Application of a tick-derived histamine-binding protein HqHBP and its encoding gene in anti-allergic reactions

Abstract

The present invention relates to the field of biotechnology, and in particular to an application of a tick-derived histamine binding protein HqHBP and a coding gene thereof in anti-allergic reactions. The Qinghai Haemaphysalis tick histamine binding protein HqHBP of the present invention is recombinantly expressed to obtain a HqHBP recombinant protein, and the purified target protein is subjected to an in vitro ELISA experiment to measure the absorbance at 450 nm, and the result shows that the protein can specifically bind to histamine. The protein can significantly reduce ear edema in a xylene-induced mouse inflammation model, and can directly reduce the content of histamine in xylene-induced skin inflammation tissue. The histamine binding protein is suitable for the development of anti-allergic reaction preparations.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology, and specifically relates to application of a tick-derived histamine binding protein HqHBP and a coding gene thereof in anti-allergic reactions. Background Art

[0002] As one of the most important blood-sucking parasites of humans and animals, ticks can trigger pathological reactions such as allergic inflammation, itching and pain when feeding on blood. Histamine is a pleiotropic biogenic amine that is involved in key physiological processes including neurotransmission, immune response, nutrition, and cell growth and differentiation. As a well-known allergic inflammatory mediator, histamine is released when the body is allergic to a substance. Histamine can also induce feelings of pain and itching in the host. It is known that histamine not only adversely affects the ability of ticks to attach to the host's skin, but also directly or indirectly reduces its success rate of feeding and reproduction. Therefore, ticks have evolved effective strategies to cope with the host's immune defense response. Lipoproteins are a class of small molecules secreted by ticks during the blood-sucking process. Histamine-binding proteins (HBPs) are lipid-binding proteins secreted by ticks that can exert their effects by specifically binding to histamine. For example, the Rhipicephalus tataricus ( Rhipicephalus appendiculatus ) can secrete histamine-binding protein into the wound site to inhibit allergic inflammatory response. Dermacentor reticulatus ) has two binding sites, one for histamine and the other for serotonin (or 5-hydroxytryptamine – 5-HT). Argas monolakensis ) 、 The tick ( Argas reflexus ) 、 Ornithodorospermum szechwani Ornithodoros savignyi ) and Ixodes scapularis ( Ixodes scapularis ) tick lipoproteins have been characterized as histamine and / or 5-HT binding proteins. These HBPs locally trap secreted histamine molecules, preventing them from reaching target cells.

[0003] To date, various drugs used to treat allergic diseases are usually accompanied by various side effects such as ulcers, sedation, and palpitations. Natural bioactive substances and their derivatives are important sources for the development of new drugs. Many drugs derived from nature have been used in clinical practice. Tick saliva is increasingly considered to be a rich source of bioactive molecules with specific functions. In this study, we successfully cloned the lysine tick ( Haemaphysalis qinghaiensis ) A new gene Hq018 of salivary gland. The recombinant protein HqHBP was successfully expressed in the prokaryotic expression system. The experimental results showed that the recombinant protein HqHBP has efficient histamine binding activity. Summary of the invention

[0004] The newly discovered Qinghai blood tick HqHBP protein of the present invention can inhibit local pain and allergic inflammatory reactions by binding to the histamine produced by the host at the tick bite site, reduce the host's perception of local pain and the allergic reaction caused by the tick's long-term blood sucking, and help the tick to successfully suck blood; due to its specific histamine binding function, the protein can inhibit the allergic inflammatory reaction of local tissues and can be used to prepare anti-allergic reaction preparations.

[0005] The first aspect of the present invention discloses a tick histamine binding protein HqHBP, wherein the histamine binding protein is a recombinant protein derived from the salivary gland of Haemaphysalis qinghaiensis, and the amino acid sequence thereof is shown in SEQ ID NO.1.

[0006] MQVFVLLMFVGSFSHAYTNPPGAISSSQTTTCTTGPLEEQDGWEFLKRQTPMLVAMRNFDTNYSITHQTDCIFPITTKSDRRKLQISQNYLVHSQKPDEWVTFEKHFTAKK EVDKEACHVFSSRHEGEPRDYTIGYSSELCLVVHLPRNLYGVQTPCELLVRPRYFRNKDRECCGYYFNTLCGGDGRIVSNKRSCYGLTKQEAEKKVEELRRAASSS (SEQID NO.1).

