Chemistry: molecular biology and microbiology – Vector – per se
Reexamination Certificate
1995-11-17
2001-09-25
Campell, Bruce R. (Department: 1632)
Chemistry: molecular biology and microbiology
Vector, per se
C435S173300, C435S069100, C435S325000, C424S093200, C514S04400A
Reexamination Certificate
active
06294377
ABSTRACT:
The present invention relates to new viral vectors, to their preparation and to their use in gene therapy. It also relates to pharmaceutical compositions containing the said viral vectors. More especially, the present invention relates to the use of recombinant adenoviruses of animal origin as vectors for gene therapy.
Gene therapy consists in correcting a deficiency or an abnormality (mutation, aberrant expression, and the like) by introducing genetic information into the cell or organ affected. This genetic information may be introduced either in vitro into a cell extracted from the organ, the modified cell then being reintroduced into the body, or directly in vivo into the appropriate tissue. In this second place, different techniques exist, including various techniques of transfection involving complexes of DNA and DEAE-dextran (Pagano et al., J. Virol. 1 (1967) 891), of DNA and nuclear proteins (Kaneda et al., Science 243 (1989) 375) and of DNA and lipids (Felgner et al., PNAS 84 (1987) 7413), the use of liposomes (Fraley et al., J. Biol. Chem. 255 (1980) 10431), and the like. More recently, the use of viruses as vectors for gene transfer has been seen to be a promising alternative to these physical transfection techniques. In this connection, different viruses have been tested for their capacity to infect certain cell populations. This applies especially to retroviruses (RSV, HMS, MMS, and the like), the HSV virus, adeno-associated viruses and adenoviruses.
Among these viruses, the adenoviruses display certain properties which are advantageous for use in gene therapy. In particular, they have a fairly broad host range, are capable of infecting resting cells and do not integrate in the genome of the infected cell. For these reasons, adenoviruses have already been used for in vivo gene transfer. To this end, different vectors derived from adenoviruses have been prepared, incorporating different genes (&bgr;-gal, OTC, &agr;-1AT, cytokines, and the like). All the vectors derived from the adenoviruses described in the prior art for the purposes of use in gene therapy in humans have hitherto been prepared from adenoviruses of human origin. These appeared, in effect, to be the most suitable for such a use. To limit the risks of multiplication and the formation of infectious particles in vivo, the adenoviruses used are generally modified so as to render them incapable of replication in the infected cell. Thus, the constructions described in the prior art are adenoviruses from which the E1 (E1a and/or E1b) and, where appropriate, E3 regions have been deleted, at the site of which regions sequences of interest are inserted (Levrero et al., Gene 101 (1991) 195; Gosh-Choudhury et al., Gene 50 (1986) 161). However, in addition to this necessary modification step, the vectors described in the prior art retain other drawbacks which limit their exploitation in gene therapy, and in particular risks of recombination with wild-type adenoviruses. The present invention provides an advantageous solution to this problem.
The present invention consists, in effect, in using recombinant adenoviruses of animal origin for gene therapy in humans. The present invention is the outcome of the demonstration that adenoviruses of animal origin are capable of infecting human cells very effectively. The invention is also based on the demonstration that adenoviruses of animal origin are incapable of propagating in the human cells in which they have been tested. Lastly, the invention is based on the surprising discovery that adenoviruses of animal origin are in no way trans-complemented by adenoviruses of human origin, thereby eliminating all risk of recombination and propagation in vivo in the presence of a human adenovirus, capable of leading to the formation of an infectious particle. The vectors of the invention are hence especially advantageous since the risks inherent in the use of viruses as vectors in gene therapy, such as pathogenicity, transmission, replication, recombination, and the like, are greatly reduced or even abolished.
The present invention thus provides viral vectors which are especially suitable for the transfer and/or expression of desired DNA sequences in humans.
A first subject of the present invention hence relates to the use of a recombinant adenovirus of animal origin containing a heterologous DNA sequence for the preparation of a pharmaceutical composition intended for the therapeutic and/or surgical treatment of the human body.
Adenoviruses of animal origin which are usable in the context of the present invention may be of diverse origins, with the exception of human adenoviruses. Human adenoviruses are those which are naturally infectious in man, generally designated by the term HAd or Ad.
In particular, the adenoviruses of animal origin which are usable in the context of the present invention may be of canine, bovine, murine (example: Mav1, Beard et al., Virology 75 (1990) 81), ovine, porcine, avian or alternatively simian (example: SAV) origin.
More especially, among avian adenoviruses, there may be mentioned the serotypes 1 to 10 which are available in the ATCC, such as, for example, the strains Phelps (ATCC VR-432), Fontes (ATCC VR-280), P7-A (ATCC VR-827), IBH-2A (ATCC VR-828), J2-A (ATCC VR-829), T8-A (ATCC VR-830), K-11 (ATCC VR-921), or alternatively the strains referenced ATCC VR-831 to 835. Among bovine adenoviruses, the different known serotypes may be used, and in particular those available in the ATCC (types 1 to 8) under the references ATCC VR-313, 314, 639-642, 768 and 769. There may also be mentioned murine adenoviruses FL (ATCC VR-550) and E20308 (ATCC VR-528), ovine adenovirus type 5 (ATCC VR-1343) or type 6 (ATCC VR-1340); porcine adenovirus 5359), or simian adenoviruses such as, in particular, the adenoviruses referenced in the ATCC under the numbers VR-591-594, 941-943, 195-203, and the like.
In the context of the invention, it is preferable to use adenoviruses of canine origin, and in particular all strains of CAV2 adenoviruses [strain manhattan or A26/61 (ATCC VR-800), for example]. Canine adenoviruses have formed the subject of many structural studies. Thus, complete restriction maps of CAV1 and CAV2 adenoviruses have been described in the prior art (Spibey et al., J. Gen. Virol. 70 (1989) 165), and the E1a and E3 genes as well as the ITR sequences have been cloned and sequenced (see, in particular, Spibey et al., Virus Res. 14 (1989) 241; Linné, Virus Res. 23 (1992) 119, WO 91/11525). Moreover, canine adenoviruses have already been used for the preparation of vaccines intended for immunizing dogs against rabies, parvoviruses, and the like (WO 91/11525). However, hitherto, the possibility of using these adenoviruses for gene therapy in humans has never been suggested in the prior art. Furthermore, the advantages of such a use had never been weighed up.
The adenoviruses used in the context of the invention should preferably be defective, that is to say incapable of propagating autonomously in the body in which they are administered. As mentioned above, the Applicant has shown that adenoviruses of animal origin are capable of infecting human cells but not of propagating therein. In this sense, they are hence naturally defective in humans and, in contrast to the use of human adenoviruses, do not require genetic modification in this connection. However, the defective character of these adenoviruses may be amplified by genetic modifications of the genome, and in particular by modification of the sequences needed for replication of the said virus in cells. These regions may be either removed (wholly or partially), or rendered non-functional, or modified by insertion of other sequences, and in particular of the heterologous DNA sequence.
Depending on the origin of the adenovirus, the sequences needed for replication can vary somewhat. Nevertheless, they are generally localized close to the ends of the genome. Thus, in the case of CAV-2, the E1a region has been identified, cloned and sequenced (Spibey et al., Virus Res. 14 (1989) 241). It is located on
Haddada Hedi
Klonjkowski Bernard
Perricaudet Michel
Vigne Emmanuelle
Campell Bruce R.
Priebe Scott D.
Rhone-Poulenc Rorer SA
LandOfFree
Adenoviral vectors of canine origin does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Adenoviral vectors of canine origin, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Adenoviral vectors of canine origin will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2541867