The patent application of the invention is a divisional application with the application number of '201810573403.3', the application date of the original application is '06 months 06 days in 2018', the application number is '201810573403.3', and the invention name is 'an anti-recombinant human basic fibroblast growth factor nano antibody and application thereof'.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a nano antibody for resisting recombinant human basic fibroblast growth factor, which can specifically neutralize human bFGF (namely FGF-2).
The invention also aims to provide application of the anti-recombinant human basic fibroblast growth factor nano-antibody.
The purpose of the invention is realized by the following technical scheme:
an anti-recombinant human basic fibroblast growth factor nanobody, comprising a variable region domain consisting of framework regions fr (framework regions) and complementary-determining regions CDRs (complementary-determining regions), said variable region domain comprising CDRs 1, CDR2 and CDR3 selected from the group consisting of:
(1) CDR1 shown by any amino acid sequence of SEQ ID No. 1-4;
(2) CDR2 shown by any amino acid sequence of SEQ ID No. 5-8;
(3) CDR3 shown in any amino acid sequence of SEQ ID Nos. 9-12.
The variable region domain comprises a CDR1, a CDR2, and a CDR3 selected from any one of:
(1) CDR1 shown in SEQ ID No.1, CDR2 shown in SEQ ID No.5, and CDR3 shown in SEQ ID No. 9;
(2) CDR1 shown in SEQ ID No.2, CDR2 shown in SEQ ID No.5 or SEQ ID No.6, and CDR3 shown in SEQ ID No.9 or SEQ ID No. 10;
(3) CDR1 shown in SEQ ID No.3, CDR2 shown in SEQ ID No.7, and CDR3 shown in SEQ ID No. 11;
(4) CDR1 shown in SEQ ID No.4, CDR2 shown in SEQ ID No.8, and CDR3 shown in SEQ ID No. 12.
The framework region FR is selected from the group consisting of FR1, FR2, FR3 and FR 4:
(1) FR1 represented by any one of SEQ ID Nos. 13-15;
(2) FR2 represented by any amino acid sequence of SEQ ID Nos. 16-19;
(3) FR3 represented by any amino acid sequence of SEQ ID Nos. 20-24;
(4) FR4 represented by any amino acid sequence of SEQ ID Nos. 25 to 27.
The amino acid sequence of the anti-recombinant human basic fibroblast growth factor nano antibody is selected from any one of the amino acid sequences shown in SEQ ID NO. 28-33; the method comprises the following specific steps:
or
Or
Or
Or
Or
The anti-recombinant human basic fibroblast growth factor nano antibody comprises an amino acid sequence which has at least 90%, preferably at least 95% and more preferably at least 99% of sequence identity with any amino acid sequence shown in SEQ ID No. 28-33.
Any one of the amino acid sequences shown in SEQ ID NO. 28-33 is subjected to substitution, deletion or addition of one or more amino acids.
The substitution preferably comprises one or more amino acid substitutions, preferably conservative amino acid substitutions compared with any one of amino acid sequences shown in SEQ ID NO. 28-33. For example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 conservative amino acid substitutions are included.
The nucleotide sequence of the anti-recombinant human basic fibroblast growth factor nano-antibody is preferably as follows:
nucleotide sequences encoding the amino acid sequences shown as SEQ ID NO. 28-33 are respectively and sequentially shown as SEQ ID NO. 34-39.
The nanobody consists of 342 bases, 336 bases or 369 bases, codes 114 amino acids, 112 amino acids or 123 amino acids, and consists of 4 Framework Regions (FRs) and 3 Complementary Determining Regions (CDRs) of the antibody: the CDR1 of the nanobody encodes 10 amino acids, CDR2 encodes 7 amino acids, and CDR3 encodes 11 amino acids; or CDR1 encodes 10 amino acids, CDR2 encodes 7 amino acids, CDR3 encodes 9 amino acids; or CDR1 encodes 10 amino acids, CDR2 encodes 8 amino acids, CDR3 encodes 19 amino acids; 3 CDR regions are specific sequences.
The function of the nano antibody is determined by specific nucleotide sequences in antibody antigenic determinants CDR1, CDR2 and CDR3 (which are functional active regions of the invention), and corresponding amino acid sequences form antibody specific bFGF antigen binding regions.
The application of the anti-recombinant human basic fibroblast growth factor nano antibody comprises the following steps: the functional neutralizing antibody gene specifically combined with bFGF is determined by the gene sequence of CDR specificity in the complementarity determining region of the antibody, and based on the above-mentioned complementarity determining region gene, it can adopt gene engineering method to obtain small molecule gene engineering antibody with several forms by means of construction and expression,such as Fab antibodies, F (ab)2Antibodies, single chain antibodies (scFv), antibody fusion proteins, and IgG whole antibodies.
A recombinant expression vector contains the nucleotide sequence of the anti-recombinant human basic fibroblast growth factor nano antibody.
A recombinant engineered cell containing the above recombinant expression vector; the recombinant engineering cell can express the anti-recombinant human basic fibroblast growth factor nano antibody.
The nano antibody gene or any gene containing the complementary determining region of the nano antibody gene reconstructed based on the gene can be expressed in prokaryotic cells, yeast cells, insect cells and eukaryotic cells to obtain an antibody product with neutralizing human bFGF, and the gene can be applied to the following applications: (1) used for diagnosing tumor, (2) inhibiting tumor angiogenesis and tumor growth and metastasis, and (3) inhibiting liver, lung and kidney fibrosis.
The anti-recombinant human basic fibroblast growth factor nano antibody is applied to the preparation of a tumor antibody treatment drug or a cancer diagnosis kit or reagent.
The tumor is preferably melanoma.
The cancer diagnosis kit or reagent is preferably a cancer diagnosis kit or reagent for detecting human bFGF.