[0007] In addition to protecting the above-mentioned histamine binding protein HqHBP, the present invention further protects a fusion protein obtained by connecting a tag to the N-terminus or / and the C-terminus of the above-mentioned protein;

[0008] And polypeptides or protein molecules having functions similar to the histamine binding protein of the present invention obtained by substitution and / or deletion and / or addition of one or several amino acid residues; or proteins derived from Haemaphysalis qinghaiensis and having more than 98% homology with the histamine binding protein HqHBP and related to allergy and anti-inflammation.

[0009] The second aspect of the present invention discloses a nucleic acid molecule encoding the above-mentioned histamine-binding protein or analogs, wherein the sequence of the nucleic acid molecule Hq018 encoding the histamine-binding protein HqHBP is shown as SEQ ID NO.2.

[0010] (SEQ ID NO.2)

[0011] The nucleotide sequence from positions 46 to 699 in the gene sequence shown in SEQ ID NO.2 is translated to obtain a protein with an amino acid sequence as shown in SEQ ID NO.1, wherein the nucleotide sequence from positions 46 to 699 in the gene sequence shown in SEQ ID NO.2 has a termination codon at the end, taa.

[0012] The nucleic acid molecule is the coding gene Hq018 of the histamine binding protein HqHBP of Haemaphysalis qinghaiensis. The nucleotide sequence disclosed in the present invention is disclosed for the first time, and no homologous sequence similar to it is found in the search of the prior art.

[0013] In the present invention, it is well known to those skilled in the art that, due to the degeneracy of protein genetic codons, there are usually more than one codon that determines an amino acid, and the substitution of the third nucleotide in a triplet codon often does not change the composition of the amino acid, so the nucleotide sequences of genes encoding the same protein may be different. Based on the known codon table, those skilled in the art can completely deduce the nucleotide sequences of genes that can encode them from the amino acid sequences disclosed in the present invention, and obtain the nucleotide sequences by biological methods (such as PCR methods, mutation methods) or chemical synthesis methods. Therefore, the partial nucleotide sequences should be included in the protection scope of the present invention.

[0014] The present invention utilizes a reporter gene commonly used in the art to connect with the gene of the present invention to obtain an open reading frame. Preferably, the open reading frame also includes a promoter and / or an enhancer.

[0015] The third aspect of the present invention discloses a recombinant vector comprising the above-mentioned Haemaphysalis qinghaiense histamine-binding protein HqHBP encoding gene Hq018.

[0016] In the present invention, the recombinant vector can be either a recombinant cloning vector or a recombinant expression vector. Preferably, the recombinant vector is a recombinant expression vector. Further preferably, the recombinant expression vector is selected from any one of recombinant prokaryotic expression vectors. In a preferred embodiment of the present invention, the recombinant vector is a recombinant vector obtained by connecting the gene provided by the present invention with the prokaryotic expression vector pET30a.

[0017] The "vector" mentioned herein refers to a DNA construct containing a DNA sequence operably linked to an appropriate control sequence, so as to express the target gene in a suitable host. The vector used in the present invention is not particularly limited and can be any vector known in the art as long as it can be replicated in the host. That is, the vector includes but is not limited to plasmids, bacteriophages, etc.

[0018] The fourth aspect of the present invention discloses a recombinant microbial host cell, comprising the above-mentioned recombinant vector; the recombinant microbial host cell is preferably Escherichia coli.

[0019] Recombinant microbial host cells are specifically achieved by transformation. Here, "transformation" has the meaning generally understood by those skilled in the art, that is, the process of introducing exogenous DNA into a host. The method of transformation includes any method of introducing nucleic acid into a cell, including but not limited to electroporation, calcium phosphate (CaPO4) precipitation, calcium chloride (CaCl2) precipitation, microinjection, polyethylene glycol (PEG) method, DEAE-dextran method, cationic liposome method, and lithium acetate-DMSO method.

