COMPOSITION FOR DIFFERENTIAL DIAGNOSIS OF ACANTHAMOEBA KERATITIS COMPRISING CHORISMATE MUTASE PROTEIN ANTIBODIES, AND ACANTHAMOEBA KERATITIS DIAGNOSIS KIT USING SAME

Abstract

The present invention relates to: a composition for differentially diagnosing Acanthamoeba keratitis, the composition comprising chorismate mutase antibodies; and an Acanthamoeba keratitis diagnosis kit using same. The composition comprising chorismate mutase antibodies according to the present invention causes an antigen-antibody reaction only specific to a chorismate mutase protein secreted from Acanthamoeba, thus making it possible to diagnose Acanthamoeba keratitis and differentiate the cause of Acanthamoeba keratitis more rapidly and accurately than existing methods for diagnosing Acanthamoeba keratitis. The composition is expected to be widely applicable to the production of Acanthamoeba keratitis diagnosis kits, therapeutic agents, contact lens disinfecting agents, and the like using the composition.

Claims

1. A composition for differentially diagnosing Acanthamoeba keratitis, comprising an antibody specific to a chorismate mutase protein.

2. The composition of claim 1, wherein the chorismate mutase protein consists of an amino acid sequence of SEQ ID NO: 1.

3. The composition of claim 1, wherein the chorismate mutase protein is secreted from pathogenic Acanthamoeba.

4. The composition of claim 1, wherein the antibody specifically binds to an amino acid sequence site of SEQ ID NO: 2 in the chorismate mutase protein.

5. A kit for differentially diagnosing Acanthamoeba keratitis, comprising the composition of claim 1.

6. A method for providing information for differentially diagnosing keratitis of a patient with Acanthamoeba keratitis, the method comprising: measuring an antigenantibody reaction of an antibody specific to a chorismate mutase protein for a subjectderived biological sample.

7. A use of an antibody specific to a chorismate mutase protein for preparing a composition for differentially diagnosing Acanthamoeba keratitis.

Description

DESCRIPTION OF DRAWINGS

[0019] FIG. 1A illustrates the nucleotides of chorismate mutase among proteins secreted from Acanthamoeba castellanii.

[0020] FIG. 1B illustrates the amino acids of chorismate mutase among proteins secreted from Acanthamoeba castellanii.

[0021] FIG. 2A illustrates the results of analyzing a secondary structure according to an amino acid sequence of chorismate mutase.

[0022] FIG. 2B illustrates a highly antigenic portion of the protein structure of chorismate mutase.

[0023] FIG. 3 illustrates the results of comparing the similarity of chorismate mutases of the causative bacteria and fungi of keratitis with respect to the highly antigenic portion in the protein structure of chorismate mutase.

[0024] FIG. 4 illustrates the chorismate mutase detected in Acanthamoeba cell lysates.

[0025] FIG. 5 illustrates the chorismate mutase detected in Acanthamoeba culture solutions.

[0026] FIG. 6 illustrates the results of specifically detecting Acanthamoeba in human corneal cells infected with Acanthamoeba using chorismate mutase antibodies.

MODES OF THE INVENTION

[0027] The present inventors have intensively researched chorismate mutase among proteins secreted from pathogenic Acanthamoeba to prepare the corresponding antibody, confirmed that the antibody caused an antigen-antibody reaction only specific to Acanthamoeba among cell lysates and culture solutions of Staphylococcus aureus, Pseudomonas aeruginosa, Fusarium solani, Acanthamoeba castellanii and a clinical isolate Acanthamoeba spp., which may be the cause of keratitis, and completed the present invention.

[0028] Thus, the present invention provides a composition for differentially diagnosing Acanthamoeba keratitis, including an antibody specific to a chorismate mutase protein.

[0029] As used herein, the term “antibody” includes an immunoglobulin molecule having immunological reactivity with a certain antigen, and includes both a monoclonal antibody and a polyclonal antibody. Furthermore, the antibody includes a form produced by genetic engineering, such as a chimeric antibody (for example, a humanized murine antibody) and an antibody binding to two different types of antigen (for example, a bispecific antibody).

