Background of the Invention
Technical Field
[0001] The present invention relates to compositions for prevention, treatment, and diagnosis
of chronic obstructive pulmonary disease (COPD).
Background Art
[0002] Chronic obstructive pulmonary disease (COPD) is currently defined as chronic disease
showing irreversible obstruction of airways resulting from the progression of two
major underlying diseases including chronic bronchitis and pulmonary emphysema. Chronic
bronchitis is defined clinically as the persistence of cough, sputum, and difficult
breathing, an pulmonary emphysema is defined histopathologically as an irrevesible
destruction of airway walls distal to the terminal bronchiole and clinically shows
slowly progressive respiratory difficulties (GOLD workshop summary,
Am J Respir Crit Care Med 2001; 163:1256-1276). Therefore, current definition of COPD excludes a bronchial asthma showing reversible
obstruction of airways. COPD is currently the fourth leading cause of death in the
United States and Europe, and causes of death in patients with COPD are complications
of the disease such as respiratory failure or infection (GOLD workshop summary,
Am J Respir Crit Care Med 2001; 163:1256-1276).
[0003] Currently, smoking is regarded as the most important risk factor for the development
of COPD. And secretions of many inflammatory mediators (IL-8 etc.) from airway epithelial
cells stimulated by smoking and other factors including air pollution or chronic infection
by bacteria or virus are considered to be responsible for the development of chronic
inflammation of airway tissue in COPD (GOLD workshop summary,
Am J Respir Crit Care Med 2001; 163:1256-1276). However, the reason for the chronic persistence of inflammation after acute inflammation
induced by those external stimuli is not determined yet. Accordingly, it is suggested
that other pathogenetic mechanisms besides smoking may be involved in the pathogenetic
mechanism of COPD (
0'Byrne PM, Postma DS. Am J Respir Crit Care Med 1999; 159:S41-S66). Especially, the reasons for the persistence of airway inflammation and apoptosis
of airway epithelial cells in COPD patients even after stop of smoking are not explained
yet (
Hodge S et al., Eur Respir J 2005;25:447-54). The etiology and pathogenetic mechanism of COPD are not determined yet, and therefore,
fundamental treatment of COPD is difficult now. The COPD patients having advanced
disease and severely decreased pulmonary function are at a high risk of the disease-associated
premature death (GOLD workshop summary,
Am J Respir Crit Care Med 2001;163:1256-1276).
[0004] Currently, diagnosis of chronic obstructive pulmonary disease can be made when the
patients complain of typical clinical symptoms (cough, sputum, and dyspnea, etc.)
and their FEV1 measured following the inhalation of bronchodilator showed less than
80% of predictive value and the ratio of FEV1/FVC was less than 70% on pulmonary function
test (GOLD workshop summary,
Am J Respir Crit Care Med 2001;163:1256-1276). However, there is still no laboratory test which can be used for the early detection
of patients with COPD who complain of typical clinical symptoms but show normal pulmonary
function and therby used for the prevention of further progession of COPD.
[0005] As a pharmacological therapy of COPD, bronchodilator and corticosteroid are known
to be effective for the improvement of clinical symptoms. Direct administration of
corticosteroid to the target airway tissue by inhalation devices is preferred method
over systemic administration to avoid systemic side effects. Additional medications
such as theophylline can also be useful. However, there is still no available therapeutic
agent which can induce complete remission of COPD or fundamentally improve COPD and
modify a natural course of the disease.
[0006] Detection of autoantibodies to antigens of airway or lung tissues in COPD patients
has been reported (
Wagner V, et al., Acta Allergol 1965;20:1-9). Although a hypothesis that COPD is caused by autoimmune mechanism has been proposed
(
Agusti A, et al., Thorax 2003;58:832-834), this hypothesis has not been clearly demonstrated because an autoantigen reacting
with autoantibodies in the blood of patients with COPD has not been identified yet.
Recently, it has been demonstrated that pulmonary emphysema (one of major underlying
diseases causing COPD) could have been developed in animals by autoimmune response
against the vascular endothelial autoantigen (
Taraseviciene-Stewart L, et al., Am J Respir Crit Care Med. 2005;171:734-42). In the above study, it has been reported that rats immunized by antigens extracted
from human vascular endothelial cells to induce autoimmune response developed pulmonary
emphysema, and passive transfer of CD4+ cells from spleens of the above pulmonary
emphysema-developed rats to naive rats resulted in pulmonary emphysema in recipient
rats, and pulmonary emphysema has been also caused in mouse after injection of anti-endothelial
cell antibodies obtained from serum of rats immunized with vascular endothelial cells
(
Taraseviciene-Stewart L, et al., Am J Respir Crit Care Med. 2005;171:734-42). This study showed that antibodies to vascular endothelial cell antigens were sufficient
to trigger the development of pulmonary emphysema, although target autoantigens involved
in development of the disease was not identified yet. On the basis of aboves, it has
been suggested that autoimmune mechanism might be involved in the pathogenesis of
COPD.
Disclosure
Technical problem
[0007] However, previous studies could not establish a causal relationship between autoimmunity
and COPD due to the lack of an identified autoantigen associated with patients with
COPD and lack of a logical association between the autoantibodies in the bodily fluid
of patients with COPD and the damage of airway tissue. So, autoantibody testing is
not currently used for the diagnosis or classification of COPD
[0008] Because the primary etiology and mechanism causing the development of COPD is not
completely understood yet, a treatment method that can induce complete remission of
COPD has not been developed yet. Current pharmacological therapy for COPD can improve
the clinical symptoms and pulmonary function only during the continuous administration
of medication, but there is no treatment method which can modify the long-term natural
course of COPD or prevent a death due to COPD.
[0009] A cytokeratin 18 protein, which is identified as a target autoantigen of COPD, is
a cytoskeletal protein found primarily in epithelial cells lining the respiratory
and gastrointestinal tracts, including bronchial epithelial cells and lung (alveolar)
epithelial cells (
Moll, R. et al., Cell 1982; 31:11-24). Although cytokeratin 18 is a predominantly intracellular protein, its strong expression
on the cell surface was also observed in epithelial cells (
Moll, R. et al., Cell 1982; 31:11-24;
Saarloos, M.N. et al., Curr Eye Res 1999; 19:439-449).