[0020] The "host cell" has a meaning generally understood by those of ordinary skill in the art, that is, a cell into which the nucleic acid having promoter activity of the present invention can be introduced, and after the introduction, it is called a recombinant host cell. In other words, the present invention can utilize any host cell, as long as the cell contains the nucleic acid having promoter activity of the present invention and is operably linked to a gene to mediate the transcription of the gene. The host cell of the present invention can be a prokaryotic cell or a eukaryotic cell, preferably Escherichia coli. The host cell can be any strain, as long as the strain has the ability to produce the recombinant protein HqHBP, including wild-type strains and recombinant strains.

[0021] The fifth aspect of the present invention discloses a method for preparing the above-mentioned histamine-binding protein, comprising the following steps:

[0022] S1. Design primers and use the positive clone Hq018 obtained from the cDNA library of Haemaphysalis qinghaiense as a template for PCR amplification to obtain the Hq018 gene;

[0023] S2, insert the Hq018 gene obtained in S1 into the pGEM-T-easy vector to construct a recombinant cloning plasmid;

[0024] S3, expanding the positive clones obtained in S2 and extracting the recombinant clone plasmids;

[0025] S4, the recombinant cloning plasmid obtained in S3 and the prokaryotic expression vector pET30a were respectively N I and XOt I is used for enzyme digestion to obtain the target gene insertion fragment and linearized vector;

[0026] S5, ligating the inserted fragment obtained in S4 and the linearized vector with T4 ligase to construct a recombinant prokaryotic expression plasmid pET30a-Hq018, transforming competent cells DH5α with the constructed recombinant prokaryotic expression plasmid, and extracting the recombinant expression plasmid;

[0027] S6. The recombinant expression plasmid verified by sequencing in S5 was transformed into Escherichia coli competent cells Rosetta (DE3). After kanamycin resistance screening, the induced expressed protein was purified to obtain the recombinant protein HqHBP.

[0028] The gene Hq018 in the present invention is cloned from the cDNA library of the salivary gland of the tick, the gene sequence length is 776bp, the gene sequence contains an open reading frame (ORF) with a length of 654bp (46 to 699), the encoded amino acid sequence length is 217aa, the theoretical molecular weight is 25kDa, and the isoelectric point pI is 8.05. The coding sequence after removing the signal peptide is connected with the pET30a expression vector to construct a recombinant expression plasmid, and the plasmid is transformed into Escherichia coli Rosetta (DE3), and the recombinant protein HqHBP is induced to express. The carboxyl end of the expressed recombinant protein introduces a LEHHHHHH purification tag, and the recombinant protein contains 210 amino acid residues, a theoretical molecular weight of 24.4kDa, and an isoelectric point pI of 7.88. In vitro ELISA experiments and in vivo xylene-induced inflammation model experiments using purified recombinant protein confirmed that the tick-derived histamine-binding protein HqHBP molecule has biological activity of specific binding to histamine and anti-edema, and can be used to prepare anti-allergic preparations.

[0029] Preferably, in S1, the nucleotide sequences of the primers are as shown in SEQ ID NO. 3 and SEQ ID NO. 4.

[0030] The sixth aspect of the present invention discloses the use of the above-mentioned histamine binding protein HqHBP, the above-mentioned nucleic acid molecule Hq018, the above-mentioned recombinant vector or the above-mentioned recombinant microbial host cell in the preparation of an antiallergic drug. The antiallergic drug is used for the treatment and relief of allergic reactions.

[0031] The seventh aspect of the present invention discloses an antiallergic drug, comprising the above-mentioned histamine binding protein HqHBP and a pharmaceutically acceptable carrier, wherein the histamine binding protein HqHBP serves as an active ingredient of the antiallergic drug.

[0032] Compared with the prior art, the present invention has the following significant effects:

[0033] The histamine binding protein HqHBP of Haemaphysalis qinghaiense of the present invention is obtained after recombinant expression. The purified target protein is subjected to an in vitro ELISA experiment to measure the absorbance at 450 nm. The result shows that the protein can specifically bind to histamine. The protein can significantly reduce ear edema in a xylene-induced mouse inflammation model and can directly reduce the content of histamine in xylene-induced skin inflammation tissue. The histamine binding protein is suitable for the development of anti-allergic reaction preparations. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the electrophoresis diagram of the PCR amplification product of the target gene fragment.

[0035] Figure 2 Construct maps for recombinant expression plasmids.

