Detection of HIV-1 p24  Gag in plasma by a nanoparticle-based bio-barcode-amplification method. (June 2008)

• Record Type: Journal Article
• Authors: Kim, Eun-Young; Stanton, Jennifer; Korber, Bette TM; Krebs, Kendall; Bogdan, Derek; Kunstman, Kevin; Wu, Samuel; Phair, John P; Mirkin, Chad A; Wolinsky, Steven M
• Is Part Of: Nanomedicine. Volume 3:Number 3(2008)
• Page Start: 293
• Page End: 303
• Publication Date: 2008-06
• Subjects: bio-barcode-amplification method -- HIV-1 -- major core protein of HIV-1 (p24 Gag); Nanotechnology -- Periodicals; Medical technology -- Periodicals; Nanotechnology -- Therapeutic use -- Periodicals; 610.28
• DOI: 10.2217/17435889.3.3.293
• Languages: English
• ISSNs: 1743-5889

Abstract

Background: Detection of HIV-1 in patients is limited by the sensitivity and selectivity of available tests. The nanotechnology-based bio-barcode-amplification method offers an innovative approach to detect specific HIV-1 antigens from diverse HIV-1 subtypes. We evaluated the efficacy of this protein-detection method in detecting HIV-1 in men enrolled in the Chicago component of the Multicenter AIDS Cohort Study (MACS).Methods: The method relies on magnetic microparticles with antibodies that specifically bind the HIV-1 p24 Gag protein and nanoparticles that are encoded with DNA and antibodies that can sandwich the target protein captured by the microparticle-bound antibodies. The aggregate sandwich structures are magnetically separated from solution, and treated to remove the conjugated barcode DNA. The DNA barcodes (hundreds per target) were identified by a nanoparticle-based detection method that does not rely on PCR.Results: Of 112 plasma samples from HIV-1-infected subjects, 111 were positive for HIV-1 p24 Gag protein (range: 0.11––71.5 ng/ml of plasma) by the bio-barcode-amplification method. HIV-1 p24 Gag protein was detected in only 23 out of 112 men by the conventional ELISA. A total of 34 uninfected subjects were negative by both tests. Thus, the specificity of the bio-barcode-amplification method was 100% and the sensitivity 99%. The bio-barcode-amplification method detected HIV-1 p24 Gag protein in plasma from all study subjects with less than 200 CD4 + T cells/µµl of plasma (100%) and 19 out of 20 (95%) HIV-1-infected men who had less than 50 copies/ml of plasma of HIV-1 RNA. In a separate group of 60 diverse international isolates, representative of clades A, B, C and D and circulating recombinant forms CRF01_AE and CRF02_AG, the bio-barcode-amplification method identified the presence of virus correctly.Conclusions: The bio-barcode-amplification method was superior to the conventional ELISA assay for the detection of HIV-1 p24 Gag protein in plasma with a breadth of coverage for diverse HIV-1 subtypes. Because the bio-barcode-amplification method does not require enzymatic amplification, this method could be translated into a robust point-of-care test.