Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Review Article
  • Published:

A journey into the brain: insight into how bacterial pathogens cross blood–brain barriers

Key Points

  • The blood–central nervous system (CNS) barriers are tight and protect the brain parenchyma from insults, including those of infectious origin. This barrier function is due to the presence of tight junctions between the endothelial cells of the brain. The formation of these junctions is the consequence of interactions inside the neurovascular unit.

  • There are two blood–CNS barriers that can potentially be circumvented by bacterial pathogens: the blood–brain barrier (BBB) and the blood–cerebrospinal fluid barrier (BCSFB). The BCSFB corresponds to the choroid plexuses and the microvessels of the leptomeninges.

  • Bacteria can invade the meninges from the bloodstream through the choroid plexuses or directly through the microvessels of the leptomeninges and/or the brain parenchyma. In the case of crossing from parenchyma vessels, bacteria are drained to the subarachnoid space through the glymphatic pathway.

  • Regardless of the site of crossing, meningeal invasion requires the crossing of two cellular barriers: an endothelial monolayer (in the choroid plexus or in the brain parenchyma and/or leptomeninges) followed by an epithelial monolayer (the choroid plexus ependyma, or the leptomeningeal monolayer of the pia mater or of a subarachnoid trabecula).

  • A limited number of blood-borne bacteria can cross the blood–CNS barriers and cause meningitis. The extracellular pathogens that are involved are usually Neisseria meningitidis, Streptococcus pneumoniae or, in newborns, group B Streptococcus and Escherichia coli K1.

  • Regardless of the mechanisms that are used to invade the meninges from the bloodstream, the level of bacteraemia plays a key part in meningeal tropism.

  • The extracellular bacteria interact directly with the blood–CNS barriers.

  • N. meningitidis is believed to cross the blood–CNS barriers by interacting with the leptomeninges and/or brain microvessels, and to open intercellular junctions following signals that are induced by the adhesion of bacteria to the endothelial cells.

  • S. pneumoniae invades the meninges following interaction with the brain microvessels and is believed to transcytose through the endothelial cells following interactions with several host cell receptors.

  • E. coli is believed to transcytose through endothelial cells, to have several attributes that enable it to adhere to endothelial cells and to induce signalling events that lead to bacterial invasion.

Abstract

The blood–brain barrier, which is one of the tightest barriers in the body, protects the brain from insults, such as infections. Indeed, only a few of the numerous blood-borne bacteria can cross the blood–brain barrier to cause meningitis. In this Review, we focus on invasive extracellular pathogens, such as Neisseria meningitidis, Streptococcus pneumoniae, group B Streptococcus and Escherichia coli, to review the obstacles that bacteria have to overcome in order to invade the meninges from the bloodstream, and the specific skills they have developed to bypass the blood–brain barrier. The medical importance of understanding how these barriers can be circumvented is underlined by the fact that we need to improve drug delivery into the brain.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Overview of the brain meninges.
Figure 2: Intercellular junctions in brain parenchyma capillaries.
Figure 3: Structures of blood–central nervous system barriers.
Figure 4: Adhesion of different bacterial species to human brain endothelial cells.
Figure 5: Mechanism of Neisseria meningitidis–endothelial cell interactions.

Similar content being viewed by others

References

  1. Thigpen, M. C. et al. Bacterial meningitis in the United States, 1998–2007. N. Engl. J. Med. 364, 2016–2025 (2011).

    CAS  PubMed  Google Scholar 

  2. Kim, K. S. Human meningitis-associated Escherichia coli. EcoSal Plus http://dx.doi.org/10.1128/ecosalplus.ESP-0015-2015 (2016).

  3. Maisey, H. C., Doran, K. S. & Nizet, V. Recent advances in understanding the molecular basis of group B Streptococcus virulence. Expert Rev. Mol. Med. 10, e27 (2008).

    PubMed  PubMed Central  Google Scholar 

  4. Tazi, A. et al. The surface protein HvgA mediates group B Streptococcus hypervirulence and meningeal tropism in neonates. J. Exp. Med. 207, 2313–2322 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  5. Segura, M. et al. Latest developments on Streptococcus suis: an emerging zoonotic pathogen: part 1. Future Microbiol. 9, 441–444 (2014).

    CAS  PubMed  Google Scholar 

  6. Be, N. A., Kim, K. S., Bishai, W. R. & Jain, S. K. Pathogenesis of central nervous system tuberculosis. Curr. Mol. Med. 9, 94–99 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  7. Disson, O. & Lecuit, M. Targeting of the central nervous system by Listeria monocytogenes. Virulence 3, 213–221 (2012).

