VI Autologous Bone Marrow Transplantation.pdf - Blog Science ...

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THE BIOLOGY 0FCD34.
D. Robert Sutherland and Armand Keating
ONCOLOGY RESEARCH, AND THE UNIVERSITY OF TORONTO
AUTOLOGOUS BONE MARROW TRANSPLANT PROGRAM, THE
TORONTO HOSPITAL, TORONTO, CANADA.
INTRODUCTION
The CD34 antigen is of interest because it is the only molecule identified to
date whose expression within the blood system, is restricted to a small number
of primitive progenitor cells in the bone marrow (BM). The availability of CD34
antibodies has greatly aided the development of techniques for the enrichment
of primitive progenitor cells for a variety of studies of hematopoiesis in vitro.
Additionally, the use of CD34 antibodies for the 'positive selection' of hematopoietic
stem/progenitor cells represents an alternative strategy to 'purging' for
the large-scale manipulation of cells prior to transplantation. The availability of
pure populations of the most primitive hematopoietic progenitor cells may also
facilitate the development of genetic techniques for the repair of specific blood
cell disorders. Though its precise function remains unknown, the pattern of expression
of the the CD34 structure suggests that it plays an important role in
early hematopoiesis.
SEROLOGY AND EPITOPE MAPPING STUDIES
All seven antibodies, MY10, B1.3C5,12.8,115.2, ICH3, TUK3, and QBEND
10, assigned to the CD34 cluster ( n
, identify an antigen which is expressed on 1-
3% of normal BM cells. This population has been shown to include virtually all
unipotent, and multipotent myeloid progenitors as well as pre-CFU. Primitive T
and B lymphocyte precursors and leukemias of primitive myeloid and lymphoid
lineages also express CD34. Significantly, CD34+ BM cells can reconstitute
all lineages of the hematopoietic system in lethally-irradiated baboons and rhesus
monkeys, suggesting, that the 'stem cells' responsible for long-term reconstitution
of hematopoiesis, express the CD34 antigen (see 2
and refs therein). This
population is also capable of reconstituting hematopoiesis in humans