HPV Life Cycle & Vaccination: Possible Relevance for HSV Vaccines

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1 HPV Life Cycle & Vaccination: Possible Relevance for HSV Vaccines Douglas R. Lowy Center for Cancer Research, NCI Deputy Director, NCI National Institutes of Health Herpes Virus Infection & Immunity Meeting Fondation Mérieux Conference Center Veyrier du Lac June 20, 2012 The views expressed are my own and do not necessarily reflect those of NCI/NIH

2 Disclosure The National Institutes of Health (NIH) has patents on papillomavirus L1 VLP and L2 vaccine technologies. I am an inventor of these technologies. The NIH has licensed the L1 VLP technology to Merck and GlaxoSmithKline, the two companies with commercial versions of the vaccine.

3 Outline of Presentation HPV vaccine characteristics HPV life cycle and mechanism of vaccineinduced protection Possible relevance to HSV vaccine development

4 United States: Annual Incidence and Distribution of Cancers Attributable to HPV HPV16/18 Cervix ~70% Anus Male Female Vulva/vagina Penis HPV cases Total cases >90% Oropharynx 0 2,000 4,000 6,000 8,000 10,000 12,000 Annual number of cases Pap screening has reduced the incidence of cervical cancer by ~ 80% Incidence of HPV-positive oropharynx cancer increased 225% MMWR, 2012; Chaturvedi et al, J Clin MMWR Oncology, Weekly 2011; 61:253-80, Gillison, 2012 Chaturvedi, and Lowy., 2008

5 Laboratory of Cellular Oncology, CCR, NCI Patricia Day Jeffrey Roberts Rhonda Kines Susana Pang Cynthia Thompson Nicolas Cuburu Alessandra Handisurya Rebecca Cerio John Schiller Chris Buck, Diana Pastrana - LCO, CCR, NCI Bethesda Peter Choyke, Marcelino Bernardo - Molecular Imaging, CCR, NCI, Bethesda Aimee Kreimer, Allan Hildesheim, Mark Schiffman, Ligia Pinto - DCEG, NCI, Bethesda Diane Solomon DCP, NCI, Bethesda Benes Trus - Center for Information Technology, NIH, Bethesda Richard Roden, Subhashini Jagu, Clayton Harro - Johns Hopkins, Baltimore Rolando Herrero IARC, Lyon Bryce Chackerian - University of New Mexico Reinhard Kirnbauer - University of Vienna, Austria

6 HPV Neutralization Epitopes Papillomaviruses encode two proteins that contain neutralization epitopes, the two capsid proteins L1 and L2. L1 contains the immunodominant neutralization epitopes. They are conformationally dependent. L1 can self-assemble to make empty particles with a conformation that induces high levels of neutralizing antibodies.

7 HPV Virion Prophylactic HPV Vaccines Are L1 Virus Like Particles (VLPs) L1 coding region L1 Insertion in Baculovirus Expression Vector Production in Insect Cells HPV16 L1 VLPs Spontaneous assembly of L1 into VLPs Induce high titers of virion neutralizing antibodies Non-infectious, Non-oncogenic Reinhard Kirnbauer et al. PNAS 1992

8 Two Distinct Commercial HPV L1 VLP Vaccines GlaxoSmithKline: HPV16 Cervarix 70% of Cervical Cancer HPV18 ASO4 Adjuvant (Aluminum + MPL) Made in insect cells Merck: Gardasil HPV16 HPV18 HPV6 HPV11 Aluminum Adjuvant Made in yeast 70% of Cervical Cancer 90% of Genital Warts Three intramuscular injections given over 6 months

9 HPV vaccine efficacy trial outcomes Efficacy measured as prevention of incident (new) infection and disease caused by the HPV types in each vaccine (fully vaccinated women, years old) Study Vaccine Number of subjects End-points Vaccine efficacy Vaccine Control % (95% confidence limits) Munoz 10 6/11/16/ CIN2/3, (AIS), VIN2/3, VAIN2/3, GW 100 (90-100) 95 (70-100) Lehtinen 11 16/ CIN3+, (AIS) 100 (85-100) HPV6/11/16/18 = Merck vaccine (Gardasil); HPV16/18 = GlaxoSmithKline vaccine (Cervarix) CIN = Cervical Intraepithelial Neoplasia; 2 = Intermediate, 3 = Severe; AIS = AdenoCa In Situ VIN = Vulvar Intraepithelial Neoplasia; VAIN = VAginal Intraepithelial Neoplasia GW = Genital Warts Vaccine efficacy against non-vaccine HPV types was more limited: GSK>Merck Munoz et al, J Natl Cancer Inst 2:868-78, 2010 (4 year data); Lehtinen et al, Lancet Oncology, November 9, 2011 (4 year data)

10 HPV vaccine efficacy phase III trials: Males Efficacy measured as prevention of incident (new) infection and disease caused by the HPV types in each vaccine (fully vaccinated males, years old) Study Vaccine Number of subjects End-points Vaccine efficacy Giuliano 11 6/11/16/ Palefsky 11 6/11/16/ Vaccine Control % (95% confidence limits) Genital warts Persistent infection AIN 1/2/3 Persistent infection 90 (69-98) 83 (83-93) 77 (40-93) 95 (80-99) HPV6/11/16/18 = Merck vaccine (Gardasil): AIN = Anal Intraepithelial Neoplasia; 1 = mild, 2 = Intermediate, 3 = Severe Giuliano et al, New Eng J Med 364:401-11, 2011 (3 year data); Palefsky et al, New Eng J Med 365: , 2011 (3 year data)

11 >13-fold higher Durability of Antibody Response to Cervarix Month: High level protection Plateau phase Mean titer after natural infection >11-fold higher Mean titer after natural infection Month: HPV16 Neutralization Assay From The GSK Vaccine HPV-007 Study Group. Lancet 374:301-14, years sustained immunogenicity and efficacy (Roteli-Martins et al, Hum Vaccin Immunother, 2012)

12 NCI Costa Rica vaccine trial: Efficacy against Oral infection (End-point: HPV16/18 infection) 7,466 women 18-25, population-based, controlled, randomized trial: Testing HPV16/18 vaccine (GSK) 5840 oral swabs at 4-year visit; balanced between control and vaccine group 93% vaccine efficacy (1/16 infections in vaccine group) 12 HPV16 infections; 4 HPV18 infections Suggestive evidence that HPV vaccination can protect against oropharyngeal cancer attributable to HPV infection Rolando Herrero, Allan Hildesheim, Aimee Kreimer and their colleagues, submitted

13 One or two vaccine doses (Cervarix, GSK) can induce 4 years of protection against persistent (6 months) HPV infection with HPV16/18 HPV vaccine Number Vaccine Number Number Rate per efficacy of doses arm of women of events 100 women % (95% CI) 3 doses 2 doses 1 dose Control % HPV % Control % HPV % Control % HPV % Kreimer et al, JNCI 103: , (77-88) 81 (63-94) 100 (79-100) Similar protection was seen against 12 month persistent infection It is unknown whether these results can be extrapolated to Gardasil

14 Prospective post-licensure assessment of 600,558 doses (Gardasil) from 7 managed care organizations No vaccine-related increased risk to prespecified outcomes: Guillan- Barré syndrome, stroke, venous thromboembolism, appendicitis, seizure, allergic reactions Prespecified outcomes were derived from CDC analysis from VAERS [Vaccine Adverse Events Reporting System]: Slade et al, JAMA 2009 Rate of anaphylaxis (1 case, 26 y.o.) similar to other vaccines Rate of fainting similar to that of other adolescent vaccines

15 Mechanisms of HPV infection and Vaccine-induced protection Question: How does systemic immunization with a sub-unit vaccine prevent a local mucosal or local skin infection? A two-part answer: (1) Local wounding and virion binding to the basement membrane are required for HPV infection (2) Infection is prevented by exudation of systemic protective antibodies at these potential sites of infection

16 Following microtrauma, HPV s bind to the basement membrane, infect basal cells, and replicate in suprabasal cells Virion Assembled Virus Stratified squamous epithelium Virion Suprabasal cells HPV DNA replication Basement membrane Dermis Basal cells HPV DNA