Compared with the prior art, the invention has the following advantages and beneficial effects:
1. the invention immunizes alpaca with human bFGF (namely FGF-2), then utilizes the alpaca peripheral blood lymphocytes to establish a nano antibody gene library aiming at the human bFGF, couples the human bFGF on an enzyme label plate in the test, utilizes the phage display technology to screen the immune nano antibody gene library (camel heavy chain antibody phage display gene library) by the antigen in the form, thereby obtaining the nano antibody gene aiming at the specificity of the human bFGF, transfers the gene into escherichia coli, and further establishes the nano antibody strain which can be efficiently expressed in the escherichia coli.
2. The anti-human bFGF nano antibody has the characteristics of small molecular weight, strong specificity, high affinity, high stability, easy expression, strong cell/blood vessel penetrability, strong antigen binding capacity, capability of being expressed in a prokaryotic expression system and the like, overcomes the defects of long development period, low stability, harsh storage conditions and the like of the traditional antibody, can effectively neutralize the bFGF excessively expressed in the bodies of patients with tumors and fibrosis, can effectively inhibit the generation of blood vessels and the growth and metastasis of the tumors, and can also be used for inhibiting the formation of fibrosis of the liver, the lung or the kidney and the like.
Detailed Description
The present invention will be described in further detail with reference to examples and drawings, but the present invention is not limited thereto.
Example 1 construction of anti-recombinant human basic fibroblast growth factor (bFGF) Nanobody
1. Construction of nano antibody library gene
(1) Alpaca (alee Biotechnology & Pharmaceuticals Co., usa) was immunized with recombinant human basic fibroblast growth factor (bFGF, available from Sigma, beijing, buzz) at a concentration of 0.2mg/mL, 0.2mg of bFGF was mixed with freund's adjuvant in equal volume once every two weeks for 4 immunizations, except for complete freund's adjuvant (available from Sigma) for the first time and freund's adjuvant (available from Sigma) for the remaining several times. The immune process stimulates B cells to express antigen-specific single chain antibodies. (2) After 4 immunizations, 100mL of alpaca peripheral blood lymphocytes were extracted, total RNA was extracted using Trizol reagent (purchased from Invitrogen), and cDNA was synthesized by reverse transcription using AMV First Strand cDNA Synthesis kit (for details, see kit product Specification of NEB). (3) Primers were designed to perform PCR amplification of the variable region of heavy chain antibody (see Table 1 for reaction system and Table 2 for PCR conditions). The PCR product was recovered and purified by QIA quick PCR Purification kit (purchased from QIAGEN) to obtain about 330-370 bp of alpaca heavy chain variable region PCR product.
TABLE 1 PCR amplification reaction System for the variable region of the Single-chain antibody of alpaca
TABLE 2 PCR amplification conditions for the alpaca single chain antibody variable region (cover temperature set at 105 ℃ C.)
2. Construction of a Nanobody phage antibody library
(1) Mu.g of pComb3X (from Allle Biotechnology and Pharmaceuticals) phage display vector and 10. mu.g of alpaca heavy chain variable region PCR product were digested with the restriction enzyme Sfi I (from NEB) and the two fragments were ligated using T4 DNA ligase (from NEB). The ligation products were electroporated into electroporation competent cells XL1-Blue (from Allle Biotechnology and Pharmaceuticals) and then 1mL of SOC medium (from NEB) was added five times to the broth in the resuspension cup of the electroporation cuvette, and 5mL of the broth was incubated for 1h at 250rpm in a shaker at 37 ℃. (2) 10mL of SB medium (preparation method: weighing 8g of MOPs, 24g of peptone and 16g of yeast extract, diluting to 800mL, sterilizing at 121 ℃ for 20min, wherein the culture medium contains 10mg/L tetracycline) and 3. mu.L of ampicillin stock solution (100g/L ampicillin) are added into 5mL of the culture solution, 1. mu.L of the culture solution is diluted by 100 times after mixing, and the mixture is uniformly coated on an LB plate (containing 100mg/L ampicillin) to detect the storage capacity. The remaining culture broth was incubated at 37 ℃ and 275rpm for 1 h. To the culture broth, 4.5. mu.L of an ampicillin stock solution (100g/L of ampicillin) was added, and the culture was continued for 1 hour. To the culture broth 2mL of the helper phage VCSM13 (purchased from Allle Biotechnology and Pharmaceuticals; titer 10)12~1013pfu/mL), SB medium (containing 10mg/L tetracycline) was added to 200mL, and 92.5. mu.L of ampicillin stock (100g/L ampicillin) was added and incubated at 37 ℃ and 275rpm for 2 h. To the culture medium was added 400. mu.L of kanamycin stock solution (35g/L kanamycin) and cultured overnight. (3) The next day, the cells will be cultured overnightThe resulting bacterial solution was centrifuged at 3000g for 15min at 4 ℃. The supernatant was transferred to a 50mL centrifuge tube containing 4% (w/v) PEG-8000 and 3% (w/v) NaCl, vortexed, and incubated at 4 ℃ for 30min for phage precipitation. Centrifuge at 15000 g for 15min at 4 ℃. The supernatant was discarded and the phage pellet resuspended in 2mL TBS. Centrifuging the supernatant at the maximum rotation speed for 5min at the temperature of 4 ℃, and filtering the supernatant by using a 0.22 mu m filter to a sterile EP tube, thus obtaining the phage original library of the anti-bFGF nano antibody.
