Purification of common acute lymphoblastic leukemia antigen positive cells
from normal human bone marrow
P Hokland, LM Nadler, JD Griffin, SF Schlossman and J Ritz
Mononuclear cells expressing the common acute lymphoblastic leukemia
antigen (CALLA) were purified from normal adult human bone marrow, where
they constitute a small fraction of the total population. This was
accomplished by a two-step purification from Ficoll-Hypaque- isolated
mononuclear cells. Isolated mononuclear cells were first labeled with a
mixture of monoclonal antibodies (MoAb) specific for myeloid and erythroid
precursor cells, and immune rosettes were then formed with sheep
erythrocytes coated with rabbit anti-mouse antibodies (R/M-SRBC).
Sedimentation through Ficoll-Hypaque then eliminated the majority of mature
myeloid cells. The second step consisted of labeling the remaining
rosette-negative cells with CALLA-specific MoAb and purifying CALLA+ cells
by fluorescence activated cell sorting. Alternatively, CALLA+ cells were
purified in a second R/M-SRBC rosette sedimentation step. The purified
CALLA+ cells, which morphologically were medium to large lymphoid cells,
were subsequently studied using dual fluorescence techniques to identify
surface markers as well as intracytoplasmic staining to detect terminal
deoxynucleotidyl transferase enzyme (TdT) and intracytoplasmic mu. While
the CALLA+ cell suspensions contained very few mature myeloid cells or T
lymphocytes, the finding that 5% to 11% of them were cyto-mu+ and 13% to
22% expressed the B1 differentiation antigen clearly indicated that at
least some of these cells were B cell precursors. Because 48% to 63% of the
cells were TdT+ and practically all of them expressed Ia antigen, it
appears that these cells are a mixture of very early lymphoid precursor
cells as well as more differentiated pre-B cells. The phenotype of these
normal cells is very similar to that of common ALL cells. Differences in
the surface marker phenotypes between adult and fetal CALLA+ cells that
have previously been purified were also identified.
Volume 64,
Issue 3,
pp. 662-666,
09/01/1984
Copyright © 1984 by The American Society of Hematology
