Roles of hematopoietin and cytokine tyrosine kinase receptors in early lymphopoiesis

Research output: ThesisDoctoral Thesis (compilation)


Cytokines have been shown to have important roles in lymphopoiesis. However, many questions remain unresolved. Among other, while the action of interleukin (IL)-7 in alpha beta T cell development in mouse seems to be largely mediated through permissive survival signaling, the possible permissive role of IL-7 in early B cell development is disputed. Furthermore, FMS-like tyrosine kinase-3 ligand (FLT3L) has been shown to be important in IL-7 receptor alpha chain (IL-7R)-independent B and T lymphopoiesis but little is known of its mode(s) of action. Moreover, although little direct evidence exists, thymic stromal lymphopoietin (TSLP) has been suggested to be a key regulator of fetal and adult IL-7-independent lymphopoiesis. Herein, I explored, through studies of single and double cytokine receptor and ligand knockout mice, the relative roles of TSLP, IL-7 and FLT3L as well as a potential permissive role for FLT3L and IL-7 in early B and T cell development.
We demonstrate that rather than TSLP, IL-7 and FLT3L are critical for B and T cell generation in mice. Furthermore, we demonstrate that ectopic expression of B cell lymphoma 2 (BCL2) is sufficient not only to correct the T cell phenotype of FLT3L deficient mice but can also rescue the virtually complete loss of all discernable stages of early T lymphopoiesis in double FLT3L and IL-7R deficient mice. Furthermore, the same overexpression studies suggest that FLT3 and IL-7R are capable of also mediating survival signaling in early B cell development. These findings implicate a permissive role of cytokine receptors of the hematopoietin as well as the tyrosine kinase families in early B and T lymphopoiesis.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Cell and Molecular Biology


  • IL -7, FLT3 Ligand, cytokines, lymphopoiesis, hematopoiesis, TSLP, apoptosis
Original languageEnglish
Awarding Institution
Supervisors/Assistant supervisor
  • Sten Eirik W Jacobsen, Supervisor
Award date2007 Dec 20
  • Hematopoietic Stem Cell Laboratory
Print ISBNs978-91-85897-49-0
Publication statusPublished - 2007
Publication categoryResearch

Bibliographic note

Defence details Date: 2007-12-20 Time: 09:00 Place: BMC Segerfalksalen External reviewer(s) Name: Allman, David Title: Ph.D Affiliation: University of Pennsylvania School of Medicine ---

Related research output

Christina Jensen, Kharazi, S., Charlotta Böiers, Liuba, K. & Jacobsen, S. E. W., 2007, In : Nature Immunology. 8, 9, p. 897-897

Research output: Contribution to journalLetter

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