A technique for capturing broad subtypes and circulating recombinant forms of HIV-1 based on anionic polymer-coated magnetic beads.

Magnetic beads coated with an anionic polymer, poly(methyl vinyl ether-maleic anhydrate) [poly(MVE-MA)], were used in a method to capture human immunodeficiency virus type-1 (HIV-1). The beads were incubated with either HIV-1-infected cell culture medium or plasma from HIV-1 infected individuals and separated from the supernatant by applying a magnetic field. After thorough washing, adsorption of HIV-1 by the beads was confirmed by reverse transcription (RT)-polymerase chain reaction (PCR), real-time PCR, enzyme-linked immunosorbent assay and western blotting. The results confirmed the presence of envelope, polymerase, Nef and the viral genome of HIV-1. Furthermore, various subtypes and circulating recombinant forms (CRFs) of HIV-1 including subtype B, C and CRF01_AE and the immature form of subtype B HIV-1 could be captured. Preincubation with neutralizing antibody against HIV-1 envelope gp41 decreased the capture efficiently, suggesting that poly(MVE-MA) binds HIV-1 via gp41. We believe that this capture procedure will be a valuable tool for detecting various types of HIV-1 in both clinical and experimental samples.