    PubMed  PubMed Central  Google Scholar 

  8. Banks, W. A. From blood–brain barrier to blood–brain interface: new opportunities for CNS drug delivery. Nat. Rev. Drug Discov. 15, 275–292 (2016).

    CAS  PubMed  Google Scholar 

  9. Weller, R. O. Microscopic morphology and histology of the human meninges. Morphologie 89, 22–34 (2005). A manuscript that describes in detail the structures of the meningeal envelope.

    CAS  PubMed  Google Scholar 

  10. Louveau, A., Harris, T. H. & Kipnis, J. Revisiting the mechanisms of CNS immune privilege. Trends Immunol. 36, 569–577 (2015).

    CAS  PubMed  PubMed Central  Google Scholar 

  11. Brochner, C. B., Holst, C. B. & Mollgard, K. Outer brain barriers in rat and human development. Front. Neurosci. 9, 75 (2015).

    PubMed  PubMed Central  Google Scholar 

  12. Alcolado, R., Weller, R. O., Parrish, E. P. & Garrod, D. The cranial arachnoid and pia mater in man: anatomical and ultrastructural observations. Neuropathol. Appl. Neurobiol. 14, 1–17 (1988). A principle work on the histology and organization of the meninges.

    CAS  PubMed  Google Scholar 

  13. Laman, J. D. & Weller, R. O. Drainage of cells and soluble antigen from the CNS to regional lymph nodes. J. Neuroimmune Pharmacol. 8, 840–856 (2013).

    PubMed  PubMed Central  Google Scholar 

  14. Strazielle, N. & Ghersi-Egea, J. F. Choroid plexus in the central nervous system: biology and physiopathology. J. Neuropathol. Exp. Neurol. 59, 561–574 (2000). A detailed explanation of the function and structure of the choroid plexus.

    CAS  PubMed  Google Scholar 

  15. Iliff, J. J. et al. A paravascular pathway facilitates CSF flow through the brain parenchyma and the clearance of interstitial solutes, including amyloid β. Sci. Transl Med. 4, 147ra111 (2012). A report that details the circulation of the liquid in the brain parenchyma and identifies the glymphatic pathway.

    PubMed  PubMed Central  Google Scholar 

  16. Abbott, N. J., Patabendige, A. A., Dolman, D. E., Yusof, S. R. & Begley, D. J. Structure and function of the blood–brain barrier. Neurobiol. Dis. 37, 13–25 (2010). A comprehensive review on the BBB.

    CAS  PubMed  Google Scholar 

  17. Keaney, J. & Campbell, M. The dynamic blood–brain barrier. FEBS J. 282, 4067–4079 (2015).

    CAS  PubMed  Google Scholar 

  18. Alvarez, J. I. et al. The Hedgehog pathway promotes blood-brain barrier integrity and CNS immune quiescence. Science 334, 1727–1731 (2011).

    CAS  PubMed  Google Scholar 

  19. Bell, R. D. et al. Apolipoprotein E controls cerebrovascular integrity via cyclophilin A. Nature 485, 512–516 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  20. Wosik, K. et al. Angiotensin II controls occludin function and is required for blood–brain barrier maintenance: relevance to multiple sclerosis. J. Neurosci. 27, 9032–9042 (2007).

    CAS  PubMed  PubMed Central  Google Scholar 

  21. Daneman, R., Zhou, L., Kebede, A. A. & Barres, B. A. Pericytes are required for blood–brain barrier integrity during embryogenesis. Nature 468, 562–566 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  22. Armulik, A. et al. Pericytes regulate the blood–brain barrier. Nature 468, 557–561 (2010).

    CAS  PubMed  Google Scholar 

  23. Brinker, T., Stopa, E., Morrison, J. & Klinge, P. A new look at cerebrospinal fluid circulation. Fluids Barriers CNS 11, 16 (2014).

    Google Scholar 

  24. Redzic, Z. Molecular biology of the blood–brain and the blood–cerebrospinal fluid barriers: similarities and differences. Fluids Barriers CNS 8, 3 (2011). An investigation that underlines the structural and anatomical differences between the two main barriers that divide the blood and the brain.

    PubMed  PubMed Central  Google Scholar 

  25. Allt, G. & Lawrenson, J. G. Is the pial microvessel a good model for blood–brain barrier studies? Brain Res. Brain Res. Rev. 24, 67–76 (1997).

