Detection of Candida proteinase by enzyme immunoassay and interaction of the enzyme with alpha-2-macroglobulin

Rüchel, R.; Böning, Birgitt

doi:10.1016/0022-1759(83)90014-5

Cited by 37 publications

(23 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Macdonald and Odds (133) were the first to detect proteinase-specific IgG antibodies in sera of patients with disseminated candidiasis at significantly higher levels than those found in healthy individuals. These findings were later confirmed by Ray and Payne (172) and Rüchel et al (186,187), further demonstrating the production of proteinases during systemic candidiasis. However, in the latter study, sera of a fifth of the patients suffering from candidiasis did not produce high titers of antibodies against purified Sap2, probably reflecting the inability of many high-risk patients to mount a normal immune response (185).…”

Section: Sap Protein Production and Sap Immune Responses In Animal Anmentioning

confidence: 61%

“…albicans proteinases may also evade host defenses by directly degrading molecules such as salivary lactoferrin, lactoperoxidase, cathepsin D (an intracellular lysosomal enzyme of leukocytes), and complement (72,94,106). In addition, Sap2 can degrade ␣ 2 -macroglobulin, a natural proteinase inhibitor in human plasma (187), and cystatin A, a cysteine proteinase inhibitor found in human epidermal tissues and fluids (238). Furthermore, the proinflammatory cytokine interleukin-1␤ can be activated from its precursor by Sap2, suggesting a role for proteinases in the activation and maintenance of the inflammatory response at epithelial surfaces in vivo (8).…”

Section: Degradation Of Human Proteins and Structural Analysis Inmentioning

confidence: 99%

See 1 more Smart Citation

Candida albicansSecreted Aspartyl Proteinases in Virulence and Pathogenesis

Naglik

Challacombe

Hube

2003

Microbiol Mol Biol Rev

1,027

970

View full text Add to dashboard Cite

Candida albicans is the most common fungal pathogen of humans and has developed an extensive repertoire of putative virulence mechanisms that allows successful colonization and infection of the host under suitable predisposing conditions. Extracellular proteolytic activity plays a central role in Candida pathogenicity and is produced by a family of 10 secreted aspartyl proteinases (Sap proteins). Although the consequences of proteinase secretion during human infections is not precisely known, in vitro, animal, and human studies have implicated the proteinases in C. albicans virulence in one of the following seven ways: (i) correlation between Sap production in vitro and Candida virulence, (ii) degradation of human proteins and structural analysis in determining Sap substrate specificity, (iii) association of Sap production with other virulence processes of C. albicans, (iv) Sap protein production and Sap immune responses in animal and human infections, (v) SAP gene expression during Candida infections, (vi) modulation of C. albicans virulence by aspartyl proteinase inhibitors, and (vii) the use of SAP-disrupted mutants to analyze C. albicans virulence. Sap proteins fulfill a number of specialized functions during the infective process, which include the simple role of digesting molecules for nutrient acquisition, digesting or distorting host cell membranes to facilitate adhesion and tissue invasion, and digesting cells and molecules of the host immune system to avoid or resist antimicrobial attack by the host. We have critically discussed the data relevant to each of these seven criteria, with specific emphasis on how this proteinase family could contribute to Candida virulence and pathogenesis

show abstract

Section: Sap Protein Production and Sap Immune Responses In Animal Anmentioning

confidence: 61%

Section: Degradation Of Human Proteins and Structural Analysis Inmentioning

confidence: 99%

Candida albicansSecreted Aspartyl Proteinases in Virulence and Pathogenesis

Naglik

Challacombe

Hube

2003

Microbiol Mol Biol Rev

1,027

970

View full text Add to dashboard Cite

show abstract

“…Rüchel et al (66) used polyclonal anti-Sap antibodies in a sandwich ELISA format to detect circulating Sap antigen in serum specimens from patients with candidiasis. Sap was detected in only 50% of suspected plus confirmed cases (66), and it was later hypothesized that sensitivity may have been reduced by the formation of complexes between Sap and alpha-2-macroglobulin in the circulation (64). Later, Na and Song (50) compared two different antigen detection ELISAs for Sap in serum, a sandwich ELISA and an a C. albicans-infected rabbits included those receiving C. albicans by the intravenous or intragastric route with evidence of dissemination to deep organs by positive culture; negative control rabbits included all uninfected rabbits, rabbits colonized with C. albicans intragastrically or intraurethrally, and rabbits intravenously infected with bacteria or fungi other than C. albicans.…”

