Lab of BiochemistryDivision of Influenza viruses, Korea Center for

Disease Control and Prevention

Mi-Seon Kim

Introduction Identification method In vitro experiments In vivo experiments Conclusion

Contents

Introduction

• What’s Candida albicans?

– Opportunistic fungal

pathogen of humans

– Invasion to internal organs

through the bloodstream

systemic infections

– C. albicans & Mortality rate

<Oral cavity infection>

Introduction• Previous work

– Target : Cell wall protein

• Why is the Cell-surface protein?

–More accessible to drugs than intercellular tar-

gets

• Cell surface protein– ALS1

– HWP1

Domain organization of a typical fungal cell-wall protein

Glycosylation

CSF4

Procedure of Identification of cell-surface proteins in C. albicans

6 CSF 1~6

RT-PCR using primers inter-nal to the ORF

180 candidates

Primary sequence analysis of C.albicans Csf4 protein

< CSF4 - gene product of ORF6.1639 >

s

First allele replacement

Second allele replacement

First deletion cassette generated by 3-way PCR

Second deletion cassette

Target sequence

Target sequence

Filamentation assay

Clinical isolation Parental strain Mutant

• Invasion upon Agar• Filamentation(Hyphae formation)

•Growth on the Agar surface•Severe defect of Filamentation•No filaments around colony

• Targeted gene = No growth factor• Viable csf4 null mutant• Similar growth rate (csf4 null mutant & wild type)

• Support a role for Csf4 in the adhesion of C.albicans to mammalian cell

Adherence assay

Wild-type

Virulence Assay in vivoCsf4 null_HC

SC5314

Uninfected

BWP17_ARG/HC

SC5314

Csf4 null_HC

als1 null_HC

• CSF4– Factor of Rapid

invasion – Destrction of

key organ

Virulence Assay in vivo

Conclusion• Cell-surface proteins represent very attractive tar-

gets

• Csf4 belongs to the familly of yeast glycosidases

• Csf4 is important for adhesion of C.albicans to

mammalian cells in vitro

• Csf4 is good candidates for new virulence factor

• Csf4 is represents a very promising target for the

development of antifungal drugs

★Thank you