Generation and application of ssDNA aptamers against glycolipid antigen ManLAM of Mycobacterium tuberculosis for TB diagnosis - 14/04/16

Summary |
The development of effective Mycobacterial antigen diagnostic reagents remains a high priority. Mannose-capped lipoarabinomannan (ManLAM) is a lipoglycan serving as a major cell wall component. ManLAM is also an early released antigen in the blood circulation system during Mycobacteria tuberculosis (M.tb) infection and is a perfect target antigen for TB diagnosis. In this study, ssDNA aptamers “antibodies” against ManLAM of the predominant clinical epidemic M.tb Beijing genotype strains were generated by the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) technique. The selected single aptamer T9 demonstrated the highest specificity and binding affinity, with an equilibrium dissociation constant (Kd) of 668 ± 159 nmol/L. We further detected ManLAM antigens in serum and sputum samples from active pulmonary tuberculosis (aPTB) patients, extrapulmonary TB (EPTB) patients and healthy donors by using a T9 based enzyme-linked oligonucleotide assay (ELONA). The results showed that the specificity and sensitivity were 95.31% and 83.00% (for 100 aPTB serum samples), 98.70% and 92.71% (for 96 aPTB sputum samples), and 94.44% and 88.71% (for 62 EPTB serum samples), respectively. A good correlation was observed between the T9 aptamer-based ELONA and the clinical T-SPOT.TB. Thus, T9 based ELONA has potentials for diagnosis of TB, including inactive TB, smear-negative TB, EPTB, and TB with immunodeficiency, and assist the diagnosis of LTBI albeit it could not distinguish LTBI and active TB.
Le texte complet de cet article est disponible en PDF.Highlights |
• | A high-affinity aptamer T9 for ManLAM of M.tb Beijing genotype strains was screened by SELEX. |
• | T9 based-ELONA was used for TB antigen diagnosis with serum or sputum samples. |
• | A good correlation was observed between T9-based ELONA and clinical T-SPOT.TB. |
• | T9 is a new potential TB diagnostic agent with high specificity and sensitivity. |
• | T9 may diagnose M.tb infection, including inactive TB, AFB−TB, EPTB, and TB with immunodeficiency. |
Keywords : Aptamer, Diagnosis, Mannosylated lipoarabinomannan (ManLAM), Mycobacteria tuberculosis (M.tb), Tuberculosis (TB), Enzyme-linked oligonucleotide assay (ELONA)
Plan
Vol 72 - N° 5
P. 573-586 - mai 2016 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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