[0010] WO 03/098211 concerns the detection of autoantibodies to cytokeratin 18 protein in patients with
bronchial asthma and chronic rhinitis, and its applications including a kit for diagnosing
bronchial asthma and chronic rhinitis comprising mammalian cytokeratin 18 protein.
WO 2006/073254 concerns composition for prevention, treatment and diagnosis of chronic inflammatory
airway diseases and is an Article 54(3) EPC document in regard to the current invention.
WO 03/023002 concerns novel human proteins, polynucleotides encoding them and methods using the
same.
Ryu and Scanlon (i.e. Mayo Clin. Proc. 2001: 76: 1144-1153) concerns obstructive lung diseases: chronic obstructive pulmonary disease, asthma,
and many imitators.
Jeffery (i.e. Proc Am Thorac Soc vol 1. pp 176-183, 2004) concerns remodelling and inflammation of bronchi in asthma and chronic obstructive
pulmonary disease.
Technical Solution
[0011] The present inventors judged that autoantigen proteins involved in the development
of COPD might be present in the airway epithelial cells on the basis of previous reports
and results from deductive ratiocination of present inventors, and therefore, analyzed
the airway epithelial autoantigen proteins reacting with IgG autoantibodies by Immunoblot
method using proteins from cultured human airway epithelial cells.
[0012] Consequently, the inventors discovered autoantibodies to airway epithelial cells
in serum samples of patients with COPD, and identified that the airway epithelial
autoantigen was cytokeratin 18 protein. Also, inventors demonstrated significant inhibitions
of autoantibody-induced cytotoxicity of airway epithelial cells by adsorption of autoantibodies
from patients with COPD with cytokeratin 18 protein, and thereby the inventors made
the present invention.
[0013] It is an object of the present invention to provide a pharmaceutical composition
for preventing or treating COPD comprising cytokeratin 18 protein as an active ingredient,
wherein the cytokeratin 18 protein has an amino acid sequence of SEQ ID NO: 2.
[0014] The present invention provides a pharmaceutical composition for preventing or treating
COPD comprising cytokeratin 18 protein as an active ingredient, wherein the cytokeratin
18 protein has an amino acid sequence of SEQ ID NO: 2.
[0015] Cytokeratin 18 protein used in the present invention has an amino acid sequence of
SEQ ID NO: 2.
[0016] The amino acid sequence of SEQ ID NO: 1 is an amino acid sequence of human (
Homo sapiens) cytokeratin 18 protein (NCBI accession no. P05783), and an amino acid sequence of
SEQ ID NO: 2 is an amino acid sequence of bovine (
Bos taurus) cytokeratin 18 protein (NCBI accession no. XP_582930).
[0017] Cytokeratin 18 protein can be produced by recombinant genetic engineering technology
using one of DNA base sequence encoding the amino acid sequence of SEQ ID NO: 2 ,
therby isolating them from cells or tissues of mammals, or microorganisms and purifying
them.
[0018] The "Chronic obstructive pulmonary disease (COPD)" in the present invention includes
pulmonary emphysema and chronic bronchititis.
[0019] The present invention is based on the fact identifying cytokeratin 18 protein as
an airway epithelial autoantigen binding with IgG autoantibodies in the blood samples
of patients with COPD, for the first time.
[0020] It can be judged from the previous reports and results of Examples in the present
invention that autoantibodies in the blood of patients with COPD can directly induce
cytotoxicity to airway epithelial cells through binding to cytokeratin 18 proteins
of airway epithelial cells or indirectly induce cytotoxicity to airway epithelial
cells and induce chronic inflammation of airway tissue through the formation of immune
complexes consisted of autoantibodies and autoantigen and secondary complement activation
and chemotaxis of inflammatory cells. And these damages of airway epithelial cells
and chronic inflammation of airway tissue can cause clinical symptoms of COPD through
the developments of irreversible structural changes of airway tissues.
[0021] In the Examples of the present invention, IgG antibodies purified from blood samples
of patients with COPD induced cytotoxicity to airway epithelial cells. Also, the administration
of cytokeratin 18 protein of the present invention into the model of IgG antibody-induced
airway epithelial cell cytotoxicity, induced adsorptions of autoantibodies in the
blood of patients with COPD, and thereby inhibited IgG antibody-induced cytotoxicity
to airway epithelial cells.
[0022] Thus, the pharmaceutical compositon comprising cytokeratin 18 protein wherein the
cytokeratin 18 protein has an amino acid sequence of SEQ ID NO: 2 of the present invention
can be used as a medicament preventing, alleviating or treating COPD.
[0023] The pharmaceutical compositon comprising cytokeratin 18 protein wherein the cytokeratin
18 protein has an amino acid sequence of SEQ ID NO: 2 as an active ingredient may
further comprise pharmaceutically and physiologically acceptable additives besides
the active ingredient. Such additives may include, for example, excipients, disintergrating
agents, sweeting agents, binding agents, coating agents, inflating agents, lubricants,
glidants, flavoring agents, solubilizers, etc.
[0024] The pharmaceutical composition comprising cytokeratin 18 protein wherein the cytokeratin
18 protein has an amino acid sequence of SEQ ID NO: 2 as an active ingredient may
further comprise one or more pharmaceutically acceptable carriers to be formulated
appropriately for administration.
[0025] For liquid formulation, the pharmaceutically acceptable carriers should be sterilized
and suitable to living bodies. For example, the pharmaceutically acceptable carriers
may include saline, sterilized water, linger solution, bufferd saline, albumin injection
solution, dextrose solution, malto dextrine solution, glycerin, ethanol, or the mixture
of one or more of the above ingredients. If necessary, other common additives can
be added, such as antioxidants, buffers, bacteriostatic agents, etc. Also, diluting
agents, dispersing agents, surfactants, binders or lubricants can be further added
in order to formulate the composition to injection formulations such as aquous solution,
suspension, emulsion, pills, capsules, granules, Tablets, etc. Further more, the present
pharmaceutical compositon can be appropriately formulated depending on each disease
or ingredient of the composition, by using the disclosed method in
Remington's Pharmaceutical Science, Mack Publishing Company, Easton PA, as a preferable method in the art.
