SFL 23.6: a monoclonal antibody reactive with CFU-E, erythroblasts, and
erythrocytes
AD Gupta, MK Samoszuk, T Papayannopoulou and G Stamatoyannopoulos
A cytotoxic (IgG2b) monoclonal antibody (McAb) for a novel erythroid
differentiation antigen was generated by hyperimmunizing young mice with
mononuclear cells obtained from livers of 20- to 22-week-old fetuses. This
McAb, designated SFL 23.6, shows an extremely well- defined reactivity with
the cells of the erythroid lineage at all stages of maturation as evident
from the labeling of morphologically identifiable erythroid precursors and
of erythrocytes present in peripheral blood, bone marrow, and fetal liver,
and from its reactivity with culture-derived erythroblasts. The
nonerythroid cells present in these and other tissue preparations were not
labeled by SFL 23.6. The erythroid lineage specificity of McAb SFL 23.6 was
confirmed by a cell- sorting experiment in which 97% of the cells in the
fluorescent fraction sorted from SFL 23.6-treated bone marrow cells were
erythroid precursors at various stages of maturation. Complement-mediated
cytotoxicity and progenitor cell-sorting experiments showed that most
(greater than 90%) of the late erythroid progenitors (CFU-E) and only a
small proportion of the early erythroid progenitors (BFU-E) express the
antigenic determinant identified by SFL 23.6. The myeloid progenitors
(CFU-GM) and multilineage progenitors (CFU-GEMM) were negative for the SFL
23.6 antigenic determinant. The antigen recognized by SFL 23.6 has not been
determined as yet. Because of the pattern of its reactivity and its
dependence on sialic acid residues, the possibility of its relationship to
glycophoria A was entertained. However, previous work using antiglycophorin
McAbs (R-10) has shown that this determinant is not expressed in CFU-E.
Therefore, among the erythroid lineage-specific McAbs described thus far,
SFL 23.6 is unique in its reactivity with CFU- E and the mature erythron.
Reagents with such specificity may be useful in studies of erythroid
differentiation and commitment.
Volume 66,
Issue 3,
pp. 522-526,
09/01/1985
Copyright © 1985 by The American Society of Hematology
