Method for enrichment and expansion of virus antigen-specific T cells

Abstract

The present invention relates to a method for inducing and proliferating target virus antigen-specific dual activated T cells, and can produce target virus antigen-specific dual activated T cells by treating monocytes, which are isolated from peripheral blood, with a cytokine and a virus antigen peptide mixture and culturing the same.

Claims

1. A method for inducing and proliferating virus antigen-specific dual activated T cells comprising: culturing peripheral blood mononuclear cells under IFN-γ and a virus antigen peptide mixture for 4 days to selectively induce virus antigen-specific dual activated T cells; and proliferating the virus antigen-specific dual activated T cells under the presence of IL-2 and in the absence of anti-CD3 antibodies after the culturing step, wherein the proliferated virus antigen-specific dual activated T cells comprise CD3+CD8+CD56-cells and CD3+CD8+CD56+cells.

2. The method of claim 1, wherein the peripheral blood mononuclear cells are obtained from a normal person or a patient.

3. The method of claim 1, wherein the IFN-γ is used at a concentration of 500 U/mL to 1,000 U/mL.

4. The method of claim 1, wherein the IL-2 is used at a concentration of 200 U/mL to 1,000 U/mL.

5. The method of claim 1, wherein the induction and proliferation of the dual activated T cells is carried out for a total of 20 days or more.

6. The method of claim 5, wherein the induction and proliferation of the dual activated T cells is carried out for a total of 21 days.

7. The method of claim 1, wherein the virus antigen comprises antigens selected from the group consisting of a cytomegalovirus (CMV), Epstein-Barr virus (EBV), an adenovirus (ADV), and BK virus (BKV).

Description

DESCRIPTION OF DRAWINGS

(1) FIG. 1 shows a process of culturing CMV antigen-specific CIK cells.

(2) FIG. 2 shows the results of measuring the number of CMV antigen-specific dual activated T cells using flow cytometry.

(3) FIG. 3 shows the results of measuring the CMV antigen-specific dual activated T cells using a pentamer assay.

(4) FIG. 4 shows the results of comparing phenotypes of the dual activated T cells after the dual activated T cells are cultured for 21 days.

(5) FIG. 5 shows the results of measuring an IFN-γ secretion rate in the dual activated T cells and CIK cells after the dual activated T cells and CIK cells are stimulated with a CMV antigen peptide.

(6) FIG. 6 shows a killing effect of the dual activated T cells on tumor cells.

(7) FIG. 7 shows the results of measuring the number of the CMV antigen-specific CIK cells using flow cytometry.

(8) FIG. 8 shows the results of comparing phenotypes of the CIK cells after the CIK cells are cultured for 21 days.

(9) FIG. 9 shows the results of measuring the CMV antigen-specific CIK cells using a pentamer assay.

BEST MODE

(10) Hereinafter, the configurations of the present invention will be described in detail.

(11) The present invention provides a method for inducing and proliferating virus antigen-specific dual activated T cells, which includes treating peripheral blood mononuclear cells with IFN-γ and a virus antigen peptide mixture upon the culture of the peripheral blood mononuclear cells; and treating the peripheral blood mononuclear cells with IL-2.

(12) In the present invention, the term “virus antigen-specific dual activated T cells” refers to T cells that are treated with a virus antigen peptide mixture upon the culture of the T cells to exhibit target virus antigen-specific characteristics, wherein the T cells exhibit both an MHC-independent anti-tumor effect and the function of MHC-dependent antiviral T cells. The dual activated T cells according to the present invention include CD3+ T cells and CD3+CD56+ NKT cells, but a high proportion of virus antigen-specific T cells are contained in the CD3+ T cells. Therefore, the dual activated T cells according to the present invention may exhibit an effect of preventing or treating a virus-mediated disease because the dual activated T cells have additional target virus antigen-specific characteristics in addition to this general function of the T cells.

(13) In the present invention, the term “peripheral blood mononuclear cells (PBMCs)”, “PBMCs” or “mononuclear cells” refers to mononuclear cells that are isolated from peripheral blood generally used for anticancer immunotherapy. The peripheral blood mononuclear cells may be obtained from blood drawn from a person using a known method such as Ficoll density-gradient centrifugation.

(14) According to one exemplary embodiment of the present invention, the peripheral blood mononuclear cells may be obtained from a normal person or a patient. The peripheral blood mononuclear cells used in the present invention do not necessarily have to be autologous, and peripheral blood mononuclear cells derived from the same species may be used to induce and proliferate the virus antigen-specific dual activated T cells according to the present invention.

