Lacticase Bacillus rhamnosus strain and its immune-enhancing uses

Abstract

This application relates to a Bacillus rhamnosus strain of lactis and its use in enhancing immunity.

Description

[Technical Field]

[0001] This application relates to a Bacillus rhamnosus strain of lactis and its use in enhancing immunity. [Background technology]

[0002] Immunity is a defense mechanism in which the internal environment of the living body recognizes various substances that have invaded from the outside as foreign bodies, and eliminates and metabolizes them. However, immune function can be impaired due to various causes, and various immune-enhancing agents are needed to prevent or treat such disorders.

[0003] The intestinal microbiota that inhabits the human gastrointestinal tract provides various health benefits through close interaction with the host. Recently, the demand for probiotics has increased significantly worldwide, spurring the development of health functional foods and drugs that use probiotics. Summary of the Invention [Problem to be solved by the invention]

[0004] Under these circumstances, the present inventors have demonstrated that the Lacticaseibacillus rhamnosus KBL352 strain has the effect of activating immune cells and enhancing immunity. Thus, one example of the present application provides an immune-enhancing use of the Lacticaseibacillus rhamnosus KBL352 strain. [Means for solving the problem]

[0005] One example of the present application relates to the Lacticaseibacillus rhamnosus KBL352 strain, which has the deposit number KCTC15267BP, and its use for enhancing immunity or for preventing or treating immune-compromised diseases. The strain may have a 16S rRNA sequence as set forth in SEQ ID NO: 3.

[0006] The present application will now be described in more detail. One example of the present application relates to an immune-enhancing composition comprising one or more members selected from the group consisting of Lacticaseibacillus rhamnosus KBL352 strain having deposit number KCTC15267BP, a culture of the strain, a homogenate of the strain, and an extract of the strain. In the examples of the present application, treatment of macrophages with the strain according to one example of the present application resulted in activation of the macrophages. Therefore, the immune enhancement may be achieved by activating macrophages, and the composition may be an immune stimulator.

[0007] Specifically, the composition may have one or more properties selected from the group consisting of the following (1) to (10): (1) promotion of macrophage phagocytic activity, for example, macrophage phagocytic activity is 1.1 times or more, 1.2 times or more, 1.3 times or more, or 1.35 times or more compared to the untreated control group; (2) promotion of nitric oxide secretion by macrophages, for example, the amount of nitric oxide secreted by macrophages is 1.1 times or more, 1.2 times or more, 1.3 times or more, 1.4 times or more, 1.5 times or more, 2 times or more, 2.5 times or more, 3 times or more, 3.5 times or more, 4 times or more, 5 times or more, 6 times or more, 7 times or more, 8 times or more, 10 times or more, 11 times or more, 12 times or more, 13 times or more, 14 times or more, or 15 times or more, compared to the untreated control group; (3) Promotion of COX-2 expression in macrophages, (4) Promotion of PGE2 secretion by macrophages, for example, the amount of PGE2 secreted by macrophages is 1.5 times or more, 1.8 times or more, 1.9 times or more, 2 times or more, 3 times or more, 4 times or more, 5 times or more, 8 times or more, 9 times or more, 10 times or more, 12 times or more, 14 times or more, 15 times or more, 20 times or more, or 25 times or more compared to the untreated control group, (5) promoting cytokine secretion from macrophages, for example, promoting the secretion of TNF-α and / or IL-6; (6) Enhancement of the expression and phosphorylation of NF-κB and / or IκBα in macrophages, (7) Promoting MAPK activation in macrophages, (8) Preventing weight loss due to immune deficiency (9) Increase in the proportion of NK cells in the spleen, and (10) Increased activity of NK cells in the spleen.

[0008] Another example of the present application relates to a food composition containing the immune-improving composition. The food may be a functional health food, and may be in the form of, for example, meat, bread, chocolate, candy, jelly, snacks, confectionery, kimchi, soy sauce, cheese, dairy products, powders, drinks, or vitamin complexes.

