Human embryonic stem cells for in-vitro developmental toxicity testing

Transcription

1 Human embryonic stem cells for in-vitro developmental toxicity testing HESI workshop on alternatives assays for developmental toxicity Raimund Strehl

2 Cellartis The company Founded in early 2001, University spin-off, 36 employees Focus on human embryonic stem cells for in-vitro drug discovery and toxicology Operating on a high quality standard Academic & Industry collaborations 150+ Major research grants: NIH - US$ JDRF - US$ EU grants - 3 million BetaCellTherapy Vitrocellomics HeartRepair Stems InvitroHeart Carcinogenomics

3 Cellartis - Facilities Cellartis Sweden Tailor-made for hes cell work Cell culture laboratories comply with GMP standard (3 EU standard + 1 US standard) Cellartis UK Upscaling of hes cell production Three cell culture laboratories that comply with GMP (EU standard) Operational in mid 2007

4 Human embryonic stem (hes) cell lines

5 hes cell lines >30 Cellartis cell lines + collaborative lines (e.g. CECOL14 from Latin America) Two hes cell lines + subclones on the NIH stem cell registry Six hes cell lines for use in Germany Twenty hes cell lines in the UK stem cell registry First derivation of a truly xeno-free hes cell line Preparation and quality control of working cell banks (>100 vials) = LOT Ellerström et al., Stem Cells 2007 (provisionally accepted) Bibikova et al., Genome Research 2006 (in press) Ellerström et al., Stem Cells on line 2006 June 1 Caisander et al., Chrom Res 2006, 14: Heins et.al. J Biotechnol. 2005, 122: Maitra et al., Nature Genetics 2005, 37: Noaksson et al., Stem Cells 2005, 23: Darnfors et al., Stem Cells 2005, 23: Sjögren et.al. Reprod Biomed Online. 2004, 9: Heins et. al. Stem Cells 2004, 22:

6 hes cell lines - Establishment and expansion Cellartis

7 hes cell lines - LOT quality control Morphology Thawing recovery rate of frozen LOT:s Stem cell markers: SSEA-3, SSEA-4, SSEA-1, TRA-1-60, TRA-1-81, and Oct-4 ALP- and Telomerase activity Cytogenetic analysis (Karyotyping, FISH, MLPA) In-vitro and in-vivo pluripotency Mycoplasma and human viruses (Human Immunodeficiency Virus type 1 and 2, Hepatitis B and C, Cytomegalovirus, Herpes Simplex Virus type 1 and 2, Epstein-Barr Virus, Human Papilloma Virus)

8 hes cell lines - Summary SA001, LOT AK001 Parameter LOT preparation Thawing recovery rate SSEA-1 SSEA-3 SSEA-4 TRA-1-60 TRA-1-81 Oct-4 Alkaline phosphatase Karyotype FISH (X, Y, 13, 18 and 21) MLPA (sub-telomeric regions) Telomerase activity Pluripotency in vitro Pluripotency in vivo Passage p13 p13 - p14 p31 p31 p31 p31 p31 p31 p31 p26, p27, p50 and p52 p32 and p51 p26 p27 p29 p19 Result >100 vials 100% Negative Positive Positive Positive Positive Positive Positive 46, XY Diploid, XY No deletions Positive Endo-, ecto-, mesoderm Endo-, ecto-, mesoderm

9 hes cell lines - Increasing demand for pluripotent hes cells Production of pluripotent hes cells Two shifts Scaleable culture methods Automated production / Reactors Demand for pluripotent hes cells Mostly for internal R+D Hepatocytes Cardiomyocytes Increased distribution to commercial collaborators Mostly for products Hepatocytes Cardiomyocytes Screening

10 hes cell lines Overcoming culture challenges Manual microdissection Highest quality (Hand-picked) Maintains normal lines Not scaleable Laborios and expensive Enzymatic propagation Easier culture More cells / dish Scaleable Relatively cheap Automateable in the future

11 hes cell lines Robust Upscaling Improved feeder-systems Single cell passaging Flask / Multiwell culture Defined culture systems