(15) The dual activated T cells according to the present invention are induced and proliferated by treating peripheral blood mononuclear cells with cytokines and a virus antigen peptide mixture upon the culture of the peripheral blood mononuclear cells.

(16) In the present invention, the term “virus antigen” refers to an antigen protein such as a membrane protein or partial peptides thereof that causes a disease in a target subject to be treated by transplanting the dual activated T cells. For example, the virus antigen may be an antigen of a human latent virus such as a cytomegalovirus (CMV), Epstein-Barr virus (EBV), an adenovirus (ADV), BK virus (BKV), and the like.

(17) In the present invention, peptides of the “peptide mixture” refer to peptides that constitute a viral protein which functions as an antigen and have a length of 10 to 20 amino acids. Therefore, the term “peptide mixture” refers to a mixture of the peptides.

(18) In the present invention, the treating of the peripheral blood mononuclear cells with the IFN-γ and the virus antigen peptide mixture upon the culture of the peripheral blood mononuclear cells may further include isolating the mononuclear cells from a person's peripheral blood.

(19) The treating of the peripheral blood mononuclear cells with the IFN-γ and the virus antigen peptide mixture upon the culture of the peripheral blood mononuclear cells may be carried out on day 0 of the culture, but the present invention is not limited thereto.

(20) In the present invention, the treating of the peripheral blood mononuclear cells with the IL-2 may be carried out on day 4 of the culture. Specific culture conditions such as a treatment time of the cytokines, a certain temperature, and the like may vary depending on the type of virus antigens.

(21) In the present invention, the term “cytokine” refers to an immunostimulatory cytokine that may be used to induce the peripheral blood mononuclear cells into cytokine-derived killer cells. In the present invention, IL-2 and IFN-γ are used as such cytokines.

(22) The IFN-γ may be used at a concentration of 500 U/mL to 1,000 U/mL, for example, a concentration of 800 U/mL to 1000 U/mL, and the IL-2 may be used at a concentration of 200 U/mL to 1,000 U/mL, for example, a concentration of 200 U/mL to 800 U/mL.

(23) When the peripheral blood mononuclear cells are treated with the cytokines and the target virus antigen peptide and cultured according to the present invention, the target virus-specific dual activated T cells may be obtained. The dual activated T cells thus obtained may be treated to treat a virus-mediated disease or a cancer.

(24) The virus-mediated disease may include diseases caused by viral infections or virus-induced cancers. The diseases caused by the viral infections are, for example, found in immunocompromised patients whose immune system is damaged through graft engineering when there are mismatches between human leukocyte antigens (HLAs), and may include diseases mediated by human latent viruses, such as a cytomegalovirus (CMV), Epstein-Barr virus (EBV), an adenovirus (ADV), BK virus (BKV), and the like. The virus-induced cancers may, for example, include EBV-induced Burkitt's lymphoma, post-transplant lymphoproliferative disease (PTLD), Hodgkin's lymphoma, NK/T cell lymphoma, diffuse large B-cell lymphoma (DLBCL), primary effusion lymphoma, and the like, but the present invention is not limited thereto.

(25) In the present invention, as a medium that may be used to culture the peripheral blood mononuclear cells any conventional medium used to induce and proliferate the peripheral blood mononuclear cells into T cells may be used without limitation. Media such as RPMI, DMEM, X-Vivo10, X-Vivo20, Cellgro SCGM, and the like may, for example, be used as such a medium. In addition, the culture conditions such as a temperature, and the like may follow conventional culture conditions for peripheral blood mononuclear cells.

(26) The induction and proliferation of antigen-specific peripheral blood mononuclear cell-derived dual activated T cells according to the present invention may be carried out for 10 to 30 days, for example, 10 days to 25 days, 12 days to 25 days, 12 days to 21 days, 15 days to 21 days, 18 days to 21 days, or 20 days to 21 days.

(27) According to one exemplary embodiment, the method may include treating CMV antigen-specific dual activated T cells with IFN-γ and a peptide mixture on day 0 of the culture upon the culture of the CMV antigen-specific dual activated T cells, treating the CMV antigen-specific dual activated T cells with IL-2 on day 4 of the culture, and treating the CMV antigen-specific dual activated T cells with IL-2 every 2 to 3 days for 21 days.

(28) The present invention also provides a pharmaceutical composition including the antigen-specific dual activated T cells obtained according to the method.

