BVIG/SBMI Meeting Bart N. Lambrecht, MD, PhD. Department of Respiratory Diseases University Hospital Gent, Belgium

Transcription

1 Dendritic cells : from bench to bedside BVIG/SBMI Meeting 2007 Bart N. Lambrecht, MD, PhD Department of Respiratory Diseases University Hospital Gent, Belgium Outline Role of DCs in the immune system Role in asthma > how to find new therapeutics Role in cancer > how to find better immunotherapy 1

2 Mucosae and skin are full of DCs 2

3 Localisation of DCs in epithelium Dual photon imaging by Hamida Hammad, unpublished DCs probe the mucosa for incoming antigen Dual photon live imaging by Hamida Hammad, unpublished 3

4 Airway DCs capture inhaled FITC-labeled OVA B cells : red DCs : FITC MHC II : red FITC : green Vermaelen et al. J.Exp.Med. 193:51. Protease activated receptors Toll like receptors 1-9 Complement receptors NOD like receptors C-type lectin receptors -Dectin -MMR -DEC BDCA Prostanoid receptors Neuropeptide receptors Purinergic receptors Receptors X for uric acid heat shock proteins... Microbial patterns Damage associated patterns 4

5 Increase in DCs following 2h LPS baseline 2h LPS Dual photon live imaging by Hamida Hammad, unpublished Dynamics of DC movement baseline 2h LPS Dual photon live imaging by Hamida Hammad, unpublished 5

6 Dendritic cells determine the outcome of T cell priming Allergy/Parasites Extracel. infections Tolerance Autoimmunity Intracel. Infections Cancer Lambrecht and Hammad, Nat Rev Immunol

7 Lambrecht and Hammad, Nat Rev Immunol 2003 Dendritic cells in asthma 7

8 Airway pathology in mild and persistent asthma Normal Asthmatic Increased numbers of activated DCs are found in human respiratory disease tissues Increased numbers of activated DC in nasal tissue of subjects with allergic rhinitis healthy control, allergic rhinitis (Klein-Jan et al J Allergy Clin Immunol, 118: 1117, 2006) Increased activation state of DC in induced sputum of subjects with atopic asthma (McCarthy et al, Clin Exp Allergy, 37: 72, 2007) 8

9 Are dendritic cells necessary for inducing or maintaining airway inflammation in a Th2 sensitized individual? CD11c DTR GFP Diphteria toxin only kills CD11c + cells Steffen.Jung CD11c MHCII van Rijt, et al. J. Exp. Med, 2005, 201:

10 Role of airway DCs during ongoing inflammation OVA/alum I.t. DT sensitisation OVA OVA CD11c-DTR transgenic or PBS van Rijt, et al. J. Exp. Med, 2005, 201: Dendritic cell depletion abolishes typical features of asthma van Rijt, et al. J. Exp. Med, 2005, 201:

11 Can we find therapeutics that target DCs? What turns the system on? Protease activated receptors Toll like receptors 1-9 Complement receptors Prostanoid receptors C-type lectin receptors -Dectin -MMR -DEC BDCA Neuropeptide receptors Purinergic receptors Receptors X for uric acid heat shock proteins... Microbial patterns Damage associated patterns 11

12 Toll like receptors 1-9 C-type lectin receptors -Dectin -MMR -DEC BDCA Protease activated receptors Stressed cells Complement Cell receptors death Platelet aggregation Prostanoid receptors extracellular ATP Neuropeptide receptors Purinergic receptors Receptors X for uric acid heatp2x/p2y shock proteins... Microbial patterns Damage associated patterns Segmental allergen provocation induces release of ATP in BAL fluid of human asthmatics luminometer counts T 0 NaCl T 1 NaCl T 0 Allergen T 1 Allergen Marco Idzko, collaboration with J.C. Virchow 12