[0026] Formulation type of the present pharmaceutical compositon comprising cytokeratin
18 protein as an active ingredient, can be granules, powder, coated tablets, tablets,
capsules, suppositories, syrup, juice, suspensions, emulsions, drops, injectable liquid
formulation or slowly-released formulation of active compound, etc.
[0027] The present pharmaceutical compositon comprising cytokeratin 18 protein as an active
ingredient, can be administered intravenously, intraarterially, intraperitoneally,
intramuscularly, intrasternally, percutaneously, intranasally, rectally, orally, intraocularly,
intradermally, locally, or by inhalation, according to ordinary methods.
[0028] The dosage of the present pharmaceutical composition comprising cytokeratin 18 protein
wherein the cytokeratin 18 protein has an amino acid sequence of SEQ ID NO: 2 as an
active ingredient means an effectective amount to inhibit or treat damage or inflammatory
reaction of airway epithelial cells and tissues. Thus, this dosage can be modified
depending on various factors such as the kind of a disease to be treated, severity
of the disease, kinds and amounts of active ingredients and other ingredients contained
in the composition, age, weight, general health status and sex of the patient, diet,
time and route of administration, secretion rate of the composition, period of treatment
drugs used simultaneously, etc. In adults, when cytokeratin 18 protein wherein the
cytokeratin 18 protein has an amino acid sequence of SEQ ID NO: 2 is administrated
one or several times per day, the preferable dosage of said cytokeratin 18 protein
is 0.01 mg/kg-100 mg/kg.
[0029] Also, the present invention provides a method for preventing or treating COPD by
administering cytokeratin 18 protein wherein the cytokeratin 18 protein has an amino
acid sequence of SEQ ID NO: 2. Preferably, the above COPD can be pulmonary emphysema
or chronic bronchitis.
[0030] The present specification shows that the administration of cytokeratin 18 proteins
can adsorb autoantibodies in the blood of patients with COPD thereby inhibiting autoantibody-induced
cytotoxicity to airway epithelial cells and inhibiting the development of secondary
inflammation of airway tissue.
[0031] The present invention provides a method of preventing or treating COPD by administering
cytokeratin 18 protein wherein the cytokeratin 18 protein has an amino acid sequence
of SEQ ID NO: 2. In this method, cytokeratin 18 protein wherein the cytokeratin 18
protein has an amino acid sequence of SEQ ID NO: 2 can be administrated intravenously,
intraarterially, intraperitoneally, intramuscular, intrasternally, percutaneously,
intranasally, rectally, orally, intraocularly, intradermally, locally, or by inhalation,
according to ordinary methods.
[0032] In the method of preventing or treating COPD by administering cytokeratin 18 protein
wherein the cytokeratin 18 protein has an amino acid sequence of SEQ ID NO: 2, the
dosage of said cytokeratin 18 protein to be administrated can be referred as an effectective
amount to inhibit or treat autoantibody-induced cytotoxicity to airway epithelial
cells or secondary inflammatory reaction of airway tissues caused by the formation
of immune complex consisted of autoantigen-autoantibodies. In adults, when said cytokeratin
18 protein is administrated one or several times per day, the preferable dosage of
cytokeratin 18 proteins is 0.01 mg/kg - 100 mg/kg. This dosage can be modified depending
on various factors such as the kind of a disease to be treated, severity of the disease,
kinds and amounts of active ingredients and other ingredients contained in the composition,
age, weight, general health status and sex of the patient, diet, time or route of
administration, secretion rate of composition, period of treatment, drugs used simultaneously,
etc.
[0033] Also, the present invention provides the use of cytokeratin 18 protein wherein the
cytokeratin 18 protein has an amino acid sequence of SEQ ID NO: 2. for the manufacture
of a medicament for COPD.
[0034] The diagnostic composition comprising cytokeratin 18 protein as disclosed herein
can react with biological samples of patients with COPD, thereby showing positive
results. Thus, the diagnostic composition can be used for the diagnosis of COPD.
[0035] The diagnostic composition disclosed herein comprising cytokeratin 18 protein can
be used for the detection, diagnosis, and classification of COPD with higher sensitivity
as shown in the present Examples.
[0036] The diagnostic composition can comprise buffer or reaction solution which makes maintain
physiological acivity or structure of proteins, besides the proteins. Also, the diagnostic
composition can be provided in the form of powder, or in the solubilized state in
an appropriate buffer, or maintained at 4°C, in order to maintain stability.
[0037] A diagnostic kit for diagnosing COPD is described comprising diagnostic composition
comprising cytokeratin 18 protein for diagnosing COPD.
[0038] The diagnostic kit can comprise buffer or reaction solution which makes to maintain
physiological acivity or structure of proteins, besides cytokeratin 18 proteins. Further,
the proteins can be provided in the form of powder, or in the solubilized state in
an appropriate buffer, or maintained at 4°C, in order to maintain stability.
[0039] The diagnostic kit can comprise components other than cytokeratin 18 protein. For
the positive control result, the diagnostic kit can comprise polyclonal antibodies
or monoclonal antibodies to cytokeratin 18 protein from mammals, or human' s biological
samples of which autoantibodies to cytokeratin 18 protein are positive. For the negative
control result, the diagnostic kit can comprise other antibodies or buffers. If necessary,
the diagnostic kit can further comprise other components required for the detection
of autoantibodies to cytokeratin 18 protein from biological samples of subjects.
[0040] Other components required for immunodetecting reaction include anti-human IgG antibodies
produced from rat, mouse, rabbit, cow, pig, or goat, etc., as the secondary antibodies,
and colorizing agents, buffers, etc.
[0041] As the secondary antibodies, alkaline phosphatase (AP)-conjugated, horse radish peroxidase
(HRP)-conjugated, biotin-conjugated antibodies, or fluorescent material(for example,
rhodamine, Texas Red, fluorescein, phycoerythrin, etc.)-conjugated antibodies can
be used.
[0042] The biotin-conjugated secondary antibodies can use AP or HRF enzyme-conjugated avidin,
AP-conjugated secondary antibodies can use BCIP/NBT as color couplers, and HPR-conjugated
secondary antibodies can use DAB (diaminobenzidine), etc. as color couplers, thereby
inducing color reaction to determine the presence of autoantibodies. The secondary
antibodies to which fluorescent materials are conjugated, can be monitored on a fluorescence
microscope. Thus, from the fluorescence microscopy, the presence of autoantibodies
can be determined.