3. Screening of phage antibody libraries
(1) bFGF antigen (purchased from Beijing Yiqiao Shenzhou Biotechnology Co., Ltd.) was diluted to 2. mu.g/well, coated on a 96-well plate, and coated overnight at 4 ℃. The next day, after blocking with 5% skim milk (2.5g of skim milk completely dissolved in 50mL of 0.05% PBST solution) at 37 ℃ for 1 hour, the phage library preparation solution (i.e., the phage stock obtained in step 2) (10)14pfu/mL) was added to the antigen-coated wells and incubated at 37 ℃ for 2 hours. XL1-blue bacterial suspension (OD 0.8-1) was added thereto at 100. mu.L/well, and the mixture was incubated at room temperature for 15 min. The step is repeated for a plurality of times until 2mL of infected bacterial liquid is obtained. 2mL of the infected inoculum was added to 6mL of SB medium (containing 10mg/L tetracycline) and 1.6. mu.L of ampicillin stock (100g/L ampicillin) was added. Infected bacterial liquid 1. mu.L is diluted 100 times, smeared on LB plate (containing 10mg/L tetracycline), cultured overnight at 37 ℃, and the antibody library titer is determined. After 8mL of the culture was incubated at 37 ℃ and 275rpm for 1 hour, 2.4. mu.L of an ampicillin stock solution (100g/L of ampicillin) was added thereto and the culture was further continued for 1 hour. To the medium was added 1mL of the helper phage VCSM13, SB medium (containing 10mg/L tetracycline) was added to a final volume of 100mL, and 92. mu.L of ampicillin stock (100g/L ampicillin) was added. 100mL of the culture medium was cultured at 37 ℃ and 275rpm for 1.5-2 hours. 200. mu.L of kanamycin stock (35g/L kanamycin) was added and cultured overnight at 37 ℃ and 275 rpm. The next day, the purified phage was used for the next round of panning, and the same panning process was repeated for 3 rounds. The results are shown in fig. 2, in the process of continuous screening, the positive clones are continuously enriched, thereby achieving the purpose of screening the anti-bFGF specific antibody in the antibody library by using the phage display technology.
(2) 84 positive clones were selected from the plates from round 3 panning, inoculated into 1mL SB medium (containing 10mg/L tetracycline, 100mg/L ampicillin) and the helper phage was used as a negative control for this experiment, and the culture was shake-cultured at 37 ℃ for 5 h. Then adding 10 mu L/hole of VCSM13 helper phage, and culturing for 1.5-2 h. mu.L of kanamycin stock (35g/L kanamycin) was added and shake-cultured overnight at 37 ℃. The next day, the culture broth was centrifuged at 3000g for 15min at 4 ℃. mu.L of the supernatant was taken and 200. mu.L of a 5-fold concentrated mixture of 4% PEG-8000 and 3% NaCl was added, and incubated at 4 ℃ for 30 min. The culture was centrifuged at 15000 g for 15min at 4 ℃. Discard the supernatant, add 200. mu.L TBS, and gently shake well. 50 μ L of suspension was added to a 96-well plate coated with 200 ng/well bFGF antigen. The mixed solution of any 3-well sample is used as a positive control, the auxiliary phage is used as a negative control of the experiment, and PBS is used as a blank control of the experiment. The 96-well plate was incubated at 37 ℃ for 1 h. Anti-M13 antibody (purchased from Sigma) was then incubated at 100 ng/well for 1 hour. 100. mu.L/well of TMB color developing solution (from NEB) was added and incubated for 15 mins. And measuring the light absorption value at 450nm, and defining the clone strain with the experimental group OD value more than 3 times of the auxiliary phage OD value as a positive clone strain. The results are shown in FIG. 3, and a total of 69 clones were positive clones, with a positive proportion of 82%. The positive clones were subjected to plasmid extraction and sent to Biotechnology engineering (Shanghai) GmbH for sequencing. DNA sequencing results were analyzed by Bioedit, and clones having the same amino acid sequence were regarded as the same clones, and clones having different amino acid sequences were regarded as different clones, and finally 6 nanobodies having different amino acid sequences were obtained.
The gene sequence of the coding nano antibody is shown as any one of the gene sequences of SEQ ID NO. 34-39; the gene electrophoresis chart of the 6 bFGF nanobody is shown in FIG. 1.
4. Expression and purification of bFGF nanobody
(1) A group of specific primers (shown in Table 3) are used for carrying out PCR amplification on the target gene of the nano antibody on the pComb3x carrier (the reaction system is shown in Table 4, and the PCR conditions are shown in Table 5).
TABLE 3 amplification primers for target genes of Nanobodies
(underlined Hind III and Nde I sites added)
TABLE 4 PCR amplification system for target gene of nano antibody
TABLE 5 PCR amplification reaction time for the target Gene of the Nanobody
The PCR product is recovered and purified by a QIA quick PCR Purification kit (purchased from QIAGEN), and a nano antibody PCR product of about 330-370 bp is obtained. The expression vector pET22b (available from Novagen) and the target gene of the nanobody were digested with restriction enzymes Hind III (available from Thermo) and Nde I (available from Thermo), and the two fragments were ligated with T4 DNA ligase. The ligation product-transformed expression host bacterium BL21 (DE3) (available from Biotechnology, Inc., Shanghai) was plated on plates containing LB solid medium (containing 100mg/L ampicillin) overnight at 37 ℃.
(2) Individual colonies were picked and inoculated into 5mL of LB medium (containing 100mg/L ampicillin) and shake-cultured overnight at 37 ℃. Then, 1mL of overnight strain was inoculated into 400mL of LB medium (containing 100mg/L ampicillin), and shake-cultured at 37 ℃ and when OD was 0.6-1, IPTG (final concentration: 0.5mmol/L) was added, and shake-cultured at 18 ℃ for 20 hours. The next day, the mixture is centrifuged at 6000rpm for 15min at 4 ℃ to collect the bacteria. The mycelia were resuspended in PBS and sonicated for 10 min. Centrifuging at 8000rpm for 30min to obtain supernatant as expression product coarse extractive solution. Purifying the antibody protein by nickel column ion affinity chromatography. In order to obtain the high-purity antibody, an imidazole gradient elution method is adopted, low-concentration imidazole eluent (100 mmol/L) is used for washing impurity bands, high-concentration imidazole eluent (300mmol/L) is used for eluting target protein, and finally the protein with the purity of more than 90% can be prepared. The results are shown in fig. 4, from left to right: lane 1 shows the standard protein molecules, and lanes 2-7 show the protein samples eluted with 300mmol/L imidazole eluate (Nb 1-6 in this order). The result shows that the purity of the nano antibody can reach more than 90 percent after the nano antibody is purified.
