Concanavalin A-immobilized polystyrene nanospheres capture HIV-1 virions and gp120: Potential approach towards prevention of viral transmission

Abstract

To establish an effective tool for the prevention of HIV-1 transmission, lectin-immobilized polystyrene nanospheres were synthesized and examined for their HIV-1 capture activity. When concanavalin A (Con A) was immobilized on the surface of polystyrene nanospheres (400 nm in diameter) with poly(methacrylic acid) branches and incubated with HIV-1 suspension at room temperature for 60 min, the nanospheres (Con A-NSs) achieved a >3.3 log and a 2.2 log reduction of viral infectivity in HIV-1 (IIIB strain) suspension at a concentration of 2 and 0.5 mg/ml, respectively. Meanwhile, Con A-free nanospheres, which were not immobilized with Con A, achieved only a 0.29 log reduction at 0.5 mg/ ml. Con A-NSs (2 mg/ml) could also reduce the gp120 level of III(B) and HE strains to <7.1% and 5.5% of each control, respectively. The combination of Con A-NS treatment followed by filtration with a microporous membrane efficiently removed virion-free gp120 as well as infectious viral particles from HIV-1 suspension. Electron microscopic examination demonstrated that HIV-1 virions were trapped on the surface of Con A-NSs. Thus, Con A-NSs can capture HIV-1 virions and gp120 with high affinity, and may have potential as an effective tool for the prevention of HIV-1 transmission.

A Review of Current Intravaginal Drug Delivery Approaches Employed for the Prophylaxis of HIV/AIDS and Prevention of Sexually Transmitted Infections

“…Its original function is believed to be an antiprotease defense against neutrophils at the mucosal surfaces (155). In vitro laboratory studies have shown that SLPI can inhibit HIV entry into CD4 + cells by interacting with targeted cells blocking access as a barrier function.…”

“…This may provide a reason as to the low rate of HIV infection through oral sex due to the presence of SLPI in saliva. Data from studies of various mucosal tissues such as the mouth, gut, rectum and endocervix, suggest an inverse relationship between infectious HIV and the presence of SLPI (155). Further studies of SLPI as "a natural endogenous product" need to be performed since it has been shown to have the potential to function as an effective microbicide (155)(156)(157).…”

Graft copolymers having hydrophobic backbone and hydrophilic branches. XXX. Preparation of polystyrene-core nanospheres having a poly(2-methacryloyloxyethyl phosphorylcholine) corona

“…22,23 Lectins have been covalently conjugated to a poly-(methacrylic acid) corona of the same polySt core and used to capture HIV-1 gp120 and virions with the interaction between lectins on the nanosphere and mannose of gp120. 17,18 Lactose has also been covalently bonded to a poly(vinylamine) corona of the same core and used to recognize a lectin. 24,25 Very recently, we directly observed cross-sectional morphologies of core-corona nanospheres by transmission electron microscopy (TEM).…”

Targeting of Antigen to Dendritic Cells with Poly(γ-Glutamic Acid) Nanoparticles Induces Antigen-Specific Humoral and Cellular Immunity

“…We have previously reported that Con A-immobilized polystyrene NPs could efficiently capture HIV-1 particles and gp120 Ags (20). Immunization with inactivated HIV-1-capturing NPs induced HIV-1-specific IgA Abs in the genital tract of mice (21,22).…”