Cool Tools 2: Development of a Candida albicans Cell Surface Protein Microarray

Abstract

The cell surface of Candida albicans is necessary for colonization of the human host and is also the target of the immune system when C. albicans enters the bloodstream as an opportunistic pathogen. In a study to develop C. albicans cell surface protein microarray, cell surface antigens that are specific to different phases (i.e., acute phase and early and midconvalescence) of candidemia, were identified. The study identified a set of 13 cell surface antigens capable of distinguishing acute candidemia from healthy individuals and uninfected hospital patients with commensal colonization. Studies need to address whether the serodiagnostic antigens identified in this study could provide protection from hematogenously disseminated candidiasis and whether sero-logical differences exist between superficial (i.e., thrush and vaginal candidiasis) and systemic infections. The increasing number of candidal infections necessitates the assay development of protein microarrays that include the whole proteome of not just C. albicans but also other pathogenic Candida species, as these studies may elucidate additional sero-diagnostic antigens and/or vaccine candidates. A high-throughput in vivo transformation system using a pXT7 linear vector was employed for cloning PCR products of genes encoding cell surface proteins. For PCR amplification, all forward and reverse primers had common 33-nucleotide-long sequences at the 5' end, followed by a gene-specific sequence (20 to 26 nucleotides). The protein microarray was produced by printing the in vitro-expressed proteins in duplicate onto nitrocellulose-coated FAST glass slides at a density of 960 spots per slide using an automatic GMS417 robot and the OmniGrid 100.