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2. May 23-26, 2012 in Bucharest, Romania
“TB and M/XDR-TB: from clinical management to control and elimination”
ERS School
TB disease and infection:
Do we have real news?
Martina Sester
Department of Transplant and Infection Immunology
Saarland University; Germany

3. Overview – Facts and news…*
• Worldwide epidemiology of tuberculosis
• M. tuberculosis infection: continuum from
latency to active disease
– Implications for diagnosis of M. tuberculosis
infection
• Host-pathogen interactions
– Role of innate immunity
• The vaccine pipeline
*an immunologist´s view on 2011´s news…

4. Tuberculosis – the facts
• 7. position of leading causes of deaths
• 1/3 of the world's population could be
infected
• > 80% can be cured
• prevention can be > 90% effective
Global tuberculosis control: WHO report 2011

5. Tuberculosis – the facts
• 1.45 million people died in 2010 due to TB
• equally to 3800 deaths per day
• 8.8 million new cases of TB in 2010
• Global incidence rate of 128/100 000
• Most cases occurred in
– Asia (59%) and
– Africa (26%)
WHO report 2011

6. Estimated TB incidence rates 2010
WHO report 2011

7. The global burden of TB in 2010
in relation to HIV co-infection
Estimated
number of cases
Estimated number
of deaths
All forms of TB 8.8 Mio
(8.5–9.2 Mio)
1.45 Mio
(1.2–1.5 Mio)
HIV-associated
TB
1.1 Mio (13%)*
(1.0–1.3 Mio)
0.35 Mio
(0.32–0.39 Mio)
WHO report 2011
*82% of TB cases among people living
with HIV originate from the African region

8. Estimated HIV prevalence
in new TB cases 2010
WHO report 2011

9. Trends in TB incidence rates
Lawn and Zumla (2011) Lancet 378: 57

10. Overview – Facts and news…
• Worldwide epidemiology of tuberculosis
• M. tuberculosis infection: continuum from
latency to active disease
– Implications for diagnosis of M. tuberculosis
infection
• Host-pathogen interactions
– Role of innate immunity
• The vaccine pipeline

11. TB disease and infection - definitions
TB disease
• Detection of M. tuberculosis and/or clinical
symptoms compatible with tuberculosis
Latent infection with M. tuberculosis (LTBI)
• Presence of an immune response in a skin
test or an IFN-γ release assay (IGRA)
• Absence of clinical symptoms

12. LTBI
M. tuberculosis
exposure
infection
Recent contacts
High TB prevalence
Old healed TB
Years after contact
Low TB prevalence
Successful TB/LTBI treatment
Protective immunity
Latency
90%
Never TB
Natural course of
M. tuberculosis infection
Latency
5% 2-5%
Progression
1%
TB disease
Bacterium extinguished?
Live bacilli?
Immunosuppression
Immunosuppression
Chemoprophylaxis efficient
Chemoprophylaxis not necessary
Latency
5% 2-5%
Latency
5% 2-5%

13. Prevalence of latent infection with
M. tuberculosis and risk for progression
Horsburg and Rubin (2011) N Engl J Med 364:1441

14. APC
T cell
antigens/
peptides
cytokine
induction
cytokine
induction
activation/
cytokine
induction
cytokine
induction
ELISA ELISPOT assay Flow-cytometry
cytokine
activationmarker
Skin test
Immunodiagnosis of
latent M. tuberculosis infection
T.SPOT.TBQuantiFERON TB gold
IGRA
IFN-γ release assayPPD
ESAT-6/CFP-10/TB7.7
Negative controls
Positive controls, i.e. mitogens
PHA/SEB

15. Test PPV NPV
TST 2.3-3.3 99.7
QFT-G-IT 2.8-14.3 99.8
T-SPOT.TB 3.3-10.0 97.8
Diel et al. (2011) Eur Respir J 37: 88
PPV and NPV of immune-based assays
for the development of tuberculosis

16. Test Sensitivity Specificity
TST 0.65 0.75
QFT-G-IT
blood 0.80 0.79
extrasang. 0.48 0.82
T-SPOT.TB
blood 0.81 0.59
extrasang. 0.88 0.82
Sester, Sotgiu et al. Eur Respir J (2011), 37: 100
Sensitivity and specificity of immune-
based assays to diagnose active TB
summary of pooled values

17. New experimental tests
LTBI
• Antigen different from the commercial RD1
peptides
• Markers different from IFN-γ
• Readouts different from ELISA or ELISPOT
• Biological sample different from blood
More details in the following talk:
IGRA testing to diagnose TB disease and infection.
What is new in clinical practice and for programmatic management? - D. Goletti, M Sester

18. Diagnosis of active tuberculosis
• Patient history
• Chest X-ray
• Culture
• Acid-fast bacilli staining
• Nucleic acid amplification testing

