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
1999-04-29
2003-04-08
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...
C514S014800, C514S015800, C514S016700, C435S005000, C530S327000, C530S328000
Reexamination Certificate
active
06544520
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
Peptides and other molecules which inhibit the assembly of the hepatitis B virus, methods of treatment, and pharmaceutical compositions comprising them.
BACKGROUND OF THE INVENTION
The present invention relates to peptide compositions specific for the diagnosis, treatment or prevention of hepatitis B virus infection.
Hepatitis B virus (“HBV”) infects human at a very high rate. It is estimated that at least about 300 million people are chronic carriers of HBV. Despite extensive research, additional safe and effective therapies remain to be identified.
HBV infections thus continue to represent a major public health problem worldwide. Infection with the virus results in a gamut of clinical symptoms ranging from minor flu-like symptoms to death. Available vaccines produced from the serum of HBV carriers do not provide the appropriate means to control and eradicate the disease worldwide because of limited resources and production costs involved. Vaccines produced based upon recombinant DNA technology overcome some of these disadvantages, however, there is still a need for additional means to control and eradicate the HBV virus.
The biology, structure and immunochemistry of HBV and the genetic organization of its DNA genome are known. Ganem, D., Varmus, H. E., Ann. Rev. Biochem. 56: 651-693 (1987). The virus is transmitted by three general mechanisms: (1) by inoculation with infected blood or body fluids, (2) by close family or sexual contact, or (3) by infection during pregnancy, where the mother transmits the virus to her child. HBV consists of a nucleocapsid, a small 3.2-kb DNA genome, and the viral polymerase enclosed by the core antigen of the virus, surrounded in turn by the HBV surface antigen (HBsAg). The viral envelope contains three different, but related HBsAg polypeptides, which overlap extensively from their carboxyl termini and arise from variable use of initiation triplets at different points within a continuous open reading frame. The long polypeptide (L polypeptide) is the product of the entire reading frame and comprises the pre-S 1 domain of 108 amino acids (or 119, depending on virus subtype) at its amino terminus, followed by the pre-S2 domain of 55 amino acids, and the short polypeptide (S polypeptide) region of 226 amino acids. The medium-length polypeptide (M polypeptide) has the pre-S2 domain at its amino terminus followed by the S region, whereas the S polypeptide, which is the most abundant form, consists of only the S region. The pre-S regions are believed to play a role in both viral assembly and attachment to the host cell. The S form is more abundant than the M and L forms of HBsAg in the virus, and occurs in both glycosylated and nonglycosylated forms. In addition to its presence in the viral envelope, HBsAg is found in large quantities in the serum of infected individuals as both spherical and filamentous particles, and proportions of the L, M and S polypeptides in these three forms varies appreciably.
The immunologic markers of HBV infection include the surface antigen (HBsAg), the core antigen (HBcAg), the “e” antigen (HBeAg) and their respective antibodies as well as virus polymerase and x antigen (“HBxAg”). Antibodies against HBsAg are protective against HBV infection.
The hepatitis B virus nucleocapsid plays a central role in the production of infectious “Dane” particles. During the formation of the virus, the core particle must recruit into its structure the essential ingredients of viral replication, the pregenomic RNA and the viral reverse transcriptase. On its completion, the core particle must migrate to the endoplasmic reticulum, where the viral surface antigens and lipids are continuously assembled into envelope structures, and delivered to the extracellular environment via the secretory pathway. Thus, formation of the infectious virion requires the nucleocapsid to “capture” the assembling surface proteins and pass through the secretory passageway.
Antibodies to proteins have been generated by immunization with short peptides having an amino acid sequence corresponding to the sequence of preselected protein fragments. Nima, et al, PNAS USA, 80: 4949-4953 (1983). Nevertheless, the generation of antibodies which recognize the native protein may depend on the appropriate conformation of the synthetic peptide immunogen, among other factors. Neurath et al., PNAS, 79:7871-7875 (1982). For this reason, immunization with synthetic peptide analogues of various virus proteins has only rarely resulted in production of virus-neutralizing antisera comparable to those elicited by the virus proteins themselves. Thus the preparation of synthetic immunogens mimicking antigenic determinants on intact viruses remains a challenge.
It has been suggested that HBV cores are not released from the cell without expression of envelope proteins, in contrast to the situation observed in retroviral assembly in general, where nucleocapsids can be exported in the absence of envelope gycoproteins. Bruss et al., PNAS, 88 1062-1063 (1991).
Certain vaccines have been described containing peptides with an amino acid chain of at least six consecutive amino acids within the pre-S gene coded region of the envelope of the hepatitis B virus. U.S. Pat. No. 5,204,096. However, these peptides do not appear to inhibit the assembly of the virus.
No safe and effective therapeutic treatment is presently available for hepatitis B infection, and clinical exploration of promising antiviral agents, such as nucleoside analogues, is hampered because of significant side-effects, resulting, for example, from their a specific body distribution.
Thus, there is a need for effective therapeutic and/or prophylactic agents against infection and diseases associated with HBV. The need has become even more urgent in view of the recent emergence of escape mutants of HBV that are not neutralized by vaccine induced antibodies.
SUMMARY OF THE INVENTION
Accordingly, the present invention is directed to novel peptides, and methods of treatment of diseases associated with HBV, which substantially obviate one or more of the problems due to the limitations and disadvantages of the related art. The peptides and small molecules taught and described herein are useful specifically for inhibiting the assembly of the HBV, thereby preventing disease and spread of infection.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the compositions, and methods particularly pointed out in the written description and claims hereof, as well as the appended drawings.
To achieve these and other advantages, and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention relates to isolated, purified peptides which inhibit the assembly of the hepatitis B virus by binding to the core antigen of the virus, and thus prevent binding of the core antigen to the surface antigen. Specifically, the invention is directed to peptides which have a half maximal concentration (IC
50
) less than about 5, preferably less than 2, more preferably less than about 1, and most preferably less than about 0.5 &mgr;M. Preferred peptides include, but are not limited to SLLGRMKG(&bgr;-A)C (SEQ ID NO: 30), RSLLGRMKGA (SEQ ID NO: 31), HRSLLGRMKGA (SEQ ID NO: 32), MHRSLLGRMKGA (SEQ ID NO: 33), and RSLLGRMKGA(&bgr;-A)C (SEQ ID NO: 34), or peptides derived therefrom.
In other embodiments, the invention is directed to compositions for inhibiting the assembly of the hepatitis B virus comprising the peptides described above. Further embodiments encompass methods of treatment and prevention, as well as pharmaceutical compositions such as vaccines.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
Dyson Michael Richard
Murray Kenneth
Biogen Inc.
Fish & Neave
Foley Shanon
Haley Jr. James F.
Housel James
LandOfFree
Hepatitis B virus inhibitors does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hepatitis B virus inhibitors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hepatitis B virus inhibitors will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3082434