[0009] Another example of the present application relates to a quasi-pharmaceutical composition containing the immune-improving composition, which may be in a form selected from the group consisting of toothpaste, gag solution, mouth spray, oral ointment, mouthwash, mouth cleaner, adhesive bandage, and pest (mosquito, tick, etc.) repellent.

[0010] Another example of the present application relates to a composition for preventing or treating immunosuppression, comprising one or more selected from the group consisting of Lacticaseibacillus rhamnosus KBL352 strain having deposit number KCTC15267BP, a culture of the strain, a homogenate of the strain, and an extract of the strain.

[0011] The immunocompromise occurs when immune cells are unable to defend against external pathogens or cancer cells due to a lack of immunity, and may be, for example, an immunodeficiency syndrome, specifically, a secondary or acquired immunodeficiency.

[0012] The immunocompromised disease may be one or more selected from the group consisting of herpes, tuberculosis, meningitis, capillary inflammation, and bacterial or viral infection.

[0013] The term "strain" in this application may refer to live or heat-inactivated strains of a strain according to an example of this application.

[0014] The term "strain culture" in the present application refers to a product obtained after culturing a strain according to an example of the present application. The culture may be a whole culture of a strain according to an example of the present application, a dilution, concentrate, dried product, lyophilized product, disrupted product, and / or fraction thereof. The concentrate may be obtained by centrifuging or evaporating the culture. The dried product may be obtained by drying the culture using a dryer, etc. The lyophilized product may be obtained by freeze-drying the culture using a freeze-dryer, etc. The disrupted product may be obtained by physically or sonicating the strain or culture. The fraction may be obtained by subjecting the culture or disrupted product to centrifugation, chromatography, or other methods. The culture may be in a solid phase (solid, e.g., dried product), a liquid phase (liquid), or a fluidized bed, but is not limited thereto. For example, the culture may refer to a whole medium containing a cultured strain, its metabolites, and / or excess nutrients obtained by culturing a strain according to an example of the present application for a certain period of time. For example, the culture may or may not contain the strain according to an example of the present application removed. For example, the culture may refer to the remaining components obtained by removing the strain (bacterial cells) from a culture medium in which a strain according to an example of the present application is cultured. For example, the culture may be a culture broth (or culture product) obtained by culturing a strain according to an example of the present application in a medium and removing the strain (bacterial cells). The culture broth (or culture product) from which the strain has been removed may be a cell-free culture broth (or culture product) or a culture broth containing killed cells, for example, a filtrate (supernatant after centrifugation) obtained by removing the strain by filtration or centrifugation, and / or a culture broth (or dried culture product) containing killed cells. Specifically, the culture may exhibit anti-inflammatory activity or prophylactic, ameliorating, or therapeutic activity for inflammatory diseases at the same level as the activity exhibited by the strain according to an example of the present application.

[0015] The term "lysate of a strain" in the present application may refer to a product obtained by disrupting a strain according to an example of the present application by chemical or physical force. Specifically, the lysate may exhibit the same level of anti-inflammatory activity or activity for preventing, improving, or treating inflammatory diseases as the activity exhibited by the strain according to an example of the present application.

[0016] The term "extract" as used herein may refer to a product obtained by extracting a strain according to an example of the present application, a culture of the strain, a homogenate of the strain, or a mixture thereof, regardless of the extraction method, extraction solvent, extracted component, or extract form. It is a broad concept that includes all substances that may be obtained by processing or treating the strain in other ways after extraction. For example, the extract may be an extract of a strain according to an example of the present application, an extract of a culture of the strain, or an extract of a homogenate of the strain. Specifically, the extract may exhibit anti-inflammatory activity or preventive, ameliorative, or therapeutic activity for inflammatory diseases at the same level as the activity exhibited by a strain according to an example of the present application, a culture of the strain, or a homogenate of the strain.

