Conflict of interest

Transcription

1 Helsinki 2012 HPV vaccines for developing countries Lutz Gissmann Conflict of interest LG is a consultant to GSK and Sanofi Pasteur MSD and, due to existing IP, receives royalties from sales of Gardasil and Cervarix TM 2 Gissmann

2 Cervical cancer: 0.5 mio cases p.a. N. America 14,670 Europe 59,931 Africa 78,897 C-S. America 71,862 Asia 265,884 < 9.2 < 16.1 < 26.2 < 32.6 < 87.3* * per 100, Gissmann Parkin DM & Bray F. Vaccine 2006; 24(Suppl 3):S11 S25. Prevention of cervical cancer: Pap screening Brazil UK Bosch, Gissmann

3 Prevention of cervical cancer prevention of infection and subsequent events removal of HSIL detected by Pap screening programs Months Years Decades acute HPVinfection persistent infection ( 12 months) LSIL HSIL cervical cancer 60-80% of all women worldwide Frequency Zusammengefasst: Koutsky LA. Am J Med 1997; 102: 3-8; Bosch FX, et al. J Natl Cancer Inst Monogr 2003; Parkin DM & Bray F. Vaccine 2006; 24(Suppl 3):S11 S25; Clifford GM et al. Int. Papillomavirus Conference 2004; Globocan 2002 (EU + Norway, Switzerland + Iceland). 5 Gissmann 1-4% of women worldwide Nov 17, 2011: GAVI* To Make HPV Vaccine Available In Developing Countries *GAVI: Global Alliance for Vaccines and Immunization 6 Gissmann NPR s Health Blog

4 Nov 17, 2011: GAVI To Make HPV Vaccine Available In Developing Countries Negotiations to secure an affordable price for the three-shot HPV vaccine began in June when Merck pledged to make doses available at $5 a pop. Beginning in 2012, countries will be invited to apply for the vaccine. As part of the application, they'll have to demonstrate that they can actually get it out to people and that they can let people know it's available. By 2015, GAVI expects that 2 million girls in nine countries will have received the HPV vaccine once negotiations with Merck and GlaxoSmithKline are finalized. 7 Gissmann NPR s Health Blog Current HPV vaccines: virus-like particles (VLP) of HPV (6, 11), 16, copies L1 protein spontaneous assembly VLPs consist of only one protein (L1) VLPs are virus particles without DNA hence are not infectious VLPs are immunogically identical to infctious virus Antibodies induced by VLPs specifically and efficiently bind to infectious virus thus prevent its entry into cells 8 Gissmann

5 Current HPV vaccines Despite their excellent safety, immunogenicity and effectiveness in clinical studies they are far from being perfect: don t prevent all cases of cervical cancer and precursors don t treat existing infections or lesions require multiple invasive immunizations cannot be distributed in areas of highest need given the high costs and low stability 9 Gissmann Shortcomings of the existing vaccines Special need for developing countries AFFORDABLE robust multivalent long-protecting without boosting immunogenic by non-invasive application 10 Gissmann

6 Needle-less single-dose immunization: recombinant Adeno-Associated Virus (AAV) AAVs are apathogenic in humans AAVs induce persistent infections 11 Gissmann HPV 16 L1 raav induces neutralizing antibodies after a single i.n. immunization 12 Gissmann Kuck et al. 2006

7 HPV 16 L1 raav induces L1-specific CTL after i.n. immunization 13 Gissmann Kuck et al Pre-existing AAV 5-specific abs can be overcome by different AAV serotype 14 Gissmann Kuck et al. 2006

8 Single-dose immunization (intranasal) induces long-lasting immune response 15 Gissmann Kuck et al Production of HPV vaccine in plants Bioreactor low costs for production transgenic plants or infection by recombinant plant viruses easy purffication (targeting to specific organelles) vehicle for oral vaccinatin edible vaccine hard to standardize 16 Gissmann

9 Production of HPV vaccine in plants HPV 16 L1 expressed in tobacco or potato 17 Gissmann HPV 16 L1 is produced as 0.5% of total protein in transgenic tobacco Biemelt et al., Gissmann

10 HPV 16 L1 expressed by TG tobacco forms VLPs Biemelt et al., Gissmann VLPs produced by TG tobacco are immunogenic Biemelt et al., Gissmann