Example 2 test of physicochemical Properties and biological Activity of anti-bFGF Nanobody
1. Specificity analysis of anti-bFGF Nanobody
50 ng/well of bFGF, aFGF, KGF, EGF, TNF alpha, VEGF (all from Beijing Yiqian Shenzhou Biotechnology Co., Ltd.), BSA, and milk were added to a 96-well plate and coated overnight at 4 ℃. The next day, after blocking the microplate with 5% skim milk for 2h, positive control bFGF mAb (purchased from Sigma) at a concentration of 100 ng/well, blank control PBS and the anti-bFGF nanobody prepared in example 1 were added, respectively, and incubated at 37 ℃ for 1 h. Then 100 ng/well of anti-Flag tag antibody (purchased from Sigma) was added and incubated for 1 h. Adding 100. mu.L/well of TMB color developing solution, and incubating for 10 min. Finally, the reaction was terminated with 2.29% sulfuric acid, and the absorbance at 450nm was measured. And (3) defining the antibody clone with the absorbance value of the anti-bFGF nano antibody and the corresponding antigen bFGF being more than 3 times that of other control antigens as positive.
The results are shown in fig. 5, in which 6 strains of anti-bFGF nanobody have strong specific binding ability with bFGF, and weak binding ability with 7 other control antigens.
2. Affinity assay for anti-bFGF Nanobodies
And (3) measuring the affinity of the anti-bFGF nano antibody by adopting a surface plasma resonance biosensor. 0.4mol of N-ethyl-N' - (dimethylaminopropyl) carbodiimide and 0.1mol of N-hydroxysuccinimide are mixed in equal volume and then introduced into an instrument at the flow rate of 20 mu L/min to activate the surface of the chip. After diluting bFGF protein to 2mg/mL with 0.2mol of acetic acid buffer solution having a pH of 4.2, the bFGF protein was allowed to flow over the chip surface. After the fixed amount reaches the required amount, PBS buffer is introduced. The remaining ester bonds were inactivated by passing 1mol ethanolamine (pH 8.5) solution for 7 min. Various concentrations (3.125, 6.25, 12.5, 25, 50, 100, 200nM) of the anti-bFGF nanobody were passed into the instrument at a flow rate of 20. mu.L/min. And (3) calculating the affinity of the anti-bFGF nano antibody through instrument software. As shown in Table 6, the anti-bFGF nanobody has high affinity, and the highest affinity reaches 0.69 nM. The affinity constants of the remaining anti-bFGF nanobodies were 11.32nM, 317.60nM, 5.37nM, 12.37 nM and 10.32nM, respectively.
TABLE 6 affinity constants of anti-bFGF nanobody
|
Nb1
|
Nb2
|
Nb3
|
Nb4
|
Nb5
|
Nb6
|
KD(nM)
|
11.32
|
317.60
|
5.37
|
0.69
|
12.37
|
10.32 |
3. Determination of thermal stability
Placing the screened nano antibodies (namely Nb 1-6) at four different temperatures of 25 ℃, 37 ℃, 60 ℃ and 90 ℃ for 10min, 30min, 60min, 120min and 180min respectively; a bFGF monoclonal antibody (purchased from Sigma, murine antibody) was also used as a positive control. Samples treated at different temperatures and different times are collected, and the binding property of the samples to the bFGF is detected by an ELISA method, namely whether the antibody has the capacity of binding to the bFGF after the samples are treated at different temperatures and different times. The detection result of fig. 6 shows that, compared with the untreated nano antibody, the relative activity of the nano antibody is maintained above 90% after treatment at 25 ℃ and 37 ℃, and the relative activity of the nano antibody is reduced to some extent after treatment at 60 ℃, but still maintained above 80%. But after 90 ℃ treatment, the relative activity of the nano-antibody is remarkably reduced, wherein the relative activity is reduced to 0% after 60min treatment of Nb5, the relative activity is reduced to 0% after 180min treatment of Nb6, and the relative activity of other groups of nano-antibodies is reduced to 0% after 120min treatment. This is a clear advantage over the bFGF monoclonal antibody as a positive control, although the bFGF monoclonal antibody has a relative activity of more than 90% at three different temperatures of 25 ℃, 37 ℃ and 60 ℃, after 90 ℃ treatment, its relative activity has already decreased to 0% within 10 min. Therefore, it was demonstrated that the nanobody has better stability in high-temperature treatment than the conventional murine monoclonal antibody.
4. Competitive binding assays
(1) Detection of Nanobodies (Nb) of the invention by competitive ELISAbFGF) Competed with FGFR2 (purchased from beijing yinqiao shenzhou biotechnology limited) for the ability to bind bFGF (purchased from beijing yinqiao shenzhou biotechnology limited). In the experiment, a quantitative 100ng of nano antibody and a variable (0-1 mu g) of FGFR2 are added into a flat plate coated with 50ng of bFGF at the same time for incubation, if the content detected by the nano antibody is less and less along with the increase of the concentration of FGFR2, the nano antibody is consistent or similar to the binding epitope of FGFR2 and the bFGF, or the affinity of the nano antibody and the bFGF is different from that of FGFR2 and the bFGF; if the FGFR2 concentration is gradually increased, the content of the nano antibodyAnd if the nano antibody and the FGFR2 are not changed, the binding epitope with the bFGF is not consistent, or the binding tightness between the nano antibody and the bFGF is higher than that between the FGFR2 and the bFGF. As a result, as shown in fig. 7, the Nb2 and Nb4 contents remained stable with the increase of the FGFR2 content, and it can be presumed that their binding epitopes to bFGF are not consistent with those of FGFR2 and bFGF, or that their affinity to bFGF is higher than that of FGFR 2. The binding force of four nano antibodies Nb1, Nb3, Nb5 and Nb6 to bFGF shows a descending trend along with the increase of the concentration of FGFR2, which indicates that the binding epitope of the four nano antibodies to bFGF is consistent with or close to that of FGFR2 to bFGF, or the affinity of the four nano antibodies to bFGF is lower than that of FGFR2 to bFGF.
