In Vivo Analysis of Secreted Aspartyl Proteinase Expression in Human Oral Candidiasis

Abstract

Secreted aspartyl proteinases are putative virulence factors inCandida infections. Candida albicans possesses at least nine members of a SAP gene family, all of which have been sequenced. Although the expression of the SAPgenes has been extensively characterized under laboratory growth conditions, no studies have analyzed in detail the in vivo expression of these proteinases in human oral colonization and infection. We have developed a reliable and sensitive procedure to detect C. albicans mRNA from whole saliva of patients with oral C. albicans infection and those with asymptomaticCandida carriage. The reverse transcription-PCR protocol was used to determine which of the SAP1 to SAP7genes are expressed by C. albicans during colonization and infection of the oral cavity. SAP2 and the SAP4to SAP6 subfamily were the predominant proteinase genes expressed in the oral cavities of both Candida carriers and patients with oral candidiasis; SAP4, SAP5, orSAP6 mRNA was detected in all subjects. SAP1and SAP3 transcripts were observed only in patients with oral candidiasis. SAP7 mRNA expression, which has never been demonstrated under laboratory conditions, was detected in several of the patient samples. All seven SAP genes were simultaneously expressed in some patients with oral candidiasis. This is the first detailed study showing that the SAP gene family is expressed by C. albicans during colonization and infection in humans and that C. albicans infection is associated with the differential expression of individualSAP genes which may be involved in the pathogenesis of oral candidiasis.

Differential expression of Candida albicans secreted aspartyl proteinase in human vulvovaginal candidiasis

“…In general, Sap2 is the main C. albicans proteinase. 5,9,10 Our results are consistent with the premise that Sap2 is a predominant proteinase of C. albicans, as SAP2 expression was observed in all patients with VVC, RVVC and all Candida carrier individuals ( Table 2). In support of this conclusion is the broad substrate specificity of Sap2, 2 and its role in causing tissue damage as assessed in an reconstituted human epithelium (RHE) oral model 6 and virulence in a rat vaginitis model.…”

“…An RT-PCR was used for analysis of SAP1 to SAP7 gene expression in vivo infection as described elsewhere. 9 Nine RT-PCRs were performed for each sample of RNA isolated from each patient vaginal secretion sample. These included the five experimental reactions for SAP detection (SAP1, SAP2, SAP3, SAP4-6, and SAP7) and four different control reactions, as follows: two actin control reactions to demonstrate the presence or absence of Candida species, a negative (water) control reaction, and a positive control reaction carried out by using total RNA isolated from SAP2 mRNA-expressing C. albicans ATCC 14053 cells (SAP2 RNA).…”

“…2,3 The differential expression of SAP genes has been detected under a variety of laboratory conditions, 4,5 in experimental models of reconstituted human cutaneous, oral and vaginal C. albicans infection [6][7][8] and in vivo, both in animal models of infection and in humans suffering from oral and vaginal candidiasis. 9,10 Different SAP genes appear to be essential for mucosal (SAP1-SAP3 6,[11][12][13] and systemic (SAP4-SAP6) 14 infections and also are involved in C. albicans adherence, 15 tissue damage, 16 and evasion of host immune responses. 17 The expression and importance of SAP1, SAP2, SAP3 during murine vaginal candidiasis were also demonstrated by using RT-PCR and SAP-deficient mutants.…”

Expression of Secreted Aspartyl Proteinases in an Experimental Model of Candida albicans‐Associated Denture Stomatitis

“…The first in vivo study detecting C. albicans mRNA from whole saliva of patients with oral C. albicans infection indicated that the pathogenesis of Candida-associated DS may be associated with the differential expression of individual SAP genes. 38 Furthermore, the significant differences in SAP activity between C. albicans strain isolates from diseased and healthy patients suggested a correlation between in vitro biofilm-associated proteinase activity and severity of disease. 28 However, given the clinical spectrum of disease for patients with DS, the salivary flow or presence of biofilm alone does not explain the clinical presentation, since it is clear that host immune factors are likely to play a role in the pathogenesis.…”

Erythematous candidosis in patients with complete dentures and HIV+/AIDS

“…4 Proteinase specificity acts as a key factor in the degradation and invasion of the host, and it is important to destroy the main defense barriers of the oral mucosa. 5 The pathogenesis of EC by C. albicans is associated with its capability to produce exoenzymes, such as proteinase and phospholipase. 6 Proteinase and phospholipase production facilitates yeast adherence and invasion of the mucosa.…”