[0030] As used herein, the term “chorismate mutase” refers to an enzyme that catalyzes a chemical reaction for converting chorismate into prephenate by the production pathways of phenylalanine and tyrosine, and the chorismate mutase of the present invention is not limited to the chorismate mutase secreted from various microorganisms, but is preferably chorismate mutase secreted from Fusarium solani, Staphylococcus aureus, Pseudomonas aeruginosa and Acanthamoeba castellanii, and specifically is more preferably chorismate mutase secreted from pathogenic Acanthamoeba castellanii.

[0031] The chorismate mutase according to the present invention may consist of an amino acid sequence of SEQ ID NO: 1, and may consist of an amino acid sequence having a sequence homology of 70% or more, preferably 80% or more, more preferably 90% or more, and most preferably 95%, 96%, 97%, 98%, 99% or more with SEQ ID NO: 1.

[0032] As another exemplary embodiment of the present invention, the antibody according to the present invention may specifically bind to an amino acid site of highly antigenic SEQ ID NO: 2 consisting of a random coil portion confirmed by secondary structural analysis in a chorismate mutase protein, and may specifically bind to a site consisting of an amino acid sequence having a sequence homology of 70% or more, preferably 80% or more, more preferably 90% or more, and most preferably 95%, 96%, 97%, 98%, 99% or more with SEQ ID NO: 2.

[0033] The present inventors confirmed the effectiveness for the differentiation and diagnosis of a patient with keratitis using a composition including an antibody specific to the chorismate mutase protein.

[0034] In an exemplary embodiment of the present invention, as a result of performing western blot on cell cultures of human corneal epithelial (HCE) cells, non-pathogenic Acanthamoeba (Acanthamoeba castellanii #30011-nonpathogenic), pathogenic Acanthamoeba (Acanthamoeba castellanii #30868-pathogenic), a clinical isolate (Acanthamoebas spp.), F. solani, P. aeruginosa and S. aureus, it was confirmed that chorismate mutase was specifically detected only in Acanthamoeba (see Example 3), and further, as a result of performing western blot by obtaining the culture solution of each sample used in Example 3, it was confirmed that chorismate mutase was specifically detected only in Acanthamoeba (see Example 4).

[0035] Through the results, it was confirmed that a composition including the chorismate mutase antibody of the present invention could be usefully used for differential diagnosis of keratitis of a patient with Acanthamoeba keratitis.

[0036] As another aspect of the present invention, the present invention provides a kit for differentially diagnosing Acanthamoeba keratitis, including the composition.

[0037] As an exemplary embodiment of the present invention, the kit for differentially diagnosing Acanthamoeba keratitis may consist of one or more other constituent compositions, solutions or devices suitable for the analytical method.

[0038] As still another aspect of the present invention, the present invention provides a method for providing information for differentially diagnosing keratitis of a patient with Acanthamoeba keratitis, the method including: measuring an antigen-antibody reaction of an antibody specific to a chorismate mutase protein for a subject-derived biological sample.

[0039] As used herein, the term “method for providing information for differentially diagnosing keratitis of a patient with keratitis” means to provide objective information necessary for diagnosing a keratitis disease as a diagnosis or differentiation step, and excludes the physician's clinical judgment or findings. The subject-derived biological sample is not limited to, but may be, for example, a tissue, a cell, and the like, and is preferably a tissue or a cell derived from a patient with keratitis.

[0040] As yet another aspect of the present invention, the present invention provides a use of an antibody specific to a chorismate mutase protein for preparing a composition for differentially diagnosing Acanthamoeba keratitis.

[0041] Hereinafter, the present invention will be described in more detail through Examples. These Examples are only for exemplifying the present invention, and it will be apparent to those of ordinary skill in the art that the scope of the present invention is not to be construed as being limited by these Examples.

EXAMPLES

Example 1. Obtaining Chorismate Mutase from Proteins Secreted from Acanthamoeba

[0042] Obtaining chorismate mutase ORF

[0043] By obtaining the ORF of chorismate mutase among secreted proteins of pathogenic Acanthamoeba (ATCC #30868), 585 bp nucleotides of chorismate mutase, as illustrated in FIG. 1A, and 194 amino acids of chorismate mutase, as illustrated in FIG. 1B, were confirmed.

