Candida albicans frequently causes superficial infections by invading and damaging epithelial cells, but may also cause systemic infections by penetrating through epithelial barriers. C. albicans is a remarkable pathogen because it can invade epithelial cells via two distinct mechanisms: induced endocytosis, analogous to facultative intracellular enteropathogenic bacteria, and active penetration, similar to plant pathogenic fungi. Here we investigated the contributions of the two invasion routes of C. albicans to epithelial invasion. Using selective cellular inhibition approaches and differential fluorescence microscopy, we demonstrate that induced endocytosis contributes considerably to the early time points of invasion, while active penetration represents the dominant epithelial invasion route. Although induced endocytosis depends mainly on Als3-E–cadherin interactions, we observed E–cadherin independent induced endocytosis. Finally, we provide evidence of a protective role for serum factors in oral infection: human serum strongly inhibited C. albicans adhesion to, invasion and damage of oral epithelial cells.
References
[1]
Mavor AL, Thewes S, Hube B (2005) Systemic fungal infections caused by Candida species: epidemiology, infection process and virulence attributes. Curr Drug Targets 6: 863–874.
[2]
Odds FC (1988) Ecology and epidemiology of candidiasis. Baltimore: University Park Press.
[3]
Ruhnke M (2002) Skin and mucous membrane infections. Washington DC: American Society for Microbiology Press. pp. 307–325.
Sundstrom P (2002) Adhesion in Candida spp. Cell Microbiol 4: 461–469.
[6]
Tronchin G, Pihet M, Lopes-Bezerra LM, Bouchara JP (2008) Adherence mechanisms in human pathogenic fungi. Med Mycol 46: 749–772.
[7]
Odds FC (1994) Pathogenesis of Candida infections. J Am Acad Dermatol 31: S2–5.
[8]
Zakikhany K, Naglik JR, Schmidt-Westhausen A, Holland G, Schaller M, et al. (2007) In vivo transcript profiling of Candida albicans identifies a gene essential for interepithelial dissemination. Cell Microbiol 9: 2938–2954.
[9]
Dalle F, Wachtler B, Coralie L, Holland G, Bannert N, et al. (2009) Cellular interactions of Candida albicans with human oral epithelial cells and enterocytes. Cell Microbiol.
[10]
Phan QT, Myers CL, Fu Y, Sheppard DC, Yeaman MR, et al. (2007) Als3 is a Candida albicans invasin that binds to cadherins and induces endocytosis by host cells. PLoS Biol 5: e64.
[11]
Sun JN, Solis NV, Phan QT, Bajwa JS, Kashleva H, et al. (2010) Host cell invasion and virulence mediated by Candida albicans Ssa1. PLoS Pathog 6: e1001181.
[12]
Wachtler B, Wilson D, Haedicke K, Dalle F, Hube B (2011) From attachment to damage: defined genes of Candida albicans mediate adhesion, invasion and damage during interaction with oral epithelial cells. PLoS One 6: e17046.
[13]
Stevenson B, Choy HA, Pinne M, Rotondi ML, Miller MC, et al. (2007) Leptospira interrogans endostatin-like outer membrane proteins bind host fibronectin, laminin and regulators of complement. PLoS One 2: e1188.
[14]
Vanier G, Segura M, Gottschalk M (2007) Characterization of the invasion of porcine endothelial cells by Streptococcus suis serotype 2. Can J Vet Res 71: 81–89.
[15]
Eitel J, Dersch P (2002) The YadA protein of Yersinia pseudotuberculosis mediates high-efficiency uptake into human cells under environmental conditions in which invasin is repressed. Infect Immun 70: 4880–4891.
[16]
Bergmann S, Lang A, Rohde M, Agarwal V, Rennemeier C, et al. (2009) Integrin-linked kinase is required for vitronectin-mediated internalization of Streptococcus pneumoniae by host cells. J Cell Sci 122: 256–267.
[17]
Zipfel PF, Skerka C, Kupka D, Luo S (2011) Immune escape of the human facultative pathogenic yeast Candida albicans: The many faces of the Candida Pra1 protein. Int J Med Microbiol 301: 423–430.
[18]
Santoni G, Spreghini E, Lucciarini R, Amantini C, Piccoli M (2001) Involvement of alpha(v)beta3 integrin-like receptor and glycosaminoglycans in Candida albicans germ tube adhesion to vitronectin and to a human endothelial cell line. Microb Pathog 31: 159–172.
[19]
Filler SG, Sheppard DC (2006) Fungal invasion of normally non-phagocytic host cells. PLoS Pathog 2: e129.
[20]
Drago L, Mombelli B, De Vecchi E, Bonaccorso C, Fassina MC, et al. (2000) Candida albicans cellular internalization: a new pathogenic factor? Int J Antimicrob Agents 16: 545–547.
[21]
Denk C, Hulsken J, Schwarz E (1997) Reduced gene expression of E-cadherin and associated catenins in human cervical carcinoma cell lines. Cancer Lett 120: 185–193.
[22]
Kumamoto CA (2008) Molecular mechanisms of mechanosensing and their roles in fungal contact sensing. Nat Rev Microbiol 6: 667–673.