[0017] The composition according to one example of the present application contains 1.0×10 Lacticaseibacillus rhamnosus KBL352 strain having accession number KCTC15267BP. 3 ~1.0X10 15 CFU, 1.0X10 3 ~1.0X10 14 CFU, 1.0X10 3 ~1.0X10 13 CFU, 1.0X10 3 ~1.0X10 12 CFU, 1.0X10 3 ~1.0X10 11 CFU, 1.0X10 3 ~1.0X10 10 CFU, 1.0X10 5 ~1.0X10 15 CFU, 1.0X10 5 ~1.0X10 14 CFU, 1.0X10 5~1.0X10 13 CFU, 1.0X10 5 ~1.0X10 12 CFU, 1.0X10 5 ~1.0X10 11 CFU, 1.0X10 5 ~1.0X10 10 CFU, 1.0X10 7 ~1.0X10 15 CFU, 1.0X10 7 ~1.0X10 14 CFU, 1.0X10 7 ~1.0X10 13 CFU, 1.0X10 7 ~1.0X10 12 CFU, 1.0X10 7 ~1.0X10 11 CFU, 1.0X10 7 ~1.0X10 10 CFU, 1.0X10 8 ~1.0X10 15 CFU, 1.0X10 8 ~1.0X10 14 CFU, 1.0X10 8 ~1.0X10 13 CFU, 1.0X10 8 ~1.0X10 12 CFU, 1.0X10 8 ~1.0X10 11 CFU, or 1.0X10 8 ~1.0X10 10 The concentration of CFU may be included.

[0018] The term "prevention" in this application means inhibiting or delaying the onset of a disease, disorder, or condition. Prevention can be considered complete if the onset of a disease, disorder, or condition is inhibited or delayed within a predetermined period of time.

[0019] The term "treatment" in this application means to partially or completely alleviate, ameliorate, relieve, inhibit, or delay the symptoms of a particular disease, disorder, and / or condition, or to reduce the severity or occurrence of one or more symptoms or characteristics of a condition.

[0020] The compositions of the present application, for example, pharmaceutical compositions or food compositions, may contain one or more additional active ingredients that exhibit the same or similar functions in addition to the active ingredients.

[0021] Furthermore, the compositions according to the present application, for example, pharmaceutical compositions or food compositions, can be prepared in unit dose forms or in multi-dose containers by formulating them with pharmaceutically acceptable carriers in a manner clearly within the skill of a person in the art to which the invention pertains. The term "carrier" as used herein means a compound that facilitates the addition of a compound into cells or tissues, and the term "pharmaceutically acceptable" refers to a composition that is physiologically acceptable and does not normally cause gastrointestinal disorders, allergic reactions such as dizziness, or similar reactions when administered to humans.

[0022] The pharmaceutically acceptable carriers include those commonly used in formulations, such as lactose, dextrose, sucrose, sorbitol, mannitol, starch, acacia gum, calcium phosphate, alginate, gelatin, calcium silicate, microcrystalline cellulose, polyvinylpyrrolidone, cellulose, water, syrup, methylcellulose, methylhydroxybenzoate, propylhydroxybenzoate, talc, magnesium stearate, and mineral oil, but are not limited thereto.

[0023] Furthermore, the compositions according to the present application, for example, pharmaceutical compositions or food compositions, may further contain additives such as fillers, anti-agglomerating agents, lubricants, humectants, flavorings, emulsifiers, preservatives, etc. In the present application, the content of the additives contained in the composition is not particularly limited and may be appropriately adjusted within the content range used in conventional formulations.