    CAS  PubMed  Google Scholar 

  26. Rascher, G. & Wolburg, H. The tight junctions of the leptomeningeal blood–cerebrospinal fluid barrier during development. J. Hirnforsch. 38, 525–540 (1997). A paper that proposes that there is a functional barrier in the leptomeningeal vessels.

    CAS  PubMed  Google Scholar 

  27. Dando, S. J. et al. Pathogens penetrating the central nervous system: infection pathways and the cellular and molecular mechanisms of invasion. Clin. Microbiol. Rev. 27, 691–726 (2014).

    PubMed  PubMed Central  Google Scholar 

  28. van Ginkel, F. W. et al. Pneumococcal carriage results in ganglioside-mediated olfactory tissue infection. Proc. Natl Acad. Sci. USA 100, 14363–14367 (2003).

    CAS  PubMed  PubMed Central  Google Scholar 

  29. Smith, A. L. et al. in Haemophilus Influenzae: Epidemiology, Immunology and Prevention of Disease (eds Sell, S. H. & Wright, P. F.) 89–109 (Elsevier Science, 1982).

    Google Scholar 

  30. Virji, M., Kayhty, H., Ferguson, D. J., Alexandrescu, C. & Moxon, E. R. Interactions of Haemophilus influenzae with cultured human endothelial cells. Microb. Pathog. 10, 231–245 (1991).

    CAS  PubMed  Google Scholar 

  31. Virji, M., Kayhty, H., Ferguson, D. J., Alexandrescu, C. & Moxon, E. R. Interactions of Haemophilus influenzae with human endothelial cells in vitro. J. Infect. Dis. 165 (Suppl. 1), S115–S116 (1992).

    PubMed  Google Scholar 

  32. Madsen, L. W., Svensmark, B., Elvestad, K., Aalbaek, B. & Jensen, H. E. Streptococcus suis serotype 2 infection in pigs: new diagnostic and pathogenetic aspects. J. Comp. Pathol. 126, 57–65 (2002).

    CAS  PubMed  Google Scholar 

  33. Sanford, S. E. Gross and histopathological findings in unusual lesions caused by Streptococcus suis in pigs. II. Central nervous system lesions. Can. J. Vet. Res. 51, 486–489 (1987).

    CAS  PubMed  PubMed Central  Google Scholar 

  34. Williams, A. E. & Blakemore, W. F. Pathogenesis of meningitis caused by Streptococcus suis type 2. J. Infect. Dis. 162, 474–481 (1990).

    CAS  PubMed  Google Scholar 

  35. Pron, B. et al. Interaction of Neisseria meningitidis with the components of the blood–brain barrier correlates with an increased expression of PilC. J. Infect. Dis. 176, 1285–1292 (1997).

    CAS  PubMed  Google Scholar 

  36. Mairey, E. et al. Cerebral microcirculation shear stress levels determine Neisseria meningitidis attachment sites along the blood–brain barrier. J. Exp. Med. 203, 1939–1950 (2006).

    CAS  PubMed  PubMed Central  Google Scholar 

  37. Iovino, F., Orihuela, C. J., Moorlag, H. E., Molema, G. & Bijlsma, J. J. Interactions between blood-borne Streptococcus pneumoniae and the blood–brain barrier preceding meningitis. PLoS ONE 8, e68408 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  38. Kim, K. S. et al. The K1 capsule is the critical determinant in the development of Escherichia coli meningitis in the rat. J. Clin. Invest. 90, 897–905 (1992).

    CAS  PubMed  PubMed Central  Google Scholar 

  39. Zelmer, A. et al. Differential expression of the polysialyl capsule during blood-to-brain transit of neuropathogenic Escherichia coli K1. Microbiology 154, 2522–2532 (2008).

    CAS  PubMed  Google Scholar 

  40. Bell, L. M., Alpert, G., Campos, J. M. & Plotkin, S. A. Routine quantitative blood cultures in children with Haemophilus influenzae or Streptococcus pneumoniae bacteremia. Pediatrics 76, 901–904 (1985).

    CAS  PubMed  Google Scholar 

  41. Dietzman, D. E., Fischer, G. W. & Schoenknecht, F. D. Neonatal Escherichia coli septicemia — bacterial counts in blood. J. Pediatr. 85, 128–130 (1974).

    CAS  PubMed  Google Scholar 

  42. Sullivan, T. D., LaScolea, L. J. & Neter, E. Relationship between the magnitude of bacteremia in children and the clinical disease. Pediatrics 69, 699–702 (1982).