19. New experimental tests
active tuberculosis
• Assays for childhood tuberculosis
• Assays for smear negative tuberculosis
• Faster assays
• Improved NAAT tests (i.e. Xpert MTB/RIF
assay)
More details in the following talk:
The new horizons of molecular diagnosis:
do we still need conventional microbiology? - D. Cirillo

20. Overview – Facts and news…
• Worldwide epidemiology of tuberculosis
• M. tuberculosis infection: continuum from
latency to active disease
– Implications for diagnosis of M. tuberculosis
infection
• Host-pathogen interactions
– Role of innate immunity
• The vaccine pipeline

21. Pathogenesis and
immune effector mechanisms
Kaufmann (2010) Immunity 33: 567

22. Pathogenesis and
immune effector mechanisms
Kaufmann (2010) Immunity 33: 567
Apoptosis/necrosis of
Macrophages affects
bacterial growth and T-
cell priming Immuno-
pathogenesis
of IRIS
Macrophage activation
Interplay IFN-γ/VitD signaling

23. Role of innate immunity
• Controlling early pathogen growth
• Instructing adaptive immunity
infection time
M.tuberculosisload
normal immunity
without innate immunity
without adaptive immunity

24. Role of innate immunity
• Controlling early pathogen growth
• Instructing adaptive immunity
Fremond et al. (2004) J Clin Invest 114: 1790; Feng et al. (2005) J Immunol 174: 4185

25. Apoptosis versus necrosis
• Apoptotic macrophages decrease bacterial
load and accelerate T-cell priming
• Necrotic macrophages increase bacterial load
and slow down T-cell priming
Divangahi et al. (2010) Nat Immunol 11: 751; Divangahi et al. (2009) Nat Immunol 10: 899

26. Apoptosis versus necrosis
• Apoptotic macrophages decrease bacterial
load and accelerate T-cell priming
• Necrotic macrophages increase bacterial load
and slow down T-cell priming
Divangahi et al. (2010) Nat Immunol 11: 751; Divangahi et al. (2009) Nat Immunol 10: 899

27. Suppression of apoptosis as innate
defence mechanism of virulent strains
Divangahi et al. (2010) Nat Immunol 11: 751; Divangahi et al. (2009) Nat Immunol 10: 899; Behar et al. (2010) Nat Rev Microbiol 8: 668
Increased bacterial load
Delay in T-cell priming
Decreased bacterial load
Accelerated T-cell priming
Interference with
plasma membrane
repair

28. Pathogenesis and
immune effector mechanisms
Kaufmann (2010) Immunity 33: 567
Macrophage activation
Interplay IFN-γ/VitD signaling

29. Vitamin D deficiency
and susceptibility to tuberculosis
Vitamin D3 at start of antimicrobial treatment,
and after 14, 28, and 42 days
Martineau et al. (2011) Lancet 377: 242

30. Vitamin D deficiency
and susceptibility to tuberculosis
Vitamin D3 at start of antimicrobial treatment,
and after 14, 28, and 42 days
Median time to culture conversion
• 36·0 days in the intervention group and
• 43·5 days in the placebo group
Adjusted hazard ratio 1·39, 95% CI 0·90–2·16; p=0.14.
Martineau et al. (2011) Lancet 377: 242

31. Vitamin D deficiency
and susceptibility to tuberculosis
Median time to sputum culture conversion
• 36·0 days - intervention group
• 43·5 days - placebo group
Adjusted hazard ratio 1·39, 95% CI 0·90–2·16; p=0.14.
Martineau et al. (2011) Lancet 377: 242
Effect of TaqI genotype
Enhanced response with
tt genotype (8.09, 95% CI 1.36–48.01; p=0.02)
Tt genotype (0.85, 95% CI 0.45–1.63; p=0.63)
TT genotype (1.13, 95% CI 0.60–2.10; p=0.71)

32. Active TB is associated with
vitamin D deficiency
Martineau et al. (2011) Proc Natl Acad Sci U S A 108: 19013
Effect of vitamin D deficiency is
more pronounced in HIV infected
patients
Patients from Cape Town

33. Seasonal variation in vitamin D status
and tuberculosis notifications
Martineau et al. (2011) Proc Natl Acad Sci U S A 108: 19013

34. Antimicrobial effect of
vitamin D and T-cell derived IFN-γ
Fabri et al. (2011) Sci Transl Med 3: 104ra102

35. Antimicrobial effect of
vitamin D and T-cell derived IFN-γ
Fabri et al. (2011) Sci Transl Med 3: 104ra102
Induction of autophagy

36. Antimicrobial effect of
vitamin D and T-cell derived IFN-γ
Fabri et al. (2011) Sci Transl Med 3: 104ra102
Induction of antimicrobial peptides

37. Mechanistic link - vitamin D deficiency
and HIV-induced immunodeficiency
Fabri et al. (2011) Sci Transl Med 3: 104ra102
Antimicrobial effect via induction of antimicrobial peptides and autophagy
Martineau et al. (2011) Proc Natl Acad Sci U S A 108: 19013

38. Pathogenesis and
immune effector mechanisms
Kaufmann (2010) Immunity 33: 567
Immuno-
pathogenesis
of IRIS

39. HIV-associated IRIS
Immune reconstitution inflammatory syndrome
• May occur in up to 30% of HIV infected patients
after start of ART
• Tissue destructive inflammation
• Microbial co-infections as risk factor
• Recovering CD4 T cells as immediate effectors?
• Pathological T cell responses?

