Cell-penetrating peptides enhance the transduction of adeno-associated virus serotype 9 in the central nervous system

Abstract

Recombinant adeno-associated viruses (rAAVs) have been widely used in the gene therapy field for decades. However, because of the challenge of effectively delivering rAAV vectors through the blood-brain barrier (BBB), their applications for treatment of central nervous system (CNS) diseases are quite limited. In this study, we found that several cell-penetrating peptides (CPPs) can significantly enhance the in vitro transduction efficiency of AAV serotype 9 (AAV9), a promising AAV vector for treatment of CNS diseases, the best of which was the LAH4 peptide. The enhancement of AAV9 transduction by LAH4 relied on binding of the AAV9 capsid to the peptide. Furthermore, we demonstrated that the LAH4 peptide increased the AAV9 transduction in the CNS in vitro and in vivo after systemic administration. Taken together, our results suggest that CPP peptides can interact directly with AAV9 and increase the ability of this AAV vector to cross the BBB, which further induces higher expression of target genes in the brain. Our study will help to improve the applications of AAV gene delivery vectors for the treatment of CNS diseases.

A novel strategy for deliveringNiemann‐Pick typeC2proteins across the blood–brain barrier using the brain endothelial‐specificAAV‐BR1virus

“…This is favorable when using AAV gene therapy since increased risks of developing hepatocellular carcinoma following accumulation of AAV vectors have previously been reported (Chandler et al, 2015; Donsante et al, 2001; Nault et al, 2015; Rosas et al, 2012). By comparison, AAV9 vectors or peptide‐conjugated AAV vectors reportedly with natural tropism for the CNS (Duque et al, 2009; Gray et al, 2011; Meng et al, 2021; Yang et al, 2014) are often associated with marked vector accumulation and off‐target effects in non‐neuronal tissues, including the liver. The liver, kidney, lung, heart, and spleen of mice injected with the AAV‐BR1 vector revealed no signs of fibrosis or malignancy (Dogbevia et al, 2017).…”

Current advances in gene therapy of mitochondrial diseases

“…These sequences form amphipathic helices that vary largely in primary sequence but are characterized by a length of about 15–60 residues, a net charge of + 3 to + 6, the absence of negatively charged residues and a high content of hydroxylated amino acids [ 86 , 87 ]. Rational design methods have also been utilized for the creation of new viral capsids with penetrating peptides or mitochondria localization signals [ 88 , 89 ].…”

Enhancement of adeno‐associated virus serotype 6 transduction into T cells with cell‐penetrating peptides

“…This was indicated by reduced expression of inflammation factors and decreased T lymphocyte infiltration within the mouse tissue. 25 Histopathologic analysis of CPP-mediated transduction of mouse muscle tissues with AAV2 revealed no significant changes, and immunohistochemical examination indicated comparable rates of T lymphocyte infiltration between muscles injected with AAV2 alone or with AAV2-CPP. 24 There was no significant difference in induced cytokine transcripts between the two groups, indicating that CPPs did not heighten the host cell immune response to AAV vectors when complexed with AAV2.…”

“…24,[51][52][53] Microscopy analysis (Figure 3) showed increased uptake of AAV6-LAH4 complexes into immortalized and primary T cells (Figure 3B,D), consistent with previous reports. 24,25 The histidine-rich LAH4 peptide 54 binds to the plasma membrane via electrostatic interactions with heparan sulfate proteoglycan (HSPG). 55,56 Although AAV6 also binds HSPG, 57 its cellular uptake does not depend on this receptor; 14,58 instead, it utilizes n-linked sialic acid as a primary receptor for transduction.…”

“…23 Previous research has demonstrated the ability of CPPs to enhance the in vitro and in vivo transduction of AAV serotypes 2, 8 and 9 in human and murine cells. 24,25 In the present study, we report the evaluation of five different CPPs for the enhancement of AAV6-mediated gene delivery in vitro.…”