13 Apyrase inhalation prior to OVA challenge in sensitized mice suppresses airway ATP levels and asthma lumiometer counts PBS/PBS/OVA OVA/PBS/OVA OVA/Apyrase/OVA number of cells PBS/Vehicle/PBS *** *** ** ** OVA/Vehicle/OVA OVA/Apyrase/OVA *** ** *** *** 0 macrophages neutrophils lymphocytes eosinophils PBS/Vehicle/PBS PBS/Vehicle/OVA PBS/apyrase/OVA cytokines pg/ml ****** IL-4 * IFN-γ *** ** IL-5 *** ** IL-13 PBS/Vehicle/OVA OVA/Vehicle/OVA OVA/Apyrase 4 U/ml /OVA Marco Idzko and Hamida Hammad, Nature Med., 2007 A stable analogue of ATP induces DC migration to the MLN No of Ag + DCs in MLN CCR7 expression Number of OVA-FITC+ DC ** ** 0 PBS OVA-PBS OVA-ATPγS CCR7 Expression net to NTC PBS-DC ATP-PBS-DC OVA-DC OVA-ATP-DC Marco Idzko and Hamida Hammad, Nature Med.,

14 Dendritic cells in cancer Meta analysis of cancer immunotherapy All patients enrolled in vaccine trials for metastatic cancers at the National Cancer Institute New adjuvants, adenoviral vectors, dendritic cells, etc 1306 patients over 10 years Objective response rate of 3.3%!! Rosenberg et al Nat Med 10:909 14

15 Adjuvants BCG bacterial DNA (CpG) αgalcer, ASO2B Cytokines GM-CSF Flt3 Interferon α Costimulators 15

16 Inject mature tumor pulsed Dendritic Cells Dendritic cell immunotherapy First succesful use: B-cell lymphoma Nat Med Jan;2(1):52-58 Clinical trials and case reports : Melanoma Prostate carcinoma Renal and bladder carcinoma Non-small cell lung cancer Neuroblastoma Multiple myeloma Non-Hodgkin s Thyroid carcinoma Glioma etc 16

17 Dendritic cell immunotherapy First succesful use: B-cell lymphoma Nat Med Jan;2(1):52-58 Clinical trials and case reports : Melanoma Prostate carcinoma Renal and bladder carcinoma Non-small cell lung cancer Neuroblastoma Multiple myeloma Non-Hodgkin s Thyroid carcinoma Glioma etc Mesothelioma? 11 september : people exposed to asbestos 17

18 Can we prevent the development of murine mesothelioma by i.v. injection of tumor loaded dendritic cells (DC)? Day 14: PBS or Tumor-pulsed DC Day 7: PBS or Tumor-pulsed DC Day x 10 6 AB1 mesothelioma cells Prevention of murine mesothelioma outgrowth by tumor lysate pulsed DCs 100 DCs loaded with tumor % survival days after tumor injection No DCs Hegmans et al. Am. J. Resp. Crit. Care. Med

19 DC immunotherapy in humans Joost Hegmans. PhD Joachim Aerts, MD, PhD Mesothelioma Applied Research Foundation USA Phase 1 3 injections (IV+ID) 19

20 All procedures have to be performed according to GMP guidelines + All reagents must be GMP approved 0.9 % NaCl Tumor lysate 0.05x10 6 cells Tumor lysate 1x10 6 cells Tetanus toxoid 2Lf DC (+KLH) 2.6x10 6 Tumor lysate 0.5x10 6 cells Tumor lysate 0.1x10 6 cells DC (-KLH) 2.4x10 6 KLH 100 ug 20

21 CT-scan December 9 th,2005 CT-scan July 21 st, 2006 Problems with DC immunotherapy Costly ( Є/patient) without reimbursment Very labor-intensive in laboratory Expectations of patients and refering physicians is very high Does it have a chance in advanced disease? 21

22 Deplete regulatory T cells Change immunosuppression Presence of Treg cells in human mesothelioma biopsies Foxp3 Hegmans et al. Eur Resp J :

23 Removal of Tregs in mice using endoxan ameliorates DC based therapy 23

24 Drugable pathways of immune subversion What s on the immediate horizon? 24

25 The future of immunotherapy? - Early stage disease Give to surgically cured patients Preventive Immunotherapy (cfr infectious diseases) Identification of high risk patients - BRCA mutations, HNPPC syndrome, etc Inhibiting the progression of premalignant lesions? Marco Idzko Hamida Hammad Leonie van Rijt Mirjam Kool NOW HIRING PEOPLE : bart.lambrecht@ugent.be 25