(2) Detection of Nb by competitive ELISAbFGFCompeted with the commercial murine monoclonal antibody bFGF mAb (FB-8) (purchased from Sigma) for the ability to bind bFGF. FIG. 8 shows that Nb4 levels off with increasing bFGF mAb levels, presumably by not matching the binding epitope for bFGF to that of bFGF mAb, or that Nb4 has higher affinity for bFGF than bFGF mAb. The binding force of five nano antibodies Nb1, Nb2, Nb3, Nb5 and Nb6 to bFGF shows a descending trend along with the increase of the concentration of bFGF mAb, which indicates that the binding epitopes of the five nano antibodies to bFGF are consistent with or close to the binding epitopes of bFGF mAb and bFGF, or the affinity of the five nano antibodies to bFGF is lower than that of the bFGF mAb to bFGF.
Example 3 use of anti-bFGF Nanobodies for the treatment of melanoma in mice
The inoculation density of the soft skin part of the outer thigh of the right hind limb of 18C 57BL/6J mice (purchased from Guangdong province medical laboratory animal center, SPF grade, 6-7 weeks old, female) is 5 multiplied by 106Mouse melanoma B16 cells (purchased from Shanghai cell Bank of Chinese academy) at 0.1 mL/cell. And when the average longest diameter of the tumor is 1-3 mm, eliminating mice without tumor growth and with the longest diameter larger than 5 mm. The mice were then randomly assigned to negative control groups, anti-bFGF nanobody groups, 6 per group. Mice were administered subcutaneously around the tumor. PBS control group is given 1 XPBS 0.1 mL/L/day, anti-bFGF nanoThe antibody group was administered with bFGF nanobody (Nb6) at 20 mg/kg/day. The administration was carried out 14 times consecutively. Mice were sacrificed 24h after the last dose and tumor masses were dissected and photographed, and the results are shown in fig. 9. As a result, the tumor body weights of the mice in the negative control group and the anti-bFGF nanobody group were found to be (3.45. + -. 1.73) g and (0.96. + -. 0.81) g, respectively, and the tumor inhibition rate of the anti-bFGF nanobody group was 72.24% compared with that in the negative control group. The anti-bFGF nano antibody can obviously inhibit the proliferation of melanoma in a mouse body.
Example 4 use of Nanobody against bFGF as a diagnostic reagent for the detection of bFGF
1. Pairing experiment of anti-bFGF nano antibody
To construct a double sandwich ELISA method capable of detecting the concentration of antigen bFGF, bFGF nanobodies were paired, wrapped with Nb1(His-HA tag), Nb2(His-HA tag), Nb3(His-HA tag), Nb5(His-HA tag), Nb6(His-HA tag) at a concentration of 5. mu.g/mL, and after 2. mu.g/mL of antigen FGF-2 was added, Nb4(His-Flag tag) at a concentration of 2. mu.g/mL, 1. mu.g/mL, and 0.5. mu.g/mL was incubated, followed by Anti-Flag tag-HRP (purchased from Sigma, cat # A8592-2 MG) as a detection antibody, and finally developed with TMB, and absorbance values were measured at a wavelength of 450 nm.
As shown in FIG. 10, the absorbance values of the experiments of pairing Nb4(His-Flag tag) with the remaining bFGF nanobodies at different concentrations were all more than 3 times higher than that of the control group 1 XPBS, and the highest absorbance values were Nb4(His-Flag tag) and Nb4(His-Flag tag)FGF-26(His-HA tag). Therefore, we determined that Nb6(His-HA tag) was used as a capture antibody in the double sandwich ELISA method for detecting the concentration of the antigen bFGF, and Nb4(His-Flag tag) was used as a detection antibody for the antigen.
2. Determination of concentration range of antigen bFGF (basic fibroblast growth factor) detected by double-sandwich ELISA (enzyme-linked immunosorbent assay) method
After determining two strains of nano antibodies required in the double-sandwich ELISA method for detecting the concentration of the antigen bFGF, adding the antigens with different concentrations, and determining the detection range of the method on the antigen bFGF. The plates were plated with Nb6(His-HA tag) at a concentration of 5. mu.g/mL, plus 2000ng/mL, 1000ng/mL, 500ng/mL, 250ng/mL, 125ng/mL, 62.5ng/mL, 31.25ng/mL, 15.63ng/mL, 7.81ng/mL, 3.91ng/mL, 1.95 ng/mLng/mL, 0.98ng/mL, 0.49ng/mL of bFGF antigen, and incubating with 2. mu.g/mL of NbbFGF4(His-Flag tag), followed by Anti-Flag tag-HRP as detection antibody, and finally developed with TMB, and absorbance value was measured at a wavelength of 450 nm.
The results are shown in FIG. 11, which shows that antigen was detected at a concentration of 7.81ng/mL or more by this detection method (FIG. 11A); the results were plotted as a scatter plot with antigen concentration on the abscissa and absorbance values on the ordinate, and it was found that the change in absorbance was significant when the antigen concentration was between 7.81ng/mL and 500ng/mL (FIG. 11B).
