Toll-like receptor stimulation increases phagocytosis of Cryptococcus neoformans by microglial cells

Journal of Neuroinflammation

Roland Nau²  Helmut Eiffert⁴  Sandra Schütze³  Sandra Ribes³  Sandra Redlich¹ 

[1] Department of Neuropathology, Georg-August-University, Göttingen, Robert-Koch Str. 40, Göttingen, 37075, Germany;Department of Geriatrics, Ev. Krankenhaus Weende, Göttingen, Germany;Institute of Neuropathology, University Medical Center, Göttingen, Germany;Department of Medical Microbiology, University Medical Center, Göttingen, Germany

关键词: Phagocytosis;    Microglia;    Cryptococcosis;    Meningitis;    Toll-like receptor;   

Others  :  1159954
DOI  :  10.1186/1742-2094-10-71

 received in 2013-02-10, accepted in 2013-05-22,  发布年份 2013

【 摘 要 】

Background

Toll-Like receptors (TLRs) belong to the family of pattern-recognition receptors with a crucial function of recognising pathogen-associated molecular patterns (PAMPs). Cryptococcal meningitis is a potentially fatal disease with a high mortality and risk of neurological sequelae.

Methods

We studied the ability of microglial cells to increase the phagocytosis of cryptococci after stimulation with agonists of TLR1/2, TLR3, TLR4 and TLR9.

Results

Stimulation of murine microglial cells with these TLR agonists for 24 h increased the phagocytosis of encapsulated Cryptococcus neoformans. Stimulation increased the release of TNF-α, CXCL1 (KC), IL-6, IL-10 and MIP-2, which indicated the activation of microglial cells. Unstimulated and TLR agonist-stimulated MyD88-deficient cells showed a reduced ability to phagocytose cryptococci compared to their wild-type counterpart. Intracellular killing of cryptococci was also increased in TLR-stimulated cells compared to unstimulated microglial cells.

Conclusion

Our observation suggests that stimulation of microglial cells by TLR agonists can increase the resistance of the brain against CNS infections caused by Cryptococcus neoformans. This may be of interest when an immunocompromised patient is unable to eliminate Cryptococcus neoformans despite antifungal therapy.

