Drug – bio-affecting and body treating compositions – Designated organic active ingredient containing – Carbohydrate doai
Reexamination Certificate
1998-10-29
2003-02-25
Beckerleg, A.M. S. (Department: 1632)
Drug, bio-affecting and body treating compositions
Designated organic active ingredient containing
Carbohydrate doai
C435S320100, C435S325000, C514S002600, C530S350000
Reexamination Certificate
active
06525029
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method of inhibiting an immune response to a recombinant vector, as well as a vector and a composition for use in the method.
BACKGROUND OF THE INVENTION
A broad spectrum of eukaryotic viruses, including adenoviruses, adeno-associated viruses, Herpes viruses and retroviruses, has been used in gene therapy. Each type of vector has demonstrated a viral-dependent combination of advantages and disadvantages. Accordingly, careful consideration must be given to the advantages and disadvantages inherent to a particular type of vector when deciding which vector should be used in a particular application of gene therapy.
The advantages of adenoviruses with respect to gene therapy include ease of use, high titer production (i.e., up to about 10
13
viral particles/ml), efficient gene transfer to nonreplicating, as well as replicating, cells (see, for example, review by Crystal,
Science,
270, 404-410 (1995)), and a broad range of host- and cell-type specificity. Such advantages have resulted in a recombinant adenovirus being the vector of choice for a variety of gene transfer applications. Adenoviral vectors are especially preferred for somatic gene therapy of the lungs, given their normal tropism for the respiratory epithelium.
Other advantages that accompany the use of adenoviruses as vectors for gene therapy include: (1) the rare observance of recombination; (2) the absence of an ostensible correlation of any human malignancy with adenoviral infection, despite the common occurrence of infection; (3) the adenoviral genome (which is comprised of linear, double-stranded DNA) can be manipulated to carry up to about 7.5 kb of exogenous DNA, and longer DNA sequences can potentially be carried into a cell, for instance, by attachment to the adenoviral capsid (Curiel et al.,
Human Gene Therapy,
3, 147-154 (1992)); (4) an adenovirus is unlikely to interfere with normal cellular function since the vector controls expression of its encoded sequences in an epichromosomal manner; and (5) it already has been proven safe to use in humans, given that live adenovirus has been safely used as a human vaccine for many years.
Using adenoviral reporter gene constructs, it has been established that high levels of gene expression can be obtained in a variety of animal models. However, it also has been established that the high level of gene expression so obtained is transient, with reporter gene expression peaking within the first week after infection and becoming essentially undetectable about 80 days after infection. Recent studies have indicated that the limited persistence of gene expression in vivo is most likely due to an immune response of the host against virally infected cells. For example, gene expression can be maintained in immunologically privileged neuronal or retinal tissues for periods in excess of two months and in immunodeficient or immunologically naive rodents for periods in excess of six months.
Intravenous administration of adenovirus to mice results in the vast majority of adenovirus being localized to the liver (Worgall et al.,
Human Gene Therapy,
8, 37-44 (1997)). During the first 24-48 hrs of infection, 90% of vector DNA is eliminated, presumably through innate pathways of viral clearance mediated by Kupffer cells in the liver (Worgall et al. (1997), supra), well before maximal levels of transgene are expressed. In spite of the fact that the majority of virus is cleared within one to two days, over 95% of hepatocytes are transduced by the remaining small percentage of input adenoviral vectors (Li et al.,
Human Gene Therapy,
4,403-409 (1993)) with maximum transgene expression occurring during the first week of post-infection. Transgene expression, however, rapidly declines to baseline levels in immune-competent animals within 2-3 weeks of infection due to immune activation.