Antigen concentration was adjusted to fall between 10ng/mL and 400ng/mL, and then another double sandwich ELISA experiment was performed, in which Nb6(His-HA tag) at a concentration of 5. mu.g/mL was coated, and Nb4(His-Flag tag) at a concentration of 2. mu.g/mL was incubated after antigen bFGF at concentrations of 400ng/mL, 300ng/mL, 200ng/mL, 100ng/mL, 80ng/mL, 40ng/mL, 20ng/mL, and 10ng/mL, and then Anti-Flag tag-HRP was used as a detection antibody, and finally color was developed with TMB, and absorbance was measured at a wavelength of 450 nm.
And (3) drawing a scatter diagram of the result by taking the antigen concentration as an abscissa and the absorbance value as an ordinate, and solving a linear equation and a correlation coefficient of the scatter diagram: the equation is that Y is 0.0045X-0.005 and the correlation coefficient R is20.98977. The above experimental results show that in the double sandwich ELISA method for detecting an antibody using Nb6(His-HA tag) at a concentration of 5. mu.g/mL as a capture antibody and Nb4(His-Flag tag) at a concentration of 2. mu.g/mL as an antigen, the antigen bFGF can be diluted to eight concentrations, such as 400ng/mL, 300ng/mL, 200ng/mL, 100ng/mL, 80ng/mL, 40ng/mL, 20ng/mL, and 10ng/mL, and a standard curve for sample detection can be plotted using the antigen concentration as abscissa and the absorbance value as ordinate (FIG. 12).
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.
Sequence listing
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<120> anti-recombinant human basic fibroblast growth factor nano antibody and application thereof
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<213> Artificial Sequence (Artificial Sequence)
<400> 4
Gly Arg Thr Phe Ser Ser Gly Ala Met Gly
1 5 10
<210> 5
<211> 7
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 5
Ile Ser Ser Val Gly Arg Thr
1 5
<210> 6
<211> 7
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 6
Ile Ser Ser Val Gly Arg Ala
1 5
<210> 7
<211> 7
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 7
Ile Thr Pro Gly Gly Thr Arg
1 5
<210> 8
<211> 8
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 8
Ile Thr Trp Asp Gly Gly Thr Thr
1 5
<210> 9
<211> 11
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 9
His Leu Tyr Gly Asp Tyr Arg Gly Thr Gly Phe
1 5 10
<210> 10
<211> 11
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 10
Tyr Leu Tyr Gly Asp Tyr Arg Gly Thr Gly Phe
1 5 10
<210> 11
<211> 9
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 11
Asn Thr Trp Pro Tyr Glu Ser Ala Tyr
1 5
<210> 12
<211> 19
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 12
Ala Ala Arg Ser Tyr Ser Glu Ala Tyr Tyr Leu Ile Gly Ser Ser Asp
1 5 10 15
Tyr Asn Tyr
<210> 13
<211> 22
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 13
Leu Gln Glu Ser Gly Gly Asp Leu Val Gln Pro Gly Gly Ser Leu Arg
1 5 10 15
Leu Ser Cys Glu Val Ser
20
<210> 14
<211> 22
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 14
Leu Gln Gln Ser Gly Gly Gly Leu Val Gln Pro Gly Gly Ser Leu Arg
1 5 10 15
Leu Ser Cys Lys Ala Ser
20
<210> 15
<211> 22
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 15
Leu Gln Glu Ser Gly Gly Gly Leu Val Gln Ala Gly Gly Ser Leu Arg
1 5 10 15
Leu Ser Cys Ala Ala Ser
20
<210> 16
<211> 15
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 16
Trp Tyr Arg Gln Ala Pro Gly Lys Gln Arg Glu Val Val Ala Gly
1 5 10 15
<210> 17
<211> 15
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 17
Trp Tyr Arg Gln Ala Pro Gly Lys Arg Arg Glu Val Val Ala Gly
1 5 10 15
<210> 18
<211> 15
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 18
Tyr Tyr Arg Gln Ala Pro Gly Lys Glu Arg Glu Leu Val Ala Leu
1 5 10 15
<210> 19
<211> 15
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 19
Trp Phe Arg Gln Ala Pro Gly Lys Glu Pro Glu Phe Val Ala Thr
1 5 10 15
<210> 20
<211> 38
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 20
Met Tyr Gly Asp Pro Val Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn
1 5 10 15
Ala Lys Asn Met Val Tyr Leu Gln Met Asn Arg Leu Lys Ala Lys Asp
20 25 30
Thr Ala Val Tyr Tyr Cys
35
<210> 21
<211> 38
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 21