[0043] The assay methods applied to the kit are known to those skilled in the art. The assay
methods to be used for the kit include any techniques that can detect antigen-antibody
reaction, such as fluorescence immunoassays, enzyme-substrate color reaction, eyzyme
immunoassays, immunoblotting, immunoprecipitation assay, antigen-antibody agglutination
immunoassays, light-scattering immunoassays, radioimmunoassay, flow cytometry, complement-fixing
method, etc.
[0044] The kit can further comprise tubes, wells or plates required for mixing each component,
or covering letter describing the way of using, if necessary.
[0045] The present invention provides an
in vitro method of diagnosing chronic obstructive pulmonary disease by using diagnostic compositions
containing cytokeratin 18 protein as an active ingredient, comprising the steps of:
- (a) contacting a biological sample of a subject suspected to have chronic obstructive
pulmonary disease, such as pulmonary emphysema or chronic bronchitis, with cytokeratin
18 protein to induce the formation of immune complex; and
- (b) diagnosing said chronic obstructive pulmonary disease in the subject by detecting
the above immune complex to determine the presence of autoantibodies to said cytokeratin
18 protein,
wherein the cytokeratin 18 protein has an amino acid sequence of SEQ ID NO: 2, wherein
chronic obstructive pulmonary disease is diagnosed when the patients complain of typical
clinical symptoms, including cough, sputum, and dyspnea, and their FEV1 measured following
the inhalation of bronchodilator showed less than 80% of predictive value and the
ratio of FEV1/FVC was less than 70% on pulmonary function test.
[0046] In step (a) of the present diagnosing method, the biological samples can include
any fluid which can be isolated and collected from human bodies, such as blood, plasma,
serum, urine, tears, salivar, sputum, nasal secretion, bronchial secretion, bronchial
washing fluid, pulmonary secretion, alveolus washing fluid, etc.
[0047] The formation of immune complex can use immunoblotting, ELISA, etc., and can use
any methods for detecting the antigen-antibody reaction, which are ordinary in the
art.
[0048] Step (b) of the present diagnosing method is a step determining the formation of
immune complex by inducing color reactions or detecting fluorescence of immune complex,
and it can use any methods for detecting antigen-antibody reaction, which are ordinary
in the art. If the presence of immune complex is confirmed, this result means that
the subject has COPD. For the positive control result, instead of the subject' s biological
samples, what can be used are polyclonal antibodies or monoclonal antibodies to cytokeratin
18 protein wherein the cytokeratin 18 protein has an amino acid sequence of SEQ ID
NO: 2 from mammals, or human's biological samples of which autoantibodies to cytokeratin
18 protein wherein the cytokeratin 18 protein has an amino acid sequence of SEQ ID
NO: 2 are positive. For the negative control result, what can be used are antibodies
or buffers other than the antibodies to cytokeratin 18 protein wherein the cytokeratin
18 protein has an amino acid sequence of SEQ ID NO: 2.
[0049] From the prior reports of immunological studies for other autoimmune dieases, it
is known that in case of patients showing IgG autoantibodies to specific autoantigen
proteins in blood, a considerable number of patients has antigen-specific T-cell reaction
to the same autoantigen protein, and it is useful to test delayed type hypersensitivity
after intradermal injection of the same autoantigen proteins reacting with IgG autoantibodies
in the patients (
Beales PE et al, Autoimmunity 2000;32:109-113). In prior arts, skin tests of tuberculin type have been used, in which tests were
performed by injecting specific antigen to subjects, intradermally, and testing the
injected skin part after 24 to 72 hours of the injection to measuring the size of
skin swelling (induration), thus determining the presence of delayed-type hypersensitivity
reaction or late-onset skin reaction to the above antigen.
[0050] Accordingly, the diagnostic composition comprising cytokeratin 18 protein wherein
the cytokeratin 18 protein has an amino acid sequence of SEQ ID NO: 2 can be applied
to the use of the diagnostic composition to detecting patients showing autoimmune
response to cytokeratin 18 protein among patients with COPD by measuring the size
of skin swelling after 24 to 72 hours of the intradermal injection of cytokeratin
18 protein.
[0051] Also, the specification provides a method of diagnosing COPD by using a diagnostic
composition comprising cytokeratin 18 protein.
[0052] The described method of diagnosing chronic COPD comprises the following steps:
- a) selecting a subject suspected to have COPD;
- b) injecting intradermally the diagnostic compositions comprising cytokeratin 18 protein
and
- c) diagnosing the COPD by examining the injected skin part after 24 to 72 hours of
the injection and detecting the presence of the skin swelling and measuring the size
of skin swelling, thus determining the presence of delayed-type hypersensitivity reaction
or late skin reaction to cytokeratin 18 protein.
[0053] By using the present diagnostic composition and diagnosing method, the result for
the presence of COPD can be obtained easily and correctly determined. Therefore, it
can be used effectively for clinical study in a large scale. Also, it can be used
to screen therapeutic agents or to develope treatment methods for COPD.
[0054] The present invention provides the use of a composition for screening a therapeutic
agent for COPD, comprising cytokeratin 18 protein wherein the cytokeratin 18 protein
has an amino acid sequence of SEQ ID NO: 2.
[0055] The compositions for screening a therapeutic agent can comprise buffer or reaction
solution which makes maintain physiological acivity or structure of proteins, besides
cytokeratin 18 protein wherein the cytokerat in 18 protein has an amino acid sequence
of SEQ ID NO: 2. Also, the composition can be provided in the form of powder, or in
the solubilized state in an appropriate buffer, or maintained at 4°C, in order to
maintain stability.
[0056] The present compositions for screening a therapeutic agent enable the selection of
a therapeutic agent for COPD, by screening the material which inhibits binding between
cytokeratin 18 protein wherein the cytokeratin 18 protein has an amino acid sequence
of SEQ ID NO: 2 and autoantibodies to cytokeratin 18 wherein the cytokeratin 18 protein
has an amino acid sequence of SEQ ID NO: 2 in the biological samples obtained from
the patients with COPD, or inhibits cytotoxic reaction of the autoantibodies to cytokeratin
18 protein wherein the cytokeratin 18 protein has an amino acid sequence of SEQ ID
NO: 2 expressing cells.