【 授权许可】

   
2013 Redlich et al.; licensee BioMed Central Ltd.

【 图 表 】

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【 参考文献 】

• [1]Kobayashi M, Murata K, Hiroshi HO, Tokura Y: Cryptococcosis: long-lasting presence of fungi after successful treatment. Acta Derm Venereol 2004, 84:320-321.
• [2]Casadevall A, Spitzer ED, Webb D, Rinaldi MG: Susceptibilities of serial Cryptococcus neoformans isolates from patients with recurrent cryptococcal meningitis to amphotericin B and fluconazole. Antimicrob Agents Chemother 1993, 37:1383-1386.
• [3]Spitzer ED, Spitzer SG, Freundlich LF, Casadevall A: Persistence of initial infection in recurrent Cryptococcus neoformans meningitis. Lancet 1993, 341:595-596.
• [4]Baddley JW, Perfect JR, Oster RA, Larsen RA, Pankey GA, Henderson H, Haas DW, Kauffman CA, Patel R, Zaas AK, Pappas PG: Pulmonary cryptococcosis in patients without HIV infection: factors associated with disseminated disease. Eur J Clin Microbiol Infect Dis 2008, 27:937-943.
• [5]Chen J, Varma A, Diaz MR, Litvintseva AP, Wollenberg KK, Kwon-Chung KJ: Cryptococcus neoformans strains and infection in apparently immunocompetent patients, China. Emerg Infect Dis 2008, 14:755-762.
• [6]Zahra LV, Azzopardi CM, Scott G: Cryptococcal meningitis in two apparently immunocompetent Maltese patients. Mycoses 2004, 47:168-173.
• [7]Kidd SE, Hagen F, Tscharke RL, Huynh M, Bartlett KH, Fyfe M, Macdougall L, Boekhout T, Kwon-Chung KJ, Meyer W: A rare genotype of Cryptococcus gattii caused the cryptococcosis outbreak on Vancouver Island (British Columbia, Canada). Proc Natl Acad Sci USA 2004, 101:17258-17263.
• [8]Suchitha S, Sheeladevi CS, Sunila R, Manjunath GV: Disseminated cryptococcosis in an immunocompetent patient: a case report. Case Report Pathol 2012, 201:652351.
• [9]Liu TB, Perlin DS, Xue C: Molecular mechanisms of cryptococcal meningitis. Virulence 2012, 3:173-181.
• [10]Granger DL, Perfect JR, Durack DT: Virulence of Cryptococcus neoformans. Regulation of capsule synthesis by carbon dioxide. J Clin Invest 1985, 76:508-516.
• [11]Levitz SM, Nong SH, Seetoo KF, Harrison TS, Speizer RA, Simons ER: Cryptococcus neoformans resides in an acidic phagolysosome of human macrophages. Infect Immun 1999, 67:885-890.
• [12]Hanisch UK, Kettenmann H: Microglia: active sensor and versatile effector cells in the normal and pathologic brain. Nat Neurosci 2007, 10:1387-1394.
• [13]Nau R, Bruck W: Neuronal injury in bacterial meningitis: mechanisms and implications for therapy. Trends Neurosci 2002, 25:38-45.
• [14]Takeda K, Akira S: Toll receptors and pathogen resistance. Cell Microbiol 2003, 5:143-153.
• [15]Takeda K, Kaisho T, Akira S: Toll-like receptors. Annu Rev Immunol 2003, 21:335-376.
• [16]Netea MG, Ferwerda G, van der Graaf CA, Van der Meer JW, Kullberg BJ: Recognition of fungal pathogens by toll-like receptors. Curr Pharm Des 2006, 12:4195-4201.
• [17]Underhill DM: Macrophage recognition of zymosan particles. J Endotoxin Res 2003, 9:176-180.
• [18]Gantner BN, Simmons RM, Canavera SJ, Akira S, Underhill DM: Collaborative induction of inflammatory responses by dectin-1 and Toll-like receptor 2. J Exp Med 2003, 197:1107-1117.
• [19]Yamamoto H, Abe Y, Miyazato A, Tanno D, Tanaka M, Miyasaka T, Ishii K, Kawakami K: Cryptococcus neoformans suppresses the activation of bone marrow-derived dendritic cells stimulated with its own DNA, but not with DNA from other fungi. FEMS Immunol Med Microbiol 2011, 63:363-372.
• [20]Ribes S, Ebert S, Regen T, Agarwal A, Tauber SC, Czesnik D, Spreer A, Bunkowski S, Eiffert H, Hanisch UK, Hammerschmidt S, Nau R: Toll-like receptor stimulation enhances phagocytosis and intracellular killing of nonencapsulated and encapsulated Streptococcus pneumoniae by murine microglia. Infect Immun 2010, 78:865-871.
• [21]Ribes S, Ebert S, Czesnik D, Regen T, Zeug A, Bukowski S, Mildner A, Eiffert H, Hanisch UK, Hammerschmidt S, Nau R: Toll-like receptor prestimulation increases phagocytosis of Escherichia coli DH5alpha and Escherichia coli K1 strains by murine microglial cells. Infect Immun 2009, 77:557-564.
• [22]Regen T, Van Rossum D, Scheffel J, Kastriti ME, Revelo NH, Prinz M, Brück W, Hanisch UK: CD14 and TRIF govern distinct responsiveness and responses in mouse microglial TLR4 challenges by structural variants of LPS. Brain Behav Immun 2011, 25:957-970.
• [23]Ebert S, Gerber J, Bader S, Muhlhauser F, Brechtel K, Mitchell TJ, Nau R: Dose-dependent activation of microglial cells by Toll-like receptor agonists alone and in combination. J Neuroimmunol 2005, 159:87-96.
• [24]Perfect JR, Dismukes WE, Dromer F, Goldman DL, Graybill JR, Hamill RJ, Harrison TS, Larsen RA, Lortholary O, Nguyen MH, Pappas PG, Powderly WG, Singh N, Sobel JD, Sorrell TC: Clinical practice guidelines for the management of cryptococcal disease: 2010 update by the infectious diseases society of america. Clin Infect Dis 2010, 50:291-322.
• [25]McQuiston TJ, Williamson PR: Paradoxical roles of alveolar macrophages in the host response to Cryptococcus neoformans. J Infect Chemother 2012, 18:1-9.
• [26]Underhill DM: Toll-like receptors: networking for success. Eur J Immunol 2003, 33:1767-1775.
• [27]Alvarez M, Casadevall A: Cell-to-cell spread and massive vacuole formation after Cryptococcus neoformans infection of murine macrophages. BMC Immunol 2007, 8:16. BioMed Central Full Text
• [28]Olszewski MA, Zhang Y, Huffnagle GB: Mechanisms of cryptococcal virulence and persistence. Future Microbiol 2010, 5:1269-1288.
• [29]Levitz SM: Cryptococcus neoformans: intracellular or extracellular? Trends Microbiol 2001, 9:417-418.
• [30]Feldmesser M, Kress Y, Novikoff P, Casadevall A: Cryptococcus neoformans is a facultative intracellular pathogen in murine pulmonary infection. Infect Immun 2000, 68:4225-4237.
• [31]Diamond RD, Bennett JE: Growth of Cryptococcus neoformans within human macrophages in vitro. Infect Immun 1973, 7:231-236.
• [32]Schutze S, Loleit T, Zeretzke M, Bunkowski S, Bruck W, Ribes S, Nau R: Additive microglia-mediated neuronal injury caused by amyloid-beta and bacterial TLR agonists in murine neuron-microglia co-cultures quantified by an automated image analysis using cognition network technology. J Alzheimers Dis 2012, 31:651-657.
• [33]Iliev AI, Stringaris AK, Nau R, Neumann H: Neuronal injury mediated via stimulation of microglial toll-like receptor-9 (TLR9). FASEB J 2004, 18:412-414.
• [34]Dawson VL, Brahmbhatt HP, Mong JA, Dawson TM: Expression of inducible nitric oxide synthase causes delayed neurotoxicity in primary mixed neuronal-glial cortical cultures. Neuropharmacology 1994, 33:1425-1430.
• [35]Dawson TM, Zhang J, Dawson VL, Snyder SH: Nitric oxide: cellular regulation and neuronal injury. Prog Brain Res 1994, 103:365-369.
• [36]Chao CC, Hu S, Molitor TW, Shaskan EG, Peterson PK: Activated microglia mediate neuronal cell injury via a nitric oxide mechanism. J Immunol 1992, 149:2736-2741.