Met Tyr Ala Asp Pro Val Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn
1 5 10 15
Ala Lys Asn Met Val Tyr Leu Gln Met Asn Arg Leu Lys Pro Glu Asp
20 25 30
Thr Ala Val Tyr Tyr Cys
35
<210> 22
<211> 38
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 22
Asn Tyr Ala Asn Ser Val Lys Gly Arg Phe Thr Ile Ser Lys Asp Asn
1 5 10 15
Ala Lys Asn Thr Val Tyr Leu Gln Met Asn Ser Leu Gln Pro Glu Asp
20 25 30
Thr Ala Val Tyr Tyr Cys
35
<210> 23
<211> 38
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 23
Tyr Tyr Ala Asp Ser Val Lys Gly Arg Tyr Thr Ile Ser Arg Asp Asn
1 5 10 15
Ala Lys Asn Thr Val Tyr Leu Gln Met Asn Asp Leu Lys Pro Glu Asp
20 25 30
Thr Ala Val Tyr Ser Cys
35
<210> 24
<211> 38
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 24
Met Tyr Gly Asp Pro Val Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn
1 5 10 15
Ala Lys Asn Met Val Tyr Leu Gln Met Asn Arg Leu Lys Pro Glu Asp
20 25 30
Thr Ala Val Tyr Tyr Cys
35
<210> 25
<211> 11
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 25
Trp Gly Lys Gly Thr Gln Val Thr Val Ser Ser
1 5 10
<210> 26
<211> 11
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 26
Ser Gly Gln Gly Thr Gln Val Thr Val Ser Thr
1 5 10
<210> 27
<211> 11
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 27
Trp Gly Gln Gly Thr Gln Val Thr Val Ser Ser
1 5 10
<210> 28
<211> 114
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 28
Leu Gln Glu Ser Gly Gly Asp Leu Val Gln Pro Gly Gly Ser Leu Arg
1 5 10 15
Leu Ser Cys Glu Val Ser Gly Ser Asn Phe Ser Asn Asn Asp Met Gly
20 25 30
Trp Tyr Arg Gln Ala Pro Gly Lys Gln Arg Glu Val Val Ala Gly Ile
35 40 45
Ser Ser Val Gly Arg Thr Met Tyr Gly Asp Pro Val Lys Gly Arg Phe
50 55 60
Thr Ile Ser Arg Asp Asn Ala Lys Asn Met Val Tyr Leu Gln Met Asn
65 70 75 80
Arg Leu Lys Ala Lys Asp Thr Ala Val Tyr Tyr Cys His Leu Tyr Gly
85 90 95
Asp Tyr Arg Gly Thr Gly Phe Trp Gly Lys Gly Thr Gln Val Thr Val
100 105 110
Ser Ser
<210> 29
<211> 114
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 29
Leu Gln Glu Ser Gly Gly Asp Leu Val Gln Pro Gly Gly Ser Leu Arg
1 5 10 15
Leu Ser Cys Glu Val Ser Gly Ser Asn Phe Ser Ile Asn Asp Met Gly
20 25 30
Trp Tyr Arg Gln Ala Pro Gly Lys Arg Arg Glu Val Val Ala Gly Ile
35 40 45
Ser Ser Val Gly Arg Ala Met Tyr Ala Asp Pro Val Lys Gly Arg Phe
50 55 60
Thr Ile Ser Arg Asp Asn Ala Lys Asn Met Val Tyr Leu Gln Met Asn
65 70 75 80
Arg Leu Lys Pro Glu Asp Thr Ala Val Tyr Tyr Cys Tyr Leu Tyr Gly
85 90 95
Asp Tyr Arg Gly Thr Gly Phe Trp Gly Lys Gly Thr Gln Val Thr Val
100 105 110
Ser Ser
<210> 30
<211> 114
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 30
Leu Gln Glu Ser Gly Gly Asp Leu Val Gln Pro Gly Gly Ser Leu Arg
1 5 10 15
Leu Ser Cys Glu Val Ser Gly Ser Asn Phe Ser Ile Asn Asp Met Gly
20 25 30
Trp Tyr Arg Gln Ala Pro Gly Lys Arg Arg Glu Val Val Ala Gly Ile
35 40 45
Ser Ser Val Gly Arg Thr Met Tyr Ala Asp Pro Val Lys Gly Arg Phe
50 55 60
Thr Ile Ser Arg Asp Asn Ala Lys Asn Met Val Tyr Leu Gln Met Asn
65 70 75 80
Arg Leu Lys Pro Glu Asp Thr Ala Val Tyr Tyr Cys His Leu Tyr Gly
85 90 95
Asp Tyr Arg Gly Thr Gly Phe Trp Gly Lys Gly Thr Gln Val Thr Val
100 105 110
Ser Ser
<210> 31
<211> 112
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 31
Leu Gln Gln Ser Gly Gly Gly Leu Val Gln Pro Gly Gly Ser Leu Arg
1 5 10 15
Leu Ser Cys Lys Ala Ser Arg Asn Ile Phe Ser Val Asn His Met Gly
20 25 30
Tyr Tyr Arg Gln Ala Pro Gly Lys Glu Arg Glu Leu Val Ala Leu Ile
35 40 45
Thr Pro Gly Gly Thr Arg Asn Tyr Ala Asn Ser Val Lys Gly Arg Phe
50 55 60
Thr Ile Ser Lys Asp Asn Ala Lys Asn Thr Val Tyr Leu Gln Met Asn
65 70 75 80
Ser Leu Gln Pro Glu Asp Thr Ala Val Tyr Tyr Cys Asn Thr Trp Pro
85 90 95
Tyr Glu Ser Ala Tyr Ser Gly Gln Gly Thr Gln Val Thr Val Ser Thr
100 105 110
<210> 32
<211> 123
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 32
Leu Gln Glu Ser Gly Gly Gly Leu Val Gln Ala Gly Gly Ser Leu Arg
1 5 10 15
Leu Ser Cys Ala Ala Ser Gly Arg Thr Phe Ser Ser Gly Ala Met Gly
20 25 30
Trp Phe Arg Gln Ala Pro Gly Lys Glu Pro Glu Phe Val Ala Thr Ile
35 40 45
Thr Trp Asp Gly Gly Thr Thr Tyr Tyr Ala Asp Ser Val Lys Gly Arg
50 55 60
Tyr Thr Ile Ser Arg Asp Asn Ala Lys Asn Thr Val Tyr Leu Gln Met
65 70 75 80
Asn Asp Leu Lys Pro Glu Asp Thr Ala Val Tyr Ser Cys Ala Ala Arg
85 90 95
Ser Tyr Ser Glu Ala Tyr Tyr Leu Ile Gly Ser Ser Asp Tyr Asn Tyr
100 105 110
Trp Gly Gln Gly Thr Gln Val Thr Val Ser Ser
115 120
<210> 33
<211> 114
<212> PRT
<213> Artificial Sequence (Artificial Sequence)
<400> 33
Leu Gln Glu Ser Gly Gly Asp Leu Val Gln Pro Gly Gly Ser Leu Arg
1 5 10 15
Leu Ser Cys Glu Val Ser Gly Ser Asn Phe Ser Ile Asn Asp Met Gly
20 25 30
Trp Tyr Arg Gln Ala Pro Gly Lys Arg Arg Glu Val Val Ala Gly Ile
35 40 45
Ser Ser Val Gly Arg Thr Met Tyr Gly Asp Pro Val Lys Gly Arg Phe
50 55 60
Thr Ile Ser Arg Asp Asn Ala Lys Asn Met Val Tyr Leu Gln Met Asn
65 70 75 80
Arg Leu Lys Pro Glu Asp Thr Ala Val Tyr Tyr Cys His Leu Tyr Gly
85 90 95
Asp Tyr Arg Gly Thr Gly Phe Trp Gly Lys Gly Thr Gln Val Thr Val
100 105 110
Ser Ser
<210> 34
<211> 342
<212> DNA
<213> Artificial Sequence (Artificial Sequence)
<400> 34
ctgcaggagt ctgggggaga cttggtgcag cctggggggt ctctgagact ctcctgtgaa 60
gtttctggaa gcaacttcag taacaatgac atgggctggt accgccaggc tccagggaag 120
cagcgcgagg tggtcgcagg tattagtagt gttggacgta caatgtatgg agaccccgtg 180
aagggccgat tcaccatctc cagagacaac gccaagaaca tggtgtatct gcaaatgaac 240
agactgaaag ctaaagacac ggccgtctat tactgtcacc tttatggtga ctataggggg 300
actggtttct ggggcaaggg gacccaggtc accgtctcgt cg 342
<210> 35
<211> 342
<212> DNA
<213> Artificial Sequence (Artificial Sequence)
<400> 35
ctgcaggagt ctgggggaga cttggtgcag cctggggggt ctctgagact ctcctgtgaa 60
gtttctggaa gcaacttcag tatcaatgac atgggctggt accgccaggc tccggggaag 120
cggcgcgagg tggtcgcagg tattagtagt gttggacgcg caatgtatgc agaccccgtg 180
aagggccgat tcaccatctc cagagacaac gccaagaaca tggtgtactt gcaaatgaac 240
agactgaaac ctgaggacac ggccgtttat tactgttacc tttatggtga ttataggggg 300
actggtttct ggggcaaggg gacccaggtc accgtctcgt cg 342
<210> 36
<211> 342
<212> DNA
<213> Artificial Sequence (Artificial Sequence)
<400> 36
ctgcaggagt ctgggggaga cttggtgcag cctggggggt ctctgagact ctcctgtgaa 60
gtttccggaa gcaacttcag tatcaatgac atgggctggt accgccaggc tccagggaag 120
cggcgcgagg tggtcgcagg tattagtagt gttggacgca caatgtatgc agaccccgtg 180
aagggccgat tcaccatctc cagagacaac gccaagaaca tggtgtatct gcaaatgaac 240
agactgaaac ctgaggacac ggccgtctat tactgtcacc tttatggtga ctataggggg 300
actggtttct ggggcaaggg gacccaggtc accgtctcgt cg 342
<210> 37
<211> 336
<212> DNA
<213> Artificial Sequence (Artificial Sequence)
<400> 37
ctgcagcagt ctgggggagg cttggtgcag cctggggggt ctctgagact ctcctgtaaa 60
gcctctagaa acatcttcag tgtcaatcac atgggctatt accgccaggc tccagggaag 120
gagcgcgagc tggtcgcgct tattactccc ggtggtacca gaaactatgc aaactccgtg 180
aagggccgat tcaccatctc caaagacaac gccaagaaca cggtgtatct gcagatgaac 240
agcctgcaac ctgaggacac ggccgtctat tactgtaata cctggccata tgagtctgcc 300
tattcgggcc aggggaccca ggtcaccgtc tccaca 336
<210> 38
<211> 369
<212> DNA
<213> Artificial Sequence (Artificial Sequence)
<400> 38
ctgcaggagt ctgggggagg attggtgcag gctgggggct ctctgagact ctcctgtgca 60
gcctctggac gcaccttcag tagcggtgcc atgggctggt tccgccaggc tccagggaag 120
gagcctgagt ttgtggcaac tattacgtgg gatgggggta cgacatacta tgcagactcc 180
gtgaagggcc gatacaccat ctccagagac aacgccaaga atacggtata tctgcaaatg 240
aacgacctga aacctgagga cacggccgtt tattcctgtg cagcgagatc ttatagtgag 300
gcttactact taatcggctc gtccgattat aactactggg gtcaggggac ccaggtcacc 360
gtctcctca 369
<210> 39
<211> 342
<212> DNA
<213> Artificial Sequence (Artificial Sequence)
<400> 39
ctgcaggagt ctgggggaga cttggtgcag cctggggggt ctctgagact ctcctgtgaa 60
gtttctggaa gcaacttcag tatcaatgac atgggctggt accgccaggc tccagggaag 120
cgacgcgagg tggtcgcagg tattagtagt gttggacgca caatgtatgg agaccccgtg 180
aagggccgat tcaccatctc cagagacaac gccaagaaca tggtgtatct gcaaatgaac 240
agactgaaac ctgaggacac ggccgtctat tactgtcacc tttatggtga ctataggggg 300
actggtttct ggggcaaggg gacccaggtc accgtctcgt cg 342
<210> 40
<211> 30
<212> DNA
<213> Artificial Sequence (Artificial Sequence)
<400> 40
ataaaacata tgctgcagga gtctggggga 30
<210> 41
<211> 30
<212> DNA
<213> Artificial Sequence (Artificial Sequence)
<400> 41
ataaaacata tgctgcagca gtctggggga 30
<210> 42
<211> 33
<212> DNA
<213> Artificial Sequence (Artificial Sequence)
<400> 42
ataaaaaagc ttcttatcgt cgtcatcttt ata 33