A human challenge model for Mycobacterium tuberculosis using Mycobacterium bovis bacille Calmette-Guerin

Angela M Minassian, Iman Satti, Ian D Poulton, Joel Meyer, Adrian V S Hill, Helen McShane, Angela M Minassian, Iman Satti, Ian D Poulton, Joel Meyer, Adrian V S Hill, Helen McShane

Abstract

Background: There is currently no safe human challenge model of Mycobacterium tuberculosis infection to enable proof-of-concept efficacy evaluation of candidate vaccines against tuberculosis. In vivo antimycobacterial immunity could be assessed using intradermal Mycobacterium bovis bacille Calmette-Guérin (BCG) vaccination as a surrogate for M. tuberculosis infection.

Methods: Healthy BCG-naive and BCG-vaccinated volunteers were challenged with intradermal BCG. BCG load was quantified from skin biopsy specimens by polymerase chain reaction (PCR) and culture colony-forming units. Cellular infiltrate was isolated by suction blisters and examined by flow cytometry. Prechallenge immune readouts were correlated with BCG load after challenge.

Results: In BCG-naive volunteers, live BCG was detected at the challenge site for up to 4 weeks and peaked at 2 weeks. Infiltration of mainly CD15(+) neutrophils was observed in blister fluid. In previously BCG-vaccinated individuals, PCR analysis of skin biopsy specimens reflected a degree of mycobacterial immunity. There was no significant correlation between BCG load after challenge and mycobacterial-specific memory T cells measured before challenge by cultured enzyme-linked immunospot assay.

Conclusions: This novel experimental human challenge model provides a platform for the identification of correlates of antimycobacterial immunity and will greatly facilitate the rational down-selection of candidate tuberculosis vaccines. Further evaluation of this model with BCG and new vaccine candidates is warranted.

Figures

Figure 1.
Figure 1.
Quantification of bacille Calmette-Guérin (BCG) in skin biopsy specimens from BCG challenge sites. A, Appearance of skin 2 weeks after biopsy. B, Estimated number of BCG copies (log10) per biopsy specimen (taken at 1, 2, or 4 weeks after challenge) by quantitative polymerase chain reaction (PCR) (corrected for nanograms of DNA extracted). C, Colony-forming unit (CFU) counts after 3–4 weeks of incubation on 7H11 Middlebrook agar. Bars represent median per group. D, Correlation between CFU counts measured by culture and PCR 1, 2, and 4 weeks after challenge (Spearman rank, week 1, R = −0.22, P = .6 [left]; week 2, R = 0.77, P = .004 [middle]; week 4, R = 0.75, P = .03 [right]). E, Appearance of blister at 1 week after challenge. F, Application of CD45 marker to blister cells, compared with side scatter (SSC).
Figure 2.
Figure 2.
Variability in postchallenge colony-forming unit (CFU) counts in bacille Calmette-Guérin (BCG)–vaccinated humans. A, Comparison between culture and polymerase chain reaction (PCR) challenge results in BCG-vaccinated volunteers, log scale. B, Correlation between culture (CFU count) and PCR (Spearman rank). Comparison of PCR and culture challenge results in naive (NAIVE–BCG) and BCG-vaccinated (BCG1–BCG2) volunteers. C, PCR values (BCG copies [log10] per biopsy specimen, corrected for nanograms of DNA extracted) in BCG-naive and BCG-vaccinated groups. D, Corresponding culture values (log10 BCG CFU count per biopsy specimen). Exact P values are shown.
Figure 3.
Figure 3.
Prechallenge cultured enzyme-linked immunospot (ELISPOT) responses in bacille Calmette-Guérin (BCG)–vaccinated volunteers. Graphs show the responses per million original cultured cells, measured at day 0 (total culture period, 13 days). Combined cultured interferon γ T-cell responses to TB10.3 and 85A peptide pools are shown for each volunteer. Volunteers in order of increasing challenge colony-forming unit (CFU) count are shown along the x-axis, labeled by exact counts per biopsy specimen. Prechallenge responses are shown for BCG-vaccinated volunteers (n = 12) (A) and BCG-naive volunteers (n = 4, B); there were only enough frozen peripheral blood mononuclear cells for 4 of the naive volunteers to allow processing of cultured ELISPOT assays. C, Correlation between magnitude of memory T-cell response and bacterial load of challenge (BCG CFU count per biopsy specimen; R = −0.4, P = .2). D, Time since prior BCG vaccination versus magnitude of prechallenge cultured ELISPOT responses.