    CAS  PubMed  Google Scholar 

  43. Tenenbaum, T. et al. Polar bacterial invasion and translocation of Streptococcus suis across the blood–cerebrospinal fluid barrier in vitro. Cell. Microbiol. 11, 323–336 (2009).

    CAS  PubMed  Google Scholar 

  44. Wong, H. R. Genetics and genomics in pediatric septic shock. Crit. Care Med. 40, 1618–1626 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  45. Deghmane, A. E. et al. Emergence of new virulent Neisseria meningitidis serogroup C sequence type 11 isolates in France. J. Infect. Dis. 202, 247–250 (2010).

    PubMed  Google Scholar 

  46. Read, R. C. Neisseria meningitidis; clones, carriage, and disease. Clin. Microbiol. Infect. 20, 391–395 (2014).

    CAS  PubMed  Google Scholar 

  47. Harrison, O. B. et al. Epidemiological evidence for the role of the hemoglobin receptor, HmbR, in meningococcal virulence. J. Infect. Dis. 200, 94–98 (2009).

    CAS  PubMed  Google Scholar 

  48. Bille, E. et al. Association of a bacteriophage with meningococcal disease in young adults. PLoS ONE 3, e3885 (2008).

    PubMed  PubMed Central  Google Scholar 

  49. Nassif, X. et al. Type-4 pili and meningococcal adhesiveness. Gene 192, 149–153 (1997).

    CAS  PubMed  Google Scholar 

  50. Berry, J. L. & Pelicic, V. Exceptionally widespread nanomachines composed of type IV pilins: the prokaryotic Swiss Army knives. FEMS Microbiol. Rev. 39, 134–154 (2015).

    CAS  PubMed  Google Scholar 

  51. Join-Lambert, O. et al. Meningococcal interaction to microvasculature triggers the tissular lesions of purpura fulminans. J. Infect. Dis. 208, 1590–1597 (2013).

    PubMed  Google Scholar 

  52. Melican, K. & Dumenil, G. A humanized model of microvascular infection. Future Microbiol. 8, 567–569 (2013).

    CAS  PubMed  Google Scholar 

  53. Bernard, S. C. et al. Pathogenic Neisseria meningitidis utilizes CD147 for vascular colonization. Nat. Med. 20, 725–731 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  54. Nassif, X. et al. Roles of pilin and PilC in adhesion of Neisseria meningitidis to human epithelial and endothelial cells. Proc. Natl Acad. Sci. USA 91, 3769–3773 (1994).

    CAS  PubMed  PubMed Central  Google Scholar 

  55. Rudel, T., Scheurerpflug, I. & Meyer, T. F. Neisseria PilC protein identified as type-4 pilus tip-located adhesin. Nature 373, 357–359 (1995).

    CAS  PubMed  Google Scholar 

  56. Morand, P. C., Tattevin, P., Eugene, E., Beretti, J. L. & Nassif, X. The adhesive property of the type IV pilus-associated component PilC1 of pathogenic Neisseria is supported by the conformational structure of the N-terminal part of the molecule. Mol. Microbiol. 40, 846–856 (2001).

    CAS  PubMed  Google Scholar 

  57. Gray-Owen, S. D. Neisserial Opa proteins: impact on colonization, dissemination and immunity. Scand. J. Infect. Dis. 35, 614–618 (2003).

    CAS  PubMed  Google Scholar 

  58. Virji, M., Makepeace, K., Ferguson, D. J., Achtman, M. & Moxon, E. R. Meningococcal Opa and Opc proteins: their role in colonization and invasion of human epithelial and endothelial cells. Mol. Microbiol. 10, 499–510 (1993).

    CAS  PubMed  Google Scholar 

  59. Sa, E. C. C., Griffiths, N. J. & Virji, M. Neisseria meningitidis Opc invasin binds to the sulphated tyrosines of activated vitronectin to attach to and invade human brain endothelial cells. PLoS Pathog. 6, e1000911 (2010).

    Google Scholar 

  60. Comanducci, M. et al. NadA, a novel vaccine candidate of Neisseria meningitidis. J. Exp. Med. 195, 1445–1454 (2002).

    CAS  PubMed  PubMed Central  Google Scholar 

  61. Capecchi, B. et al. Neisseria meningitidis NadA is a new invasin which promotes bacterial adhesion to and penetration into human epithelial cells. Mol. Microbiol. 55, 687–698 (2005).

    CAS  PubMed  Google Scholar 

  62. Nagele, V. et al. Neisseria meningitidis adhesin NadA targets β1 integrins: functional similarity to Yersinia invasin. J. Biol. Chem. 286, 20536–20546 (2011).

