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

384 Glossary
suppressor gene products. Cytolysis by cytotoxic T lymphocytes or natural killer cells is
also apoptosis. The typical changes associated with apoptosis involve flipping of
phospholipids in the plasma membrane (Annexin), membrane blebbing and fragmentation
of the DNA.
B lymphocyte (B cell)
Antibody-expressing lymphocyte. They evolve from cells which are committed to the
B cell linage but have not yet rearranged their immunoglobulin genes via different
stages of pro-B development to pre-B cells with a partly rearranged immunoglobulin
genome to immature B cells that express IgM, and mature B cells that secrete IgM
and IgD. Upon contact with antigen and antigen-mediated interaction with helper
T cells these mature B cells develop into clonally expanded, IgG-producing cells that
either terminally differentiate into plasma cells or become memory cells and, thus,
form the basis of secondary immune responses. Mature B cells express MHC class I
and II molecules, and a number of adhesion and co-stimulating molcules that qualify
them to serve as antigen-presenting cells. Their antigen receptor allows for a specific accumulation
of their cognate antigen which is thus presented with high efficiency.
Bone marrow transplantation (BMT)
Therapeutic transfer of bone marrow to reconstitute, replace or support the hematopoetic
and immune system of the recipients. Generally, the recipient has received
chemotherapy or radio-chemotherapy prior to BMT which has eliminated or substantially
reduced the individual's own hematopoetic system. Two regimens are in
use ± the myeloablative approach (aimed at replacing the recipients bone marrow
with autologous or allogeneic stem cells) and the non-myeloablative approach (resulting
in a chimerism of host and donor stem cells). Because of incompatibility of
minor or major histocompatibility gene products, continuous immunosuppression
is necessary in most recipients.
Carcinoembryonic antigen (CEA)
Glycoprotein expressed by many cell types in the developing fetus and by adenocarcinomas
of endodermally derived intestinal epithelia, but also breast, lung, and some
types of thyroid and ovarian cancers. CEA is used as a tumor marker and as a target
antigen for cancer immune therapy. It has a molecular weight of 180 000 with about
60 % carbohydrate moieties. In healthy adults, CEA expression may be elevated due
to smoking, inflammation, pancreatitis and liver cirrhosis.
CD
Cluster of differentiation, nomenclature of differentiation antigens expressed by leukocytes.
Regularly held international workshops allocate CD numbers to these antigens.
CD91
Cell surface receptor for a2-macroglobulin and some heat shock proteins (gp96,
HSP90, HSP70 and calreticulin). CD91 is expressed by monocytes and their derivatives
including macrophages and dendritic cells and erythroblasts/reticulocytes. The