(29) In the following examples, CMV-pp65 antigen-specific T cells were measured for groups (examples) in which the mononuclear cells were cultured with a peptide mixture in the presence of IL-2, and groups (comparative examples) in which the mononuclear cells were cultured without a peptide mixture in the presence of IL-2. As a result, it was confirmed that the CMV-pp65 antigen-specific T cells were amplified only in the experimental groups in which the mononuclear cells were treated with the peptide mixture (FIG. 2).

(30) Therefore, the virus antigen-specific dual activated T cells obtained according to the method of the present invention may be effectively used for prevention and treatment of a virus-mediated disease.

(31) Specifically, the virus-mediated disease may include diseases caused by EBV, such as post-transplant lymphoproliferative disease (PTLD), Burkitt's lymphoma, Hodgkin's lymphoma, NK/T cell lymphoma, diffuse large B-cell lymphoma (DLBCL), primary effusion lymphoma, and the like; include diseases caused by CMVs, such as pneumonia, retinitis, enteritis, myelosuppression, and the like; include diseases caused by ADVs, such as cystitis, pneumonia, hepatitis, and the like; and include diseases caused by BKV, such as renal dysfunction, hemorrhagic cystitis, and the like, but the present invention is not limited thereto.

(32) In the present invention, the subject may be a human in need of prevention and/or treatment of the virus-mediated disease. The subject may include patients or normal persons as well.

(33) The pharmaceutical composition including the dual activated T cells according to the present invention may be formulated into a form in which the dual activated T cells are suspended at a proper concentration in an aqueous solution (for example, a phosphate buffer solution, an aqueous solution for conventional injections, and the like) containing proper ingredients, as necessary.

(34) The pharmaceutical composition according to the present invention may be administered in conventional ways through routes of intravenous, intraarterial, intraperitoneal, intramuscular, intrasternal administration, and the like.

(35) An effective amount of the dual activated T cells included in the pharmaceutical composition of the present invention refers to an amount required to achieve an effect of preventing or treating a virus-mediated disease. Therefore, the effective amount may be adjusted according to various factors including the type of a disease, the severity of a disease, the types and contents of other components included in the composition, and the age, weight, general health conditions, gender and diet of a patient, an administration time, a route of administration, a treatment period, drugs to be used in combination, and the like. For example, when administered once to several times a day, the CIK cells of the present invention may be administered, in the case of adults, at a dose of 1×10.sup.6 cells/kg to 1×10.sup.11 cells/kg, for example, a dose of 1×10.sup.6 cells/kg to 1×10.sup.8 cells/kg, but the present invention is not limited thereto.

(36) Accordingly, the present invention provides a method for treating a virus-mediated disease, which includes administering the virus antigen-specific dual activated T cells to a subject in need thereof.

(37) Also, the present invention provides a kit for preparing the virus antigen-specific dual activated T cells, which includes IFN-γ, IL-2, and a virus antigen peptide mixture.

(38) According to the present invention, because a large amount of the dual activated T cells are induced and proliferated from a small amount of the peripheral blood mononuclear cells without using expensive equipment or various expensive cytokines, the efficiency and effectiveness of prevention and treatment of the virus-mediated disease using the dual activated T cells may be remarkably enhanced.

(39) Also, the present invention provides a method for inducing and proliferating virus antigen-specific cytokine-induced killer cells (CIK cells), which includes treating peripheral blood mononuclear cells with IFN-γ and a virus antigen peptide mixture upon the culture of the peripheral blood mononuclear cells; and treating the peripheral blood mononuclear cells with an anti-CD3 antibody and IL-2.

(40) In the method for inducing and proliferating CIK cells, all the contents disclosed in the method for inducing and proliferating dual activated T cells may be equally applied to the peripheral blood mononuclear cells, the virus antigen, the peptide mixture, the cytokines, the concentrations of the cytokines, and the culture medium for the peripheral blood mononuclear cells.

(41) In the present invention, the term “virus antigen-specific cytokine-induced killer cells” refers to cells that are obtained by further treating the aforementioned dual activated T cells with an anti-CD3 antibody along with the IFN-γ, the virus antigen peptide mixture and the IL-2 to induce and proliferate the dual activated T cells.

(42) In the present invention, the treating of the peripheral blood mononuclear cells with the IFN-γ and the virus antigen peptide mixture upon the culture of the peripheral blood mononuclear cells may be carried out on day 0 of the culture, but the present invention is not limited thereto.