    PubMed  PubMed Central  Google Scholar 

  63. Scietti, L. et al. Exploring host–pathogen interactions through genome wide protein microarray analysis. Sci. Rep. 6, 27996 (2016).

    CAS  PubMed  PubMed Central  Google Scholar 

  64. Orihuela, C. J. et al. Laminin receptor initiates bacterial contact with the blood brain barrier in experimental meningitis models. J. Clin. Invest. 119, 1638–1646 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  65. Alqahtani, F. et al. Deciphering the complex three-way interaction between the non-integrin laminin receptor, galectin-3 and Neisseria meningitidis. Open Biol. 4, 140053 (2014).

    PubMed  PubMed Central  Google Scholar 

  66. Tunio, S. A. et al. The moonlighting protein fructose-1, 6-bisphosphate aldolase of Neisseria meningitidis: surface localization and role in host cell adhesion. Mol. Microbiol. 76, 605–615 (2010).

    CAS  PubMed  Google Scholar 

  67. Merz, A. J., Enns, C. A. & So, M. Type IV pili of pathogenic Neisseriae elicit cortical plaque formation in epithelial cells. Mol. Microbiol. 32, 1316–1332 (1999).

    CAS  PubMed  Google Scholar 

  68. Hoffmann, I., Eugene, E., Nassif, X., Couraud, P. O. & Bourdoulous, S. Activation of ErbB2 receptor tyrosine kinase supports invasion of endothelial cells by Neisseria meningitidis. J. Cell Biol. 155, 133–143 (2001).

    CAS  PubMed  PubMed Central  Google Scholar 

  69. Eugene, E. et al. Microvilli-like structures are associated with the internalization of virulent capsulated Neisseria meningitidis into vascular endothelial cells. J. Cell Sci. 115, 1231–1241 (2002).

    CAS  PubMed  Google Scholar 

  70. Lambotin, M. et al. Invasion of endothelial cells by Neisseria meningitidis requires cortactin recruitment by a phosphoinositide-3-kinase/Rac1 signalling pathway triggered by the lipo-oligosaccharide. J. Cell Sci. 118, 3805–3816 (2005).

    CAS  PubMed  Google Scholar 

  71. Soyer, M. et al. Early sequence of events triggered by the interaction of Neisseria meningitidis with endothelial cells. Cell. Microbiol. 16, 878–895 (2014).

    CAS  PubMed  Google Scholar 

  72. Mikaty, G. et al. Extracellular bacterial pathogen induces host cell surface reorganization to resist shear stress. PLoS Pathog. 5, e1000314 (2009).

    PubMed  PubMed Central  Google Scholar 

  73. Coureuil, M. et al. Meningococcus hijacks a β2-adrenoceptor/β-arrestin pathway to cross brain microvasculature endothelium. Cell 143, 1149–1160 (2010).

    CAS  PubMed  Google Scholar 

  74. Chamot-Rooke, J. et al. Posttranslational modification of pili upon cell contact triggers N. meningitidis dissemination. Science 331, 778–782 (2011).

    CAS  PubMed  Google Scholar 

  75. Sokolova, O. et al. Interaction of Neisseria meningitidis with human brain microvascular endothelial cells: role of MAP- and tyrosine kinases in invasion and inflammatory cytokine release. Cell. Microbiol. 6, 1153–1166 (2004).

    CAS  PubMed  Google Scholar 

  76. Linhartova, I. et al. Meningococcal adhesion suppresses proapoptotic gene expression and promotes expression of genes supporting early embryonic and cytoprotective signaling of human endothelial cells. FEMS Microbiol. Lett. 263, 109–118 (2006).

    CAS  PubMed  Google Scholar 

  77. Schubert-Unkmeir, A., Sokolova, O., Panzner, U., Eigenthaler, M. & Frosch, M. Gene expression pattern in human brain endothelial cells in response to Neisseria meningitidis. Infect. Immun. 75, 899–914 (2007).

    CAS  PubMed  Google Scholar 

  78. Jacobsen, M. C. et al. A critical role for ATF2 transcription factor in the regulation of E-selectin expression in response to non-endotoxin components of Neisseria meningitidis. Cell. Microbiol. 18, 66–79 (2016).

    CAS  PubMed  Google Scholar 

  79. Coureuil, M. et al. Meningococcal type IV pili recruit the polarity complex to cross the brain endothelium. Science 325, 83–87 (2009).

    CAS  PubMed  Google Scholar 

  80. Schubert-Unkmeir, A. et al. Neisseria meningitidis induces brain microvascular endothelial cell detachment from the matrix and cleavage of occludin: a role for MMP-8. PLoS Pathog. 6, e1000874 (2010).