[0024] Additionally, compositions according to the present application, such as pharmaceutical or food compositions, can be formulated as oral preparations. Non-limiting examples of oral preparations include tablets, troches, lozenges, aqueous suspensions, oily suspensions, prepared powders, granules, emulsions, hard capsules, soft capsules, syrups, or elixirs. To formulate pharmaceutical or food compositions according to the present application for oral administration, binders such as lactose, sucrose, sorbitol, mannitol, starch, amylopectin, cellulose, or gelatin; excipients such as dicalcium phosphate; disintegrants such as corn starch or sweet potato starch; magnesium stearate, calcium stearate, or sodium stearyl fumarate can be used, as well as sweeteners, flavorings, and syrups. Furthermore, in the case of capsules, in addition to the aforementioned substances, liquid carriers such as fatty oils can also be used.

[0025] The term "excipient" as used herein refers to a substance other than a therapeutic agent, used as a carrier or vehicle for delivery of a therapeutic agent, or added to a pharmaceutical composition. This improves handling and storage properties, or allows and facilitates the formation of a unit dose of the composition. The compositions, e.g., pharmaceutical compositions, according to the present application can be formulated and used in various forms, such as oral preparations such as solutions, suspensions, powders, granules, tablets, capsules, pills, extracts, emulsions, syrups, and aerosols, or injectable sterile injection solutions, according to conventional methods depending on the intended use. They can be administered orally or via various routes, including intravenous, intraperitoneal, subcutaneous, rectal, and topical administration. The term "oral administration" as used herein means that the active substance is administered as a substance prepared to be digested, i.e., through the gastrointestinal tract for absorption.

[0026] The preferred dosage of the composition of the present application, for example, a pharmaceutical composition or food composition, may vary depending on the patient's condition and weight, age, sex, health condition, specific dietary habits, properties of the formulation, severity of the disease, administration time of the composition, administration method, administration period or interval, excretion rate, and drug form, and can be appropriately selected by a person of ordinary skill in the art.

[0027] The term "effective dosage" in this application means an amount of a composition of an active ingredient sufficient to treat a specific symptom. This amount may vary depending on the formulation method, administration mode, administration time, and / or administration route of the pharmaceutical or food composition, and may vary depending on several factors, including the type and degree of response to be achieved by administration of the pharmaceutical or food composition, the type, age, weight, general health condition, symptoms and degree of disease, sex, diet, excretion, ingredients of other compositions of drugs used simultaneously or temporarily in the individual, and similar factors well known in the medical field. A person of ordinary skill in the art can easily determine and prescribe an effective dosage for the desired treatment.

[0028] The pharmaceutical or food composition of the present application can be administered once a day or in divided doses. The composition can be administered as an individual therapeutic agent or in combination with other therapeutic agents, and can be administered sequentially or simultaneously with conventional therapeutic agents. Taking all of the above factors into consideration, the composition can be administered in the minimum amount that will achieve the maximum effect without side effects.

[0029] For example, if the composition of the present application is 0.001 or even 10,000mg, 0.001 or even 5,000mg, 0.001 or even 1,000mg, 0.001 or even 500mg, 0.001 or even 300mg, 0.001 or even 100mg for 1kg of body weight g, 0.001 or even 50mg, 0.001 or even 30mg, 0.001 or even 10mg, 0.001 or even 5mg, 0.001 or even 1mg, 0.001 or even 0.5mg, 0.001 or even 0.1mg, 0.001 or even 0.05mg, 0.001 and even Up to 0.01mg, 0.01 to 10,000mg, 0.01 to 5,000mg, 0.01 to 1,000mg, 0.01 to 500mg, 0.01 to 300mg, 0.01 to 100mg, 0.01 to 50mg, 0.01 to 30mg, 0.01 to 10mg, 0.01 to 5mg, 0.01 to 1mg, 0.01 to 0.5mg, 0.01 to 0.1mg, 0.01 to 0.05mg, 0.1 to 10,000mg, 0.1 to 5,000mg, 0.1 to 1,000mg, 0.1 to 5,000mg, 0.1 to 1,000mg. 0.00mg, 0.1 to 500mg, 0.1 to 300mg, 0.1 to 200mg, 0.1 to 100mg, 0.1 to 50mg, 0.1 to 30mg, 0.1 to 10mg, 0.1 to 5mg, 0.1 to 1mg, 0.1 to 0.5mg, 1 to 10,000mg, 1 to 5,000mg, 1 to 1,000mg, 1 to 500mg, 1 to 300mg, 1 to 200mg, 1 to 100mg, 1 to 50mg, 1 to 10mg, 1 to 5mg, 10 to 10,000mg mg, 10 to 5,000mg, 10 to 1,000mg, 10 to 500mg, 10 to 300mg, 10 to 200mg, 10 to 100mg, 10 to 50mg, 10 to 40mg, 10 to 30mg, 10 to 20mg, 100 Even 10,000mg, 100 or even 5,000mg, 100 or even 1,000mg, 100 or even 500mg, 100 or even The daily dosage of 300 mg, 100 mg, and 200 mg is the same as the daily dosage of 300 mg, 100 mg, and 200 mg.

