Objective: Insulin-like growth factor (IGF)-binding proteins (IGFBPs) are a family of proteins thought to modulate IGF function. By employing an in vitro culture system of human hematopoietic stem cells cocultured with murine bone marrow stromal cells, we examined the effects of IGF-I and IGFBPs on early B-cell development.

Materials And Methods: Human CD34(+) bone marrow cells were cocultured with murine stromal MS-5 cells for 4 weeks, and pro-B-cell number was analyzed by flow cytometry. After administration of reagents that are supposed to modulate IGF-I or IGFBP function to the culture, the effect on pro-B-cell development was examined.

Results: After cultivation for 4 weeks, effective induction of pro-B-cell proliferation was observed. Experiments using several distinct factors, all of which neutralize IGF-I function, revealed that impairment of IGF-I function results in a significant reduction in pro-B-cell development from CD34(+) cells. In addition, when the effect of recombinant proteins of IGFBPs and antibodies against IGFBPs were tested, IGFBP-3 was found to inhibit pro-B-cell development, while IGFBP-6 was required for pro-B-cell development.

Conclusions: IGF-I is essential for development of bone marrow CD34(+) cells into pro-B cells. Moreover, IGFBPs are likely involved in regulation of pro-B-cell development.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.exphem.2006.01.009DOI Listing

Publication Analysis

Top Keywords

pro-b-cell development
20
insulin-like growth
12
bone marrow
12
growth factor
8
pro-b-cell
8
proteins igfbps
8
cells cocultured
8
cocultured murine
8
igf-i function
8
cd34+ cells
8

Similar Publications

Homeobox genes encode transcription factors which organize differentiation processes in all tissue types including the hematopoietic compartment. Recently, we have reported physiological expression of TALE-class homeobox gene IRX1 in early myelopoiesis restricted to the megakaryocyte-erythroid-progenitor stage and in early B-cell development to the pro-B-cell stage. In contrast, sister homeobox genes IRX2, IRX3 and IRX5 are aberrantly activated in the corresponding malignancies acute myeloid leukemia (AML) and B-cell progenitor acute lymphoid leukemia.

View Article and Find Full Text PDF

Disseminated Aspergillosis in X-linked Agammaglobulinemia: Beyond the norm.

J Clin Immunol

October 2024

Allergy Immunology Unit, Department of Pediatrics, Advanced Pediatrics Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, 160012, India.

Article Synopsis
  • X-linked agammaglobulinemia (XLA) is caused by a mutation in the Bruton's tyrosine kinase (BTK) gene, which prevents B cell development, resulting in low antibody levels and increased vulnerability to infections.
  • Patients with XLA often suffer from recurrent bacterial infections, but can also face serious and rare fungal infections, as seen in a case involving a 3.5-year-old boy with disseminated aspergillosis who ultimately did not survive despite antifungal treatment.
  • Genetic analysis confirmed a specific mutation in the BTK gene, underlining the severe immune system issues associated with XLA that extend beyond just B-cell deficiencies.
View Article and Find Full Text PDF

Despite major therapeutic advances in the treatment of acute lymphoblastic leukemia (ALL), resistances and long-term toxicities still pose significant challenges. Cyclins and their associated cyclin-dependent kinases are one focus of cancer research when looking for targeted therapies. We discovered cyclin C as a key factor for B-ALL development and maintenance.

View Article and Find Full Text PDF
Article Synopsis
  • During B-cell development, the pro-B-cell stage is crucial for committing to the B-cell lineage, and the transcription factor YY1 plays a key role in this process.
  • Knocking out YY1 at the pro-B-cell stage stops B-cell development and enables these cells to convert into T lineage cells, demonstrating a shift in their genetic expression profiles.
  • Research involving various sequencing techniques shows that the loss of YY1 not only affects B lineage commitment but also allows pro-B cells to exhibit flexibility in developing into multiple hematopoietic lineages due to changes in chromatin accessibility.
View Article and Find Full Text PDF

Negative regulation of activation-induced cytidine deaminase gene transcription in developing B cells by a PU.1-interacting intronic region.

Mol Immunol

November 2024

Department of Microbiology & Immunology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada; Division of Genetics and Development, Children's Health Research Institute, London, Ontario, Canada. Electronic address:

Activation-induced cytidine deaminase (AID, encoded by Aicda) plays a key role in somatic hypermutation and class switch recombination in germinal center B cells. However, off-target effects of AID are implicated in human leukemia and lymphoma. A mouse model of precursor B cell acute lymphoblastic leukemia driven by deletion of the related transcription factors PU.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!