11 Oral immunization with HPV 16 L1 transgenic tubers induces serum IgG Feeding 4x at 15 days intervals for 20h Biemelt et al., Gissmann 1 st generation prophylactic vaccines: HPV L1 VLPs N wildtyp L1 C recombinant baculovirus, yeast 5x 72x monomer 22 Gissmann capsomer 100nm capsid (VLP)

12 empty virus capsids assemble at high concentration of protein purified polyomavirus VP1 protein 250mM Na + x 5 pentamers 1M Na + x 72 Salunke, Caspar and Garcea, Gissmann capsids VLPs Structure of the HPV 16 L1 protein antiparallel -sandwich: 8 -strands (B-I) BC, DE, FG, HI-loops: type-specific neutralizing epitopes L2 Cys 428 Cys 175 Intertwining L1 molecule form capsomer C-terminus inserts between 2 L1 molecules of neighboring capsomeres 24 Gissmann Sapp and Bienkowska-Haba, FEBS J 2009, 276:7206

13 GST renders L1 soluble: purification of L1 capsomeres Thrombin cleavage site GST HPV 16 L1 L1 GST lysate + ATP, MgCl 2 + 3,5 M urea centrifugation supernatant dialysis overnight gel filtration Binding to Glutathione- sepharose beads Thrombin cleavage Elution L1 100nm 25 Gissmann HPV 16 L1 mutants 26 Gissmann

14 Purification of different L1 constructs 27 Gissmann Immunogenicity of HPV 16 L1 capsomeres 28 Gissmann

15 Immunogenicity of HPV 16 L1 capsomeres: enhancement by adjuvants 6 rhesus macaques/group, 10 g HPV 16 capsomeres (L1dCys) +/- adjuvant week 0 and 8 29 Gissmann Stahl-Henning et al Results Possible reasons for the lower immunogenicity different in LPS contamination difference in cross-presentation different in structures 30 Gissmann

16 different immunogenicity of L1 capsomeres is independent of contaminating LPS Immunization of LPS-resistant (TLR4 -/- ) mice 2 nd immunization 3 rd immunization 31 Gissmann excluding LPS contamination: DNA immunization particle formation 32 Gissmann

17 excluding LPS contamination: DNA immunization immune response 33 Gissmann different immunogenicity of L1 capsomeres is not due to different cross-presentation 34 Gissmann

18 Results Hypothesis Capsomere constructs that can assemble into higher structures lare more immunogenic than constructs that can only form capsomeres Experimental design: In vitro: Assembly assay sedimentation analysis In vivo: immunisation L1 specific neutralizing antibodies Correlation? 35 Gissmann Assembly generates particles of different size capsomer T=1 (12) T=3 (36) T=7 (72) 36 Gissmann

19 Results Assembly assay VLP-Assembly: low ph high salt Before assembly: ph M NaCl 5 mm DTT Assembly buffer: ph M NaCl 37 Gissmann Results Assembly of different capsomere constructs Before assembly After assembly L1 N absorpti on at 4 50 nm refra cti on index absorption at 450 nm refraction index fracti on s ( 600 µl ) pellet positive control negative control fractions (600 µl) pellet po sitive contro l negative control absorption at 450 nm refraction index absorption at 450 nm refraction index fractions (600 µl) pellet positive control negative control fractions (600 µl) pell et po sitive contro l negative control 38 Gissmann

20 Results Assembly of different capsomere constructs Before assembly After assembly L1 N10 h a bsorpti on at 4 50 nm refra ction index absorption at 450 nm refraction index fra cti on s ( 60 0 µl) pelle t positive control n egative c on trol fractions (600 µl) pellet po sitive contro l negative control L1 N10dCys absorpti on at 4 50 nm refra cti on index absorption at 450 nm refraction index fra cti on s ( 60 0 µl) pelle t positive control n egative c on trol fractions (600 µl) pellet po sitive contro l negative control 39 Gissmann Assembly generates particles of different size ph = mM Na + reducing agents ph = 5.5, 1M Na + capsomer T=1 T=3 T= , 428 Cys Ser ( h4) T=1, T=3, T=7? T=1, T=3? capsomeres 40 Gissmann

21 The ability of L1 capsomeres to assemble into larger particles correlates with immunogenicity ph 5.4, 1M NaCl Stable particles immunogenicity Instable particles Capsomeres Capsomeres overnight L1 N10 L1 N10dCys L1 N10 h4 41 Gissmann Thanx to Lysann Schädlich Bob Garcea 42 Gissmann