[0030] For example, the daily dosage of the composition according to the present application may be 0.001 to 10 g / day, 0.001 to 5 g / day, 0.01 to 10 g / day, or 0.01 to 5 g / day for an adult patient, based on oral administration. The total daily dosage may be divided and administered continuously or discontinuously as needed.

[0031] Another example of the present application relates to a method for enhancing immunity, comprising administering to a subject one or more selected from the group consisting of Lacticaseibacillus rhamnosus KBL352 strain having deposit number KCTC15267BP, a culture of the strain, a homogenate of the strain, and an extract of the strain. [Effects of the Invention]

[0032] The Lacticase Bacillus rhamnosus KBL352 strain having the deposit number KCTC15267BP according to an example of the present application exhibits the effect of enhancing the phagocytic ability of macrophages, increasing macrophage activity, and thereby enhancing immunity. Therefore, it can be used for immune enhancement purposes, and can provide the prevention and treatment of immunocompromise, the alleviation of side effects caused by taking immunosuppressants, antiviral effects, and infectious disease prevention effects, and can be usefully used as a probiotic material. [Brief explanation of the drawings]

[0033] [Figure 1a] 1 is a diagram confirming that the phagocytic ability of macrophages is improved by a bacterial strain according to an example of the present application. [Figure 1b] This is a continuation of Figure 1a. [Figure 2a] 1 is a diagram confirming that the iNOS expression level in macrophages was increased by a bacterial strain according to an example of the present application. [Figure 2b] 1 is a diagram confirming that the amount of NO secretion in macrophages was increased by a bacterial strain according to an example of the present application. [Figure 3a]1 is a diagram confirming that the expression level of COX-2 in macrophages was increased by a bacterial strain according to an example of the present application. [Figure 3b] 1 is a diagram confirming that the amount of PGE2 secreted from macrophages was increased by the bacterial strain according to an example of the present application. [Figure 4a] 1 is a diagram confirming that cytokine production in macrophages was increased by a bacterial strain according to an example of the present application. [Figure 4b] This is a continuation of Figure 4a. [Figure 5] 1 is a diagram confirming that the expression of NF-κB and the expression and phosphorylation levels of IκBα in macrophages were increased by a bacterial strain according to an example of the present application. [Figure 6] 1 is a diagram confirming that the phosphorylation levels of JNK, ERK, and p38 proteins in macrophages were increased by a bacterial strain according to an example of the present application. [Figure 7a] 1 is a diagram confirming the weight loss prevention effect of a bacterial strain according to an example of the present application in an immunocompromised animal model. [Figure 7b] 1 is a diagram confirming the effect of a bacterial strain according to an example of the present application in increasing the proportion of NK cells in the spleen in an immunocompromised animal model. [Figure 7c] 1 is a diagram confirming the effect of a bacterial strain according to an example of the present application on increasing the activity of NK cells in the spleen in an immunocompromised animal model. DETAILED DESCRIPTION OF THE INVENTION

[0034] The present application will be described in more detail below with reference to the following examples, which are provided for illustrative purposes only and are not intended to limit the scope of the present application.

