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Anti-Chlamydia Vaccine:From Bench to Bedside

Ashlesh Murthy, M.B.B.S., Ph.DResearch Assistant Professor

University of Texas at San Antonio

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Chlamydia

Obligate intracellular pathogen

C. trachomatis, C. pneumoniae, C. psittaci, C. pecorum, C. muridarum

C. trachomatis multiple serovars: A-K, L1-3

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Chlamydia trachomatis Infections

Trachoma and Inclusion Conjunctivitis

Serovars - A, B, Ba, C

LymphoGranuloma Venereum

Serovars - L1, L2, L3

Urogenital InfectionsSerovars - D, Da, E, F, G, Ga, H, I,

J, K

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Global Prevalence of Chlamydial STD

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Chlamydial STD

Adapted from

http://www.cdc.gov/std/stats/tables/table1.htm

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

0. 40

0. 60

0. 80

1. 00

1. 20

(Million

s)

New Cases Of Chlamydia Reported Per Year In USA

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Chlamydial STD-Ascending Infection

Eskilsden and Gupta et al., In Revision

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Vaginitis

Cervicitis

Endometritis

Salpingitis

Chlamydial STD-Ascending Infection

PID

No Symptoms

Antimicrobials

Dye alone

Dye+Chlamydia

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NormalPelvic Inflammatory Disease

Ectopic pregnancy

Infertility

Chlamydial STD-Reproductive Damage

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90 million cases

50-70% of patients initially asymptomatic: not treated

40% of untreated females – pelvic inflammatory disease

20% of PID cases- infertility

Adapted from www.cdc.gov- 2006 STD statistics

Chlamydial STD- Statistics

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Anti-Chlamydial Vaccine

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Goals for Chlamydial Vaccine

Infection

Symptoms (25%)

No Symptoms (75%)

Transmission

Sequelae

Prevent infection (Sterilizing immunity)- ideal

Reduce transmission / Duration of shedding- practical

Prevent pathological sequelae

Protection against multiple serovars

Re-Infection

Immunity

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Chlamydial Vaccine Trials of 1960s

Formalin-killed whole chlamydial organisms

Reduction in incidence for ~ 1 year

Comparable/exaggerated ocular pathology in vaccinees

Focus on sub-unit vaccines

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Chlamydial Developmental Cycle

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Vaccines Against Chlamydial STD

Major outer membrane protein (MOMP) Chlamydia-purified MOMP Recombinant MOMP MOMP DNA MOMP synthetic peptides MOMP plus outer membrane protein 2 (omp2) Chlamydia-purified MOMP refolded to native configuration

Cons: MOMP - serovar-specific

Currently no licensed vaccine against C. trachomatis

Need for identification of new vaccine candidates

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Chlamydial Developmental Cycle

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Chlamydial Protease-Like Activity Factor (CPAF)

Nucleus

Inclusion

CPAF

Overlay

Secreted into host cytosol

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CPAF-Human Antibody Responses

Sharma et al., Infect Immun. 2006

0

1

2

N ega tive Pos itive

C hlamydia Infec tion H is tory

A nti-C PAF IgG

Ab

sorb

an

ce

(6

30

nm

)

CPAF

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CPAF-Highly Conserved

Dong et al., Infect Immun. 2005

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CPAF- A Potential Vaccine Candidate

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Mouse Model of Chlamydial Infection

Days after challenge0 30 80

Vag

inal

chl

amyd

ial s

hedd

ing

Oviduct dilatation

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C. muridarum

Day –1: IL-12 (0.5 mg)

Day 0:rCPAF(15mg)+ IL-12 (0.5 mg)

Day +1: IL-12 (0.5 mg)

Day 28: rCPAF (15 mg)+ IL-12 (0.5 mg)

Day 14: rCPAF (15 mg)+IL-12 (0.5 mg)

Day 60: 5X104 IFU C. muridarum

Estimation of bacterial shedding

Examination of disease pathology

Intranasal

Vaginal challenge

Protocol For Vaccination Studies

Recombinant CPAF from C. trachomatis L2cloned into E. coli

30 day Rest

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Early Responses to Immunization

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CPAF Vaccine : Robust IFN-g Response

Murthy et al., Infect Immun. 2007

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CPAF Vaccine: Systemic Antibodies

Murthy et al., Infect Immun. 2007

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CPAF Vaccine: Mucosal Antibodies

Murthy et al., Infect Immun. 2007

CPAF Vaccine: Chlamydial Clearance

Murthy et al., Infect Immun. 2007

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CPAF+IL-12: Prevents Hydrosalpinx

Murthy et al., Infect Immun. 2007

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CPAF Vaccine: Preserves Fertility

Murthy et al., In Review, 2010

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Role of Human HLA-DR

Murthy et al., Infect Immun. 2006

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Minimal Role for Antibody

Murthy et al., FEMS Immunol. Med. Microbiol. 2009

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Role of CD4+ T-cells

CD4+ T cell adoptive transfer

Murphey et al., Cell. Immunol. 2006

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Role of IFN-g

Murthy et al., J. Immunol. 2008

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Summary

CPAF vaccine administered with Th1 adjuvant:

Enhances clearance of infection Protects against severe pathology Induces robust cellular IFN-g response Induces systemic and mucosal antibody

Protection is dependent upon CPAF-specific cellular IFN- g responses but not antibody

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Ongoing Collaborative Effort

US Patent Application No. 12/243,769: Inventors- Arulanandam, Murthy, Zhong

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Bench to Bedside

Anti-Chlamydia vaccine

Vaccine antigen discovery

Identification of pathogenic

mechanisms

Validation of protection and pathogenesis

correlates in clinical samples

Routes, Delivery systems

Non-Human Primates

Clinical Trials

Adjuvants, Formulations

Bernard Arulanandam, Ph.D., M.B.A.

Weidang Li, M.D., Ph.D.

Bharat Chaganty, MS

Sangamithra Kamalakaran, B.Tech

Kishan Evani, MS

Rishein Gupta, Ph.D.

Yu Cong, M.D.

Madhulika Jupelli, Ph.D.

Cathi Murphey, M.S.

Acknowledgements

Guangming Zhong, M.D., Ph.D., UTHSCSA

M. Neal Guentzel, Ph.D., STCEID, UTSA

Aruna Mittal, Ph.D, IOP, India

1R03AI088342

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