[0036] Figure 3 The SDS-PAGE electrophoresis diagram of the induced expressed target protein and its purified product, where M is the standard molecular weight protein marker; 1. Recombinant bacterial lysate; 2. Purified target protein.

[0037] Figure 4 The results are of the in vitro ELISA and histamine binding assay of the present invention.

[0038] Figure 5 This is the in vivo xylene-induced ear edema inflammation model of the present invention, and the experimental result of protein inhibiting ear edema.

[0039] Figure 6 This is the in vivo xylene-induced skin inflammation model of the present invention, and the experimental result of protein inhibiting skin histamine. DETAILED DESCRIPTION

[0040] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are selected according to conventional methods and conditions, or according to the product specifications. The raw materials and equipment used in the examples are well known to those skilled in the art, and are all available on the market or easily obtained or prepared.

[0041] The experimental methods in the following examples, unless otherwise specified, are all conventional methods, and are performed according to the techniques or conditions described in the literature in the field or according to the product instructions. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained from commercial channels.

[0042] Example 1

[0043] This example is used to illustrate the cloning of the protein encoding gene provided by the present invention.

[0044] (1) The positive clone Hq018 obtained from the cDNA library of Haemaphysalis qinghaiensis was used as the template for PCR reaction. The upstream primers: atcatatgtatacgaaccctcccgga (SEQ ID NO.3) and the downstream primers: tactcgagtgacgaagacgcggctcgt (SEQ ID NO.4) were used to amplify the signal peptide coding region of the target gene fragment. Agarose electrophoresis showed that the amplified product was consistent with the theoretical value of 654 bp. See Appendix. Figure 1 .

[0045] (2) The PCR amplification product of step (1) was recovered by gel excision and purified, and the purified PCR product was cloned into the pGEM-T-easy vector (purchased from Promega) to construct a recombinant cloning plasmid.

[0046] (3) The plasmid from step (2) was used to transform competent E. coli cells DH5α (purchased from Shanghai Weidi Biotechnology Co., Ltd.), and the recombinant cloning plasmid was extracted.

[0047] Example 2

[0048] This example is used to illustrate the construction and expression of a recombinant prokaryotic expression plasmid.

[0049] (1) The recombinant cloning plasmid obtained in step (3) of Example 1 and the prokaryotic expression vector pET30a (purchased from Novagen) were digested with restriction endonucleases Nde I and Xho I, respectively, to obtain the target gene insert and the linearized vector.

[0050] (2) The insert fragment obtained in step (1) and the linearized vector were ligated using T4 ligase (purchased from Promega) to construct the recombinant prokaryotic expression plasmid pET30a-Hq018 (see Appendix). Figure 2 ), the constructed plasmid was used to transform competent cells DH5α, and the recombinant expression plasmid was extracted.

[0051] (3) The recombinant expression plasmid extracted in step (2) was sent to Beijing Liuhe BGI Genomics Co., Ltd. for sequence determination to confirm that the target gene fragment was inserted into pET30a.

[0052] (4) The recombinant expression plasmid verified to be correct by sequencing in step (3) was transformed into Escherichia coli competent cells Rosetta (DE3) (purchased from Shanghai Weidi Biotechnology Co., Ltd.), and single clones were selected for kanamycin resistance. The colonies were inoculated into LB liquid culture medium (containing 50 μg / mL kanamycin) and cultured overnight at 37°C and 200 rpm with shaking to obtain seed solution.

[0053] (5) The seed solution obtained in step (4) was inoculated into 2×YT liquid culture medium (containing 50 μg / mL kanamycin) at a ratio of 1:100, and cultured at 37°C and 200 rpm with shaking until the OD600 was approximately 0.6-0.8.

[0054] (6) Add IPTG to the culture medium obtained in step (5) to a final concentration of 0.1 mmol / L, and induce expression at 26°C, 200 rpm for 10 hours. Centrifuge the bacterial solution at 4°C, 9000 g for 15 min, discard the supernatant, and collect the precipitate.

[0055] Example 3

[0056] This example is used to illustrate the purification of recombinant protein.