[0035] Example 1. Identification of Bacillus rhamnosus KBL352 strain A fecal sample from a 3-month-old infant was provided through Samsung Medical Center, Seoul. The sample was streak-inoculated onto a selective medium (TOS-propionate agar medium; 43314 Transgalactosylated oligiosaccharide agar medium, Fluka) and cultured at 37°C in an anaerobic environment for 48 hours. Afterwards, the bacteria were isolated by colony picking and pure culture.

[0036] The strains were then cultured in a CO2 incubator at 37°C under an anaerobic environment for one day and then centrifuged at 13,000 rpm at 4°C to obtain the isolates. Next, 0.2 μL of the strain pellet was added to 25 μL of lysis buffer (pH 10; 2.5 M NaCl, 100 mM EDTA, 10 mM Trizma base, 1% Triton X-100) and heat-treated at 95°C for 10 minutes to obtain the template. The V4 region of 16S rRNA was then amplified by polymerase chain reaction using the G-Taq PCR kit to obtain the PCR product. The nucleotide sequences of the primers used are shown in Table 1. In the nucleotide sequences of the primers below, "M" can be selected from A or C, and "Y" can be selected from C or T.

[0037] [Table 1]

[0038] The PCR product was then purified using an Ultra Clean PCR clean-up Kit (Mobio Laboratories Inc.), and the strain was identified by requesting gene sequence analysis from Macrogen Co., Ltd. (sequencing@macrogen.com). The 16S rRNA sequence of the strain is shown in SEQ ID NO: 3.

[0039] As a result, the identified bacteria was confirmed to be a strain of the genus Lacticaseibacillus, and the strain was named Lacticaseibacillus rhamnosus KBL352. The strain was deposited with the Korean Collection for Type Culture, an international depository institution under the Budapest Treaty, and was assigned the accession number KCTC15267BP.

[0040] Example 2: Effect of improving macrophage phagocytic activity The phagocytic ability of macrophages was analyzed using Candida albicans MYA-4788 (hereafter referred to as C. albicans). Murine macrophage line RAW264.7 was treated with live Lacticaseibacillus rhamnosus KBL352 at a 1:200 concentration and co-cultured for 24 hours. RAW264.7 cells were then washed twice with 1x PBS. As a control, LPS was treated at a concentration of 10 ng / ml. RAW264.7 cells were then treated with yeast-state C. albicans at a 1:10 concentration and incubated at 37°C for 1 hour. After co-culture with C. albicans, RAW264.7 cells were washed twice with 1x PBS, fixed with 2.5% glutaraldehyde, and stained with 0.5% methylene blue. The stained cells were observed under a microscope, and if one or more C. albicans cells were found in a macrophage, it was considered that phagocytosis had occurred. The microscopic observation results are shown in Figure 1a, and the phagocytic activity of the macrophages was calculated using the following formula 1 and is shown in Figure 1b and Table 2: [Formula 1] Phagocytic ability (%) = (number of macrophages that caused phagocytosis) / (number of macrophages observed) x 100

[0041] [Table 2]

[0042] As shown in Figure 1a, Figure 1b, and Table 2, a significant increase in the phagocytic ability of macrophages was confirmed when treated with live Bacillus rhamnosus KBL352.

[0043] Example 3. Effect of increasing iNOS expression and NO secretion in macrophages Murine macrophage line RAW264.7 was treated with live Bacillus rhamnosus KBL352 bacteria at a concentration gradient up to 200-fold higher than that of RAW264.7 cells, and the expression levels of iNOS, a protein involved in nitric oxide (NO) production, and the amount of NO secreted by macrophages were measured. As a control, LPS was treated at 10 ng / ml or 100 ng / ml. To confirm that the protein used in Figure 2a was consistent across all samples, the expression levels of the housekeeping protein β-actin were also monitored. The iNOS expression levels are shown in Figure 2a, and the amount of NO secreted by macrophages is shown in Figure 2b and Table 3.