[0044] Analysis of secondary structure of chorismate mutase and confirmation of antigenicity of chorismate mutase

[0045] As a result of analyzing the secondary structure of and confirming the antigenicity of the chorismate mutase protein obtained in Example 1-1, the secondary structure was analyzed as illustrated in FIG. 2A, and two highly antigenic portions Prediction 1 (GQDVLDSSRESVVLANAR) and Prediction 2 (RLQVETLNSEFNAGLPVPVQHAD) were confirmed as illustrated in FIG. 2B.

Example 2. Comparison of Antigenicity of Chorismate Mutase in Causative Bacteria and Fungi of Keratitis

[0046] As a result of comparing the similarity between the highly antigenic portions (Prediction 1 and Prediction 2) derived in Example 1-2 and chorismate mutases of Fusarium oxysprum (1 and 2), Staphylococcus aureus, and Pseudomonas aeruginosa, which may be the cause of keratitis, as illustrated in FIG. 3, the results of exhibiting the difference of chorismate mutase were derived, and a relatively highly antigenic portion Prediction 2 (RLQVETLNSEFNAGLPVPVQHAD) was selected as an antibody-binding site.

Example 3. Confirmation of Detection of Chorismate Mutase Proteins in Cell Lysates

[0047] As a result of obtaining an antibody specifically binding to the protein-antibody binding site of Acanthamoeba chorismate mutase selected in Example 2 by a known method and performing western blot on cell lysates of human corneal epithelial (HCE) cells, non-pathogenic Acanthamoeba (Acanthamoeba castellanii #30011-nonpathogenic), pathogenic Acanthamoeba (Acanthamoeba castellanii #30868-pathogenic), a clinical isolate (Acanthamoebas spp.), F. solani, P. aeruginosa and S. aureus, as illustrated in FIG. 4, it was confirmed that chorismate mutase was specifically detected only in Acanthamoeba cell lysates (2, 3 and 4 lines).

Example 4. Confirmation of Detection of Chorismate Mutase Proteins in Cell Culture Solution

[0048] As a result of obtaining an antibody specifically binding to the protein-antibody binding site of Acanthamoeba chorismate mutase selected in Example 2 by a known method and performing western blot in cell culture solutions of human corneal epithelial (HCE) cells, non-pathogenic Acanthamoeba (Acanthamoeba castellanii #30011-nonpathogenic), pathogenic Acanthamoeba (Acanthamoeba castellanii #30868-pathogenic), a clinical isolate (Acanthamoeba spp.), F. solani, P. aeruginosa and S. aureus, as illustrated in FIG. 5, it was confirmed that chorismate mutase was specifically detected only in Acanthamoeba cell culture solutions (2, 3 and 4 lines).

[0049] From the results, it could be confirmed that the antibody of the present invention specifically binds only to Acanthamoeba.

Example 5. Confirmation of Detection of Acanthamoeba in Corneal Cells Infected with Acanthamoeba

[0050] After human corneal epithelial (HCE) cells were infected with Acanthamoeba (Acanthamoeba castellanii #30868-pathogenic), the presence of cells was confirmed by staining the infected cells with 4′,6-diamidino-2-phenylindole (DAPI) (B of FIG. 6), and the cells were reacted with an antibody specifically binding to a protein-antibody binding site of Acanthamoeba chorismate mutase selected in Example 2.

[0051] As a result, as illustrated in C of FIG. 6, it was confirmed that only Acanthamoeba was specifically detected.

[0052] The above-described description of the present invention is provided for illustrative purposes, and those skilled in the art to which the present invention pertains will understand that the present invention can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the above-described embodiments are only exemplary in all aspects and are not restrictive.

INDUSTRIAL APPLICABILITY

[0053] The composition of the present invention can cause an antigen-antibody reaction only specific to chorismate mutase secreted from Acanthamoeba, thus making it possible to diagnose Acanthamoeba keratitis and differentiate the cause of Acanthamoeba keratitis more rapidly and accurately than existing methods for diagnosing Acanthamoeba keratitis. The composition is expected to be widely applicable to the production of Acanthamoeba keratitis diagnosis kits, therapeutic agents, contact lens disinfecting agents, and the like.