白色念珠菌是人體主要的真菌致病菌。白色念珠菌貼附於宿主細胞是造成白色念珠菌感染的初始步驟，同時也是最關鍵的過程之一。白色念珠菌的細胞壁在貼附的步驟中扮演極重要的角色。LL-37是人體cathelicidin抗菌胜肽已知的唯一成員，並且藉由與白色念珠菌的細胞表面接觸及破壞達到殺菌效果。在我們實驗室的其他研究中發現LL-37可與白色念珠菌細胞壁的結合進而降低其貼附的能力。因此，本論文研究的主要目的是進一步探討LL-37對於白色念珠菌細胞壁完整性的可能影響。實驗中發現LL-37和細胞壁干擾劑有加成白色念珠菌死亡的效果且LL-37處理過的細胞壁主要成分含量也有所改變。另外，Mkc1所調控的細胞壁完整性訊息傳遞途徑也發現參與白色念珠菌對LL-37的反應。LL-37也同時影響了細胞壁β-(1,3)-glucan的重組，且白色念珠菌主要的exo-β-(1,3)-glucanase, Xog1與此β-(1,3)-glucan的重組有關。最後，白色念珠菌RLM1和 XOG1兩個與細胞壁重組和完整性相關的基因表現也受到LL-37的影響。總結來說，LL-37會引起白色念珠菌細胞壁的破壞，活化特定的訊息傳遞途徑去維持細胞壁完整性，並且影響細胞壁中β-(1,3)-glucan的重組。本研究提供了LL-37殺菌效果新的可能機制；透過LL-37破壞白色念珠菌的細胞壁，進而導致細胞壁修復或死亡。這些結果對未來治療及防範白色念珠菌的策略提供新的方向。

1. Pfaller, M.A. and D.J. Diekema, Epidemiology of invasive candidiasis: a persistent public health problem. Clin Microbiol Rev, 2007. 20(1): p. 133-63.
2. Singh, N., et al., Antifungal management practices and evolution of infection in organ transplant recipients with cryptococcus neoformans infection. Transplantation, 2005. 80(8): p. 1033-9.
3. Edmond, M.B., et al., Nosocomial bloodstream infections in United States hospitals: a three-year analysis. Clin Infect Dis, 1999. 29(2): p. 239-44.
4. Wisplinghoff, H., et al., Nosocomial bloodstream infections in US hospitals: analysis of 24,179 cases from a prospective nationwide surveillance study. Clin Infect Dis, 2004. 39(3): p. 309-17.
5. Lass-Florl, C., The changing face of epidemiology of invasive fungal disease in Europe. Mycoses, 2009. 52(3): p. 197-205.
6. Eggimann, P., J. Garbino, and D. Pittet, Epidemiology of Candida species infections in critically ill non-immunosuppressed patients. Lancet Infect Dis, 2003. 3(11): p. 685-702.
7. Yang, Y.L., et al., The distribution of species and susceptibility of amphotericin B and fluconazole of yeast pathogens isolated from sterile sites in Taiwan. Med Mycol, 2010. 48(2): p. 328-34.
8. Wilson, D., et al., Identifying infection-associated genes of Candida albicans in the postgenomic era. FEMS Yeast Res, 2009. 9(5): p. 688-700.
9. Naglik, J.R., S.J. Challacombe, and B. Hube, Candida albicans secreted aspartyl proteinases in virulence and pathogenesis. Microbiol Mol Biol Rev, 2003. 67(3): p. 400-28, table of contents.
10. Sheppard, D.C., et al., Functional and structural diversity in the Als protein family of Candida albicans. J Biol Chem, 2004. 279(29): p. 30480-9.
11. Staab, J.F., et al., Adhesive and mammalian transglutaminase substrate properties of Candida albicans Hwp1. Science, 1999. 283(5407): p. 1535-8.
12. Nobile, C.J., et al., Function of Candida albicans adhesin Hwp1 in biofilm formation. Eukaryot Cell, 2006. 5(10): p. 1604-10.
13. Doss, M., et al., Human defensins and LL-37 in mucosal immunity. J Leukoc Biol, 2010. 87(1): p. 79-92.
14. Klotman, M.E. and T.L. Chang, Defensins in innate antiviral immunity. Nat Rev Immunol, 2006. 6(6): p. 447-56.
15. Lai, Y. and R.L. Gallo, AMPed up immunity: how antimicrobial peptides have multiple roles in immune defense. Trends Immunol, 2009. 30(3): p. 131-41.
16. Ganz, T., et al., Defensins. Natural peptide antibiotics of human neutrophils. J Clin Invest, 1985. 76(4): p. 1427-35.
17. Yang, D., et al., Multiple roles of antimicrobial defensins, cathelicidins, and eosinophil-derived neurotoxin in host defense. Annu Rev Immunol, 2004. 22: p. 181-215.
