Process for preparing and cultivating hematopoietic progenitor c

Details Process for preparing and cultivating hematopoietic progenitor c Process for preparing and cultivating hematopoietic progenitor c

1996-04-29

1999-05-18

Chambers, Jasemine C.

Chemistry: molecular biology and microbiology

Animal cell, per se ; composition thereof; process of...

Primate cell, per se

435355, 435375, 435377, C12N5/00

Patent

active

059050411

DESCRIPTION:

BRIEF SUMMARY
FIELD OF THE INVENTION

The present invention relates to a) process for the preparation and in vitro cultivation of haematopoietic progenitor cells, particularly of the erythroidal series.


DESCRIPTION OF RELATED ART

During normal haematopoiesis, pluripotent stem cells develop into progenitor cells which are intended for a specific developmental series (these progenitors are referred to as "committed"); these cells are thought to differ from the pluripotent stem cells in two respects: firstly, they are restricted in their ability to differentiate into a single developmental series or a small number of specific developmental series. Secondly, these committed progenitor cells are generally thought to be either incapable of replicating continuously without simultaneous differentiation (this property is also referred to as the capacity for self renewal) or they do so only transiently (Till and McCulloch, 1980). It is therefore assumed that the progenitor cells, committed to a specific developmental series, begin a predetermined programme of changes in gene expression which ends with the formation of a terminally differentiated cell. Pluripotent stem cells, on the other hand, are thought to retain their capacity to undergo numerous cell divisions without changing their state of differentiation or gene expression. The programme which the progenitor cells undergo is obviously compatible with undergoing numerous cell divisions, but it is assumed that during each division the cells will undergo changes, however slight, in their state of differentiation or gene expression (Keller, 1992).
This view that a fixed determination/differentiation programme determines the development of the committed progenitor cells has recently been called into question in various ways: firstly, some observations lead one to assume that normal committed progenitors can undergo extended phases of expansion, indicating self-renewal or related processes. Murine B-lymphocyte progenitors renew themselves constantly under a series of culture conditions (stromal feed cell layers plus interleukin 7), but differentiate under other conditions into mature B-cells (Rolink et al., 1991). Similarly, individual murine granulocyte macrophage colony forming cells (GM-CFC), depending on the concentration of GM-CSF, may produce between 100 and more than 10,000 mature granulocytes and macrophages (Metcalf, 1980).
Another phenomenon which is difficult to reconcile with a fixed programme of the development of committed progenitors consists of leukaemias. Although in some cases these start from pluripotent stem cells, other leukaemias clearly derive from committed progenitors (Sawyers et al., 1991). Regarding the latter type there is a frequently expressed concept that the genetic changes which occur in leukaemia cells give them the abnormal ability of self-renewal, a quality which the corresponding normal progenitor cell does not have. Whereas in the chronic phase of chronic myeloid leukaemia (CML) clones of altered, multi-potent progenitor cells overgrow the corresponding normal clones (possibly on account of their greater capacity for self-renewal) other mutations which take place during the blast crisis lead to a massive outgrowth of immature progenitors and maturing cells of a special development series, which is interpreted as self-renewal of abnormal committed progenitors (Daley et al., 1990; Elefanty et al., 1990; Kelliher et al., 1990).
Recently, it was shown, in chicken cells, that normal haematopoietic progenitors which are committed to the erythroid developmental series are capable under certain conditions of sustained self-renewal (Schroeder et al., 1993; Hayman et al., 1993). It was shown that the combined effect of TGF.alpha. (Transforming Growth Factor, a ligand for the chicken homologue of epidermal growth factor receptorlc-erbB-protooncogene (TGF.alpha.R/c-erbB; Lax et al., 1988) and oestradiol induced the outgrowth of normal progenitors from chicken bone marrow. These cells are known as SCF/TGF.alpha.-progenitor cells on account of their ab

REFERENCES:
patent: 5270458 (1993-12-01), Lemischka
patent: 5405772 (1995-04-01), Ponting
patent: 5670351 (1997-09-01), Emerson et al.
Hayman, M.J., et al., "Self-Renewal and Differentiation of Normal Avian Erythroid Progenitor Cells: Regulatory Roles of the TGF.alpha./c-ErbB and SCF/c-Kit Receptors," Cell 74(1):157-169 (Jul. 16, 1993).
Schroeder, C., et al., "The Estrogen Receptor Cooperates with the TFG.alpha. Receptor (c-erbB) in Regulation of Chicken Erythroid Progenitor Self-Renewal," EMBO J. 12(3):951-960 (Mar. 1993).
A copy of the International Search Report for the corresponding PCT Application, WIPO Publication No. WO 96/00777 (International Application No. PCT/EP95/02516).

Affiliated with

Also associated with

Rating

Process for preparing and cultivating hematopoietic progenitor c does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Process for preparing and cultivating hematopoietic progenitor c, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for preparing and cultivating hematopoietic progenitor c will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1759361