40. Mouse model for
lymphopenia-induced IRIS
Barber et al. (2012) Nat Rev Microbiol 10: 150
IRIS develops in context of
• Chronic microbial infection
• CD4 T cell deficiency

41. Model for IRIS involving a dysregulated
innate immune response
Barber et al. (2012) Nat Rev Microbiol 10: 150

42. Overview – Facts and news…
• Worldwide epidemiology of tuberculosis
• Infection cycle
• M. tuberculosis infection: continuum from latency
to active disease
– Implications for diagnosis of M. tuberculosis infection
• Host-pathogen interactions
– Role of innate immunity
• The vaccine pipeline

43. Characteristics of successful vaccines
Rappuoli & Aderem (2011) Nature 473: 463
CMV

44. BCG vaccine
• Developed 1921
• 120 Mio doses administered/year
• Provides 80% protection against severe and
disseminated disease in children
∀≈50% risk reduction in adults (0-80% efficacy)
– Genetic divergence
– Differences in T-cell
response

45. Vaccine candidates
• Subunit and live viral vectors
– Antigens: ESAT-6, TB10.4, Ag85A, Ag85B, Mtb32
and 39 and fusions thereof
– Adjuvants: IC31, AS01, AS02, CAF01
– Live viral vectors: Adenovirus, Vaccinia
• Live attenuated or killed bacteria
– rBCG
– M. tuberculosis
– M. vaccae

46. Adjuvants used for fusion proteins
Kaufmann (2011) Lancet Infect Dis 11: 633
• Serve to improve immunogenicity
• i.e. ligands for pattern recognition receptors

47. Vaccines – where they should act
• Pre-exposure vaccination
• Post-exposure vaccination
• Therapeutic vaccination
Kaufmann (2011) Lancet Infect Dis 11: 633

48. Therapeutic vaccine candidates

49. Pre-/post-exposure vaccines

50. Most advanced vaccine candidates
Kaufmann (2011) Lancet Infect Dis 11: 633
12 candidates have reached clinical trials
Animal models: Prevention of tuberculosis, no eradication of M. tuberculosis
(to replace BCG)
(after BCG)

51. Most advanced vaccine candidates
Kaufmann (2011) Lancet Infect Dis 11: 633
12 candidates have reached clinical trials
Animal models: Prevention of tuberculosis, no eradication of M. tuberculosis
(to replace BCG)
(after BCG)

52. Most advanced vaccine candidates
Kaufmann (2011) Lancet Infect Dis 11: 633
12 candidates have reached clinical trials
Animal models: Prevention of tuberculosis, no eradication of M. tuberculosis
(to replace BCG)
(after BCG)

53. Most advanced vaccine candidates
Kaufmann (2011) Lancet Infect Dis 11: 633
12 candidates have reached clinical trials
Animal models: Prevention of tuberculosis, no eradication of M. tuberculosis
(to replace BCG)
(after BCG)

54. Post-exposure vaccines

55. Effective vaccine for
pre- and post-exposure
H56 vaccine
• Early antigen Ag85B
• Early antigen ESAT-6
• Latency antigen Rv2660c
– expressed during starvation
Vaccination of mice
Aagaard et al. (2011) Nat Med 17: 189

56. Effective vaccine for
pre- and post-exposure
H56 vaccine
• Pre-exposure
Aagaard et al. (2011) Nat Med 17: 189
6 weeks after challenge 24 weeks after challenge
• T cells induced are
polyfunctional

57. Effective vaccine for
pre- and post-exposure
H56 vaccine
• Post-exposure
Aagaard et al. (2011) Nat Med 17: 189
35 weeks p.i.
blood
35 weeks p.i.
spleen

58. Effective vaccine for
pre- and post-exposure
H56 vaccine
• Post-exposure
Aagaard et al. (2011) Nat Med 17: 189
35 weeks p.i.
blood
35 weeks p.i.
spleen
2 vaccinations
3 vaccinations
2 vaccinations
2 vaccinations
2 vaccinations
2 vaccinations
Analysis between 23 and 43 weeks p.i.

59. Future candidates?
• Up to now, no vaccine candidate has
achieved sterilising immunity

60. Conclusions
• Understanding the continuum from latency to
active disease will lead to improved diagnosis of
patients at risk and targeted therapy
• Knowledge of the role of innate immunity will lead
to improved understanding of host-pathogen
interactions
• Rationale vaccine design has achieved success, but
clinical studies are still proceeding at slow pace