18. Oppenheim, F.G., et al., Histatins, a novel family of histidine-rich proteins in human parotid secretion. Isolation, characterization, primary structure, and fungistatic effects on Candida albicans. J Biol Chem, 1988. 263(16): p. 7472-7.
19. Xu, T., et al., Anticandidal activity of major human salivary histatins. Infect Immun, 1991. 59(8): p. 2549-54.
20. Burton, M.F. and P.G. Steel, The chemistry and biology of LL-37. Nat Prod Rep, 2009. 26(12): p. 1572-84.
21. Brogden, K.A., Antimicrobial peptides: pore formers or metabolic inhibitors in bacteria? Nat Rev Microbiol, 2005. 3(3): p. 238-50.
22. Jenssen, H., P. Hamill, and R.E. Hancock, Peptide antimicrobial agents. Clin Microbiol Rev, 2006. 19(3): p. 491-511.
23. Wu, M., et al., Mechanism of interaction of different classes of cationic antimicrobial peptides with planar bilayers and with the cytoplasmic membrane of Escherichia coli. Biochemistry, 1999. 38(22): p. 7235-42.
24. Henzler Wildman, K.A., D.K. Lee, and A. Ramamoorthy, Mechanism of lipid bilayer disruption by the human antimicrobial peptide, LL-37. Biochemistry, 2003. 42(21): p. 6545-58.
25. Yang, L., et al., Barrel-stave model or toroidal model? A case study on melittin pores. Biophys J, 2001. 81(3): p. 1475-85.
26. Oren, Z. and Y. Shai, Mode of action of linear amphipathic alpha-helical antimicrobial peptides. Biopolymers, 1998. 47(6): p. 451-63.
27. Koshlukova, S.E., et al., Salivary histatin 5 induces non-lytic release of ATP from Candida albicans leading to cell death. J Biol Chem, 1999. 274(27): p. 18872-9.
28. Sun, J.N., et al., Uptake of the antifungal cationic peptide Histatin 5 by Candida albicans Ssa2p requires binding to non-conventional sites within the ATPase domain. Mol Microbiol, 2008. 70(5): p. 1246-60.
29. Vylkova, S., et al., Histatin 5 initiates osmotic stress response in Candida albicans via activation of the Hog1 mitogen-activated protein kinase pathway. Eukaryot Cell, 2007. 6(10): p. 1876-88.
30. Wunder, D., et al., Human salivary histatin 5 fungicidal action does not induce programmed cell death pathways in Candida albicans. Antimicrob Agents Chemother, 2004. 48(1): p. 110-5.
31. Dorschner, R.A., et al., Cutaneous injury induces the release of cathelicidin anti-microbial peptides active against group A Streptococcus. J Invest Dermatol, 2001. 117(1): p. 91-7.
32. Kai-Larsen, Y. and B. Agerberth, The role of the multifunctional peptide LL-37 in host defense. Front Biosci, 2008. 13: p. 3760-7.
33. den Hertog, A.L., et al., Candidacidal effects of two antimicrobial peptides: histatin 5 causes small membrane defects, but LL-37 causes massive disruption of the cell membrane. Biochem J, 2005. 388(Pt 2): p. 689-95.
34. Nather, K. and C.A. Munro, Generating cell surface diversity in Candida albicans and other fungal pathogens. FEMS Microbiol Lett, 2008. 285(2): p. 137-45.
35. Ruiz-Herrera, J., et al., Molecular organization of the cell wall of Candida albicans and its relation to pathogenicity. FEMS Yeast Res, 2006. 6(1): p. 14-29.
36. Brown, G.D., et al., Dectin-1 is a major beta-glucan receptor on macrophages. J Exp Med, 2002. 196(3): p. 407-12.
37. Goodridge, H.S., A.J. Wolf, and D.M. Underhill, Beta-glucan recognition by the innate immune system. Immunol Rev, 2009. 230(1): p. 38-50.
38. Boxx, G.M., et al., Influence of mannan and glucan on complement activation and C3 binding by Candida albicans. Infect Immun, 2010. 78(3): p. 1250-9.
39. Kapteyn, J.C., et al., The cell wall architecture of Candida albicans wild-type cells and cell wall-defective mutants. Mol Microbiol, 2000. 35(3): p. 601-11.
40. Klis, F.M., P. de Groot, and K. Hellingwerf, Molecular organization of the cell wall of Candida albicans. Med Mycol, 2001. 39 Suppl 1: p. 1-8.
41. Masuoka, J., Surface glycans of Candida albicans and other pathogenic fungi: physiological roles, clinical uses, and experimental challenges. Clin Microbiol Rev, 2004. 17(2): p. 281-310.