[0057] Also, the specification describes a method of screening a therapeutic agent for COPD,
by using compositions comprising one or more of cytokeratin 18 protein, antibodies
to cytokeratin 18 protein, or autoantibodies to cytokeratin 18 from the patients with
COPD, as target materials.
[0058] The method of screening a therapeutic agent for COPD comprises the following step:
- (a) isolating autoantibodies from biological samples obtained from the patients with
COPD;
- (b) contacting test materials with the autoantibodies obtained in step (a); and
- (c) selecting a therapeutic agent for COPD by determining whether the test materials
can inhibit binding of the autoantibodies to cytokeratin 18 protein, or inhibit cytotoxic
effects of the autoantibodies to cytokeratin 18 protein-expressing cells.
[0059] In the described method of screening a therapeutic agent, the test materials can
be nucleic acids, proteins, extracts, or compounds which are expected to have possibilities
of inhibitor for COPD according to ordinary selecting method, or randomly selected.
[0060] In the described method for screening a therapeutic agent, for the confirmation of
the reaction between the composition for screening and the test materials, common
methods used to confirm protein-protein reaction including antigen-antibody reaction
or protein-compound reaction can be used.
[0061] For example, the following methods can be used: a method which reacts cytokeratin
18 proteins or autoantibodies with the test material, thereby determining the activity,
yeast two-hybrid method, screening method of phage-displayed peptide clone binding
to cytokeratin 18 proteins, high throughput screening (HTS) method using natural product,
chemical library etc., drug hit HTS method, cell-based screening method, or screening
method using DNA array, etc.
[0062] In present inventon, matters relating to genetic engineering technology will be more
clear from the contents of Sambrook' s literature etc. (
Sambrook, et al., Molecular Cloning, A Laboratory Manual. Cold Spring Harbor laboratory
Press, Cold Spring Harbor, N. Y. (2001)).
- 1. A pharmaceutical composition for use in a method for preventing or treating chronic
obstructive pulmonary disease comprising cytokeratin 18 protein as an active ingredient,
wherein the cytokeratin 18 protein has an amino acid sequence of SEQ ID NO: 2.
- 2. The composition for use according to item 1, wherein the chronic obstructive pulmonary
disease is pulmonary emphysema or chronic bronchitis.
- 3. The use of cytokeratin 18 protein as an active ingredient for the manufacture of
a pharmaceutical composition for use in a method for preventing or treating chronic
obstructive pulmonary disease, wherein the cytokeratin 18 protein has an amino acid
sequence of SEQ ID NO: 2.
- 4. The use of according to item 3, wherein the chronic obstructive pulmonary disease
is pulmonary emphysema or chronic bronchitis.
- 5. An in vitro method of diagnosing chronic obstructive pulmonary disease by using diagnostic compositions
containing cytokeratin 18 protein as an active ingredient, comprising the steps of:
- (a) contacting a biological sample of a subject suspected to have chronic obstructive
pulmonary disease, with cytokeratin 18 protein to induce the formation of immune complex;
and
- (b) diagnosing said chronic obstructive pulmonary disease in the subject by detecting
the above immune complex to determine the presence of autoantibodies to said cytokeratin
18 protein,
wherein the cytokeratin 18 protein has an amino acid sequence of SEQ ID NO: 2, wherein
chronic obstructive pulmonary disease is diagnosed when the patients complain of typical
clinical symptoms, including cough, sputum, and dyspnea, and their FEV1 measured following
the inhalation of bronchodilator showed less than 80% of predictive value and the
ratio of FEV1/FVC was less than 70% on pulmonary function test.
- 6. The method of item 5, wherein the chronic obstructive pulmonary disease is pulmonary
emphysema or chronic bronchitis.
- 7. A use of a composition comprising cytokeratin 18 as target material for screening
a therapeutic agent for chronic obstructive pulmonary disease, wherein cytokeratin
18 protein has the amino acid sequence of SEQ ID NO: 2.
- 8. The use according to item 7, wherein the chronic obstructive pulmonary disease
is pulmonary emphysema or chronic bronchitis.
- 9. An in vitro method to aid in the detection of chronic obstructive pulmonary disease in a human
subject, comprising the steps of:
- (a) contacting a biological sample from the human subject with the cytokeratin 18
protein to form an immune complex between the cytokeratin 18 protein and the autoantibodies
biological sample, and
- (b) determining the presence of the autoantibodies against said cytokeratin 18 protein
in the biological sample by detecting the immune complex, wherein the presence of
the autoantibodies bears a positive correlation with the existence of chronic obstructive
pulmonary disease in the human subject,
wherein the cytokeratin 18 protein has an amino acid sequence of SEQ ID NO: 2, wherein
chronic obstructive pulmonary disease is diagnosed when the patients complain of typical
clinical symptoms, including cough, sputum, and dyspnea, and their FEV1 measured following
the inhalation of bronchodilator showed less than 80% of predictive value and the
ratio of FEV1/FVC was less than 70% on pulmonary function test.
- 10. The method of item 9, wherein the chronic obstructive pulmonary disease is pulmonary
emphysema or chronic bronchitis.
Advantageous effects
[0063] As decribed in the above, cytokeratin 18 protein is identified as an autoantigen
recognized by autoantibodies in the serum samples of patients having COPD. Thus, a
pharmaceutical composition of the present invention cytokeratin 18 wherein the cytokeratin
18 protein has an amino acid sequence of SEQ ID NO: 2 protein as an active ingredient
can be used as a medicament for preventing, alleviating, and treating COPD through
the inhibition of autoantibody-induced cytotoxicity to airway epithelial cells and
the inhibition of the secondary development of chronic airway epithelial inflammation
induced by the formation of immune complexes consisted of autoantibodies and autoantigen.
[0064] Also, a diagnostic composition comprising cytokeratin 18 protein can be used for
detecting, diagnosing or classifying COPD.
