Tetrazyklin- induzierbare, Proliferations- regulierende Gene zur Etablierung und Funktionsanalyse langzeitig wachsender hämatopoietischer Progenitorzelllinien

• Antragsteller: Professor Dr. Fritz Melchers
• Fachliche Zuordnung: Immunologie
• Förderung: Förderung von 2009 bis 2015
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 112926979

• Erstellungsjahr: 2015

Zusammenfassung der Projektergebnisse

First, we have refined methods to generate highly diverse, doxycycline (dox)-controlled full length cDNA expression libraries in retroviral vectors which are specifically suited to transduce hematopoietic cells from pHSC and other progenitors to B lymphoid cells at different stages of their development to plasmablasts and plasma cells. Dox-control allows not only to monitor changes in phenotypes and functions of the transduced cells, but also to distinguish cDNA expression-dependent reversible from irreversible changes in these phenotypes and functions. In the future, such cDNA libraries from human B-cell leukemias will help to identify new oncogenes, thus, targets of therapy. To test transformation of B-lineage cells by the overexpression of one of these cDNA genes to ligand-uncontrolled, malignant states we have developed “ in vitro” and “in vivo” tests. It was a surprise, that transplantation of cDNA-transduced B-lineage cells detects at least five to ten times higher numbers of transformation-inducing oncogenes than do the “in vitro” proliferation and/or survival assays. This now allows a new classification of transforming oncogenes, which should be informative in the identification of such cDNA genes from human B-cell leukemias. Our highly diverse cDNA libraries contain a considerable number of oncogenes cooperating with a first (e.g. c-myc) oncogene in transforming B-lineage cells to malignancy. As a surprise, we have identified the overexpression of a truncated as well as the wildtype form of exoscf-1, one of the ten components of the exosome complex, hence, of a house keeping function, as a transforming gene. Many of these genes promise to open new, unexplored avenues of molecular-biological research of the ways that a cell can take to become premalignant.

Projektbezogene Publikationen (Auswahl)

• Experimental limitations using reprogrammed cells for hematopoietic differentiation. J Biomed Biotechnol. 2011;2011:895086
  Seiler K, Tsuneto M, Melchers F
  
• Induced pluripotent stem cells expressing elevated levels of sox-2, oct-4, and klf-4 are severely reduced in their differentiation from mesodermal to hematopoietic progenitor cells. Stem Cells Dev. 2011 Jul;20(7):1131-42
  Seiler K, Soroush Noghabi M, Karjalainen K, Hummel M, Melchers F, Tsuneto M
  
• Biphenotypic B-lymphoid/myeloid cells expressing low levels of Pax5: potential targets of BAL development. Blood. 2012 Nov 1;120(18):3688-98
  Simmons S, Knoll M, Drewell C, Wolf I, Mollenkopf HJ, Bouquet C, Melchers F
  
• Pim1 and Myc reversibly transform murine precursor B lymphocytes but not mature B lymphocytes. Eur J Immunol. 2012 Feb;42(2):522-32
  Bouquet C, Melchers F
  
• Reprogramming to iPS cells and their subsequent hematopoietic differentiation is more efficient from MEFs than from preB cells. Immunol Lett. 2012 Mar 30;143(1):70-6
  Reimer A, Seiler K, Tornack J, Tsuneto M, Melchers F
  
• The Basel Institute for Immunology. Annu Rev Immunol. 2012;30:23-38
  Melchers F
  
• B-cell progenitors and precursors change their microenvironment in fetal liver during early development. Stem Cells. 2013 Dec;31(12):2800-12
  Tsuneto M, Tokoyoda K, Kajikhina E, Hauser AE, Hara T, Tani-Ichi S, Ikuta K, Melchers F
  
• Ectopic Runx1 expression rescues Tal-1-deficiency in the generation of primitive and definitive hematopoiesis. PLoS One. 2013 Jul 29;8(7):e70116
  Tornack J, Seiler K, Grützkau A, Grün JR, Onodera M, Melchers F, Tsuneto M
  
• miR-221 redirects precursor B cells to the BM and regulates their residence. Eur J Immunol. 2013 Sep;43(9):2497-506
  Knoll M, Simmons S, Bouquet C, Grün JR, Melchers F
  
• Environments of B cell development. Immunol Lett. 2014 Jan-Feb;157(1-2):60-3
  Tsuneto M, Kajikhina E, Seiler K, Reimer A, Tornack J, Bouquet C, Simmons S, Knoll M, Wolf I, Tokoyoda K, Hauser A, Hara T, Tani-ichi S, Ikuta K, Grün JR, Grützkau A, Engels N, Wienands J, Yanagisawa Y, Ohnishi K, Melchers F
  
• Checkpoints that control B cell development. J Clin Invest. 2015 Jun;125(6):2203-10
  Melchers F
  
• Chemokine polyreactivity of IL7Rα+CSF-1R+ lymphomyeloid progenitors in the developing fetal liver. Sci Rep. 2015 Aug 3;5:12817
  Kajikhina K, Melchers F, Tsuneto M
  
• Environments of hematopoiesis and B-lymphopoiesis in foetal liver. Clin Exp Rheumatol. 2015 Jul-Aug;33(4 Suppl 92):S91-3
  Kajikhina K, Tsuneto M, Melchers F