12 Application of hes cells in developmental toxicology

13 Developmental toxicology - A humanized EST? A human developmental toxicity assay composed of two parts: 1. Cytotoxicity assays to detect a selective effect of substances on the viability of human embryonic cells. 2. hes cell based in-vitro development assay to evaluate influences on the mechanisms of human embryonic differentiation. Substance to be tested Cytotoxicity in embryonic cells Influence on differentiation Mathematical correlation model Prediction of developmental toxicity

14 Developmental toxicology - Differential cytotoxicity Comparative cytotoxicity assays using 3 human cell types of increasing degree of maturation Degree of maturation Undifferentiated hes cells hes cell derived progenitors Human foreskin fibroblasts

15 Developmental toxicology - Viability endpoint Test protocol: Day -1: Seed cells Day 0: Start exposure Day 4: Change medium Day 7: Change medium Day 10: Analysis in plate reader ATP content (Promega CellTiterGlo TM ) Resazurin reduction

16 Developmental toxicology - Non-toxicant vs. Strong toxicant 150 Saccharin hff Prog cells FU hff Prog cells hescs hescs viability in % 50 viability in % ,01 0, conc. in um 0,01 0, conc. in um Saccharin 5-Fluorouracil IC50 hesc No IC50 at 1mg/ml IC50 hesc 0,044 µm IC50 Prog No IC50 at 1mg/ml IC50 Prog 0,080 µm IC50 hff No IC50 at 1mg/ml IC50 hff 0,304 µm

17 Developmental toxicology - Retinoids 150 ATRA hff Prog cells CRA hff Prog cells hescs hescs viability in % viability in % ,01 0, conc. in um 0 0,01 0, conc. in um ATRA 13-cis retinoic acid IC50 hesc 30,38 µm IC50 hesc 15,85 µm IC50 Prog 0,001 µm IC50 Prog 0,0004 µm IC50 hff 133,7 µm IC50 hff 301,6 µm

18 Developmental toxicology - Cardiac differentiation Contracting areas appear during spontaneous differentiation of hes cells and can be maintained for up to 3 months (~30-100bpm) High variability in the human system Not suitable as an endpoit

19 Developmental toxicology - Improved human endpoints Recapitulate early human embryonic development in-vitro Measure endpoints on protein level using novel mabs Measure endpoints on gene level using RT-qPCR or reporter cell lines (under development in collaboration with Invitrogen) Ectoderm Marker 01 Marker 02 Marker 01 Marker 02 Differentiation Mesoderm Marker 03 Marker 04 Marker 03 Marker 04 Endoderm Marker 05 Marker 06 Marker 05 Marker 06 Undifferentiated hes cells In-vitro Development Germ layer Gene level Protein level

20 Developmental toxicology - Novel monoclonal antibodies 10x 20x 10x 20x Novel monoclonal antibodies for hesc In-house derived mabs Surface markers Directed against undifferentiated hes cells and early lineage determination 10x 10x 20x 20x

21 Developmental toxicity - Screening Screening using monoclonal surface antibodies or engineered cell lines Endoderm Novel monoclonal antibodies for hesc Mesoderm Ectoderm t t t Normal development Inhibition Directed differentiation

22 Metabolism

23 Metabolism - Hepatoblast/cyte-like cells from hes cells Hepatoblast-like cells Hepatocyte-like cells

24 Metabolism - Hepatocyte-like cell characterization A B C D Glycogen storage C E α-1-at F AFP G Albumin H CK18 Foxa2 LFABP

25 hp hepatocytes (M) hp hepatocytes (F) Keratinocytes Metabolism - Induction experiments Phase 1 enzymes SA002 untreated SA002 induced SA002.5 untreated SA002 induced HepG2 CYP1A CYP3A β-actin

26 HepG2 MEF Metabolism - Induction experiments Phase 2 enzymes hp hep. (F) hp hep. (M) SA002.5 untr. SA002.5 ind. SA167 untr. SA167 ind. hr GSTs liver microsomes GST A1-1 GST M1-1 GST P1-1 b-actin Söderdahl et al, submitted

27 Thank you!