[0057] (1) The recombinant bacterial precipitate obtained in step (6) of Example 2 was fully resuspended in PBS buffer (137mmol / LNaCl, 1mmol / L KH2PO4, 8mmol / L Na2HPO4·12H2O, 2.7mmol / L KCl, pH 7.5), and the recombinant bacteria were lysed for 3 rounds using a high-pressure homogenizer until the lysate was transparent.

[0058] (2) The recombinant bacterial lysate obtained in step (1) was centrifuged at 8500 g for 15 min at 4°C, and the precipitate was collected. The precipitate was washed with inclusion body detergent (50 mmol / L NaH2PO4·2H2O, 10 mmol / L NaCl, 2 mol / L Urea) under ultrasonic conditions for 10 min, and the precipitate was centrifuged again at 8500 g for 15 min. This step was repeated twice. Finally, the inclusion bodies were lysed with inclusion body lysis buffer (6 mol / L guanidine hydrochloride, 20 mmol / L sodium phosphate, 0.5 mol / L NaCl, pH 7.5) on ice overnight, and the supernatant was collected and centrifuged at 9500 g for 10 min at 4°C. Before passing through the column, the cell debris was removed by filtering with a 0.45 μm filter. The filtrate can be directly applied to the column for purification.

[0059] (3) Use binding buffer (8 mol / L Urea, 50 mmol / L Tris, 250 mmol / L NaCl and 10 mmol / L imidazole, pH 7.5) to equilibrate the Ni-NTA Agarose protein purification column (purchased from Invitrogen) and add the filtered bacterial lysate from step (2) to the protein purification column.

[0060] (4) Rinse the column with about 10 times the volume of the column bed with washing buffer (8 mol / L Urea, 50 mmol / L Tris, 500mmol / L NaCl, 30 mmol / L imidazole, pH 7.5) until the absorbance value is close to background and no longer decreases.

[0061] (5) Elute the column with elution buffer (8 mol / L Urea, 50 mmol / L Tris, 500 mmol / L NaCl, 250 mmol / L imidazole, pH 7.5) to collect the target protein.

[0062] (6) The target protein was dialyzed against dialysis buffer (50 mmol / L Tris, 500 mmol / L NaCl) containing 4 mol, 2 mol, and 1 mol urea, respectively, to renature the protein.

[0063] (7) Detect the target protein using 15% SDS-PAGE gel electrophoresis and Coomassie Brilliant Blue staining. The results are shown in the attached Figure 3 As shown. Figure 3 It can be seen that the recombinant strain can express the target protein well, and a high-purity target protein was obtained after purification.

[0064] Example 4

[0065] This example is used to illustrate the histamine binding and anti-allergic reaction function verification of the recombinant protein of the present invention.

[0066] Each well of a Nunc 96-well microplate was coated with 0.2 mg, 0.1 mg, and 0.05 mg of HqHBP recombinant protein, with dialysis buffer (50 mmol / L Tris, 500 mmol / L NaCl, 1 mol / LUrea, pH 7.5) as a control, and three replicates were set for each concentration. The microplate was incubated at 4°C for 12 hours. After incubation, the wells were washed three times with 300 μL of wash buffer (PBS-T). The water in the wells was blotted dry with absorbent paper. Then, 100 μL of 5% skim milk powder was added to each well and blocked at 37°C for 1 hour. After discarding the blocking solution, the wells were washed three times as above. The water in the wells was blotted dry with absorbent paper. 100 μL of Histamine-HRP (Neogen Veratox®, Lansing, MI, USA) was added to each well and incubated at 37°C for 2 hours. After washing the wells three times as described above, add 100 μL of the mixed chromogenic substrate to each well. After the reaction has been going on for 10 minutes, add 100 μL of the stop solution to the wells. Measure the absorbance (OD) value at 450 nm. The results are shown in the attached figure. Figure 4 shown.

[0067] Six Kunming mice were randomly selected. Ear edema was induced by applying xylene (40 μL per mouse ear) to the inner and outer surfaces of the ears. 20 minutes later, 200 μL of dialysis buffer (50 mmol / L Tris, 500 mmol / L NaCl and 1 mol / L Urea) was applied to the left ear of three of the mice, and 200 μL of recombinant protein HqHBP (2 mg / mL) was applied to the right ear; the other three mice were applied 200 μL of recombinant protein HqHBP (2 mg / mL) to the left ear and 200 μL of dialysis buffer (50 mmol / L Tris, 500 mmol / L NaCl and 1 mol / L Urea) to the right ear. 30 minutes later, the mice were killed, and ear samples with a diameter of 6 mm were cut from the same position of the left and right ears using a 6 mm perforator. The weight difference between the left and right ear punch samples of the same mouse was measured. Edema was defined as the weight difference between the two ears. The results are shown in the attached figure. Figure 5 shown.