Description of Drawings
[0065]
Fig. 1 shows immunoblot analysis of human airway epithelial cell (A549) proteins reacting
with IgG autoantibodies in serum samples of healthy controls, pulmonary emphysema
patients having normal pulmonary function, and patients with COPD;
Fig. 2 shows immunoblot detection of IgG autoantibodies to recombinant human cytokeratin
18 protein in serum samples of healthy controls, pulmonary emphysema patients with
normal pulmonary function, and patients with COPD;
Fig. 3 shows the bindings of IgG autoantibodies in serum samples of COPD with the
recombinant human cytokeratin 18 proteins and the commercially available purified
bovine cytokeratin 18 protein detected by immunoblot anlaysis;
Fig. 4 shows the detection of antibody-induced cytotoxicity to human airway epithelial
cells (A549) by IgG antibodies purified from serum samples of patients with COPD;
Fig. 5 shows inhibitions of IgG autoantibody-induced cytotoxicity to airway epithelial
cells (A549) when the IgG antibodies from patients with COPD were adsorbed with human
cytokeratin 18 protein prior to addition to airway epithelial cells;
Best Mode
[0066] Hereinafter, the present invention is more specifically explained by the Examples.
However, the following examples are provided for the purpose of illustration and are
not intended to limit the scope of the present invention.
[EXAMPLE 1] Detection of IgG autoantibodies to cytokeratin 18 protein in serum samples
from patients with COPD
(1-1) Subjects
Subjects
[0067] The inventors examined serum samples obtained from 9 patients with chronic obstructive
pulmonary disease (COPD), 2 patients with pulmonary emphysema showing normal pulmonary
function and 58 healthy controls. Diagnosis of COPD was determined by recently reported
criterion of NHLBI/WHO GOLD Workshop summary (
Am J Respir Crit Care Med 2001;163:1256-1276). Both of 2 patients with pulmonary emphysema had smoking history of more than 10
pack years. They have been clinically complained dyspnea symptom and chest X-ray showed
findings compatible with pulmonary emphysema. However, they had normal findings with
values of FEV1 (forced expiratory volume in one second) and FVC (forced vital capacity)
were greater than 80% of predictive value on pulmonary function test. All 9 patients
with COPD had clinical histories compatible with COPD such as cough, sputum, dyspnea,
etc. Also, their FEV1 measured following the inhalation of bronchodilator showed less
than 80% of predictive value on pulmonary function test, and the ratio of FEV1/FVC
was less than 70%. All patients with COPD had smoking history of more than 10 pack
years, but had no signs of tuberculosis or other pulmonary diseases in chest X-ray.
The serum samples of the patients with COPD were stored at -20 °C.
(1-2) Cell Culture
(1-3) Extraction of cell protains and immunoblot analysis
[0069] Immunoblot analysis was performed with human airway epithelial cells and the serum
samples obtained from healthy controls and patients with COPD according to the above
Example (1-1), to identify human airway epithelial cell proteins which bind to IgG
autoantibodies in the serum.
[0070] Firstly, in order to extract proteins from the human airway epithelial cell A549
in the above (1-2), the cultured cells were lysed in lysis buffer containing 10 mM
Tris/HCl, pH 7.2, 2% sodium dodecyl sulphate (SDS), 158 mM NaCl, and 10 mM dithiothreitol.
[0071] The proteins in cell lysates were separated by discontinuous Sodium Dodecyl Sulfate-PolyacrylAmide
Gel Electrophoresis (SDS-PAGE). Following electrophoresis, proteins were transferred
onto a polyvinylidine difluoride (PVDF) membrane (Bio-Rad Laboratories, Hercules,
CA). After the transfer, the PVDF membrane was treated with Tris-buffered saline (TBS)
containing 5% bovine serum, 10% powdered skim milk and 0.1% Tween 20 for one or more
hours, to block non-specific bindings of proteins to PVDF, and then the PVDF membrane
was cut in 4mm strips. The cut strips were reacted with patients' serum diluted in
the same buffer in 1:100 (v/v) for 2 hours at room temperature. After washing, the
membrane was incubated with alkaline phosphates-conjugated goat anti-human IgG antibodies
(Sigma Chemical Co., St. Louis, MO) for 2 hours at room temperature. After the final
washing, the membrane was stained with a BCIP/NBT solution (5-bromo-4-chloro-3-indoyl
phosphate/nitro blue tetrazolium; Sigma) for 5 minutes to detect the proteins reacted
with patients' serum. To compare with results from patients with other disease, a
serum sample from a patient with nonallergic asthma that a detection of IgG autoantibodies
to cytokeratin 18 has been confirmed by previous report of inventors (
Nahm DH, et al. Am J Respir Crit Care Med 2002;165:1536-9) was also included in the experiments.
[0072] In order to minimize technical errors in detection rate of each test, each test comprised
a positive standard serum and negative control serum. The results of the tests were
assessed by at least two investigators independently with naked eyes. When test serum
showed strong band to certain airway epithelial cell protein compared to negative
control serum, the stained intensity of the band were the same as or stronger than
that of positive standard serum, and the result read by the two investigators corresponded
to each other, which case was defined as the positive detection of autoantibodies.
[0073] Mouse monoclonal antibody to cytokeratin 18 protein (clone CK5, Sigma Chemical Co.,
St. Louis, MO), goat antibody to human alpha-enolase protein (Santa Cruz Biotechnology,
Santa Cruz, CA) and their alkaline phosphatase-conjugated secondary antibodies were
included in each experiment to confirm the location of the reacting autoantigen proteins
when the detection results of the autoantibodies to airway epithelial cell proteins
were read.
[0074] The target autoantigen protein was determined by comparing and analyzing the results
of immunoblot localization of airway epithelial cell proteins on the PVDF membrane
reacting with IgG autoantibodies of patients and airway epithelial cell proteins reacting
with mouse monoclonal antibody to cytokeratin 18 protein (clone CK5, Sigma Chemical
Co., St. Louis, MO) or goat antibody to human alpha-enolase protein (Santa Cruz Biotechnology,
Santa Cruz, CA) in the points of staining patterns and molecular weights.