Section: Discussionmentioning

confidence: 99%

“…In contrast, urine specimens from the same rabbits gave the following inhibition results compared to preinfection urine: day 1, 12.2 Ϯ 1.3 (2); day 2, 32.5 Ϯ 3.7 (2); and day 3, 50.8 Ϯ 1.9 (3). Given these results and the variable results obtained by others using serum (50,64,66), the remainder of the inhibition ELISA testing was conducted with urine specimens.…”

Section: Comparison Of Sap Concentrations In Serum and In Urinementioning

confidence: 99%

“…Another approach to the diagnosis of systemic candidiasis involves detection of the secreted aspartyl proteinases (Saps) of C. albicans in serum specimens (50,64,66). C. albicans, along with Candida tropicalis and Candida parapsilosis, secretes inducible aspartyl proteinases that are considered to be virulence factors which aid in the invasion of host tissue (39,63,68,72).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Competitive Binding Inhibition Enzyme-Linked Immunosorbent Assay That Uses the Secreted Aspartyl Proteinase ofCandida albicansas an Antigenic Marker for Diagnosis of Disseminated Candidiasis

Morrison

Hurst

Reiss

2003

Clin Vaccine Immunol

View full text Add to dashboard Cite

The secreted aspartyl proteinases (Saps) of Candida albicans have been implicated as virulence factors associated with adherence and tissue invasion. The potential use of proteinases as markers of invasive candidiasis led us to develop a competitive binding inhibition enzyme-linked immunosorbent assay (ELISA) to detect Sap in clinical specimens. Daily serum and urine specimens were collected from rabbits that had been immunosuppressed with cyclophosphamide and cortisone acetate and infected intravenously with 10 7 C. albicans blastoconidia. Disseminated infection was confirmed by organ culture and histopathology. Although ELISA inhibition was observed when serum specimens from these rabbits were used, more significant inhibition, which correlated with disease progression, occurred when urine specimens were used. Urine collected as early as 1 day after infection resulted in significant ELISA inhibition (mean inhibition ؎ standard error [SE] compared with preinfection control urine, 15.7% ؎ 2.7% [P < 0.01]), and inhibition increased on days 2 through 5 (29.4% ؎ 4.8% to 44.5% ؎ 3.5% [P < 0.001]). Urine specimens from immunosuppressed rabbits infected intravenously with Candida tropicalis, Candida parapsilosis, Candida krusei, Cryptococcus neoformans, Aspergillus fumigatus, or Staphylococcus aureus were negative in the assay despite culture-proven dissemination. Nonimmunosuppressed rabbits receiving oral tetracycline and gentamicin treatment were given 2 ؋ 10 8 C. albicans blastoconidia orally or intraurethrally to establish colonization of the gastrointestinal tract or bladder, respectively, without systemic dissemination; urine specimens from these rabbits also gave negative ELISA results. Dissemination to the kidney and spleen occurred in one rabbit challenged by intragastric inoculation, and urine from this rabbit demonstrated significant inhibition in the ELISA (mean inhibition ؎ SE by day 3 after infection, 32.9% ؎ 2.7% [P < 0.001]). The overall test sensitivity was 83%, the specificity was 92%, the positive predictive value was 84%, the negative predictive value was 91%, and the efficiency was 89% (166 urine samples from 33 rabbits tested). The specificity, positive predictive value, and efficiency could be increased to 97, 95, and 92%, respectively, if at least two positive test results were required for a true positive designation. The ELISA was sensitive and specific for the detection of Sap in urine specimens from rabbits with disseminated C. albicans infection, discriminated between colonization and invasive disease, reflected disease progression and severity, and has the potential to be a noninvasive means to diagnose disseminated candidiasis.

show abstract