Widespread Dispersion of Adeno-Associated Virus Serotype 1 and Adeno-Associated Virus Serotype 6 Vectors in the Rat Central Nervous System and in Human Glioblastoma Multiforme Xenografts

Abstract

The transduction patterns of recombinant adeno-associated virus serotype 1 (AAV1) and serotype 6 (AAV6) vectors were assessed in human glioblastoma multiforme (GBM) cell lines, in human GBM biopsy spheroids, and in tumor xenografts growing in nude rat brains. All the cell lines tested (A172, D37, GaMg, HF66, and U373Mg) were found to be permissive to both AAV1 and AAV6 vectors, and thus displayed a transduction pattern similar to AAV2 vectors. For every cell line tested, the transduction efficiency displayed by AAV2 vectors was better than by isogenic and isopromoter AAV1 vectors. Transduction efficiency was dependent on the viral particle number used, suggesting that the receptors for these vectors are widely distributed in GBM tissues. Interestingly, AAV1, AAV2, and AAV6 vectors were able to infect and transduce the same cells when added simultaneously to monolayer cultures. Infection of human GBM biopsy spheroids with AAV1 and AAV6 vectors resulted in transgene expression both at the surface layers and in the core of the spheroids. Following injection of AAV1 and AAV6 vectors into human GBM biopsy xenografts growing in nude rat brains, reporter gene expression was seen both in the periphery as well as in the central regions of the tumors. When injected into the normal rat brain, both AAV1 and AAV6 vectors were found to transduce several central nervous system (CNS) regions. The presented results suggest a potential therapeutic role for AAV1 and AAV6 vectors in gene therapy for GBM and also for other CNS malignancies.

Cellular effects of oncolytic viral therapy on the glioblastoma microenvironment

“…The vimentin-specific antibody uniformly labels human tumor cells in the GBM spheroid model. 22,25 Lowmagnification images confirmed single-tumor-cell infiltration into the corpus callosum in GBMI lesions (Figure 7a). Central areas in this xenograft stained for vimentin, whereas anti-HSV-1 antibody labeled G207-infected cells (Figure 7b).…”

“…20 Direct transplantation of such 'organotypic' spheroids into rodent brains forms lesions that eventually recapitulate all the histopathological hallmarks of GBM in situ, such as extensive single-cell infiltration, angiogenesis the occurrence of necroses with palisading tumor cells, endothelial proliferations and dilated, thrombotic vessels. 18,21 We have recently used this model to evaluate gene transfer to human GBM cells 22,23 as well as to study the biological aspects of tumor cell invasion. 24 Since the described model reflects the key features of human glioma progression, we chose to assess the effect of G207 on a set of xenograft phenotypes that follow these biological features.…”

Oncolytic Herpes Simplex Virus Type-1 Therapy in a Highly Infiltrative Animal Model of Human Glioblastoma

“…Fifteen rats were implanted with GBM6 spheroids and used to assess therapeutic effect. Surgery was done as previously described (8). The handling of the animals and the surgical procedures were done in accordance with the Norwegian Animal Act and the local ethical committee approved the protocol.…”

“…Staining was done as previously described (8). Negative control slides, containing sections of a xenograft generated from the same patient spheroids without G207 treatment, were routinely included.…”

Viral vectors for in vivo gene transfer in Parkinson's disease: Properties and clinical grade production

“…More than 100 genotypes of AAV have been identified that fall into nine antigenically different genetic clades (Gao et al, 2004). More than 100 genotypes of AAV have been identified that fall into nine different antigenic genetic clades (Gao et al, 2004;Gao et al, 2005) but only AAV1-10 have been engineered into vectors (Davidson et al, 2000;Gao et al, 2005;Gao et al, 2002;Huszthy et al, 2005;Wang et al, 2005). Production of rAAV has been improved recently and extremely high titer pure virus is commonly obtained (Zolotukhin et al, 2002).…”