    PubMed  PubMed Central  Google Scholar 

  81. Fisher, M. J. Brain regulation of thrombosis and hemostasis: from theory to practice. Stroke 44, 3275–3285 (2013).

    PubMed  PubMed Central  Google Scholar 

  82. Nikulin, J., Panzner, U., Frosch, M. & Schubert-Unkmeir, A. Intracellular survival and replication of Neisseria meningitidis in human brain microvascular endothelial cells. Int. J. Med. Microbiol. 296, 553–558 (2006).

    CAS  PubMed  Google Scholar 

  83. Dupin, N. et al. Chronic meningococcemia cutaneous lesions involve meningococcal perivascular invasion through the remodeling of endothelial barriers. Clin. Infect. Dis. 54, 1162–1165 (2012).

    PubMed  Google Scholar 

  84. Muenzner, P. et al. Carcinoembryonic antigen family receptor specificity of Neisseria meningitidis Opa variants influences adherence to and invasion of proinflammatory cytokine-activated endothelial cells. Infect. Immun. 68, 3601–3607 (2000).

    CAS  PubMed  PubMed Central  Google Scholar 

  85. Slanina, H., Hebling, S., Hauck, C. R. & Schubert-Unkmeir, A. Cell invasion by Neisseria meningitidis requires a functional interplay between the focal adhesion kinase, Src and cortactin. PLoS ONE 7, e39613 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  86. Simonis, A., Hebling, S., Gulbins, E., Schneider-Schaulies, S. & Schubert-Unkmeir, A. Differential activation of acid sphingomyelinase and ceramide release determines invasiveness of Neisseria meningitidis into brain endothelial cells. PLoS Pathog. 10, e1004160 (2014).

    PubMed  PubMed Central  Google Scholar 

  87. Cundell, D. R., Gerard, N. P., Gerard, C., Idanpaan-Heikkila, I. & Tuomanen, E. I. Streptococcus pneumoniae anchor to activated human cells by the receptor for platelet-activating factor. Nature 377, 435–438 (1995).

    CAS  PubMed  Google Scholar 

  88. Radin, J. N. et al. β-Arrestin 1 participates in platelet-activating factor receptor-mediated endocytosis of Streptococcus pneumoniae. Infect. Immun. 73, 7827–7835 (2005).

    CAS  PubMed  PubMed Central  Google Scholar 

  89. Ring, A., Weiser, J. N. & Tuomanen, E. I. Pneumococcal trafficking across the blood–brain barrier. Molecular analysis of a novel bidirectional pathway. J. Clin. Invest. 102, 347–360 (1998).

    CAS  PubMed  PubMed Central  Google Scholar 

  90. Iovino, F., Brouwer, M. C., van de Beek, D., Molema, G. & Bijlsma, J. J. Signalling or binding: the role of the platelet-activating factor receptor in invasive pneumococcal disease. Cell. Microbiol. 15, 870–881 (2013).

    CAS  PubMed  Google Scholar 

  91. Iovino, F., Molema, G. & Bijlsma, J. J. Streptococcus pneumoniae interacts with pIgR expressed by the brain microvascular endothelium but does not co-localize with PAF receptor. PLoS ONE 9, e97914 (2014).

    PubMed  PubMed Central  Google Scholar 

  92. Zhang, J. R. et al. The polymeric immunoglobulin receptor translocates pneumococci across human nasopharyngeal epithelial cells. Cell 102, 827–837 (2000).

    CAS  PubMed  Google Scholar 

  93. Iovino, F., Molema, G. & Bijlsma, J. J. Platelet endothelial cell adhesion molecule-1, a putative receptor for the adhesion of Streptococcus pneumoniae to the vascular endothelium of the blood–brain barrier. Infect. Immun. 82, 3555–3566 (2014).

    PubMed  PubMed Central  Google Scholar 

  94. Iovino, F., Seinen, J., Henriques-Normark, B. & van Dijl, J. M. How does Streptococcus pneumoniae invade the brain? Trends Microbiol. 24, 307–315 (2016).

    CAS  PubMed  Google Scholar 

  95. Uchiyama, S. et al. The surface-anchored NanA protein promotes pneumococcal brain endothelial cell invasion. J. Exp. Med. 206, 1845–1852 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  96. Mann, B. et al. Broadly protective protein-based pneumococcal vaccine composed of pneumolysin toxoid–CbpA peptide recombinant fusion protein. J. Infect. Dis. 209, 1116–1125 (2014).