17 Formation of high titer (10 10 /ml) infectious papillomavirus pseudoviruses Codon modified L1 + L2 Helper Plasmid (12 kb) Reporter Target plasmid (6-8 kb) SV40 Ori Transfect T Ag Harvest Pseudoviru s Reporter SV40 Ori Detergent lyse Nuclease digest 800mM NaCl Optiprep Chris Buck et al, J Virol 78: , TT

18 HPV Genital Challenge Model Protocol Pre-Treatment Progesterone (Depo-Provera) 10 7 Infections Units Ori Day 4 Long Term Time Course Day 7+ Analysis by Luciferase expression. Day 0 Disruption/Infection Physical/Chemical disruption, followed by PsV 5-6 hours later ***Pseudovirions display a strict tropism for keratinocytes. Short Term Readout Sacrifice mouse; dissect out genital tissues. Analyze for RFP expression. Multispectral imaging Microscopy Roberts et al, Nat. Med. 13:857-61, 2007

19 HPV16 Binds the Basement Membrane HPV-16 Laminin-5 Mouse vaginal tract: 2 hours after exposure to HPV16 (8 hours after exposure to nonoxynol-9) Kines, Thompson, Lowy, Schiller and Day, PNAS 106: , 2009

20 Mechanisms of HPV infection and Vaccine-induced protection Question: How does systemic immunization with a sub-unit vaccine prevent a local mucosal or local skin infection? A two-part answer: (1) Local wounding and virion binding to the basement membrane are required for HPV infection (2) Infection is prevented by exudation of systemic protective antibodies at these potential sites of infection

21 VLP Vaccination Induces High Titer Antibodies that Prevent Basement Membrane Binding Virion No Infection Stratified squamous epithelium Basement membrane Virion STOP Dermis Day et al, Cell Host Microbe 8: , 2010

22 High Efficacy of VLP Vaccine The repetitive structure of the VLP immunogen is intrinsically immunogenic HPV is highly susceptible to neutralizing antibodies Tissue-associated neutralizing antibodies are exudated at potential sites of infection

23 Possible Relevance to HSV Vaccine Development It is possible to develop an effective vaccine against the local muco-cutaneous sexually transmitted infection caused by HPV The preclinical models correctly predicted the characteristics of the vaccine in people Antigens present at high density on VLPs can be more immunogenic than antigen monomers Knowing how to infect the female genital tract with HPV could lead to mucosal genetic immunization via that route

24 Intravaginal Vaccination: Background The female genital tract is generally considered a poor site for inducing immune responses Little evidence for effective Intravaginal (Ivag) vaccination with anything other than replication-competent viral vectors, which may spread beyond the genital tract Attempts to generate genital tract immunity have centered on vaccination of other mucosal sites, e.g upper respiratory tract

25 Experimental Question: Can transient expression of antigen by wounded cervicovaginal keratinocytes induce a robust and durable immune response in the female genital tract? Nicolas Cuburu

26 Mouse Model for Examining CD8 + T cell Responses to HPV PsV Ivag Immunization => Non-replicating HPV pseudovirions are a potential vector for genetic vaccination in the female reproductive tract. Graham et al. Mucosal Immunol 2009 => BALB/c H-2 d For intravaginal (ivag.) heterologous prime/boost: HPV16/45 -Luciferase or HPV16/45 -MM2* (respiratory syncytial virus M2 protein) For intramuscular (i.m.) immunization: Adenoviral type 5 -MM2* (non-replicating) HPV16 Week 2 post-prime HPV45 Week 2 to 14 post-boost Weeks 0 4 CD8 + T cell response CD8 + T cell response * Immunodominant M2 (82-90) -specific Tetramer available for monitoring response

27 Conclusions The female genital tract can be a potent inductive site for functional intra-epithelial CD8 + T cells when the antigen is expressed transiently in wounded keratinocytes Local induction of intra-epithelial CD8 + T cells may be more effective that recruiting systemic T cells to the site of infection. Possible future applications: Vaccination against STI s such as HSV