Drug – bio-affecting and body treating compositions – Antigen – epitope – or other immunospecific immunoeffector – Amino acid sequence disclosed in whole or in part; or...
Reexamination Certificate
2000-10-06
2002-08-20
Housel, James (Department: 1648)
Drug, bio-affecting and body treating compositions
Antigen, epitope, or other immunospecific immunoeffector
Amino acid sequence disclosed in whole or in part; or...
C435S005000, C435S238000, C435S239000, C530S350000, C530S403000, C530S412000
Reexamination Certificate
active
06436402
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to a novel process for purifying and processing recombinant human papillomavirus virus-like particles (VLPs), which results in compositions suitable for vaccine use which have greater stability. Also, this invention relates to the VLPs made by this process.
BACKGROUND OF THE INVENTION
Recombinant human papillomavirus (HPV) virus-like particles (VLPs), contain either L1 or a combination of L1 and L2 protein, but do not contain viral nucleic acids. They can be expressed in a variety of host cell types including yeast and insect cells and are attractive candidates for vaccine development to prevent genital HPV infection and the subsequent development of genital warts and/or cervical cancer. In animal studies, purified VLPs have been shown to induce high titers of antibodies against conformational type specific L1 epitopes. These antibodies neutralize homologous virions in in-vitro assays and protect against experimental challenge in several animal models.
“Maturation”, i.e., a change in stability, structural definition and other properties of VLPs have been observed with VLPs during purification, processing and storage. While not wishing to be bound by theory, it appears that this is due, at least in part to changes in intermolecular disulfide bond formation which is required for the assembly and further stabilization of virions.
It is important for a vaccine formulation to be stable. Thus, it would therefore be desirable to make stable VLPs which also maintain immunogenicity during storage.
DETAILED DESCRIPTION OF THE INVENTION
It has been found, in accordance with this invention, that by subjecting papillomavirus L1 or L1+L2 protein to a maturation process, virus-like particles are produced which have improved antigenicity, size distribution, and stability. Thus this invention relates to a method for making human papilloma virus (HPV) virus-like particles (VLPs) comprising the steps of:
a) expressing HPV L1 or L1+L2 proteins;
b) at least partially purifying the proteins; and
c) subjecting the at least partially purified proteins to a maturation step.
There are various maturations processes encompassed by this invention, including incubation at an elevated temperature, glutathione facilitated thiol oxidation, exposure to a metal surface and exposure to light. One preferred maturation process is the step of incubating the at least partially purified proteins at an elevated temperature. Thus, a specific embodiment of this invention is a method for making HPV VLPs comprising the steps of:
a) expressing HPV L1 or L1+L2 proteins;
b) at least partially purifying the proteins; and
c) incubating the at least partially purified proteins at an elevated temperature.
In preferred embodiments of this invention, the proteins are recombinantly produced. Further, in other preferred embodiments, the elevated temperature is from about 30° C. to about 45° C. In a particularly preferred embodiment, the temperature is about 37° C.
In another embodiment, the at least partially purified VLPs are treated with either glutathione or oxidized glutathion as a maturation step. The resulting matured VLPs are essentially the same as the heat-treated ones.
As the VLPs produced by this method can be differentiated from those produced without the maturation step, this invention also is directed to virus-like particles (VLPs) made by the process of expressing an L1 or L1+L2 proteins, at least partially purifying the proteins, and subjecting the at least partially purified proteins to a maturation step. This invention is also directed to vaccine compositions which contain the VLPs so produced.
Another aspect of this invention is a method of inducing an immune response in an individual comprising administering to the individual an effective amount of the vaccine composition comprising VLPs which were subjected to a maturation step.
REFERENCES:
patent: 5871998 (1999-02-01), Lowy et al.
patent: 5888516 (1999-03-01), Jansen et al.
patent: 5922588 (1999-07-01), Ludmerer
patent: 0 864 649 (1998-09-01), None
patent: WO-99/13056 (1999-03-01), None
patent: WO 00/37104 (2000-06-01), None
McCarthy et al. Jan. 1998. Quantitative disassembly and reassembly of human papillomavirus type 11 viruslike particles in vitro. Journal of Virology, vol. 72, No. 1, pp. 32-41.*
Rose et al. 1993. Expression of human papillomavirus type 11 prorein in insect cells: in vivo and in vitro assembly of virus-like particles. Journal of virology. vol. 67. No. 4, pp. 1936-1944.*
Moroder, L. et al. “Oxidative Folding of Cystine-Rich Peptides vs Regioselective Cysteine Pairing Strategies” Biopolymers (Peptide Science) vol. 40, 207-234 (1996) pp. 207-234.
Chang, J. “A Two-Stage Mechanism for the Reductive Unfolding of Disulfide-containing Proteins” Journal of Biological Chem vol. 272, No. 1, Jan. 1997, pp. 69-75.
Ruoppol, M. et al. “Effect of Glutaredoxin and Protein Disulfide Isomerase on the Glutathione-Dependent Folding of Ribonuclease A” Biochem vol. 376, 1997, pp. 12259-12267.
Lee, Y.S., et al. “Immunological properties of recombinant hepatitits B surface antigen expressed in mammalian cell” Archives of Pharmacal Research Oct. 1998; 21 (5) 543-548.
Wampler, D.E. et al., “Multiple chemical forms of heptatitis B surface antigen produced in yeast” Proc Natl Acad Sci USA, vol. 82, Oct. 1985, pp. 6830-6834.
Gadam Shishir
Manger Walter
Wu Shilu
Zhao Qinjian
Finnegan Alysia A.
Foley Shanon A.
Giesser Joanne M.
Housel James
Merck & Co. , Inc.
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