Purpose: The feasibility of utilizing the cell surface chemokine receptor CXCR4 for human immunodeficiency virus (HIV) entry inhibition and as an intracellular portal for targeted drug delivery was evaluated.
Methods: 4DV3, a novel tetrameric peptide ligand derived from anti-HIV chemokine vMIP-II, was synthesized and conjugated to various probes (fluorescein isothiocyanate (FITC) or biotin) and cargos with sizes ranging from 10 to 70 nm (polyethylene glycol (PEG), streptavidin, and polymeric nanoparticle). TZM-bl cells, a CXCR4-expressing reporter cell line that contains the luciferase gene sensitive to HIV-1 infection, were used to study CXCR4-specific inhibition of HIV entry by 4DV3, as well as 4DV3-mediated cellular uptake of nanocarriers. For chemotaxis assay, CXCR4-expressing Sup-T1 cells were used.
Results: 4DV3 conjugated probes inhibited HIV-1 entry into the CXCR4-expressing reporter cell line TZM-bl (IC50 at 553 nM). 4DV3 also inhibited binding of anti-CXCR4 antibody 44708 to TZM-bl cells with nanomolar potency, while the small-molecule CXCR4 antagonist AMD3100 did not. In the Sup-T1 cell chemotaxis assay, the 4DV3 ligand functioned as a CXCR4 allosteric enhancer. In addition, 4DV3 ligand-conjugated cargos with sizes ranging from 10 to 70 nm were taken up into CXCR4-expressing Sup-T1 and TZM-bl cells, demonstrating that CXCR4 could serve as a drug delivery portal for nanocarriers. The uptake of 4DV3 functionalized nanocarriers combined with the allosteric interaction with CXCR4 suggests enhanced endocytosis occurs when 4DV3 is the targeting ligand.
Conclusion: The current results indicate that 4DV3 might serve as a prototype for a new type of dual function ligand that acts as a HIV-1 entry inhibitor and a CXCR4 drug delivery targeting ligand.
In Heon Lee
– PhD Candidate, Rutgers University, North Brunswick, New JerseyIn Heon Lee
– PhD Candidate, Rutgers University, North Brunswick, New JerseyMatthew Palombo
– Rutgers University Ernest Mario School of PharmacyXiaoping Zhang
– Rutgers University Ernest Mario School of PharmacyZoltan Szekely
– Assistant Research Professor, Rutgers University Ernest Mario School of PharmacyPatrick Sinko
– Distinguished Professor, Rutgers University Ernest Mario School of PharmacyIn Heon Lee
– PhD Candidate, Rutgers University, North Brunswick, New Jersey339 Views