Using a combination of mouse strains, which are defective in specific elements of the immune system, it has been shown that the immune response against cells infected with viral vectors involves both cellular and humoral components of the immune system. For example, immunodeficient mice, which lack mature T- and B-lymphocytes express adenovirus-mediated transgenes beyond four months (Kass-Eisler et al.,
Gene Therapy,
1, 395-402 (1994); Yang et al.,
Immunity,
1, 433-442 (1994a); Yang et al.,
PNAS USA,
91, 4407-4411 (1994b); Dai et al.,
PNAS USA,
92, 1401-1405 (1995); Kay et al.,
Nat. Genet.,
11, 191-197 (1995); and Yang et al.,
J. Immunol.,
155, 2564-2570 (1995)). Similarly, transfer of CD8
+
and CD4
+
cytotoxic T-cells from adenoviral vector-infected mice to infected RAG-2 mice, which lack mature B- and T-cell lymphocytes, resulted in clearance of the vector and transgene by apoptosis (Yang et al. (1994a), supra; and Yang et al. (1995), oupra), whereas immune depletion of CD8
+
or CD4
+
cells in immunocompetent mice results in persistent transgene expression (Yang et al. (1994a), supra; Kay et al.(1995), supra; Yang et al. (1995), supra; Kolls et al.,
Hum. Gene Ther.,
7, 489-497 (1996); and Guerette et al.,
Transplantation,
62, 962-967 (1996)). While pathways involving perforin and Fas are the major pathways responsible for T-cell cytotoxicity (Kojima et al.,
Immunity,
1, 357-364 (1994); Henkart,
Immunity,
1, 343-346 (1994); Kagi et al.,
Science,
265, 528-530 (1994); and Kagi et al.,
Eur. J. Immunol.,
25, 3256-3262 (1995)), the perforin/granzyme pathway has been reported to mediate clearance of adenoviral gene transfer vectors by antigen-specific, cytotoxic T-cells (Yang et al.,
PNAS USA,
92, 7257-7261 (1995)).
In addition to limiting the persistence of gene expression from viral vectors, the immune response inhibits successful readministration of viral vectors, which limits the period of efficacy of gene therapy. For example, adenoviruses are classified into 47 different serotypes and a number of subgroups, namely A through G, based on a number of criteria, including antigenic crossreactivity. Following an initial administration of adenovirus, serotype-specific antibodies are generated against epitopes of the major viral capsid proteins, namely the penton, hexon and fiber. Given that such capsid proteins are the means by which the adenovirus attaches itself to a cell and subsequently infects the cell, such antibodies are then able to block or “neutralize” reinfection of a cell by the same serotype of adenovirus. This necessitates using a different serotype of adenovirus in order to administer one or more subsequent doses of exogenous DNA in the context of gene therapy.
The present invention seeks to address the problems presented by immune activation mediated by adenoviral gene transduction, as well as immune mediated apoptosis and anti-adenoviral neutralizing antibodies, which inhibit successful readministration of a viral vector, such as in the context of gene therapy. Accordingly, it is an object of the present invention to provide a method of inhibiting an immune response to a recombinant vector, as well as a vector and a composition for carrying out the method. These and other objects and advantages of the present invention, as well as additional inventive features, will be apparent from the following detailed description.
BRIEF SUMMARY OF THE INVENTION
The present invention provides, among other things, a method of inhibiting an immune response to a recombinant vector, such as a viral vector, specifically an adenoviral vector. The method comprises contacting a cell with (i) a recombinant vector, preferably a viral vector, most preferably an adenoviral vector, comprising a transgene and (ii) a means of inhibiting an immune response to the recombinant vector selected from the group consisting of a tumor necrosis factor (TNF) receptor fusion protein, a Fas receptor fusion protein, an interferon (IFN) receptor fusion protein, a dominant negative of an interferon consensus sequence binding protein (ICSBP), a gene encoding a TNF receptor fusion protein, a gene encoding a Fas receptor fusi
Elkon Keith
Falck-Pedersen Erik S.
Beckerleg A.M. S.
Cornell Research Foundation Inc.
LandOfFree
Method of inhibiting and immune response to a recombinant... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of inhibiting and immune response to a recombinant..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of inhibiting and immune response to a recombinant... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3123662