    CAS  PubMed  Google Scholar 

  97. Iovino, F. et al. Pneumococcal meningitis is promoted by single cocci expressing pilus adhesin RrgA. J. Clin. Invest. 126, 2821–2826 (2016).

    PubMed  PubMed Central  Google Scholar 

  98. Doran, K. S. et al. Blood–brain barrier invasion by group B Streptococcus depends upon proper cell-surface anchoring of lipoteichoic acid. J. Clin. Invest. 115, 2499–2507 (2005).

    CAS  PubMed  PubMed Central  Google Scholar 

  99. Banerjee, A. et al. Bacterial pili exploit integrin machinery to promote immune activation and efficient blood–brain barrier penetration. Nat. Commun. 2, 462 (2011).

    PubMed  Google Scholar 

  100. Maisey, H. C., Hensler, M., Nizet, V. & Doran, K. S. Group B streptococcal pilus proteins contribute to adherence to and invasion of brain microvascular endothelial cells. J. Bacteriol. 189, 1464–1467 (2007).

    CAS  PubMed  Google Scholar 

  101. Seo, H. S., Mu, R., Kim, B. J., Doran, K. S. & Sullam, P. M. Binding of glycoprotein Srr1 of Streptococcus agalactiae to fibrinogen promotes attachment to brain endothelium and the development of meningitis. PLoS Pathog. 8, e1002947 (2012).

    PubMed  PubMed Central  Google Scholar 

  102. Mu, R. et al. Identification of a group B streptococcal fibronectin binding protein, SfbA, that contributes to invasion of brain endothelium and development of meningitis. Infect. Immun. 82, 2276–2286 (2014).

    PubMed  PubMed Central  Google Scholar 

  103. Chang, Y. C. et al. Glycosaminoglycan binding facilitates entry of a bacterial pathogen into central nervous systems. PLoS Pathog. 7, e1002082 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  104. Nizet, V. et al. Invasion of brain microvascular endothelial cells by group B streptococci. Infect. Immun. 65, 5074–5081 (1997).

    CAS  PubMed  PubMed Central  Google Scholar 

  105. Cutting, A. S. et al. The role of autophagy during group B Streptococcus infection of blood–brain barrier endothelium. J. Biol. Chem. 289, 35711–35723 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  106. Kim, B. J. et al. Bacterial induction of Snail1 contributes to blood–brain barrier disruption. J. Clin. Invest. 125, 2473–2483 (2015).

    PubMed  PubMed Central  Google Scholar 

  107. Logue, C. M. et al. Genotypic and phenotypic traits that distinguish neonatal meningitis-associated Escherichia coli from fecal E. coli isolates of healthy human hosts. Appl. Environ. Microbiol. 78, 5824–5830 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  108. Cross, A. S., Kim, K. S., Wright, D. C., Sadoff, J. C. & Gemski, P. Role of lipopolysaccharide and capsule in the serum resistance of bacteremic strains of Escherichia coli. J. Infect. Dis. 154, 497–503 (1986).

    CAS  PubMed  Google Scholar 

  109. Huang, S. H. et al. Escherichia coli invasion of brain microvascular endothelial cells in vitro and in vivo: molecular cloning and characterization of invasion gene ibe10. Infect. Immun. 63, 4470–4475 (1995).

    CAS  PubMed  PubMed Central  Google Scholar 

  110. Krishnan, S., Fernandez, G. E., Sacks, D. B. & Prasadarao, N. V. IQGAP1 mediates the disruption of adherens junctions to promote Escherichia coli K1 invasion of brain endothelial cells. Cell. Microbiol. 14, 1415–1433 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  111. Khan, N. A., Kim, Y., Shin, S. & Kim, K. S. FimH-mediated Escherichia coli K1 invasion of human brain microvascular endothelial cells. Cell. Microbiol. 9, 169–178 (2007).

    CAS  PubMed  Google Scholar 

  112. Kim, Y. V., Pearce, D. & Kim, K. S. Ca2+/calmodulin-dependent invasion of microvascular endothelial cells of human brain by Escherichia coli K1. Cell Tissue Res. 332, 427–433 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  113. Parthasarathy, G., Yao, Y. & Kim, K. S. Flagella promote Escherichia coli K1 association with and invasion of human brain microvascular endothelial cells. Infect. Immun. 75, 2937–2945 (2007).

    CAS  PubMed  PubMed Central  Google Scholar 

  114. Prasadarao, N. V., Wass, C. A. & Kim, K. S. Endothelial cell GlcNAcβ1-4GlcNAc epitopes for outer membrane protein A enhance traversal of Escherichia coli across the blood–brain barrier. Infect. Immun. 64, 154–160 (1996).

