Vectofusin-1, a potent peptidic enhancer of viral gene transfer forms pH-dependent α-helical nanofibrils, concentrating viral particles

Abstract

Gene transfer using lentiviral vectors has therapeutic applications spanning from monogenic and infectious diseases to cancer. Such gene therapy has to be improved by enhancing the levels of viral infection of target cells and/or reducing the amount of lentivirus for greater safety and reduced costs. Vectofusin-1, a recently developed cationic amphipathic peptide with a pronounced capacity to enhance such viral transduction, strongly promotes the entry of several retroviral pseudotypes into target cells when added to the culture medium. To clarify the molecular basis of its action the peptide was investigated on a molecular and a supramolecular level by a variety of biophysical approaches. We show that in culture medium vectofusin-1 rapidly forms complexes in the 10 nm range that further assemble into annular and extended nanofibrils. These associate with viral particles allowing them to be easily pelleted for optimal virus-cell interaction. Thioflavin T fluorescence, circular dichroism and infrared spectroscopies indicate that these fibrils have a unique α-helical structure whereas most other viral transduction enhancers form β-amyloid fibrils. A vectofusin-1 derivative (LAH2-A4) is inefficient in biological assays and does not form nanofibrils, suggesting that supramolecular assembly is essential for transduction enhancement. Our observations define vectofusin-1 as a member of a new class of α-helical enhancers of lentiviral infection. Its fibril formation is reversible which bears considerable advantages in handling the peptide in conditions well-adapted to Good Manufacturing Practices and scalable gene therapy protocols.

Structure and Function in Antimicrobial Piscidins: Histidine Position, Directionality of Membrane Insertion, and pH-Dependent Permeabilization

“…[96][97][98][99][100] Higher pH, which is consistent with neutral histidines, was required for cell entry by the peptides. [101][102] Interestingly, the authors showed that these histidine-rich AMPs can be more disruptive when they adopt an in-plane rather than TM orientation. 12,103 An integrated model was proposed to explain how pH can affect the charges, structures, and topologies of the peptides.…”

Materials promoting viral gene delivery

“…For instance, several studies about CAR T-cell manufacturing employed kits of the peptidic enhancers Vectofusin®-1 (Miltenyi Biotec) and Protransduzin™ (JPT Peptide Technologies). 353,354,528,529 However, popular materials in research cannot seamlessly be transferred to the clinical context. Low cell viability in high concentrations limits the application of Polybrene® (Abbott Laboratories Corp.) in drug formulations.…”

The Reversible Non-covalent Aggregation Into Fibers of PGLa and Magainin 2 Preserves Their Antimicrobial Activity and Synergism

“…Whereas the interactions of antimicrobial peptides with lipids and other peptides within membranes have been the focus of prior biophysical investigations (Aisenbrey et al, 2019 ) much less is known about their interactions in solution. This is somewhat surprising because the potential of even very short polypeptides or extended amino acids to assemble into complex supramolecular assemblies has attracted increased attention in the context of biomaterials (Kumar et al, 2016 ; Chakraborty and Gazit, 2018 ; Beesley and Woolfson, 2019 ; Sun et al, 2019 ), biomedical applications (Fitzpatrick et al, 2013 ; Meier et al, 2014 ; Vermeer et al, 2017 ; Hainline et al, 2018 ) or amyloidogenic diseases (Fusco et al, 2016 ; Qiang et al, 2017 ; Ramamoorthy, 2018 ). Interestingly, the amyloid-beta peptide involved in Alzheimer disease has been found to not only assemble into fibrillar structures but to also exhibit antimicrobial activity (Soscia et al, 2010 ; Gosztyla et al, 2018 ).…”