Differential Expression ofCandida albicansSecreted Aspartyl Proteinase and Phospholipase B Genes in Humans Correlates with Active Oral and Vaginal Infections

Abstract

The in vivo expression of Candida albicans secreted aspartyl proteinase (SAP1-SAP8) and phospholipase B (PLB1 and PLB2) genes was analyzed in 137 human subjects with oral and vaginal candidiasis or carriage. Total RNA was isolated from whole unstimulated saliva or vaginal swabs, and the expression of SAP1-8 and PLB1-2 was evaluated by reverse-transcriptase polymerase chain reaction using specific primer sets. A spectrum of SAP gene expression profiles was obtained from different C. albicans strains during symptomatic disease and asymptomatic carriage. SAP2 and SAP5 were the most common genes expressed during both infection and carriage. SAP1, SAP3, SAP4, SAP7, SAP8, and PLB1 expression was correlated with oral disease, whereas SAP1, SAP3, and SAP6-SAP8 expression was correlated with vaginal disease. Furthermore, SAP1, SAP3, and SAP8 were preferentially expressed in vaginal, rather than oral, infections. This study demonstrates the differential expression of the hydrolytic enzyme genes in humans and correlates the expression of specific Candida species virulence genes with active disease and anatomical location.

Candida albicans HWP1 gene expression and host antibody responses in colonization and disease

“…colonization, among inhibitory microbial flora, to frequent occurrence of asymptomatic oral and vaginal carriage, and to virulence in immunocompetent and immunodeficient hosts, are poorly understood. In previous work, we have found that expression of specific secreted aspartyl proteinase (SAP) genes is correlated with active disease and anatomical location, whereas expression of other SAP genes reflects the presence of the organism but not disease (Naglik et al, 2003).Hyphal wall protein (Hwp1), a transglutaminase substrate which functions as an adhesin, is important for the pathogenesis of candidiasis (Staab et al, 1996(Staab et al, , 1999Sundstrom et al, 2002). HWP1 mRNA and protein are abundant in hyphae in vitro, and greatly reduced or undetectable in yeast forms (Staab et al, 1996(Staab et al, , 1999 Sharkey et al, 1999;Nantel et al, 2002).…”

“…Hypha-specific expression of Hwp1 extends to fungal growth in the host, as shown by the presence and absence of Hwp1 on hyphae and yeast, respectively, in candidiasis of the murine stomach (Sundstrom et al, 2002). To gain insight into the relationship between HWP1 gene expression and commensalism or symptomatic tissue invasion, we analysed the same carrier and candidiasis specimens that had been used previously to determine SAP and PLB gene expression in samples of whole unstimulated saliva and vaginal swabs (Naglik et al, 2003) supported a potentially important role for hyphal forms in asymptomatic infections with C. albicans. …”

“…To gain insight into the relationship between HWP1 gene expression and commensalism or symptomatic tissue invasion, we analysed the same carrier and candidiasis specimens that had been used previously to determine SAP and PLB gene expression in samples of whole unstimulated saliva and vaginal swabs (Naglik et al, 2003) supported a potentially important role for hyphal forms in asymptomatic infections with C. albicans.…”

“…Serum samples originally collected from some of the individuals in the oral RT-PCR study were supplemented with new samples from patients from the Oral Medicine clinic to obtain adequate numbers for comparison among groups. Sample numbers were based on power calculations from our previous studies (Naglik et al, 1999(Naglik et al, , 2003.RT-PCR analysis of C. albicans HWP1 mRNA expression.HWP1 gene expression was examined using qualitative and quantitative RT-PCR. A radioactive qualitative RT-PCR was developed to enable detection of the low levels of C. albicans mRNA in the oral or vaginal carrier state, a requirement for studies aimed at comparing the carrier state with candidiasis (Naglik et al, 1999(Naglik et al, , 2003.…”

“…Sample numbers were based on power calculations from our previous studies (Naglik et al, 1999(Naglik et al, , 2003.…”