Blood, Vol. 93 No. 12 (June 15), 1999:
pp. 4187-4195
Differentiation in Culture of Murine Primitive Lymphohematopoietic
Progenitors Toward T-Cell Lineage
Fumiya Hirayama,
Yuichi Aiba,
Kenji Ikebuchi,
Sadayoshi Sekiguchi, and
Makio Ogawa
From Hokkaido Red Cross Blood Center, Sapporo, Japan; and Veterans
Affairs Medical Center and Department of Medicine, Medical University
of South Carolina, Charleston, SC.
Earlier, we described a stromal cell-free two-step clonal culture
system in which murine primitive lymphohematopoietic progenitors produce myeloid and B-lymphoid lineage cells. In the same culture T-cell potential of the progenitors was maintained. We now report that,
in addition to myeloid and B-lymphoid cells, putative T-cell progenitors are also produced in culture. Lineage-negative
(Lin
) Ly-6A/E+ c-kit+ bone
marrow cells from 5-fluorouracil-treated mice were cultured in
methylcellulose in the presence of SF (Steel factor), interleukin (IL)-11, and IL-7, and the resulting primary colonies were picked and
pooled. When injected into severe combined immune deficiency (scid)
mice, the pooled cells reconstituted the T-cell compartment of the scid
mice earlier than freshly prepared primitive marrow cells. This
reconstitution activity of the pooled primary colony cells was enriched
in the Ly-6A/E+ and Fc
RII/III/low cell
fractions. Reverse transcriptase-polymerase chain reaction (RT-PCR) and
DNA-PCR analyses showed that some of the primary colony cells are
differentiated sufficiently to express messenger RNA (mRNA) of T-cell
receptor (TCR) 
-chain and pre-TCR alpha (pT
) and, although not
frequently, to perform D-J rearrangement of the TCR gene.
Micromanipulation studies confirmed the clonal origin of myeloid
lineage cells and the cells positive for the T-cell-specific
transcripts and D-J rearrangement of TCR -chain. These results
suggested that, in the presence of SF, IL-11, and IL-7, primitive
lymphohematopoietic progenitors differentiate toward T-cell lineage in
addition to myeloid and B-cell lineages.