42. Chaffin, W.L., Candida albicans cell wall proteins. Microbiol Mol Biol Rev, 2008. 72(3): p. 495-544.
43. Hoyer, L.L., The ALS gene family of Candida albicans. Trends Microbiol, 2001. 9(4): p. 176-80.
44. Kandasamy, R., G. Vediyappan, and W.L. Chaffin, Evidence for the presence of pir-like proteins in Candida albicans. FEMS Microbiol Lett, 2000. 186(2): p. 239-43.
45. Gustin, M.C., et al., MAP kinase pathways in the yeast Saccharomyces cerevisiae. Microbiol Mol Biol Rev, 1998. 62(4): p. 1264-300.
46. Lesage, G. and H. Bussey, Cell wall assembly in Saccharomyces cerevisiae. Microbiol Mol Biol Rev, 2006. 70(2): p. 317-43.
47. Levin, D.E., Cell wall integrity signaling in Saccharomyces cerevisiae. Microbiol Mol Biol Rev, 2005. 69(2): p. 262-91.
48. Dodou, E. and R. Treisman, The Saccharomyces cerevisiae MADS-box transcription factor Rlm1 is a target for the Mpk1 mitogen-activated protein kinase pathway. Mol Cell Biol, 1997. 17(4): p. 1848-59.
49. Watanabe, Y., K. Irie, and K. Matsumoto, Yeast RLM1 encodes a serum response factor-like protein that may function downstream of the Mpk1 (Slt2) mitogen-activated protein kinase pathway. Mol Cell Biol, 1995. 15(10): p. 5740-9.
50. Watanabe, Y., et al., Characterization of a serum response factor-like protein in Saccharomyces cerevisiae, Rlm1, which has transcriptional activity regulated by the Mpk1 (Slt2) mitogen-activated protein kinase pathway. Mol Cell Biol, 1997. 17(5): p. 2615-23.
51. Baetz, K., et al., Transcriptional coregulation by the cell integrity mitogen-activated protein kinase Slt2 and the cell cycle regulator Swi4. Mol Cell Biol, 2001. 21(19): p. 6515-28.
52. Madden, K., et al., SBF cell cycle regulator as a target of the yeast PKC-MAP kinase pathway. Science, 1997. 275(5307): p. 1781-4.
53. Jung, U.S., et al., Regulation of the yeast Rlm1 transcription factor by the Mpk1 cell wall integrity MAP kinase. Mol Microbiol, 2002. 46(3): p. 781-9.
54. Monge, R.A., et al., The MAP kinase signal transduction network in Candida albicans. Microbiology, 2006. 152(Pt 4): p. 905-12.
55. Chen, J., S. Lane, and H. Liu, A conserved mitogen-activated protein kinase pathway is required for mating in Candida albicans. Mol Microbiol, 2002. 46(5): p. 1335-44.
56. Csank, C., et al., Roles of the Candida albicans mitogen-activated protein kinase homolog, Cek1p, in hyphal development and systemic candidiasis. Infect Immun, 1998. 66(6): p. 2713-21.
57. Liu, H., Transcriptional control of dimorphism in Candida albicans. Curr Opin Microbiol, 2001. 4(6): p. 728-35.
58. Roman, E., C. Nombela, and J. Pla, The Sho1 adaptor protein links oxidative stress to morphogenesis and cell wall biosynthesis in the fungal pathogen Candida albicans. Mol Cell Biol, 2005. 25(23): p. 10611-27.

59. Alonso-Monge, R., et al., The Hog1 mitogen-activated protein kinase is essential in the oxidative stress response and chlamydospore formation in Candida albicans. Eukaryot Cell, 2003. 2(2): p. 351-61.
60. Enjalbert, B., et al., Role of the Hog1 stress-activated protein kinase in the global transcriptional response to stress in the fungal pathogen Candida albicans. Mol Biol Cell, 2006. 17(2): p. 1018-32.
61. Kelly, J., et al., Exposure to caspofungin activates Cap and Hog pathways in Candida albicans. Med Mycol, 2009. 47(7): p. 697-706.
62. Alonso-Monge, R., et al., Role of the mitogen-activated protein kinase Hog1p in morphogenesis and virulence of Candida albicans. J Bacteriol, 1999. 181(10): p. 3058-68.
63. Eisman, B., et al., The Cek1 and Hog1 mitogen-activated protein kinases play complementary roles in cell wall biogenesis and chlamydospore formation in the fungal pathogen Candida albicans. Eukaryot Cell, 2006. 5(2): p. 347-58.
64. Navarro-Garcia, F., et al., Functional characterization of the MKC1 gene of Candida albicans, which encodes a mitogen-activated protein kinase homolog related to cell integrity. Mol Cell Biol, 1995. 15(4): p. 2197-206.