[0075] Fig. 1 shows result of immunoblot analysis of airway epithelial cell (A549) proteins
reacting with IgG autoantibodies in serum samples of healthy controls, patients with
pulmonary emphysema showing normal pulmonary function, and patients with COPD. Lanes
1 and 2 show the results for serum samples of healthy controls, lanes 3 and 4 show
the results for serum samples of patients with pulmonary emphysema showing normal
pulmonary function, lanes 5-13 show the results for serum samples of patients with
COPD, and lane 14 shows the result for a serum sample of a patient with bronchial
asthma, lane 15 shows the result for mouse monoclonal antibodies to cytokeratin 18
protein, and lane 16 shows the result for goat antibodies to alpha-enolase.
[0076] Fig. 1 shows that IgG autoantibodies to protein band corresponding to cytokeratin
18 protein identified by mouse monoclonal antibodies were detected in 8 (89%) of total
9 patients with chronic obstructive pulmonary disease. This result showed significantly
higher detection rate than that of healthy controls (5 of 58 healthy control; 8.6%)
(chi-square test, p<0.05).
(1-4) Detection of autoantibodies in the blood samples of patients with COPD using
recombinant human cytokeratin 18 protein
[0077] By using the above subjects' serum of (1-3) and commercially available human recombinant
cytokeratin 18 protein (Research Diagnostics INC., Pleasant Hill Road Flanders, NJ)
produced from
E.
coli by the genetic engineering technology, immunoblot was performed in same sample arrangement
as in Fig 1. The results are shown in Fig. 2.
[0078] Fig. 2 shows immunoblot detection of IgG autoantibodies to recombinant human cytokeratin
18 protein using serum samples of healthy controls, patients with pulmonary emphysema
showing normal pulmonary function, and patients with COPD. Lanes 1 and 2 show the
results for serum samples of healthy controls, lanes 3 and 4 show the results for
serum samples of patients with pulmonary emphysema showing normal pulmonary function,
lanes 5-13 show the results for serum samples of patients with COPD, and lane 14 shows
the result for a serum sample of a patient with bronchial asthma, lane 15 shows the
result for mouse monoclonal antibodies to cytokeratin 18 protein, and lane 16 shows
the result for goat antibodies to alpha-enolase.
[0079] As shown in Fig. 2, IgG autoantibodies to recombinant human cytokeratin 18 protein
were clearly detected in 3 (33.3%) of 9 patients with COPD (lanes 7,11, and 13). ,
IgG autoantibodies to recombinant human cytokeratin 18 protein were also detected
in other 5 patients with COPD (lanes 5,6,8,9,10 in Fig. 2) and two patients with pulmonary
emphysema showing normal pulmonary function (lane 3,4 in Fig. 2).
[0080] As the results of Fig. 2 were consistent with the results of Fig. 1, it was confirmed
that the autoantigen reacting with IgG autoantibodies in serum samples from patients
with COPD was human cytokeratin 18 protein.
[0081] As shown in Fig. 1 and Fig. 2, IgG autoantibodies to recombinant cytokeratin 18 protein
or cytokeratin 18 protein in airway epithelial cells were positively detected in patients
with COPD.
[0082] Thus, it was recomfirmed that the autoantigen reacting with IgG autoantibodies in
the serum samples of patients with COPD was cytokeratin 18 protein (Fig. 2).
[Example 2] Immunoblot analysis for bovine cytokeratin 18 protein
[0083] In order to determine whether IgG autoantibodies in serum samples of patients with
COPD are selectively reacted with human cytokeratin 18 protein or they could react
with cytokeratin 18 proteins from other mammal, the inventors performed immunoblot
analysis.
[0084] Reaction of IgG autoantibodies in serum samples from 3 patients with COPD with commercially
available recombinant human cytokeratin 18 protein and purified bovine cytokeratin
18 protein (Research Diagnostics INC., Pleasant Hill Road Flanders, NJ) was detected
and compared by immunoblot analysis, according to the method of (1-3). The results
are shown in Fig. 3.
[0085] Fig. 3 shows immunoblot results that show comparing the reaction of IgG autoantibodies
in serum samples of patients with COPD with recombinant human cytokeratin 18 protein
and purified bovine cytokeratin 18 protein. Lanes 1, 3, 5 and 7 show the results of
the recombinant human cytokeratin 18 protein, and lanes 2, 4, 6, and 8 show the results
of purified bovine cytokeratin 18 protein. Lanes 1 & 2, lanes 3 & 4, and lanes 5 &
6 show the results obtained by reacting with 3 serum samples of 3 patients with COPD,
and lanes 7 & 8 show the result of reacting with mouse monoclonal antibodies to cytokeratin
18 protein.
[0086] From the results obtained by using the serum samples of 3 patients with COPD, it
was confirmed that IgG autoantibodies to cytokeratin 18 in their serum samples could
react with bovine cytokeratin 18 protein having the same molarcular weight of human
cytokeratin 18 protein.
[0087] As shown in the above, the test results of autoantigen-autoantibodies using human
recombinant human cytokeratin 18 protein and purified bovine cytokeratin 18 protein
corresponded to each other. Thus, it was confirmed that bovine cytokeratin 18 protein
could be used to detect autoantibodie in serum samples of patients with COPD.
[Example 3] Inhibition of IgG antibody-induced cytotoxicity to airway epithelial cells
by the administration of cytokeratin 18 protein
(3-1) Confirmation of cytotoxicity to airway epithelial cells by IgG autoantibodies
[0089] In the above test, IgG antibodies were isolated from plasma samples of 2 patients
with COPD, and a healthy control, where patients with COPD had IgG autoantibodies
to human cytokeratin 18 protein.
[0090] IgG antibodies of 1 healthy control were isolated to have a purity of 90%, by using
ethanol precipitation and ultrafiltration according to prior preparing method of IgG
antibodies (
Lebing W et al, Vox Sang 2003;84:193-201). IgG antibodies of 2 patients with COPD were isolated in purity of greater than
95% by affinity chromatography using Protein A column. The purity of the isolated
IgG antibodies was determined by SDS-PAGE and protein staining. Also, the amount of
endotoxin in the isolated IgG antibody solution was measured quantitatively by using
LAL (Limulus amebocyte lysate). As a result, the contamination of endotoxin was not
detected.
[0091] Human IgG antibodies used for intravenous administration (IVglobulin, Green Cross
Pharmaceutical Co., Korea) were commercially obtained and used as control IgG antibodies,
where the control IgG antibodies were isolated from plasma of a large mumber of blood
donors, to have a purity of more than 95%.
