Genetically engineered poxviruses for recombinant gene expression, vaccination, and safety.

Abstract

Vaccinia virus, no longer required for immunization against smallpox, now serves as a unique vector for expressing genes within the cytoplasm of mammalian cells. As a research tool, recombinant vaccinia viruses are used to synthesize and analyze the structure-function relationships of proteins, determine the targets of humoral and cell-mediated immunity, and investigate the types of immune response needed for protection against specific infectious diseases and cancer. The vaccine potential of recombinant vaccinia virus has been realized in the form of an effective oral wild-life rabies vaccine, although no product for humans has been licensed. A genetically altered vaccinia virus that is unable to replicate in mammalian cells and produces diminished cytopathic effects retains the capacity for high-level gene expression and immunogenicity while promising exceptional safety for laboratory workers and potential vaccine recipients.

Prevention of autoimmune diabetes by immunogene therapy using recombinant vaccinia virus expressing glutamic acid decarboxylase

“…The rVV was produced by homologous recombination, as described elsewhere [17,18]. The recombinant plasmid (10 µg) was transfected into CV-1 cells (ATCC, Manassas, Va., USA), which had previously been infected with wild type vaccinia virus (0.05 plaque forming units [PFU]/cell), using the calcium phosphate method.…”

“…RNA from the splenocytes of agematched and sex-matched NOD mice was used as a control. Two µg of total RNA was converted to cDNA using Superscript II reverse transcriptase (Gibco BRL, Gaithersburg, Md., USA) and oligo (dT) [12][13][14][15][16][17][18] . PCR was carried out using specific primers for various cytokine genes, as described previously [30].…”

“…Vaccinia virus has been used as a live vaccine against smallpox [15,16]. Of particular importance are the findings that rVV can induce humoral and cell-mediated immune responses to a target protein and that the induced immune responses are long lived [17,18,19,20]. For example, animals immunised with rVV expressing a protein from a pathogenic virus are protected from the disease caused by challenge with that virus [21,22].…”

CD40L expressed from the canarypox vector, ALVAC, can boost immunogenicity of HIV-1 canarypox vaccine in mice and enhance the in vitro expansion of viral specific CD8+ T cell memory responses from HIV-1-infected and HIV-1-uninfected individuals

“…Members of the poxvirus family (poxviridae) have, in recent years, received considerable attention for the development of vaccine vectors that can induce humoral and cellular immunity against virus infections as well as immunotherapy for cancer [3]. Several advantages of these vectors for vaccine development include strict cytoplasmic replication that is primarily abortive in human cells, and their good long term safety profile [4].…”

Anticancer Gene Transfer for Cancer Gene Therapy

“…Gene delivery with Poxviruses has not advanced so far as expected. The complexity of the viruses and the complicated molecular engineering that is required to achieve cloning, production and expression presents as a major barrier for the advancement of this vector as an effective gene delivery option (Gomez et al, 2008;Moss, 1996). For transgene insertion a step of homologous recombination or in vitro ligation is required in order to produce recombinant vaccinia virus (Moss, 1996).…”