic capacity. LAK activity is perforin/granzyme
dependent and not antigen specific. Natural killer cells are a major
source for LAK cells.
Major histocompatibility complex (MHC)
Gene complex that controls the rapid rejection of MHC-disparate transplants ±
hence its name. The MHC genes are highly polymorphic and map in humans [human
leukocyte antigens (HLA)] to the short arm of chromosome 6 and in mice (H-2)
to chromosome 17. Their gene products fall into two functionally and structurally
distinct classes: MHC class I molecules (HLA-A, -B, and -C in humans or H-2K, -D
and -C in mice) are heterodimers of the polymorphic transmembrane heavy chain
and the non-covalently associated non-polymorphic b2-microglobulin. They bind and
present peptides that are usually 8±10 amino acids for recognition by CD8 + T lymphocytes.
MHC class II molecules (HLA-DP, -DQ and DR in humans, and H-2A and
H-2E in mice) consist of two polymorphic non-covalently associated transmembrane
polypeptides. They bind and present peptides of 11 or more amino acids for recognition
by CD4 + T lymphocytes. MHC class I molecules are expressed by most nucleated
cells; MHC class II molecules, however, are expressed only by antigen-presenting
cells and stimulated epithelial cells. In addition to MHC class I molecules, the
MHC also encodes for the MHC class Ib molecules HLA-E, -F and -G, which resemble
MHC class I molecules in their structure but exhibit a limited polymorphism
and serve a range of different functions including the presentation of N-formylated
peptides and lipids or, independent of any antigen presentation, as inhibitory receptors
for natural killer cells.
Monocyte
Mononuclear cell that circulate in the blood, emigrate into tissues and differentiate
into phagocytic macrophages. Monocytes are a main source of dendritic cells of the
myeloid type that are used in many protocols for cancer immune therapy.
Natural killer (NK) cell
Large, lymphocyte-like cell with characteristic granula that play a role in natural resistance
to tumors and in antibody-dependent cellular cytotoxicity. NK cells variably
express killer cell immunoglobulin-like receptors (KIRs) and CD94/NKG2 that trans-