[0044] [Table 3]

[0045] As shown in Figures 2a and 2b and Table 3, the iNOS expression level and NO secretion increased depending on the strain treatment level, which means that the strain according to one example of the present application is an immunostimulant that activates immune cells.

[0046] Example 4. Confirmation of increase in COX-2 expression and PGE2 secretion Murine macrophage line RAW264.7 was treated with live Bacillus rhamnosus KBL352 bacteria at a concentration gradient up to 200-fold higher than that of RAW264.7 cells, and the expression levels of COX-2, a protein involved in PGE2 production, and the amount of PGE2 secreted by macrophages were measured. As a control, LPS was treated at 10 ng / ml or 100 ng / ml. To confirm that the protein used in Figure 2a was consistent across all samples, the expression levels of the housekeeping protein β-actin were also monitored. COX-2 expression levels are shown in Figure 3a, and the amount of PGE2 secreted by macrophages is shown in Figure 3b and Table 4.

[0047] [Table 4]

[0048] As shown in Figures 3a, 3b, and Table 4, COX-2 expression levels and PGE2 secretion levels increased depending on the level of treatment with a strain according to an example of the present application, which means that the strain according to an example of the present application is an immunostimulant that activates immune cells.

[0049] Example 5. Effect of increasing cytokine secretion in macrophages Murine macrophage line RAW264.7 was treated with live Bacillus rhamnosus KBL352 bacteria at a concentration gradient up to 200-fold higher than that of RAW264.7 cells, and the expression levels of TNF-α and IL-6 in the macrophages were measured. As a positive control, LPS was treated at a concentration of 10 ng / ml.

[0050] As shown in Figures 4a, 4b, and Table 5, the levels of TNF-α and IL-6 secretion in macrophages increased depending on the level of treatment with the strain according to an example of the present application, which means that the strain according to an example of the present application has an immune function-enhancing effect.

[0051] [Table 5]

[0052] Example 6. Confirmation of increased expression and phosphorylation of NF-κB and IκBα in macrophages Murine macrophage line RAW264.7 was treated with live Bacillus rhamnosus KBL352 bacteria at a 10- to 50-fold concentration gradient compared to RAW264.7 cells, and the expression and phosphorylation of NF-κB and IκBα proteins were examined. As a control, LPS was treated at 10 ng / mL or 100 ng / mL, and the expression levels of the housekeeping protein β-actin were also monitored to demonstrate that the proteins used were consistent across all samples.

[0053] As shown in FIG. 5, treatment with the strain according to one example of the present application increased the expression of NF-κB and the expression and phosphorylation levels of IκBα, confirming that immune competence was activated.

[0054] Example 7. Effect of MAPKs activation in macrophages Murine macrophage line RAW264.7 was treated with live Bacillus rhamnosus KBL352 bacteria at concentrations ranging from 10 to 200 times higher than those of RAW264.7 cells. This treatment promoted NO production in immune cells, and cytokine production such as TNF-α and IL-6. The expression and phosphorylation levels of MAPKs (p38, ERK, JNK, etc.), a signaling pathway important for immune cell activation, were also examined. As a control, LPS was treated at 10 ng / mL or 100 ng / mL, and the expression levels of the housekeeping protein β-actin were also monitored to demonstrate that the proteins used were consistent across all samples.

[0055] As shown in FIG. 6, treatment with the strain according to an example of the present application increased the phosphorylation levels of JNK, ERK, and p38 proteins, confirming activation of immune competence.

[0056] Example 8. Immune enhancing effect (1) Preparation of immunocompromised animal models Five-week-old male Balb / c mice were orally administered water, Bacillus rhamnosus KBL352, or red ginseng concentrate once daily (Table 6) until the end of the experiment. On days 15 and 16 of the experiment, cyclophosphamide was administered intraperitoneally to all mice except the naive group at a concentration of 150 mg / kg to induce immune suppression.