[23]
Talbot NJ (2003) On the trail of a cereal killer: Exploring the biology of Magnaporthe grisea. Annu Rev Microbiol 57: 177–202.
[24]
Aly AS, Vaughan AM, Kappe SH (2009) Malaria parasite development in the mosquito and infection of the mammalian host. Annu Rev Microbiol 63: 195–221.
[25]
Bonazzi M, Cossart P (2006) Bacterial entry into cells: a role for the endocytic machinery. FEBS Lett 580: 2962–2967.
[26]
Pizarro-Cerda J, Cossart P (2006) Bacterial adhesion and entry into host cells. Cell 124: 715–727.
[27]
Dersch P (2003) Molecular and cellular mechanisms of bacterial entry into host cells. Contrib Microbiol 10: 183–209.
[28]
Moreno-Ruiz E, Galan-Diez M, Zhu W, Fernandez-Ruiz E, d’Enfert C, et al. (2009) Candida albicans internalization by host cells is mediated by a clathrin-dependent mechanism. Cell Microbiol 11: 1179–1189.
[29]
Wilson D, Hube B (2010) Hgc1 mediates dynamic Candida albicans-endothelium adhesion events during circulation. Eukaryot Cell 9: 278–287.
[30]
Phan QT, Fratti RA, Prasadarao NV, Edwards JE Jr, Filler SG (2005) N-cadherin mediates endocytosis of Candida albicans by endothelial cells. J Biol Chem 280: 10455–10461.
[31]
Lau YE, Bowdish DM, Cosseau C, Hancock RE, Davidson DJ (2006) Apoptosis of airway epithelial cells: human serum sensitive induction by the cathelicidin LL-37. Am J Respir Cell Mol Biol 34: 399–409.
[32]
Stocks SZ, Shiels IA, Taylor SM (1999) Homologous serum-stimulated fibronectin synthesis in human retinal pigmented epithelial cells. Aust N Z J Ophthalmol 27: 247–249.
[33]
Fonzi WA, Irwin MY (1993) Isogenic strain construction and gene mapping in Candida albicans. Genetics 134: 717–728.
[34]
Gillum AM, Tsay EY, Kirsch DR (1984) Isolation of the Candida albicans gene for orotidine-5'-phosphate decarboxylase by complementation of S. cerevisiae ura3 and E. coli pyrF mutations. Mol Gen Genet 198: 179–182.
[35]
Murad AM, Lee PR, Broadbent ID, Barelle CJ, Brown AJ (2000) CIp10, an efficient and convenient integrating vector for Candida albicans. Yeast 16: 325–327.
[36]
Zhao X, Oh SH, Cheng G, Green CB, Nuessen JA, et al. (2004) ALS3 and ALS8 represent a single locus that encodes a Candida albicans adhesin; functional comparisons between Als3p and Als1p. Microbiology 150: 2415–2428.
[37]
Schaller M, Korting HC, Schafer W, Bastert J, Chen W, et al. (1999) Secreted aspartic proteinase (Sap) activity contributes to tissue damage in a model of human oral candidosis. Mol Microbiol 34: 169–180.
[38]
Rupniak HT, Rowlatt C, Lane EB, Steele JG, Trejdosiewicz LK, et al. (1985) Characteristics of four new human cell lines derived from squamous cell carcinomas of the head and neck. J Natl Cancer Inst 75: 621–635.
[39]
Scherer WF, Syverton JT, Gey GO (1953) Studies on the propagation in vitro of poliomyelitis viruses. IV. Viral multiplication in a stable strain of human malignant epithelial cells (strain HeLa) derived from an epidermoid carcinoma of the cervix. J Exp Med 97: 695–710.
[40]
Park H, Myers CL, Sheppard DC, Phan QT, Sanchez AA, et al. (2005) Role of the fungal Ras-protein kinase A pathway in governing epithelial cell interactions during oropharyngeal candidiasis. Cell Microbiol 7: 499–510.
[41]
Tsujihata M, Yoshimura K, Tsujikawa K, Tei N, Okuyama A (2006) Fibronectin inhibits endocytosis of calcium oxalate crystals by renal tubular cells. Int J Urol 13: 743–746.
[42]
Spreghini E, Gismondi A, Piccoli M, Santoni G (1999) Evidence for alphavbeta3 and alphavbeta5 integrin-like vitronectin (VN) receptors in Candida albicans and their involvement in yeast cell adhesion to VN. J Infect Dis 180: 156–166.
[43]
Naidu AS, Paulsson M, Wadstrom T (1988) Particle agglutination assays for rapid detection of fibronectin, fibrinogen, and collagen receptors on Staphylococcus aureus. J Clin Microbiol 26: 1549–1554.
[44]
da Silva Tatley F, Aldwell FE, Dunbier AK, Guilford PJ (2003) N-terminal E-cadherin peptides act as decoy receptors for Listeria monocytogenes. Infect Immun 71: 1580–1583.
[45]
Gozalbo D, Gil-Navarro I, Azorin I, Renau-Piqueras J, Martinez JP, et al. (1998) The cell wall-associated glyceraldehyde-3-phosphate dehydrogenase of Candida albicans is also a fibronectin and laminin binding protein. Infect Immun 66: 2052–2059.