    CAS  PubMed  PubMed Central  Google Scholar 

  115. Prasadarao, N. V. et al. Outer membrane protein A of Escherichia coli contributes to invasion of brain microvascular endothelial cells. Infect. Immun. 64, 146–153 (1996).

    CAS  PubMed  PubMed Central  Google Scholar 

  116. Teng, C. H. et al. NlpI contributes to Escherichia coli K1 strain RS218 interaction with human brain microvascular endothelial cells. Infect. Immun. 78, 3090–3096 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  117. Badger, J. L., Wass, C. A. & Kim, K. S. Identification of Escherichia coli K1 genes contributing to human brain microvascular endothelial cell invasion by differential fluorescence induction. Mol. Microbiol. 36, 174–182 (2000).

    CAS  PubMed  Google Scholar 

  118. Wang, M. H. & Kim, K. S. Cytotoxic necrotizing factor 1 contributes to Escherichia coli meningitis. Toxins (Basel) 5, 2270–2280 (2013).

    CAS  Google Scholar 

  119. Wang, X. et al. Sphingosine 1-phosphate activation of EGFR as a novel target for meningitic Escherichia coli penetration of the blood–brain barrier. PLoS Pathog. 12, e1005926 (2016).

    PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgements

The laboratory of X.N. is supported by the Fondation pour la Recherche Médicale, The French Agence Nationale de la Recherche, INSERM (French Institut National de la Santé et de la Recherche Médicale), CNRS (French Centre National de la Recherche Scientifique) and the University Paris Descartes, France.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Xavier Nassif.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

PowerPoint slides

Glossary

Tight junctions

Regions of neighbouring cells that are very closely associated, such that the cell membranes join together to form a barrier that is virtually impermeable to fluid. The major types of protein that are involved in these junctions are the claudins and occludin. These proteins associate with peripheral membrane proteins such as zona occludens 1 (ZO1), which are located on the intracellular side of the plasma membrane and which anchor the strands of membrane claudins and occludin to the actin cytoskeleton.

Subarachnoid space

The anatomical space between the arachnoid mater and the pia mater. It is occupied by spongy tissue that consists of trabeculae (delicate, vascularized connective tissue filaments that extend from the arachnoid mater and blend into the pia mater) and intercommunicating channels in which the cerebrospinal fluid is contained.

Venous sinuses

Venous channels that are located inside the dura mater of the brain. They can be conceptualized as trapped epidural veins. Unlike other veins in the body, they run along, rather than parallel to, arteries.

Ventricular ependyma

The thin epithelial lining of the ventricular system of the brain. These cells are in continuity with the epithelium of the choroid plexuses.

Transcytotic vesicles

Vesicles that transport bacteria or macromolecules across a cell, from the apical to the basolateral membrane.

Glia limitans

A thin barrier that is formed of astrocyte endfeet and the associated parenchymal basal lamina that surrounds the brain and spinal cord. This barrier constitutes the outermost layer of neural tissue.

Purpura fulminans

A syndrome that involves intravascular thrombosis and haemorrhagic infarction of the skin that is rapidly progressive, accompanied by vascular collapse and disseminated intravascular coagulation. Neisseria meningitidis infections are the main cause of infectious purpura fulminans.

Exocytosis

The counterpart of endocytosis. In the context of this Review, exocytosis corresponds to active transport out of cells.

G protein-coupled receptor

(GPCR). A member of a large family of receptors that sense molecules outside the cell and activate intracellular signal transduction pathways. Ligand binding causes a conformational change in the GPCR, which allows it to act as a guanine nucleotide exchange factor. The GPCR can then activate an associated G protein, the α-subunit of which affects intracellular signalling proteins or targets functional proteins.

Adherens junctions

Protein complexes that occur at cell–cell junctions in epithelial and endothelial tissues and that are more basal than tight junctions. These junctions are formed by the association of cadherins.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Coureuil, M., Lécuyer, H., Bourdoulous, S. et al. A journey into the brain: insight into how bacterial pathogens cross blood–brain barriers. Nat Rev Microbiol 15, 149–159 (2017). https://doi.org/10.1038/nrmicro.2016.178

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nrmicro.2016.178

This article is cited by

Search

Quick links

Nature Briefing Microbiology

Sign up for the Nature Briefing: Microbiology newsletter — what matters in microbiology research, free to your inbox weekly.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing: Microbiology