References

    1. Minassian AM, McShane H. Tuberculosis vaccines: present and future. Expert Rev Respir Med. 2008;2:721–38.
    1. Carrat F, Vergu E, Ferguson NM, et al. Time lines of infection and disease in human influenza: a review of volunteer challenge studies. Am J Epidemiol. 2008;167:775–85.
    1. Marwick C. Volunteers in typhoid infection study will aid future vaccine development. JAMA. 1998;279:1423–4.
    1. Statler J, Mammen M, Lyons A, Sun W. Sonographic findings of healthy volunteers infected with dengue virus. J Clin Ultrasound. 2008;36:413–17.
    1. Sauerwein RW, Roestenberg M, Moorthy VS. Experimental human challenge infections can accelerate clinical malaria vaccine development. Nat Rev Immunol. 2011;11:57–64.
    1. Chen L, Wang J, Zganiacz A, Xing Z. Single intranasal mucosal Mycobacterium bovis BCG vaccination confers improved protection compared to subcutaneous vaccination against pulmonary tuberculosis. Infect Immun. 2004;72:238–46.
    1. Lagranderie MR, Balazuc AM, Deriaud E, Leclerc CD, Gheorghiu M. Comparison of immune responses of mice immunized with five different Mycobacterium bovis BCG vaccine strains. Infect Immun. 1996;64:1–9.
    1. Dobakhti F, Naghibi T, Taghikhani M, et al. Adjuvanticity effect of sodium alginate on subcutaneously injected BCG in BALB/c mice. Microbes Infect. 2009;11:296–301.
    1. Garnier T, Eiglmeier K, Camus JC, et al. The complete genome sequence of Mycobacterium bovis. Proc Natl Acad Sci U S A. 2003;100:7877–82.
    1. Minassian AM, Ronan EO, Poyntz H, Hill AV, McShane H. Preclinical development of an in vivo BCG challenge model for testing candidate TB vaccine efficacy. PLoS One. 2011;6:e19840.
    1. Hoft DF, Leonardi C, Milligan T, et al. Clinical reactogenicity of intradermal bacille Calmette-Guerin vaccination. Clin Infect Dis. 1999;28:785–90.
    1. Colditz GA, Brewer TF, Berkey CS, et al. Efficacy of BCG vaccine in the prevention of tuberculosis. Meta-analysis of the published literature. JAMA. 1994;271:698–702.
    1. Chapman AL, Munkanta M, Wilkinson KA, et al. Rapid detection of active and latent tuberculosis infection in HIV-positive individuals by enumeration of Mycobacterium tuberculosis-specific T cells. AIDS. 2002;16:2285–93.
    1. Reed JR, Vukmanovic-Stejic M, Fletcher JM, et al. Telomere erosion in memory T cells induced by telomerase inhibition at the site of antigenic challenge in vivo. J Exp Med. 2004;199:1433–43.
    1. Todryk SM, Pathan AA, Keating S, et al. The relationship between human effector and memory T cells measured by ex vivo and cultured ELISPOT following recent and distal priming. Immunology. 2009;128:83–91.
    1. Keating SM, Bejon P, Berthoud T, et al. Durable human memory T cells quantifiable by cultured enzyme-linked immunospot assays are induced by heterologous prime boost immunization and correlate with protection against malaria. J Immunol. 2005;175:5675–80.
    1. Mollenkopf HJ, Kursar M, Kaufmann SH. Immune response to postprimary tuberculosis in mice: Mycobacterium tuberculosis and Miycobacterium bovis bacille Calmette-Guerin induce equal protection. J Infect Dis. 2004;190:588–97.
    1. Baldwin SL, D'Souza C, Roberts AD, et al. Evaluation of new vaccines in the mouse and guinea pig model of tuberculosis. Infect Immun. 1998;66:2951–9.
    1. Morel C, Badell E, Abadie V, et al. Mycobacterium bovis BCG-infected neutrophils and dendritic cells cooperate to induce specific T cell responses in humans and mice. Eur J Immunol. 2008;38:437–47.
    1. Sugisaki K, Dannenberg AM, Jr, Abe Y, et al. Nonspecific and immune-specific up-regulation of cytokines in rabbit dermal tuberculous (BCG) lesions. J Leukoc Biol. 1998;63:440–50.
    1. Reece WH, Pinder M, Gothard PK, et al. A CD4+ T-cell immune response to a conserved epitope in the circumsporozoite protein correlates with protection from natural Plasmodium falciparum infection and disease. Nat Med. 2004;10:406–10.
    1. Wherry EJ, Teichgraber V, Becker TC, et al. Lineage relationship and protective immunity of memory CD8 T cell subsets. Nat Immunol. 2003;4:225–34.
    1. Vordermeier HM, Villarreal-Ramos B, Cockle PJ, et al. Viral booster vaccines improve Mycobacterium bovis BCG-induced protection against bovine tuberculosis. Infect Immun. 2009;77:3364–73.
    1. Waters WR, Palmer MV, Nonnecke BJ, et al. Efficacy and immunogenicity of Mycobacterium bovis DeltaRD1 against aerosol M. bovis infection in neonatal calves. Vaccine. 2009;27:1201–9.
    1. Stoute JA, Slaoui M, Heppner DG, et al. A preliminary evaluation of a recombinant circumsporozoite protein vaccine against Plasmodium falciparum malaria. RTS,S Malaria Vaccine Evaluation Group. N Engl J Med. 1997;336:86–91.

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