[0092] First of all, the above human IgG antibodies were diluted by using DMEM/F12 medium
at concentrations of 5mg/mℓ, 1mg/ℓ, and 0.2mg/mℓ. Then, the diluted samples were put
into 96-well Terasaki tray at a ratio of 1 µℓ/well in quadruplicate. Also, samples
containing only DMEM/F12 medium were put in 96-well Terasaki tray in quadruplicate
as negative controls.
[0093] The cultured human airway epithelial cell line A549 was treated with Trypsin/EDTA
and isolated, then 1 µℓ (2000 cells/µl) of the solution was put into each of above
wells. In order to prevent evaporation of the solution, 5 µℓ of mineral oil was put
into the wells. And then, the wells were reacted for 2 hours and 30 minutes. 5% eosin
Y dye (Sigma Chemical Co.) was put into the wells at a ratio of 5 µℓ/well to stain
the cells. Then, formalin solution was put into the wells at a ratio of 5 µℓ/well
to fix the stained cells. A coverslide was covered and the number of cells without
damage of cell membrane was counted by light microscope to determine cytotoxicity.
[0094] The cytotoxicity to airway epithelial cell by IgG antibodies was expressed as cytolysis
% according to following equation, by comparing mean number of cells in wells reacting
with the samples and mean number of cells in negative control wells containing only
DMEM/F12 medium.

[0095] The result of the test was obtained in quadruplicate to each sample, and then expressed
in terms of mean and standard deviation.
[0096] Fig. 4 show that IgG antibodies isolated from plasma samples of 2 patients with COPD
(patient 1 and patient 2) show significantly higher cytotoxicity than commercial IgG
antibodies obtained from multiple healthy donors used for intravenous administration
(IVglobulin; normal controls 1) or IgG antibodies isolated from plasma of a healthy
control (normal control 2) under the conditions of 1µg/well and 5µg/well (t-test,
p < 0.05).
(3-2) Inhibition of IgG autoantibody-induced cytotoxicity to airway epithelial cell by cytokeratin
18 protein
[0097] In order to absorb autoantibodies to cytokeratin 18 protein from patients with COPD,
50 µg of the human cytokeratin 18 protein purified according to the previous report
of the inventors (
Nahm DH, et al. Am J Respir Crit Care Med 2002;165:1536-9) and 50 µg of the purified human cytokeratin 19 protein as a negative control were
subjected to electrophoresis and transferred to PVDF membrane. PVDF membranes containing
human cytokeratin 18 protein or human cytokeratin 19 protein were cutted into small
pieces and transferred to eppendorf tubes separately.
[0098] 50 µg of IgG antibodies which were isolated from serum samples of 2 patients with
COPD and diluted in DMEM/F12 medium to have a concentration of 5 mg/mℓ were mixed
with PVDF membrane pieces containing either 50 µg of human cytokeratin 18 protein
or human cytokeratin 19 protein, and then, the mixtures were reacted for 16 hours
at 4°C. After the reaction, supernatant was collected by centrifugation, and the cytotoxicity
to human airway epithelial cell by IgG antibodies was measured in the above method
(3-1).
[0099] The result of the experiment was obtained in 6 independent experiments of each samples,
and then, expressed in terms of mean and standard deviation.
[0100] Fig. 5 shows that when the IgG antibodies of patients with COPD (patient 1, 2) were
adsorbed with human cytokeratin 18 protein prior to the addition to airway epithelial
cells, the cytotoxicity to airway epithelial cell by IgG autoantibodies (shown as
"CK18" in each graph) was significantly reduced compared to the case of adsorbtion
with the same amount of human cytokeratin 19 protein used as a control antigen (shown
as "CK19" in each graph) (Table 1) (t-test, p < 0.001).
[TABLE 1]
| Patients |
Absorption with cytokeratin 19 protein (cytolysis %) |
Absorption with cytokeratin 18 protein (cytolysis %) |
| Patient 1 |
61.9 ± 6.4* |
13.7 ± 4.5 |
| Patient 2 |
37.2 ± 6.2* |
1.8 ± 2.7 |
| *: P<0.01 |
[0101] Above results show that cytokeratin 18 protein can be used for the inhibition of
cytotoxic reaction to airway epithelial cell induced by IgG autoantibodies to cytokeratin
18 protein in the blood of patients with COPD.
[0102] Accordingly, it is evident that the cytotoxic effect and the inflammatory effect
of IgG autoantibodies can be repressed if the cytokeratin 18 protein wherein the cytokeratin
18 protein has an amino acid sequence of SEQ ID NO: 2 of the present invention is
administered into the patients with COPD.
Industrial Applicability
[0103] As decribed in the above, cytokeratin 18 protein is identified as an autoantigen
recognized by autoantibodies in the serum samples of patients having COPD. Thus, a
pharmaceutical composition of the present invention cytokeratin 18 wherein the cytokeratin
18 protein has an amino acid sequence of SEQ ID NO: 2 protein as an active ingredient
can be used as a medicament for preventing, alleviating, and treating COPD through
the inhibition of autoantibody-induced cytotoxicity to airway epithelial cells and
the inhibition of the secondary development of chronic airway epithelial inflammation
induced by the formation of immune complexes consisted of autoantibodies and autoantigen.
[0104] Also, the present invention can be used for a pharmaceutical formulation comprising
cytokeratin 18 protein wherein the cytokeratin 18 protein has an amino acid sequence
of SEQ ID NO: 2 or fragments thereof to protect patients with COPD. The present invention
also can be used to identify a pharmaceutical compound capable of inhibiting the binding
ability of autoantibodies to cytokeratin 18 from patients with COPD to cytokeratin
18 protein wherein the cytokeratin 18 protein has an amino acid sequence of SEQ ID
NO: 2 or cytokeratin 18-expressing cells wherein the cytokeratin 18 protein has an
amino acid sequence of SEQ ID NO: 2.
Sequence Listing
[0105]
<110> JEON, Sook-Yeong NAM, Dong-Ho
<120> Composition for prevention, treatment and diagnosis of chronic obstructive pulmonary
disease
<130> NP06-0017
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