[0068] (3) Randomly select six Kunming mice and shave the hair on their backs. 2 150 μL of xylene was applied to the area to induce edema. 20 minutes later, 300 μL of dialysis buffer (50 mmol / L Tris, 500 mmol / L NaCl and 1 mol / LUrea) was applied to the left side of three mice, and 300 μL of HqHBP protein (2 mg / mL) was applied to the right side. 300 μL of HqHBP protein was applied to the left side of another three mice, and 300 μL of dialysis buffer was applied to the right side. After 20 minutes, the mice were killed by cervical dislocation, and the skin of the edema-induced area was removed, and the mucosa in the skin was removed. An area of ​​about 1 cm 2 Skin samples were cut into small pieces and ground on ice in a phosphate buffer solution containing 10% protease inhibitors and 0.25 mol / L NaCl. Histamine was quantified using a histamine enzyme-linked immunosorbent assay (ELISA) kit purchased from Immunotech (Solarbio, China). Protein concentration was determined by the Bradford method using bovine serum albumin (BSA) as a protein standard. In addition, the histamine content in the skin was expressed as the amount of histamine per mg of protein. The results are shown in the Supplementary Figure 2. Figure 6 shown.

[0069] The results of Examples 1-6 show that the recombinant protein provided by the present invention has good application prospects in histamine binding and anti-allergic reactions.

[0070] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A tick histamine binding protein HqHBP, characterized in that: The histamine binding protein is a recombinant protein derived from the salivary gland of Haemaphysalis qinghaiensis, and its amino acid sequence is shown in SEQ ID NO.

1.

2. The nucleic acid molecule Hq018 encoding the histamine-binding protein according to claim 1, characterized in that: The sequence of the nucleic acid molecule Hq018 is shown in SEQ ID NO.

2.

3. A recombinant vector, characterized in that: Comprising the nucleic acid molecule of claim 2.

4. A recombinant microbial host cell, characterized in that Comprising the recombinant vector of claim 3; the recombinant microbial host cell is Escherichia coli.

5. The method for preparing the histamine-binding protein according to claim 1, characterized in that: The following steps are involved: S1. Design primers and use the positive clone Hq018 obtained from the cDNA library of Haemaphysalis qinghaiense as a template for PCR amplification to obtain the Hq018 gene; S2, insert the Hq018 gene obtained in S1 into the pGEM-T-easy vector to construct a recombinant cloning plasmid; S3, expanding the positive clones obtained in S2 and extracting the recombinant clone plasmids; S4, the recombinant cloning plasmid obtained in S3 and the prokaryotic expression vector pET30a were respectively N I and XOt I is used for enzyme digestion to obtain the target gene insertion fragment and linearized vector; S5, ligating the inserted fragment obtained in S4 and the linearized vector with T4 ligase to construct a recombinant prokaryotic expression plasmid pET30a-Hq018, transforming competent cells DH5α with the constructed recombinant prokaryotic expression plasmid, and extracting the recombinant expression plasmid; S6. The recombinant expression plasmid verified by sequencing in S5 was transformed into Escherichia coli competent cells Rosetta (DE3). After kanamycin resistance screening, the induced expressed protein was purified to obtain the recombinant protein HqHBP.

6. The preparation method according to claim 5, characterized in that: In S1, the nucleotide sequences of the primers are shown in SEQ ID NO. 3 and SEQ ID NO.

4.

7. Use of the histamine-binding protein according to claim 1, the nucleic acid molecule according to claim 2, the recombinant vector according to claim 3 or the recombinant microbial host cell according to claim 4 in the preparation of an antiallergic drug.

8. An antiallergic drug, characterized in that: The invention comprises the histamine binding protein according to claim 1 and a pharmaceutically acceptable carrier, wherein the histamine binding protein is used as an active ingredient of an antiallergic drug.

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