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Problems and prospects of development of
the subunit TB vaccine
Vladimir G. [email protected]
Gamaleya Research InsituteRussian Ministry of Health
TB may be one of the most common HIV-related opportunistic infections.
More than 30% of HIV-infected people die from tuberculosis
54% of HIV-infected people suffering from tuberculosis
Globally, TB is the 2nd leading cause of death from an infectious disease (behind HIV)TB is the leading cause of death in HIV globallyActive TB may accelerate HIV replicationHIV Infection is a Risk Factor for Activation of Latent Tuberculosis
HIV Infection as a Risk Factor for Activation of Latent TuberculosisCarlos Franco-Paredes, MD // medscape
BCG is the only licensed vaccine against tuberculosis
The bacille Calmette–Guérin (BCG) vaccine has existed for 80 years and is one of the most widely used of all current vaccines.
Protective effect against meningitis and disseminated TB in
children
It does not prevent primary infection and, more importantly,
Does not prevent reactivation of latent pulmonary infection,
the principal source of bacillary spread in the community.
BCG vaccination can not be used for HIV-infected patients. The impact of BCG vaccination on transmission of Mtb is therefore limited.
We need a new vaccine!
What kind of vaccine against TB we need?
ESAT6-CFP10 complex
•Antigens lacking in BCG but present in virulent strains –shift and broaden immune repertoire.
Ag85A
•Antigens present in BCG: prime-boost strategy.
•Both, in the form of either fused or mixed components. Looks advantageous.
•Antigens actively secreted by the infect during infection –vaccination against active disease.•Antigens expressed by dormant mycobacteria –vaccination against latent disease.
Provide a depot for slow, effective immunization.Trigger receptors of innate immunity requisite for the development of acquired, clonally shaped immune responses.In some instances may serve as a tool for intracellular antigen delivery.Very few are certified for human use.
Adjuvants – not less important than antigens
http://www.invivogen.com/review-vaccine-adjuvants
TB vaccine candidates. Clinical trials
ESAT-6-CFP-10
Ag85A
20 нм 20
нм
Декстран-связывающийдомен
Декстран 500
CpG олигонуклеотид
20 нм
M.tb антигены
DEAE-Декстран 500
Antigens Ag85A & ESAT6-CFP10Immunodominant tuberculosis antigens, it’s strong stimulate Th1 immune response
Dextrannon-toxic, biodegradable. The dextran is interact with innate immunity receptors and stimulate Th1 response. It’s creates a depot effect for antigens
DEAE-DextranImmobilize and protect CpG ODN
CpG ODNMolecular adjuvant, stimulate Th1
immune response by interact with TLR9 (stimulate secretion INFγ, TNFα)
Booster vaccine «GamTBvac»
Structural scheme of subunit protein-based vaccine against TB
INDEFINITE
Drug Discovery
Preclinical Clinical Trials FDA Review
Scale-Up to Mfg.
Post-MarketingSurveillance
ONE FDA-APPROVED
DRUG
0.5 – 2 YEARS6 – 7 YEARS3 – 6 YEARS
NUMBER OF VOLUNTEERS
PHASE 1
PHASE 2
PHASE 3
5250~ 5,000 – 10,000
COMPOUNDS
PR
E-D
ISC
OV
ER
Y
20–100
100–500 1,000–5,000
IND
SU
BM
ITTED
ND
A S
UB
MIT
TED
Sources: Drug Discovery and Development: Understanding the R&D Process, www.innovation.org
now, we are here
The Drug Discovery Process
Lymphocyte proliferation assay & The IFN-gamma ELISPOT assay
Ag85A & ESAT6-CFP10 induce antigen-specific T cell responseDextran binding domain is immunologically inertAdjuvant is not induce non-specific T cell response
Ag85A & ESAT6-CFP10 induce antigen-specific T cell responseDextran binding domain is immunologically inertAdjuvant is not induce non-specific T cell response
LPA result
ELISPOT result ELISPOT result
CFU numbers in the lungs and spleens of infected mice
log
10K
OE
(m
ean±
s.e.m
.)
CFU counts are expressed as log10 (mean±s.e.m.) 30 days post-infection in lungs or spleens. Data shown are representative of 12 mice for each group in a total of three independent experiments. Statistical differences between strains in the same phase of infection are indicated in the graphic. *P<0.05 versus day 30-infected C57BL/6;
C57Bl6 mice
Retro-orbital injection of H37Rv (8.3х106)
Antibodies recognizing mycobacterial antigens were produced in mice
The protective role of antibody responses during Mycobacterium tuberculosis infection are not understood fully
CFP10
1
10
100
1000
10000
100000
BCG Аг 85А ESAT-6 CFP-10
Группы иммунизированных мышей
Рец
ип
рокн
ые
знач
ени
я ти
тров
ан
тите
л
BCG BCG+2 вакцинации ГИ 2 вакцинации ГИ адъювант контроль
Log10
Ab
Ag85A ESAT6
GamTBvac
GamTBvac Adjuvant PBS
Clin Exp Immunol. 2009 Aug;157(2):235-43. The protective role of antibody responses during Mycobacterium tuberculosis infection.Abebe F, Bjune G.
Protective efficacy of GamTBvac and its components
C57Bl6 mice
Retro-orbital injection of H37Rv (8.3х106)%
su
rviv
al
Days post-challenge
GamTBvac
AdjuvantControl,PBS
Ag85A+Adjuvant
ESAT6-CFP10+Adjuvant
GamTBvac
Control, PBS
%
surv
ival
Days post-challenge
C57Bl6 mice
Aerosol challenge of H37Rv (5х107)
Protective efficacy of GamTBvac and its components. Prime-boost immunization
% s
urvi
val
Days post-challenge
BCG+AG85ABCG+GamTBvacBCG+ESAT6-CFP10BCGControl, PBS
C57Bl6 mice
Aerosol challenge of H37Rv (5х105)
Heterological prime-boost vaccination is better!
Lung Spleen
GamTBvacGamTBvac Control, PBS
log
10K
OE
(m
ean±
s.e.m
.)
Aerosol challenge of H37Rv (1,25х104)
Pathomorphological characteristics of lungs and spleen after challenge
CFU numbers in the lungs and spleens
ImmunizationOrgans
Lung SpleenBCG-1 ++++ ++++
BCG-1+ 2xGamTBvac ++++ ++++
2xGamTBvac+++-
small site of necrosis
++±±enlarged spleen
Adjuvant ++++ ++++
Control, PBS
Necrosis, hyperemia, enlarged
- ± ± ±enlarged spleen
The guinea pig model of tuberculosis
Safety of the candidate vaccine «GamTBvac»
Local toleranceGenotoxicity and carcinogenicity studiesSafety pharmacologyPharmacokinetic studiesAcute toxicityChronic toxicity
Our animals model:
BALBc mice
guinea pigs
Rabbits
We was investigated:
and had good results:
Candidate vaccine «GamTBvac»Adjuvant and it’s componentsRecombinant proteins (antigens)
GamTBvac is safety!
The next generation of protein-based subunit vaccines against tuberculosis of Gamaleya Research Institute
Development of new adjuvant
Since 1925
2014
Thank you for your attention!
Artem P. Tkachuk, Ph.D.Gamaleya Research Institute,E-mail: [email protected].+7(499)193-30-01
Laboratory bioactive nanostructuresIn collaboration:
Central Institute of Tuberculosis
Research Center for Microbiology and Biotechnology
Biological testing laboratory, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry