Human metapneumovirus mouse adapted strain and application thereof

Abstract

The invention belongs to the technical field of biology, and particularly relates to a human metapneumovirus mouse adapted strain and application thereof. Compared with a wild strain, the strain has higher susceptibility to animals; the strain can be used for treating BALB / c mice and can cause typical clinical symptoms and even death, for example, after the strain infects the BALB / c mice, the disease symptoms are obvious, the weight of 83% infected mice is severely reduced to 75% or below and reaches the humanity killing standard, and the death rate reaches 50% or above 4 days after the strain infects the BALB / c mice; the strain can be used for constructing a cell model or an animal model of human metapneumovirus infection or diseases caused by the human metapneumovirus infection, and is further used for screening drugs for preventing and / or treating the human metapneumovirus infection or the diseases caused by the human metapneumovirus infection. In addition, the strain can also be used for preparing medicines for preventing and / or treating human metapneumovirus infection or diseases caused by the human metapneumovirus infection, preparing antibodies or antiserum for resisting the human metapneumovirus and the like.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology, and particularly relates to a mouse-adapted strain of human metapneumovirus and applications thereof. Background Art

[0002] Since its discovery in 2001, human metapneumovirus (hMPV) has been prevalent in the human community at high levels. hMPV can infect people of all ages, often presenting with self-limited illness and often overlooked. However, the elderly, immunocompromised individuals, and children are more susceptible, and can cause severe respiratory infections, leading to secondary infections and even death. Reports indicate that in 2008, 78% of acute lower respiratory tract infections in children under five years of age were associated with hMPV infection, while 79% and 70% of hospitalizations and deaths due to acute lower respiratory tract infections, respectively, were associated with hMPV infection. In recent years, hMPV infection has been on the rise, posing a significant threat to children. However, due to the low infectivity of hMPV and the limitations of animal infection models, there are currently no approved effective drugs or vaccines for hMPV. Currently, the lack of an ideal animal infection model for hMPV has severely hampered research into its pathogenic mechanisms and the development of vaccines and therapeutics. The current methods for establishing hMPV infection models face the following problems: there are few available infection models for hMPV, and most models do not show obvious clinical symptoms after infection, or even cannot infect animals. For example, the literature (Small Animal Models for Human Metapneumovirus: Cotton Rat is More Permissive than Hamster and Mouse, Pathogens, 2014 Jul 24; 3(3): 633-55, https: / / doi.org / 10.3390 / pathogens3030633) studied the replication and pathogenicity of human metapneumovirus (hMPV) in BALB / c mice and found that BALB / c mice were not sensitive to hMPV infection, and no infected virus or viral RNA was detected. Therefore, suitable strains and models still need to be explored. Summary of the Invention

[0003] The purpose of the first aspect of the present invention is to provide a human metapneumovirus strain.

[0004] The purpose of the second aspect of the present invention is to provide a use of the human metapneumovirus strain of the first aspect of the present invention.

[0005] The third aspect of the present invention is to provide an antibody or antiserum against human metapneumovirus.

[0006] The fourth aspect of the present invention aims to provide a medicine.

[0007] The fifth aspect of the present invention aims to provide a method for constructing a cell model of human metapneumovirus infection or diseases caused by it.

[0008] The sixth aspect of the present invention aims to provide a cell model of human metapneumovirus infection or the disease caused by it.

[0009] The seventh aspect of the present invention aims to provide a method for constructing an animal model of human metapneumovirus infection or the disease caused by it.

[0010] The purpose of the eighth aspect of the present invention is to provide an application of the cell model of the sixth aspect of the present invention or the animal model obtained by the construction method of the seventh aspect of the present invention.

[0011] In order to achieve the above object, the technical solution adopted by the present invention is:

[0012] In a first aspect of the present invention, a human metapneumovirus strain is provided, wherein the amino acid sequence of the F protein of the strain is shown in SEQ ID NO:6.

[0013] In some embodiments, the nucleotide sequence of the F gene of the strain is shown as SEQ ID NO:5.

[0014] A human metapneumovirus strain, the strain is named human metapneumovirus hMPV-B1 / P10 / 202504, classified as Human Metapneumovirus, and was deposited in the China Center for Type Culture Collection on April 23, 2025, with the deposit number CCTCC NO: V202530. The deposit address is: Wuhan University, Wuhan, China.

[0015] The second aspect of the present invention provides the use of the human metapneumovirus strain of the first aspect of the present invention in any one of a1) to a8):

[0016] a1) Preparation of medicaments for preventing and / or treating human metapneumovirus infection or diseases caused by it;

[0017] a2) preparing antibodies or antisera against human metapneumovirus;

[0018] a3) Preparation of products for diagnosis of human metapneumovirus infection or diseases caused by it;

[0019] a4) Detection of human metapneumovirus;

[0020] a5) Establishing cell models of human metapneumovirus infection or diseases caused by it;

[0021] a6) Establishing animal models of human metapneumovirus infection or diseases caused by it;

[0022] a7) Screening for drugs to prevent and / or treat human metapneumovirus infection or diseases caused by it;

[0023] a8) preparing a product for use in any one of a4) to a7).

[0024] In some embodiments, the medicine a1) and a7) comprises a vaccine.

[0025] In some embodiments, the application described in a4) is: use of the human metapneumovirus strain of the first aspect of the present invention as a positive control in detecting human metapneumovirus.

[0026] In some embodiments, the applications described in a4) and a7) do not involve the diagnosis or treatment of a disease.

[0027] In some embodiments, the products described in a3) and a8) comprise reagents or kits.

[0028] The third aspect of the present invention provides an anti-human metapneumovirus antibody or antiserum obtained by immunizing an animal with the human metapneumovirus strain of the first aspect of the present invention.

[0029] In some embodiments, the animal is a mammal; further a non-human mammal; further a mouse, rat, rabbit, cat, dog, pig, cow, sheep, goat, alpaca, horse, monkey, gorilla, or chimpanzee.

[0030] The fourth aspect of the present invention provides a medicine comprising: the human metapneumovirus strain of the first aspect of the present invention, or the antibody or antiserum of the third aspect of the present invention.

[0031] In some embodiments, the medicament is a vaccine comprising the human metapneumovirus strain of the first aspect of the present invention.

[0032] In some embodiments, the drug further comprises a pharmaceutically acceptable excipient.

[0033] In some embodiments, the pharmaceutically acceptable excipients include at least one of a diluent, an excipient, a binder, a wetting agent, a surfactant, a lubricant, and a disintegrant.

[0034] In some embodiments, the dosage form of the drug is a dosage form suitable for children or a dosage form suitable for adults.

[0035] In some embodiments, the dosage form is selected from a dosage form for enteral administration or a dosage form for parenteral administration.

[0036] In some embodiments, the gastrointestinal dosage form comprises at least one of powder, tablet, granule, capsule, sustained-release agent, solution, dry suspension, effervescent tablet, emulsion, suspension, syrup, drops, and chewable tablet.

[0037] In some embodiments, the non-gastrointestinal dosage form includes an injection dosage form (e.g., an injection, including intravenous injection, intramuscular injection, subcutaneous injection, intradermal injection and intracavitary injection, etc.); a respiratory tract dosage form (such as a spray, an aerosol, a powder aerosol, etc.); a skin dosage form (such as an external solution, a lotion, a liniment, an ointment, a plaster, a paste, a patch, etc.); a mucosal dosage form (such as eye drops, nasal drops, eye ointments, gargles, sublingual tablets, adhesive tablets, patches, etc.); and a cavity dosage form (such as a suppository, an aerosol, an effervescent tablet, drops, a pill, etc., for use in the rectum, vagina, urethra, nasal cavity, ear canal, etc.).

[0038] In some embodiments, the subject to which the drug is administered is an animal.

[0039] In some embodiments, the animal is a mammal; further selected from humans, cats, cows, sheep, pigs, dogs, chickens, ducks, geese, rabbits, and mice; and further selected from humans.

[0040] A fifth aspect of the present invention provides a method for constructing a cell model of human metapneumovirus infection or a disease caused by the virus, which is obtained by infecting cells with the human metapneumovirus strain of the first aspect of the present invention.

[0041] In some embodiments, the cells are derived from an animal.

[0042] In some embodiments, the animal comprises a mammal; further comprises at least one of a human and a non-human mammal; further is a non-human mammal.

[0043] In some embodiments, the non-human mammal comprises at least one of a non-human primate, a rodent, a cow, a pig, a sheep, a dog, a rabbit, a cat, and a horse; further a rodent.

[0044] In some embodiments, the non-human primate comprises at least one of an orangutan, an ape, and a monkey.

[0045] In some embodiments, the rodent comprises at least one of a mouse, a rat, a hamster, and a guinea pig; further a mouse; and further a BALB / c mouse.

[0046] In some embodiments, the cells comprise primary cells.

[0047] In some embodiments, the primary cells comprise cells derived from the lung; further comprise lung epithelial cells; and further comprise AT cells (alveolar epithelial cells).

[0048] In some embodiments, the cells include cell lines, further including fibroblast cell lines and epithelial cell lines, for example, including but not limited to Vero cells, WI-38 cells, IMR-90 cells, CCD cells, HSF cells, L929 cells, WML2 mouse lung fibroblasts, NIH-3T3 cells, NIH-3T3 cells, 16HBE cells, A549 cells, HEK293 cells, MNT-1 cells, HeLa cells and tMK cells, etc.

[0049] The sixth aspect of the present invention provides a cell model of human metapneumovirus infection or the disease caused by it, which is obtained by the construction method of the fifth aspect of the present invention.

[0050] In some embodiments, the cells are not involved in propagation material.

[0051] The seventh aspect of the present invention provides a method for constructing an animal model of human metapneumovirus infection or a disease caused by it, which is obtained by infecting an animal with the human metapneumovirus strain of the first aspect of the present invention.

[0052] In some embodiments, the infection method comprises at least one of nasal drops, intraperitoneal injection, aerosol exposure, intratracheal inoculation, intrapulmonary inoculation, and oral-pharyngeal inoculation; further comprising nasal drops.

[0053] In some embodiments, the infection dose is 3000-7000 FFU per mouse; further 4000-6000 FFU.

[0054] In some embodiments, the animal is a non-human animal; further a non-human mammal; further comprising at least one of a non-human primate, a rodent, a cow, a pig, a sheep, a dog, a rabbit, a cat, and a horse; and further a rodent.

[0055] In some embodiments, the rodent comprises at least one of a mouse, a rat, a hamster, and a guinea pig; further a mouse; and further a BALB / c mouse.

[0056] The eighth aspect of the present invention provides the use of the cell model of the sixth aspect of the present invention, or the animal model obtained by the construction method of the seventh aspect of the present invention in any one of m1) to m2);

[0057] m1) Screening for drugs to prevent and / or treat human metapneumovirus infection or diseases caused by it;

[0058] m2) preparing a product for screening drugs for preventing and / or treating human metapneumovirus infection or diseases caused by it.

[0059] In some embodiments, the application described in m1) does not involve the diagnosis or treatment of a disease.

[0060] In the present invention, the human metapneumovirus comprises at least one of subtype A human metapneumovirus and subtype B human metapneumovirus; further comprises at least one of subtype A1 human metapneumovirus, subtype A2 human metapneumovirus, subtype B1 human metapneumovirus, and subtype B2 human metapneumovirus; further comprises at least one of subtype B1 human metapneumovirus and subtype B2 human metapneumovirus; and further comprises subtype B1 human metapneumovirus.

[0061] In the present invention, the disease comprises at least one of bronchitis, bronchiolitis, pneumonia, upper respiratory tract infection, lower respiratory tract infection, asthma, and otitis media.

[0062] The beneficial effects of the present invention are:

[0063] The present invention provides a human metapneumovirus strain, which, compared with wild strains, can show stronger susceptibility to animals and can cause typical clinical symptoms or even death. For example, after the strain infects BALB / c mice, the disease symptoms are obvious, and 83% of the mice suffer a severe weight loss to below 75% after infection, which has reached the humane sacrifice standard. In addition, the mortality rate of BALB / c mice reaches more than 50% 4 days after the strain infects BALB / c mice. The strain can be used to construct a cell model or animal model of human metapneumovirus infection or the disease caused by it, and then to screen drugs for preventing and / or treating human metapneumovirus infection or the disease caused by it. In addition, the strain can also be used to prepare drugs for preventing and / or treating human metapneumovirus infection or the disease caused by it, prepare antibodies or antisera against human metapneumovirus, prepare products for diagnosing human metapneumovirus infection or the disease caused by it, detect human metapneumovirus, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1A This is a diagram showing the difference in the F protein sequence of hMPV-B1 / GZ / 1712 (wild strain).

[0065] Figure 1B This is the result diagram of the difference in the F protein sequence of hMPV-B1-mAT5.

[0066] Figure 1C This is the result diagram of the difference in the F protein sequence of hMPV-B1-mAT10.

[0067] Figure 2 Figure 3 is a graph showing the body weight trends of mice treated with different methods.

[0068] Figure 3 Survival curves of mice treated with different methods.

[0069] Figure 4 These are pictures of AT cells infected with hMPV-B1 / GZ / 1712: A is a picture of AT cells infected with MPV-B1 / GZ / 1712 virus; B is a negative control, i.e., a picture of AT cells infected with PBS.

[0070] Figure 5 The figures show the hMPV detection results in the lung tissues of mice with different treatments: A shows the hMPV detection results in the lung tissues of mice in the negative control group; B shows the hMPV detection results in the lung tissues of mice infected with hMPV-B1 / GZ / 1712 (wild strain); C shows the hMPV detection results in the lung tissues of mice infected with hMPV-B1-mAT5; D shows the hMPV detection results in the lung tissues of mice infected with hMPV-B1-mAT10.

[0071] Figure 6 The figures are hematoxylin and eosin staining images of the lung tissues of mice with different treatments: A is the hematoxylin and eosin staining image of the lung tissues of mice in the negative control group, B is the hematoxylin and eosin staining image of the lung tissues of mice infected with hMPV-B1 / GZ / 1712 (wild strain); C is the hematoxylin and eosin staining image of the lung tissues of mice infected with hMPV-B1-mAT5; D is the hematoxylin and eosin staining image of the lung tissues of mice infected with hMPV-B1-mAT10. DETAILED DESCRIPTION

[0072] The present invention is further described in detail below through specific examples.

[0073] It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0074] Experimental procedures in the following examples, where specific conditions are not specified, generally followed conventional conditions or those recommended by the manufacturer. Materials and reagents used in these examples were commercially available unless otherwise specified. Where the manufacturer of the reagent is indicated, similar products from other manufacturers are considered substitutes.

[0075] Example 1. Acquisition and efficacy verification of B1-mAT10 strain

[0076] 1. Viral activity verification of a clinically isolated hMPV strain of subtype B1 (number hMPV-B1 / GZ / 1712)

[0077] 1. Dissect SPF-grade BALB / c mice, collect lungs, digest thoroughly, filter to obtain lung cell suspension, and isolate primary AT cells (alveolar epithelial cells) by flow cytometry;

[0078] 2. Infect the AT cells obtained in "Step 1" with hMPV-B1 / GZ / 1712 virus at an MOI of 1 (the negative control group was infected with PBS);

[0079] 3. Three days after infection, perform immunofluorescence staining on the infected cells to detect the infection status of the virus-infected AT cells.

[0080] The results are as follows Figure 4 As shown: The hMPV clinical isolate of subtype B1 (number hMPV-B1 / GZ / 1712) has viral activity and can infect AT cells.

[0081] 2. Acquisition of B1-mAT10 strain

[0082] 1. IFN(- / -) C57 mice were infected with a clinically isolated hMPV strain of subtype B1 (hMPV-B1 / GZ / 1712) at a dose of 1 x 10^5 FFU. Four days after infection, the mice were dissected and their lung tissues were removed.

[0083] 2. Thoroughly grind the lungs of infected mice, centrifuge and collect the supernatant, and identify the hMPV virus as positive to obtain the primary generation hMPV of infected mice;

[0084] 3. Dissect SPF-grade BALB / c mice, harvest lungs, thoroughly digest, and filter to obtain a lung cell suspension. Use flow cytometry to isolate primary AT cells (alveolar epithelial cells) for passage of hMPV.

[0085] 4. The hMPV obtained in "Step 2" is propagated in primary mouse AT cells in vitro. That is, the hMPV obtained in "Step 2" is inoculated into the primary alveolar epithelial cells obtained in "Step 3". After 3-7 days, after observing for cytopathic effect (CPE), the cells are harvested and the virus is obtained by freeze-thaw centrifugation and the cell supernatant is obtained;

[0086] 5. Determine the virus titer obtained in "Step 4" by immunofluorescence titration. If the virus titer is lower than 10^5 FFU / ml, perform sucrose ultracentrifugation on the virus obtained in "Step 4";

[0087] 6. Repeat steps 4-5 five times, i.e., passage the virus five times in AT cells, to obtain the hMPV strain, named hMPV-B1-mAT5;

[0088] 7. Prepare a 1x10^5 FFU / ml viral suspension of hMPV-B1-mAT5 obtained in "Step 6" and infect SPF-grade BALB / c mice with a dose of 1x10^5 FFU. Four days after infection, dissect the mice and remove their lung tissues.

[0089] 8. Repeat the operations from "Step 2" to "Step 6" and the obtained hMPV strain is named hMPV-B1-mAT10.

[0090] The name of the strain hMPV-B1-mAT10 is human metapneumovirus hMPV-B1 / P10 / 202504, and it is classified as HumanMetapneumovirus. It was deposited in the China Center for Type Culture Collection on April 23, 2025, with the deposit number CCTCCNO: V202530, and the deposit address is: Wuhan University, Wuhan, China.

[0091] 3. Analysis of F protein sequence differences among hMPV-B1 / GZ / 1712 (wild strain), hMPV-B1-mAT5, and hMPV-B1-mAT10

[0092] The F gene segments of hMPV-B1 / GZ / 1712 (wild strain), hMPV-B1-mAT5, and hMPV-B1-mAT10 were sequenced and the amino acid differences were analyzed. Figure 1A-Figure 1C

[0093] IV. Construction of BALB / c mouse infection models using hMPV-B1 / GZ / 1712 (wild strain), hMPV-B1-mAT5, and hMPV-B1-mAT10

[0094] 1. Set up B1-mAT10 group, B1-mAT5 group, wild strain group and negative control group, with 6 mice in each group;

[0095] 2. hMPV-B1-mAT10, hMPV-B1-mAT5, and the wild-type strain (hMPV-B1 / GZ / 1712) were prepared into 10^5 FFU / ml viral suspensions, and 6-week-old BALB / c mice were deeply anesthetized and inoculated with each of the three hMPV strains via intranasal inoculation at a dose of 50 μl / mouse. The negative control group was treated with PBS instead.

[0096] 3. Measure body weight and observe and record symptoms for 8 consecutive days after infection;

[0097] 4. On day 4 after infection, three mice were dissected and lung tissues were obtained in duplicate;

[0098] 5. One tissue was ground and the viral titer was measured (the animals were euthanized and dissected on the 4th day after infection, and the lung tissue was obtained. The supernatant after grinding was used to infect BHK cells, and immunofluorescence experiments were performed using a specific anti-hMPV N protein antibody). The other tissue was fixed with paraformaldehyde and pathological analysis was performed (the animals were euthanized and dissected on the 4th day after infection, and the lung tissue was obtained and fixed, then paraffin-sectioned and stained with HE).

[0099] Figure 2 shows the weight trends, survival curves, lung tissue images on day 4 post-infection (dpi4), virus status in lung tissue, and pathological analysis results of mice treated with different methods. Figure 2-3 , 5-6:

[0100] The weight of mice treated with hMPV-B1-mAT10 decreased significantly and continuously from the first day after infection, reaching the peak of the decrease 4-5 days after infection, with the maximum decrease reaching 28%. The surviving mice began to regain weight on dpi 5. In addition, when the weight decreased significantly, the mice showed symptoms such as erect hair, changes in respiratory status, and reduced food intake. When the weight loss was the largest, the mice showed symptoms such as hunched back, extremely low activity, and abdominal breathing. The weight of some mice dropped to less than 75% on dpi 4. Three of them were humanely euthanized (according to animal ethics regulations, the weight of mice dropped to 75% of the pre-infection weight). , need to be humanely killed; therefore, mice whose weight dropped to the humane killing line but did not die were humanely killed and identified as death cases) and dissected. After thoracotomy, obvious local lesions were observed in the lungs; the lung tissue was collected, ground and the supernatant was infected with BHK cells, and immunofluorescence experiments were performed using specific anti-hMPV N protein antibodies. The cells had a large amount of green fluorescence, indicating the presence of infectious hMPV virus in the lung tissue; pathological sections and hematoxylin and eosin staining of the lung tissue showed severe lung lesions, specifically manifested by a decrease in alveoli, thickening of the alveolar walls, and a large infiltration of inflammatory cells.

[0101] The weight of mice treated with hMPV-B1-mAT5 only decreased slightly on the first and second days after infection, and then began to recover; during the experiment, only mild piloerection symptoms appeared on the first day after infection, and then the hair became smooth and colorful, and no piloerection symptoms appeared again; they ate and drank normally and were active; three of the infected mice were euthanized and dissected on the fourth day after infection, and no obvious lesions were found in the lungs after thoracotomy; their lung tissues were collected, ground, and the supernatant was used to infect BHK cells, and immunofluorescence experiments were performed using specific anti-hMPV N protein antibodies. A small amount of green fluorescence was visible in the cells, indicating that hMPV virus could be isolated from the lung tissue; pathological sectioning and hematoxylin and eosin staining of their lung tissues showed mild lung lesions compared with those of mice in the PBS group, specifically slight thickening of the alveolar walls and a small amount of inflammatory cell infiltration.

[0102] Mice treated with the wild-type hMPV-B1 / GZ / 1712 virus showed no significant, sustained weight loss throughout the experimental period. Their fur remained smooth and lustrous, with no piloerection symptoms. They ate and drank normally and were active. Three of the infected mice were euthanized and autopsied on the fourth day after infection. Upon thoracotomy, the lung tissue was uniformly pink, with no lesions. The lung tissue was ground and the supernatant was used to infect BHK cells. Immunofluorescence experiments using a specific anti-hMPV N protein antibody revealed a small amount of green fluorescence in the cells, indicating that hMPV had been isolated from the lung tissue. Pathological sectioning and hematoxylin and eosin staining of the lung tissue revealed normal alveolar structure, with no significant immune cell infiltration.

[0103] The mice in the negative control group showed no obvious and sustained weight loss throughout the experimental period; their fur was smooth and colorful, and there was no piloerection; they ate and drank normally and were active; three of the mice were euthanized and dissected on the fourth day after infection, and after thoracotomy, the lung tissue was observed to be uniformly pink as a whole, with no lesions; the lung tissue was collected, ground, and the supernatant was used to infect BHK cells, and immunofluorescence experiments were performed using specific anti-hMPV N protein antibodies. The cells showed no green fluorescence, indicating that no hMPV virus was isolated from the lung tissue; pathological sections and hematoxylin and eosin staining of the lung tissue showed normal alveolar structure and no large-scale immune cell infiltration.

[0104] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. Any technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A human metapneumovirus strain, the amino acid sequence of the F protein of which is shown in SEQ ID NO: 6; Preferably, the nucleotide sequence of the F gene of the strain is shown in SEQ ID NO:

5.

2. A human metapneumovirus strain, the strain is named human metapneumovirus hMPV-B1 / P10 / 202504, deposited in the China Center for Type Culture Collection on April 23, 2025, with the deposit number CCTCC NO: V202530, and the deposit address is: Wuhan University, Wuhan, China.

3. Use of the human metapneumovirus strain according to any one of claims 1 to 2 in any one of a1) to a8): a1) Preparation of medicaments for preventing and / or treating human metapneumovirus infection or diseases caused by it; a2) preparing antibodies or antisera against human metapneumovirus; a3) Preparation of products for diagnosis of human metapneumovirus infection or diseases caused by it; a4) Detection of human metapneumovirus; a5) Establishing cell models of human metapneumovirus infection or diseases caused by it; a6) Establishing animal models of human metapneumovirus infection or diseases caused by it; a7) Screening for drugs to prevent and / or treat human metapneumovirus infection or diseases caused by it; a8) preparing a product for use in any one of a4) to a7).

4. An antibody or antiserum against human metapneumovirus, obtained by immunizing an animal with the human metapneumovirus strain according to any one of claims 1 to 2.

5. A medicament comprising: the human metapneumovirus strain according to any one of claims 1 to 2, or the antibody or antiserum according to claim 4.

6. A method for constructing a cell model of human metapneumovirus infection or a disease caused by the virus, the cell model being obtained by infecting the cell with the human metapneumovirus strain according to any one of claims 1 to 2.

7. The construction method according to claim 6, characterized in that: The cells are derived from animals; Preferably, the animal comprises a mammal; further comprises at least one of a human and a non-human mammal; Preferably, the non-human mammal comprises at least one of non-human primates, rodents, cattle, pigs, sheep, dogs, rabbits, cats, and horses; further, the non-human mammal is a rodent; Preferably, the rodent comprises at least one of a mouse, a rat, a hamster, and a guinea pig; further a mouse; and further a BALB / c mouse; Preferably, the cells comprise primary cells; Preferably, the primary cells comprise cells derived from the lung, further lung epithelial cells; further alveolar epithelial cells; Preferably, the cells include cell lines, further including fibroblast cell lines and epithelial cell lines.

8. A cell model of human metapneumovirus infection or a disease caused by it, obtained by the construction method according to any one of claims 6 to 7.

9. A method for constructing an animal model of human metapneumovirus infection or a disease caused by the virus, the animal being infected with the human metapneumovirus strain according to any one of claims 1-2.

10. The construction method according to claim 9, characterized in that: The infection method comprises at least one of nasal drops, intraperitoneal injection, aerosol exposure, intratracheal inoculation, intrapulmonary inoculation, and oral-pharyngeal inoculation; further comprising nasal drops; Preferably, the animal is a non-human animal; further a non-human mammal; further comprising at least one of a non-human primate, a rodent, a cow, a pig, a sheep, a dog, a rabbit, a cat, and a horse; further a rodent; Preferably, the rodent comprises at least one of a mouse, a rat, a hamster, and a guinea pig; further a mouse; and further a BALB / c mouse.

11. Use of the cell model according to claim 8 or the animal model obtained by the construction method according to any one of claims 9-10 in any of m1)-m2); m1) Screening for drugs to prevent and / or treat human metapneumovirus infection or diseases caused by it; m2) preparing a product for screening drugs for preventing and / or treating human metapneumovirus infection or diseases caused by it.

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