65. Navarro-Garcia, F., et al., The MAP kinase Mkc1p is activated under different stress conditions in Candida albicans. Microbiology, 2005. 151(Pt 8): p. 2737-49.
66. Navarro-Garcia, F., et al., A role for the MAP kinase gene MKC1 in cell wall construction and morphological transitions in Candida albicans. Microbiology, 1998. 144 ( Pt 2): p. 411-24.
67. Diez-Orejas, R., et al., Reduced virulence of Candida albicans MKC1 mutants: a role for mitogen-activated protein kinase in pathogenesis. Infect Immun, 1997. 65(2): p. 833-7.
68. Sampaio, P., et al., Increased number of glutamine repeats in the C-terminal of Candida albicans Rlm1p enhances the resistance to stress agents. Antonie Van Leeuwenhoek, 2009. 96(4): p. 395-404.
69. Bruno, V.M., et al., Control of the C. albicans cell wall damage response by transcriptional regulator Cas5. PLoS Pathog, 2006. 2(3): p. e21.
70. Adams, D.J., Fungal cell wall chitinases and glucanases. Microbiology, 2004. 150(Pt 7): p. 2029-35.
71. Hurtado-Guerrero, R., et al., Molecular mechanisms of yeast cell wall glucan remodeling. J Biol Chem, 2009. 284(13): p. 8461-9.
72. Nett, J., et al., Putative role of beta-1,3 glucans in Candida albicans biofilm resistance. Antimicrob Agents Chemother, 2007. 51(2): p. 510-20.
73. Wheeler, R.T. and G.R. Fink, A drug-sensitive genetic network masks fungi from the immune system. PLoS Pathog, 2006. 2(4): p. e35.
74. Brown, G.D. and S. Gordon, Immune recognition. A new receptor for beta-glucans. Nature, 2001. 413(6851): p. 36-7.
75. Galan-Diez, M., et al., Candida albicans beta-glucan exposure is controlled by the fungal CEK1-mediated mitogen-activated protein kinase pathway that modulates immune responses triggered through dectin-1. Infect Immun, 2010. 78(4): p. 1426-36.
76. Gonzalez, M.M., et al., Phenotypic characterization of a Candida albicans strain deficient in its major exoglucanase. Microbiology, 1997. 143 ( Pt 9): p. 3023-32.
77. Francois, J.M., A simple method for quantitative determination of polysaccharides in fungal cell walls. Nat Protoc, 2006. 1(6): p. 2995-3000.
78. Bergmeyer, H.U., Methods of Enzymatic Analysis. 3rd edn ed. 1986.
79. Bulik, D.A., et al., Chitin synthesis in Saccharomyces cerevisiae in response to supplementation of growth medium with glucosamine and cell wall stress. Eukaryot Cell, 2003. 2(5): p. 886-900.
80. Gaur, N.A., et al., Expression of the CDR1 efflux pump in clinical Candida albicans isolates is controlled by a negative regulatory element. Biochem Biophys Res Commun, 2005. 332(1): p. 206-14.
81. Reuss, O., et al., The SAT1 flipper, an optimized tool for gene disruption in Candida albicans. Gene, 2004. 341: p. 119-27.
82. Ram, A.F. and F.M. Klis, Identification of fungal cell wall mutants using susceptibility assays based on Calcofluor white and Congo red. Nat Protoc, 2006. 1(5): p. 2253-6.
83. Martinez-Esparza, M., et al., Comparative analysis of cell wall surface glycan expression in Candida albicans and Saccharomyces cerevisiae yeasts by flow cytometry. J Immunol Methods, 2006. 314(1-2): p. 90-102.
84. Michel. DuBois, K.A.G., J. K. Hamilton, P. A. Rebers, Fred. Smith, Colorimetric Method for Determination of Sugars and Related Substances. Analytical chemistry, 1956. 28(3): p. 350-356.
85. Fonzi, W.A., PHR1 and PHR2 of Candida albicans encode putative glycosidases required for proper cross-linking of beta-1,3- and beta-1,6-glucans. J Bacteriol, 1999. 181(22): p. 7070-9.
86. Kollar, R., et al., Architecture of the yeast cell wall. Beta(1-->6)-glucan interconnects mannoprotein, beta(1-->)3-glucan, and chitin. J Biol Chem, 1997. 272(28): p. 17762-75.
87. Gillum, A.M., E.Y. Tsay, and D.R. Kirsch, 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, 1984. 198(1): p. 179-82.
88. Fonzi, W.A. and M.Y. Irwin, Isogenic strain construction and gene mapping in Candida albicans. Genetics, 1993. 134(3): p. 717-28.
89. Kumamoto, C.A., A contact-activated kinase signals Candida albicans invasive growth and biofilm development. Proc Natl Acad Sci U S A, 2005. 102(15): p. 5576-81.