[0057] [Table 6]

[0058] (2) Prevents weight loss The body weights of the mice were measured before oral administration once a day from day 1 to the end of the experiment, and the results are shown in FIG. 7a.

[0059] As shown in FIG. 7a, the Bacillus rhamnosus KBL352 strain according to an example of the present application exhibited the effect of preventing weight loss caused by immune depression.

[0060] (3) Increase in the proportion of NK cells in the spleen After the experiment, the spleens of the mice in each group were harvested, and the number of NK cells in the spleens was determined using a flow cytometer. The results are shown in FIG. 7b.

[0061] As shown in Figure 7b, the proportion of NK cells in the spleen was significantly increased in the group administered with Lacticaceae Bacillus rhamnosus KBL352 strain according to an example of the present application, demonstrating an effect equal to or greater than that of red ginseng. Therefore, Lacticaceae Bacillus rhamnosus KBL352 strain according to an example of the present application exhibits a significantly superior immune-boosting effect, inducing rapid recovery from immune depression. Compared to the control group in Figure 7b, * indicates p<0.05; ** indicates p<0.01; *** indicates p<0.001; and **** indicates p<0.0001.

[0062] (4) Increased activity of NK cells in the spleen After the experiment, spleens were harvested from each group of mice, and the percentage of Yac-1 cells, the target of NK cells, killed by NK cells was measured using a flow cytometer. The results are shown in Figure 7c. As shown in Figure 7c, the percentage of NK cells in the spleen was significantly increased in the group administered with Lacticaceae Bacillus rhamnosus KBL352 strain according to an example of the present application, demonstrating an effect equal to or greater than that of red ginseng. Therefore, Lacticaceae Bacillus rhamnosus KBL352 strain according to an example of the present application exhibits a significantly superior immune-boosting effect, inducing rapid recovery from immune depression. In Figure 7c, * indicates p<0.05; ** indicates p<0.01; *** indicates p<0.001; and **** indicates p<0.0001 compared to the control group. [Accession number]

[0063] Depository institution name: Korea Institute of Bioscience and Biotechnology Biological Resource Center Accession number: KCTC15267BP Date of acceptance: 20230104 TIFF2026507538000008.tif238162

Claims

1. A composition for enhancing immunity, comprising one or more selected from the group consisting of Lacticaseibacillus rhamnosus KBL352 strain having deposit number KCTC15267BP, a culture of said strain, a disrupted product of said strain, and an extract of said strain.

2. The composition according to claim 1, wherein the immune enhancement is promotion of phagocytic activity of macrophages and / or promotion of nitric oxide secretion by macrophages.

3. The composition of claim 1 , wherein the composition is an immune stimulator.

4. The composition comprises: (1) Promoting the phagocytic activity of macrophages, (2) Promoting nitric oxide secretion from macrophages, (3) Promotion of COX-2 expression in macrophages, (4) Macrophage PGE ２ secretion promotion, (5) promoting cytokine secretion from macrophages; (6) promoting the expression and phosphorylation of NF-κB and / or IκBα in macrophages; (7) Promoting MAPKs activation in macrophages, (8) Prevention of weight loss due to immune deficiency, (9) an increase in the proportion of NK cells in the spleen; and (10) Increased activity of NK cells in the spleen, 10. The composition of claim 1, wherein the composition has one or more properties selected from the group consisting of:

5. A food composition comprising the composition of any one of claims 1 to 4.

6. A quasi-drug composition comprising the composition according to any one of claims 1 to 4.

7. Lacticaseibacillus rhamnosus strain KBL352, having accession number KCTC15267BP.

8. The strain of claim 7, wherein the strain has a 16S rRNA sequence of SEQ ID NO:3.

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