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Synthetic peptides mimic gp75 from Paracoccidioides brasiliensis in the diagnosis of paracoccidioidomycosis.

Caldini CP, Xander P, Kioshima ÉS, Bachi AL, de Camargo ZP, Mariano M, Lopes JD - Mycopathologia (2012)

Bottom Line: There was significant recognition of P2 by sera of untreated PCM patients when compared with normal human sera.These data indicate a potential use of P2 as diagnostic tool in PCM.Its application for serological diagnosis of PCM may contribute to the development and standardization of simpler, faster and highly reproducible immunodiagnostic tests at low cost.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo-Escola Paulista de Medicina, Disciplina de Imunologia, Rua Botucatu, 862, 4º andar, São Paulo, 04023-900, Brazil.

ABSTRACT
Paracoccidioidomycosis (PCM) is a systemic granulomatous disease, endemic in Latin America, caused by the thermal dimorphic fungus Paracoccidioides brasiliensis. Although some fungal antigens have already been characterized and used for serological diagnosis, cross-reactions have been frequently observed. Thus, the examination of fungal forms in clinical specimens or isolation of P. brasiliensis by culture is still the most frequent method for the diagnosis of this mycosis. In this study, a random peptide phage display library was used to select mimotopes of P. brasiliensis, which were employed as antigens in an indirect enzyme-linked immunosorbent assay. The protective monoclonal antibody against experimental PCM (anti-gp75) was used as molecular target to screen a phage display library. That approach led to a synthetic peptide named P2, which was synthesized and tested against PCM patients' sera to check whether it was recognized. There was significant recognition of P2 by sera of untreated PCM patients when compared with normal human sera. Sera from treated PCM group, patients with other mycosis or co-infected with HIV had much lower recognition of P2 than untreated patient group. The test showed a sensitivity of 100 and 94.59% of specificity in relation to human sera control. These data indicate a potential use of P2 as diagnostic tool in PCM. Its application for serological diagnosis of PCM may contribute to the development and standardization of simpler, faster and highly reproducible immunodiagnostic tests at low cost.

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Related in: MedlinePlus

Recognition of P2 synthetic peptide by serum of PCM patients. Sera of untreated PCM patients (n = 33), treated PCM patients (n = 31), patients co-infected with HIV and PCM (n = 10), patients co-infected with HIV and HC (n = 10), aspergillosis (Asp, n = 8), histoplasmosis (HC, n = 17), candidemia (n = 24) and human normal serum (NHS, n = 37) were tested to verify the reactivity against P2 peptide. Untreated PCM group significantly recognized P2 as compared with other groups (P < 0.005). ANOVA was followed by the Tukey–Kramer test
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Fig4: Recognition of P2 synthetic peptide by serum of PCM patients. Sera of untreated PCM patients (n = 33), treated PCM patients (n = 31), patients co-infected with HIV and PCM (n = 10), patients co-infected with HIV and HC (n = 10), aspergillosis (Asp, n = 8), histoplasmosis (HC, n = 17), candidemia (n = 24) and human normal serum (NHS, n = 37) were tested to verify the reactivity against P2 peptide. Untreated PCM group significantly recognized P2 as compared with other groups (P < 0.005). ANOVA was followed by the Tukey–Kramer test

Mentions: Given that previous works showed that infected mice sera and PCM patients’ sera react with a band of 75 kDa by Western blot assay [26, 27], and considering the hypothesis that P2 peptide may represent a mimotope of gp75, we asked whether P2 peptide could be recognized by PCM patients’ sera. In this proposal, ELISA was developed using P2 as antigen. Figure 4 shows that there was recognition of P2 peptide by sera from PCM untreated individuals. On the other hand, there was no reaction with sera from normal individuals (NHS) when compared with treated patients (P < 0.005). The cutoff was estimated by the ROC curve, and the value determined by this method was 0.4233. The sensitivity was 100% and specificity 94.59%.Fig. 4


Synthetic peptides mimic gp75 from Paracoccidioides brasiliensis in the diagnosis of paracoccidioidomycosis.

