Double-antigen sandwich ELISA for detecting Aspergillus fumigatus anti-Afmp1cr and Afmp2cr antibodies / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish two double-antigen sandwich ELISA systems to detect anti-Afmp1cr and Afmp2cr antibodies of Aspergillus fumigatus.</p><p><b>METHODS</b>Recombinant Afmp1cr and Afmp2cr proteins of A.fumigatus expressed in Pichia pastoris were obtained. Double-antigen sandwich ELISA systems for detecting specific anti-Afmp1cr and anti-Afmp2cr antibodies were developed after chessboard titrating to determine the appropriate concentrations of the recombinant proteins and HRP-labeled proteins. The sensitivity of the assay was evaluated using serum samples of rabbits immunized with Afmp1cr and Afmp2cr. The specificity of the assay was evaluated by detecting serum samples from healthy donors and patients with other pathogenic fungal and baterial infections. The performance of the two ELISA kits was furthered evaluated using serum samples from patients with suspected Aspergillus infection.</p><p><b>RESULTS</b>The established ELISA kits were capable of detecting anti-Afmp1cr and anti-Afmp2cr antibodies in immunized rabbit serum at the maximum dilutions of 800 and 3200, respectively. No cross-reactivity was observed in detecting serum from patients with other pathogenic fungal or bactetial infections. Both of the two kits yielded positive results in sera from two established Aspergillus-infected cases and a suspected case.</p><p><b>CONCLUSIONS</b>Two antibody-capture ELISA kits were developed for the laboratory diagnosis of A.fumigatus infection and can be potentially useful in the clinical diagnosis of Aspergillosis infections.</p>

A double-antigen sandwich ELISA for detecting Penicillium marneffei Mp1p-specific antibody / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish an immunological method for detecting antibodies of Penicillium marneffei.</p><p><b>METHODS</b>The recombinant Mp1p protein of Penicillium marneffei was expressed in Pichia pastoris and labeled with HRP (Mp1p-HRP) with a modified sodium periodate method. A double-antigen sandwich enzyme-linked immunosorbant assay (ELISA) was established by determining the optimal coating concentration of Mp1p protein and the concentration of the detecting protein Mp1p-HRP. The sensitivity and specificity of the assay was evaluated by detecting Mp1p antibodies in 100 serum samples from healthy donors, 15 samples from culture-confirmed penicilliosis patients, and 21 samples from patients with culture-confirmed other fungal infections.</p><p><b>RESULTS</b>A double-antigen sandwich ELISA was successfully established for detecting Mp1p-specific antibody. The specificity of the assay was 100% (121/121) for detecting Mp1p-specific antibody in the sera from healthy donors and patients with other fungal infection. The detection results of the 15 serum samples from patients with culture-confirmed penicilliosis showed positivity for Mp1p antibody in 2 samples and Mp1p antigen positivity in 12 samples; combining the detection results of Mp1p antigen and antibody obviously increased the diagnostic sensitivity to 93.3% (14/15).</p><p><b>CONCLUSION</b>The double-antigen sandwich ELISA shows a high specificity in detecting Mp1p-specific antibody, and simultaneous detection of Mp1p antigen and antibody can increase the diagnostic sensitivity for penicilliosis.</p>

Identification and priliminary application of monoclonal antibodies against inrisive Aspergillus / 中华检验医学杂志

Objective To screen monoclonal antibodies (mAbs) for early diagnosis of invisive Aspergillus. Methods Monoclonal antibodies against different antigens of Aspergillus fumigatus were produced. The two pairs of combinations of monoclonal antibodies were selected accoring the distinct epitopes and double-antibody sandwich ELISA based on mAbs above were established. The sensitivity and specificity of the methods were analyzed by detecting culture supernatants of clinical isolates and environmental isolatesof Aspergillus. spp, Penicillium Marneffei, Candidas, and serum from animal models and patients. The epitopes recognized by mAbs were identified by immunobotting. Results A total of 32 hybridoma cell lines that stably produced MAbs were obtained. Two double- antibody sandwich ELISAs were established. One method was specific for 19 clinical isolates and environmental isolates of Aspergillus. spp, whereas the other one was specific for the clinical and environmental isolates of Aspergillus fumigatus without cross-reation with other Aspergillus. spp. For the same kind of medium of Aspergillus fumigatus, the sensitivity of the first method was 10 fold higher than the second method. Conclusions The specific mAbs for early diagnosis of invisive Aspergillus were obtained. Antigen recognized by the specific mAbs was mannoprotein with molecular weights of approximately 25 000-75 000. This antigen was potential early diagnostic marker for invasive Aspergillus.