Organic compounds -- part of the class 532-570 series – Organic compounds – Carbohydrates or derivatives
Reexamination Certificate
2001-08-01
2004-04-13
Navarro, Mark (Department: 1645)
Organic compounds -- part of the class 532-570 series
Organic compounds
Carbohydrates or derivatives
C536S023720
Reexamination Certificate
active
06720409
ABSTRACT:
DETAILED DESCRIPTION OF THE INVENTION
1. Field of Industrial Application
This invention relates to an antibody against haemagglutinin of human influenza A virus, a polypeptide containing an antigen site recognized by the antibody, and a gene coding for said polypeptide.
2. Prior Art
There are three types (A, B and C) of influenza viruses and the worldwide prevalence of influenza costing a large number of deaths is caused by human influenza A virus.
Influenza A virus is further classified into various subtypes depending on the antigenicities of haemagglutinin (hereinafter referred to simply as HA) and neuraminidase (hereinafter referred to simply as NA) which are viral surface proteins. There have been known so far three subtypes of human influenza A viruses, namely, the H1N1, H2N2 and H3N2 subtypes.
The HA of influenza A virus comprises two structurally distinct regions, namely, a globular head region and a stem region. The globular head region contains a receptor binding site which is responsible for virus attachment to a target cell and participates in the haemagglutination activity of HA. On the other hand, the stem region contains a fusion peptide which is necessary for membrane fusion between the viral envelope and an endosomal membrane of the cell and thus relates to fusion activity [Wiley et al., Ann. Rev. Biochem., 56, 365-394 (1987)].
All of anti-HA antibodies, which have been obtained hitherto as an antibody capable of recognizing the H1N1 and H2N2 subtypes, recognize the globular head region of HA. However, this region most frequently undergoes antigen mutation. Therefore, these antibodies are not common to the subtypes of human infleunza A virus and, further, lose the recognizing ability with antigenic changes in the HA of the virus.
On the other hand, Green et al. have synthesized a polypeptide based on an amino acid sequence in the stem region of HA of the H3N2 subtype and obtained antibodies against this polypeptide. However, these antibodies have a low neutralization activity (Published Japanese Translation of PCT Patent Applications from Other Countries, No. 501714/1984). Furthermore, the polypeptide per se employed as an antigen does not react with rabbit antiviral serum obtained by immunizing with the H3N2 subtype, which suggests that there is a problem from the viewpoint of antigenicity too [Cell, 28, 477-487 (1982)].
The infectivity of the HA of influenza A virus is activated when the HA is cleaved at one site with a protease. The larger polypeptide thus obtained is called HA1 while the smaller one HA2. It is believed that between these polypeptide HA2 will undergo less antigen mutation due to the subtype.,
In East German Patent Laid-Open No. 228737, H. Glathe et. al. describe that HA2 is taken out by treating viral particles successively with an acid and trypsin or with a reducing agent alone.
By these treatments, however, HA molecules are destroyed in the stereostructure and irreversibly denatured. As a result, the HA2 thus obtained does not have its inherent stereostructure. In addition, the above-mentioned patent is silent whether the efficacy of the obtained HA2 as a vaccine has been specifically confirmed or not.
[Problems to be Solved by the Invention]
Human influenza A virus periodically changes types of HA and NA and thus causes wide prevalence. It is often observed that vaccinization before winter, i.e, the season of prevalence, produces no effect, since the prevalence is caused by a virus of a different type. If an antibody, which is common to virus subtypes in HA and NA molecules and capable of recognizing an antigen site hardly undergoing antigenic mutation, in particular, the configuration, and has neutralization activity for viruses, can be acquired, this antibody is usable in the diagnosis, prevention and treatment of infection with the A virus. Furthermore, the antigen site per se is useful as a vaccine.
It is an object of the present invention to provide an antibody which has a cross recognizing ability for influenza A virus subtypes and has a virus neutralization activity, an antigen site polypeptide which is usable as a vaccine, and a gene coding for said polypeptide.
[Means for Solving the Problems]
To sum up, the first invention relates to an anti-human influenza virus antibody characterized by having the characteristics (a) and (b) specified below:
(a) recognizing the stem region of HA molecule of the H1N1 and H2N2 subtypes of human influenza A virus but not recognizing the stem region of a HA molecule of the H3N2 subtype thereof; and
(b) having neutralization activity for the H1N1 and H2N2 subtypes of human influenza A virus but no neutralization activity for the H3N2 subtype thereof.
The second invention relates to an immunogenic artificial polypeptide characterized by having an antigenicity substantially same as that of the stem region in HA molecule of human influnza A virus.
The third invention relates to an immunogenic artificial polypeptide characterized by having an antigenicity substantially same as that of the stem region in HA molecule of human influenza A virus and lacking a globular head region of HA molecule.
The forth invention relates to a gene coding for the immunogenic artificial polypeptide of the second invention.
The fifth invention relates to a gene coding for the immunogenic artificial polypeptide of the third invention.
The present inventors have conducted extensive studies and consequently found out that an antibody against an antigen site, which is conserved commonly in the stem regions of HA molecule of H1N1 and H2N2 subtypes of human influenza A virus, has a potent neutralization activity for viruses of the H1N1 and H2N2 subtypes, that this antibody is highly useful in the treatment and prevention of influenza and that a polypeptide having an antigen site which is conserved commonly in the stem region of HA molecule of human influenza A virus is useful as a vaccine. And the present inventors have found out that a polypeptide having an antigen site, which is conserved commonly in the stem regions of HA molecule of human influenza A virus, and lacking the globular head region of HA molecule of human influenza A virus is highly useful as a vaccine. And then the present inventors have created a gene coding for said polypeptides which is useful for manufacture of said polypeptides by the genetic recombination technology. Thus the present invention was completed.
Examples of the immunogenic artificial polypeptide of the present invention, which has an antigenicity substantially the same as the stem region of HA molecule of the influenza A viruses and lacks a globler head region of HA molecules, includes polypeptide which lacks a globler head regions of HA molecule by artificial proteolysis, and which is expressed by the HA gene lacking specificaly a globular head regions of HA molecules. These polypeptides should only have the configuration which the antibody recognizing an antigen site common to the stem regions of HA molecule specificaly can recognize, may lack some part of the molecule or also may have the additional amino acid sequence.
Furthermore, these polypeptides may be partially digested with a protease in the process for producing the same by the protein engineering or genetic engineering technique.
Namely, the expression “having an antigenicity substantially the same as that of the stem region in HA molecule” as used herein means that the polypeptide has an antigenicity of both of the HA1 and HA2 in the stem region of HA molecule which is efficiently usable as a vaccine. Therefore such a polypeptide comprising HA2 alone, the inherent stereostructure of which has been destroyed due to denaturation, as the one reported by H. Glathe et. al. as cited above is excluded from the scope of the present invention.
As examples of the immunogenic artificial polypeptide of the present invention which is the most effective as a vaccine, the following ones may be cited.
(1) An immunogenic artificial polypeptide which contains at least a TGLRN polypeptide sequence represented
Isegawa Yuji
Okuno Yoshinobu
Sasao Fuyoko
Ueda Shigeharu
Navarro Mark
Takara Shuzo Co. Ltd.
Wenderoth , Lind & Ponack, L.L.P.
LandOfFree
Anti-human influenza virus antibody does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Anti-human influenza virus antibody, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Anti-human influenza virus antibody will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3220691