Recombinant adeno-associated virus type 2, 4, and 5 vectors: Transduction of variant cell types and regions in the mammalian central nervous system

Abstract

Recombinant adeno-associated virus vectors based on serotype 2 (rAAV2) can direct transgene expression in the central nervous system (CNS), but it is not known how other rAAV serotypes perform as CNS gene transfer vectors. Serotypes 4 and 5 are distinct from rAAV2 and from each other in their capsid regions, suggesting that they may direct binding and entry into different cell types. In this study, we examined the tropisms and transduction efficiencies of ␤-galactosidase-encoding vectors made from rAAV4 and rAAV5 compared with similarly designed rAAV2-based vectors. Injection of rAAV5 ␤-galactosidase (␤gal) or rAAV4␤gal into the lateral ventricle resulted in stable transduction of ependymal cells, with approximately 10-fold more positive cells than in mice injected with rAAV2␤gal. Major differences between the three vectors were revealed upon striatal injections. Intrastriatal injection of rAAV4␤gal resulted again in striking ependyma-specific expression of transgene, with a notable absence of transduced cells in the parenchyma. rAAV2␤gal and rAAV5␤gal intrastriatal injections led to ␤-gal-positive parenchymal cells, but, unlike rAAV2␤gal, rAAV5␤gal transduced both neurons and astrocytes. The number of transgene-positive cells in rAAV5␤gal-injected brains was 130 and 5,000 times higher than in rAAV2␤gal-injected brains at 3 and 15 wk, respectively. Moreover, transgene-positive cells were widely dispersed throughout the injected hemisphere in rAAV5␤gal-transduced animals. Together, our data provide in vivo support for earlier in vitro work, suggesting that rAAV4 and rAAV5 gain cell entry by means of receptors distinct from rAAV2. These differences could be exploited to improve gene therapy for CNS disorders.

In utero administration of Ad5 and AAV pseudotypes to the fetal brain leads to efficient, widespread and long-term gene expression

“…This is consistent with the findings of Lubansu et al where AAV serotype 5 was shown to be ineffective in transducing rat embryonic (E15) ganglionic eminence cultures. These data are in contrast to studies showing that AAV serotype 5 was efficient at transducing cells in adult mouse 31,32 and non-human primate brain. 33,34 This discrepancy suggests that the availability of AAV5-binding sites, such as 2,3-linked sialic acid, 35 and potential receptors may vary from gestation through to adulthood.…”

Adeno-associated virus vector-mediated transduction in the cat brain

“…27 Cross-packaging of the AAV2 vector genome into other AAV serotypes demonstrated that the amino acids of the capsids are responsible for some of the differences in cellular tropism. 16,17,26,28,29 The different capsids likely result in differences in binding to cellular receptors as evidenced by the ability of AAV1, AAV2, and AAV3 to bind to heparan sulfate, while AAV4 and 5 do not. 25,27 The receptors for AAV2 and AAV5, heparan sulfate proteoglycans and 2,3-linked sialic acid, respectively, have been determined.…”

“…15,16 Comparison of the ability of three different AAV serotypes, AAV2, 4, and 5, to transduce the mouse brain revealed that while intrastriatal injection of either AAV2 or AAV5 led to transgene-positive parenchymal cells, AAV5 resulted in the greatest number of transgenepositive cells. 17 We compared the ability of three rAAV serotypes, AAV1, 2, and 5, to achieve gene transfer in the normal cat brain. b-glucuronidase (GUSB) was used as a marker gene due to the ability to monitor enzyme expression using histochemical staining and mRNA expression using in situ hybridization on frozen brain sections.…”

Herpes Simplex Virus Type 1/Adeno-Associated Virus Hybrid Vectors

“…AAV2 has shown higher transduction efficiency in glioblastoma in vitro and in vivo when compared to serotypes 4 and 5 [183]. However, other studies have demonstrated a higher distribution and transduction in the CNS when using rAAV serotypes 1 and 5 [175, 184, 185]. The different AAV serotypes have been exploited on their ability to efficiently transduce distinct regions of the brain due to different cellular tropisms [174, 183, 186].…”