Research Article

Phenotypic Definition of the Progenitor Cells with Erythroid Differentiation Potential Present in Human Adult Blood

Figure 1

CD36/CD34 expression profiling of AB MNC. (a) Representative coulter plot analyses for CD36/CD34 expression of MNC from a representative AB and summary of the frequency of the different populations identified by this analyses. CD36/CD34 profiling identified five populations: C D 3 4 p o s C D 3 6 n e g cells (population A, red), C D 3 4 p o s C D 3 6 p o s cells (population B, black), and C D 3 4 n e g C D 3 6 n e g cells (population E, green). A fourth C D 3 4 n e g C D 3 6 p o s population contained numerous C D 1 4 p o s cells which are represented by monocytes (see Figure 1(b)). Exclusion of these C D 1 4 p o s cells from the analyses revealed two C D 3 4 n e g / C D 3 6 p o s populations which express CD36 al low ( C D 3 4 n e g C D 3 6 p o s , population C, purple) and high ( C D 3 4 n e g C D 3 6 h i g h cells, population D, blue) levels, respectively. The table on the right summarizes the mean frequency (±SD) of each population among MNC obtained from 3 different donors. All the results presented in this figure and in Figure 2(a) are presented with the same color code. (b) Prospective isolation of AB MNC on the basis of CD34/CD36 expression. MNC were first divided in two populations enriched or deprived of C D 3 4 p o s cells by CD34-coated magnetic bead adsorption. The C D 3 4 p o s population was further purified and divided into C D 3 6 n e g and C D 3 6 p o s cells by sorting. The CD34 beads flow-through fraction (enriched for C D 3 4 n e g cells) was further divided into C D 3 6 p o s and C D 3 6 n e g cells by magnetic bead isolation. The cells eluted from the beads were purified by sorting on the basis of lack of expression of CD14 and low level of CD36 expression (population C, purple). The C D 1 4 n e g C D 3 6 h i g h cells (population D, blue) were not isolated because expressed high levels of the megakaryocytic marker CD42a. Finally, the CD36 beads flow-through fraction was enriched for C D 3 6 n e g cells by sorting. These C D 3 6 n e g cells were also C D 3 4 n e g upon reanalyses (not shown). Whenever feasible, the prospectively isolated cells were reanalyzed for purity. Results are representative of those obtained in 3 independent purifications.
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