Development of an Ad7 cosmid system and generation of an Ad7ΔE1ΔE3HIVMN env/rev recombinant virus

Abstract

A strategy to circumvent immune responses to adenovirus (Ad) resulting from natural infection or repeated vector administrations involves sequential use of vectors from different Ad serotypes. To further develop an Ad-HIV recombinant AIDS vaccine approach, a replication-defective recombinant Ad from a non-subgroup C virus was required. Using a cosmid system, we generated an Ad7deltaE1deltaE3HIV(MN) env/rev recombinant virus and compared expression of the inserted HIV genes with a similarly constructed replication-competent Ad7deltaE3HIV(MN)env/rev recombinant. Ad7deltaE1deltaE3HIV(MN)env/rev expressed both HIV env and rev gene products. The envelope protein was correctly processed and functional, mediating syncytia formation of Ad7deltaE1deltaE3HIV(MN) env/rev-infected cells and CD4(+) T lymphocytes. Ad7deltaE1deltaE3HIV(MN)env/rev could be amplified on 293-ORF6 cells, containing the E4 ORF6 gene, shown earlier to support production of an Ad7 vector lacking the E1a gene. The utility of this cell line is now extended to the production of replication-defective Ad7 recombinants lacking E1a, E1b, and protein IX genes. Sequential immunizations with Ad-HIV recombinants based in different Ad serotypes have been shown to effectively elicit both humoral and cellular HIV-specific immune responses. The recombinant Ad7deltaE1deltaE3HIV(MN)env/rev will be useful in such AIDS vaccine strategies. Further, these studies have created new cosmid vectors that can be applied to generation of single- or double-deleted Ad7 recombinants with foreign genes inserted into the E1 and/or E3 regions.

Development and Assessment of Human Adenovirus Type 11 as a Gene Transfer Vector

“…Ads containing group B fibers are able to efficiently infect cell types expressing no or low levels of CAR, including important gene therapy target cells (13,17,27,52,57,61,62). More recently, vectors based entirely on the group B serotypes Ad7 and Ad35 have also been developed (14,41,49,51,69).…”

Identification of a Suppressor Mutation That Improves the Yields of Hexon-Modified Adenovirus Vectors

“…293-ORF6 cells express both Ad5 early region 1 (E1) and E4 gene products (43). They support the growth of E1/E4-deleted vectors based on Ad5 as well as alternative adenovirus serotypes (43)(44)(45)(46). Adherent 293-ORF6 cells were maintained in DMEM supplemented with 10% FBS, and suspension 293-ORF6 cells were grown in shaker flasks and maintained in serum-free 293SFM II medium with L-glutamine (Life Technologies, NY).…”

Circumventing Antivector Immunity: Potential Use of Nonhuman Adenoviral Vectors

“…This indicates that these serotypes could be potentially used to evade preexisting immunity. Vectors have been developed from multiple HAdV serotypes with lower seroprevalence than HAdV-5: HAdV-11 (Holterman et al, 2004;Stone et al, 2005;Abbink et al, 2007), HAdV-35 (Gao et al, 2003;Sakurai et al, 2003Sakurai et al, , 2009Seshidhar Reddy et al, 2003;Vogels et al, 2003;Barouch et al, 2004;Wu and Tikoo, 2004;Abbink et al, 2007;Brouwer et al, 2007;Sakurai, 2008;McVey et al, 2010;Geisbert et al, 2011), HAdV-49 (Lemckert et al, 2006;Abbink et al, 2007), HAdV-26, -48, and -50 (Abbink et al, 2007;Geisbert et al, 2011), HAdV-7 (Nan et al, 2003), and HAdV-6 (Capone et al, 2006). However, since the presence of NAbs depends on AdV exposure, which is closely related to geographical location, seroprevalence studies in different specific populations are very important.…”