1. GENERATION OF CELLS OF THE IMMUNE SYSTEM STEM CELLS

2. EMBRYONIC STEM CELLS BONE MARROW DERIVED STEM CELLS CD34 + HEMATOPOIETICMESENCHYMAL

3. Spleen of irradiated mouse Colony forming units (CFU) Discovery of stem cells Till és McCullogh 1960 FERTILIZED EGG Omnipotent Omnipotent EMBRYONAL STEM CELL Pluripotent TISSUE STEM CELL Multipotent MYELOID LYPHOID DECISION OF CELL DIFFERENTIATION

4. EARLY MOUSE EMBRYOS Blastocyst stage of differentiation 4.5 DAY5.5 DAY Ectoplacental part EXTRAEMBRYONAL PARTS EMBRYONAL PARTS Blastocoel Dorsal part Trophectoderm Primitive ectoderm Primitive endoderm Extraembryonal ectoderm Embryonal ectoderm Inner endoderm Primitive amnion Primitive sheet Inner Cell Mass ICM In vitro fertilization – IVF – human embryos

5. GENERATION OF BLOOD CELLS DURING LIFE SPAN BEFORE BIRTHAFTER BIRTH Spleen Liver Yolk sac Cell number (%) BIRTH months years Flat bones Tubular bones BONE MARROW TRANSPLANTATION

6. CELL TYPES OF THE BONE MARROW Dendritic cell B-cell precursors Stem cells Stromal cells BONE Central sinus Unspecialized stem cells with unlimited proliferating capacity Osteoblasts Osteoclasts ProgenitorsPrecursors Blood circulation

7. MYELOID LYMPHOID BONE MARROW CMPCLP CD34+ HSC ERYTHROID BLOOD CELLS Endothelial cells Mesenhymal Stem Cells (MSC) FatBone Cartilage Other Stem Cells Neuronal cellsEpithelial cells of the liver, kidney, skin, myocytes of the heart and muscle, GI tract

8. Continuous replenishment of the hematopoietic system Continuous replenishment of the hematopoietic system Continuous generation of peripheral immune cells Continuous generation of peripheral immune cells Circulating progenitors/precursors - BLOOD Circulating progenitors/precursors - BLOOD Tissue-specific progenitors/precursors - TISSUES Tissue-specific progenitors/precursors - TISSUES LIMITED TISSUE – SPECIFIC REGENERATIVE POTENTIAL At least one differentiated cell Progenitor/Precursor More differentiated cell Progenitors/Precursors Self renewal + Assimmmetric cell division IMPORTANCE OF TISSUE STEM CELLS

9. SOMATIC CELLS STEM CELLS Telomerase + ARE STEM CELLS EVER - YOUNG CELLS? What about aging? Replicative scenescence is inhibited by telomerase Stromal cells – ‘niche’ is aging as other cell types The number and the differentiating capacity of pluripotent stem cells is decreasing with age GC, HSC Telomer length

10. HSC – assymetric cell division self renewal cell differentiation Dendritic cell HSC Stromal cell Central sinus Bone SELF RENEWAL AND POTENCY OF DIFFERENTIATION OF STEM CELLS IS REGULATED BY: The stem cell ‘niche’ Cytokines (LIF, SCF) Special signalling molecules JAK – STAT variants Transcription factors Oct-4 Pluripotency maintaining factor Nanog HSC self renewing factor Bmi-1 - inhibits the anti-proliferative, apoptosis promoting factors p16/p19 Arf - enhances telomerase function

11. PLURIPOTENT BONE MARROW STEM CELLS REGENERATIVE MEDICINE EctodermalMesodermalEndodermal ADULTADULT Liver Pancreas Gut Asahara & Kawamoto 2004 Am J Physiol Cell Physiol L M HMB Pericyte EPC endothel VASCULO / ANGIOGENESIS SkinNeuro HSCEndothel Bone Cartilage, Muscle, Fat MSC Osteoblast Osteoclast

12. Differentiation of HSC from a more pluripotent SC HYERARCHY PROPOSED MECHANISMS FOR ADULT STEM CELL PLASTICITY HSC Indirect trans- differentiation of HSC through a more pluripotent SC HSC Direct trans- differentiation of HSC Fusion of HSC with tissue cell TRANSDIFFERENTIATION - FLEXIBILITY GET THROUG ECTO-/ENDO-/MEZODERM BARRIERS LYMPHOID/MYELOID BARRIERS

13. HEMOGENIC ENDOTHELIUM HSC EMBRYONAL DEVELOPMENT OF ENDOTHELIAL CELLS Chen MJ et al. Nature 457:887, Lancrin C et al. Nature 457:892, Eilken HM et al. Nature 457:896, 2009Hemangioblaszt Flk-1 + brachury + Hemogenic endothelium Tie2 high c-Kit + CD41 - Primitive hematopoesis CD41 - CD45 - Scl/Tal1 Hematopoesis CD41 + CD45 - Runx1/AML1 LT-HSCST-HSC CMP CLP