Caldini CP, Xander P, Kioshima ÉS, Bachi AL, de Camargo ZP, Mariano M, Lopes JD - Mycopathologia (2012)

Recognition of P2 synthetic peptide by serum of PCM patients. Sera of untreated PCM patients (n = 33), treated PCM patients (n = 31), patients co-infected with HIV and PCM (n = 10), patients co-infected with HIV and HC (n = 10), aspergillosis (Asp, n = 8), histoplasmosis (HC, n = 17), candidemia (n = 24) and human normal serum (NHS, n = 37) were tested to verify the reactivity against P2 peptide. Untreated PCM group significantly recognized P2 as compared with other groups (P < 0.005). ANOVA was followed by the Tukey–Kramer test
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3368115&req=5

Fig4: Recognition of P2 synthetic peptide by serum of PCM patients. Sera of untreated PCM patients (n = 33), treated PCM patients (n = 31), patients co-infected with HIV and PCM (n = 10), patients co-infected with HIV and HC (n = 10), aspergillosis (Asp, n = 8), histoplasmosis (HC, n = 17), candidemia (n = 24) and human normal serum (NHS, n = 37) were tested to verify the reactivity against P2 peptide. Untreated PCM group significantly recognized P2 as compared with other groups (P < 0.005). ANOVA was followed by the Tukey–Kramer test
Mentions: Given that previous works showed that infected mice sera and PCM patients’ sera react with a band of 75 kDa by Western blot assay [26, 27], and considering the hypothesis that P2 peptide may represent a mimotope of gp75, we asked whether P2 peptide could be recognized by PCM patients’ sera. In this proposal, ELISA was developed using P2 as antigen. Figure 4 shows that there was recognition of P2 peptide by sera from PCM untreated individuals. On the other hand, there was no reaction with sera from normal individuals (NHS) when compared with treated patients (P < 0.005). The cutoff was estimated by the ROC curve, and the value determined by this method was 0.4233. The sensitivity was 100% and specificity 94.59%.Fig. 4

Bottom Line: There was significant recognition of P2 by sera of untreated PCM patients when compared with normal human sera.These data indicate a potential use of P2 as diagnostic tool in PCM.Its application for serological diagnosis of PCM may contribute to the development and standardization of simpler, faster and highly reproducible immunodiagnostic tests at low cost.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo-Escola Paulista de Medicina, Disciplina de Imunologia, Rua Botucatu, 862, 4º andar, São Paulo, 04023-900, Brazil.

ABSTRACT
Paracoccidioidomycosis (PCM) is a systemic granulomatous disease, endemic in Latin America, caused by the thermal dimorphic fungus Paracoccidioides brasiliensis. Although some fungal antigens have already been characterized and used for serological diagnosis, cross-reactions have been frequently observed. Thus, the examination of fungal forms in clinical specimens or isolation of P. brasiliensis by culture is still the most frequent method for the diagnosis of this mycosis. In this study, a random peptide phage display library was used to select mimotopes of P. brasiliensis, which were employed as antigens in an indirect enzyme-linked immunosorbent assay. The protective monoclonal antibody against experimental PCM (anti-gp75) was used as molecular target to screen a phage display library. That approach led to a synthetic peptide named P2, which was synthesized and tested against PCM patients' sera to check whether it was recognized. There was significant recognition of P2 by sera of untreated PCM patients when compared with normal human sera. Sera from treated PCM group, patients with other mycosis or co-infected with HIV had much lower recognition of P2 than untreated patient group. The test showed a sensitivity of 100 and 94.59% of specificity in relation to human sera control. These data indicate a potential use of P2 as diagnostic tool in PCM. Its application for serological diagnosis of PCM may contribute to the development and standardization of simpler, faster and highly reproducible immunodiagnostic tests at low cost.

Show MeSH
Related in: MedlinePlus