14. Biomechanic stress GENERATION OF HEMATOPOETIC CELLS Blood cell AORTA HSC COUPLED DEVELOPMENT OF ENDOTHELIAL AND HEMATOPOETIC STEM CELLS (HSC) Adamo et al., Nature 2009, North TE, et al. Cell 2009

15. A FELNŐTT HEMATOPOETIKUS ŐSSEJTEK KÉPZŐDÉSÉT BIZTOSÍTÓ CSONTVELŐI MIKROKÖRNYEZET „NICHE” Osteoblast MSCHSC HSC HSC HSC Mobilised hematopoetic stem cells (HSC) develop in close contact with osteoblasts, mesenchymal stem cells (MSC) and endothelial cells Uccelli A et al. Nat Rev Immunol 2008 Nestin + MSC

16. MULTIPOTENT MESENCHYMAL STEM CELL Mesenchymal stem cells (MSC) modulate the functions of other cells through cell – to – cell interactions and through soluble factors produced by them cell – to – cell interactions and through soluble factors produced by them Uccelli A et al. Nat Rev Immunol 2008

17. CHARACTERISTICS AND FUNCTIONS OF MESENCHYMAL STEM CELLS Regulation of bone marrow HSC Integrate to the bone Not immunogenic Migrate to the site of tissue demage Traverse vessel wall Similar action in different tissues Produce trophic and induced factors React to inflammatory signals Immune suppressive - GVHD Support tumor growth –Integration –Immune suppression BYSTANDER EFFECTS –Modulation of demaged tissue environment Inhibition of proliferation Anti-inflammatory effect Inhibition of immune cells Inhibition of apoptosis Trophic effects – HSC function –WNT signaling –Notch signaling –Similar effects to bone marrow functions –Augmentation of endogenous regenerative mechanisms –Low level of integration –Low level of trans-differentiation –„Touch and go”

18. Physical stress – shear STRESS Differenciated entothelial cells Permeability is increasing Retention and modulation of lipoproteins Decrease vessel wall demage Restore regenerative mechanisms EGYENSÚLY TISSUE ENVIRONMENT Pro-angiogenic Anti-angiogenic HOMEOSTASIS OF HEALTHY ENDOTHELIAL CELLS REQUIRES CONTINUOUS REGENERATION CRONIC STRESS AgeSmoking High cholesterin levels High blood pressure Diabetes PROTECTIVE RESPONSE INFLAMMATION Modified endothelial functions Plaque formation Thrombosis Moreno et al. J Am Coll Cardiol 2009

19. Decrease demage of vessel wall Restore regenerative mechanisms EQUILIBRIUM Removal of cholesterol Generation of new vessels Angiogenesis VESSEL REGENERATION BY BONE MARROW-DERIVED STEM- AND PROGENITOR CELLS Biomechanic stress STRESS Smooth muscle progenitor cells (SMPC) Differentoated endothelial cells Hemangioblast Mesenchymal stroma cells EPC Endothelial progenitor cells (EPC) Circulating EPC number Training Statin therapy Mobilisation Lipid reducing & anti- inflammatory effects COMPETENT BONE MARROW

20. A GYULLADÁSOS FOLYAMATOK ELŐSEGÍTIK A CSONT LEBONTÁST PROTECTIVE MECHANISMS INHIBITION OF BONE FORMATION INFLAMMATORY T CELL RESPONSE BONE DESORPTION

21. Inhibition Gátlás Enhancement MM RA

22. THE INFLAMMATORY CYTOKINE IL-20 PLAYS A ROLE IN BONE RESORPTION AFTER MENOPAUSE IL-20 citokine-specific anti-body inhibits RANK receptor expression on osteoclast precursors and RANKL expression on osteoblasts Hsu Y-H et al. JEM 2011

23. BONE MARROW TRANSPLANTATION Increasing age limit Increased number of typed donors Umbilical cord banks Developing countries New indications –Autoimmune diseases –Tolerance induction –Regenerative medicine Non HSC-derived stem cells –adipose tissue-derived MSC- Gratwohl & Baldomero Curr Opin Hematol 2009 Allo Auto Csoport Replacement of complex tissuesReplacement of complex tissues Heterogenous cell populationsHeterogenous cell populations Stem- and progenitor cell reservoire in adultsStem- and progenitor cell reservoire in adults Circulation and migration to tissue through the bloodCirculation and migration to tissue through the blood Reverse migration of peripheral immune cells to the bone marrowReverse migration of peripheral immune cells to the bone marrow Increasing number of bone marrow transplantations 1990-2007