(43) In the present invention, the treating of the peripheral blood mononuclear cells with the anti-CD3 antibody and IL-2 may be carried out on day 1 of the culture. Specific culture conditions such as a treatment time of the cytokines and the anti-CD3 antibody, a temperature, and the like may vary depending on the type of virus antigens.

(44) The IFN-γ may be used at a concentration of 500 U/mL to 1,000 U/mL, for example, a concentration of 800 U/mL to 1000 U/mL, and the IL-2 may be used at a concentration of 200 U/mL to 1,000 U/mL, for example, a concentration of 200 U/mL to 800 U/mL.

(45) In the present invention, the “anti-CD3 antibody” refers to a protein that reacts specifically with CD3 antigens belonging to a group of molecules which are assembled with a T cell receptor (TCR) to form an antigen recognition complex, and the CD3 molecules have a longer intracellular area than TCR and play a role in transferring antigen recognition signals into the cells.

(46) The anti-CD3 antibody may be used at a concentration of 30 ng/mL to 150 ng/mL, for example, a concentration of 50 ng/mL to 100 ng/mL.

(47) When the peripheral blood mononuclear cells are treated with the cytokines and the target virus antigen peptide and cultured according to the present invention, the target virus-specific CIK cells may be obtained. The CIK cells thus obtained may be treated to treat a virus-mediated disease or a cancer.

(48) The virus-mediated disease may include diseases caused by viral infections or virus-induced cancers. The diseases caused by the viral infections are found in immunocompromised patients whose immune system is damaged through graft engineering when there are mismatches between human leukocyte antigens (HLAs), and may, for example, include diseases mediated by human latent viruses, such as a cytomegalovirus (CMV), Epstein-Barr virus (EBV), an adenovirus (ADV), BK virus (BKV), and the like. The virus-induced cancers may, for example, include EBV-induced Burkitt's lymphoma, post-transplant lymphoproliferative disease (PTLD), Hodgkin's lymphoma, NK/T cell lymphoma, diffuse large B-cell lymphoma (DLBCL), primary effusion lymphoma, and the like, but the present invention is not limited thereto.

(49) The induction and proliferation of the virus antigen-specific CIK cells according to the present invention may be carried out for 10 to 30 days, for example, 10 days to 25 days, 12 days to 25 days, 12 days to 21 days, 15 days to 21 days, 18 days to 21 days, or 20 days to 21 days.

(50) According to one exemplary embodiment, the method may include treating CMV antigen-specific CIK cells with IFN-γ and a peptide mixture on day 0 of the culture upon the culture of the CMV antigen-specific CIK cells, treating the CMV antigen-specific CIK cells with an anti-CD3 antibody and IL-2 on day 1 of the culture, and treating the CMV antigen-specific CIK cells with IL-2 every 2 to 3 days for 21 days. The whole culture process for the CIK cells is shown in FIG. 1.

(51) Also, the present invention provides a pharmaceutical composition including the virus antigen-specific CIK cells obtained according to the method.

(52) According to one exemplary embodiment of the present invention, CMV-pp65 antigen-specific T cells were measured for groups (examples) in which the mononuclear cells were cultured with a peptide mixture in the presence of IL-2, and groups (comparative examples) in which the mononuclear cells were cultured without a peptide mixture in the presence of IL-2. As a result, it was confirmed that the CMV-pp65 antigen-specific T cells were amplified only in the experimental groups in which the mononuclear cells were treated with the peptide mixture (FIG. 7).

(53) Therefore, the virus antigen-specific CIK cells obtained according to the method of the present invention may be used for prevention and treatment of a virus-mediated disease.

(54) Specifically, the virus-mediated disease may include diseases caused by EBV, such as post-transplant lymphoproliferative disease (PTLD), Burkitt's lymphoma, Hodgkin's lymphoma, NK/T cell lymphoma, diffuse large B-cell lymphoma (DLBCL), primary effusion lymphoma, and the like; include diseases caused by CMVs, such as pneumonia, retinitis, enteritis, myelosuppression, and the like; include diseases caused by ADVs, such as cystitis, pneumonia, hepatitis, and the like; and include diseases caused by BKV, such as renal dysfunction, hemorrhagic cystitis, and the like, but the present invention is not limited thereto.

(55) According to the present invention, the subject may be a human in need of prevention and/or treatment of the virus-mediated disease. The subject may include patients or normal persons as well.

(56) The pharmaceutical composition including the CIK cells according to the present invention may be formulated into a form in which the CIK cells are suspended at a proper concentration in an aqueous solution (for example, a phosphate buffer solution, an aqueous solution for conventional injections, and the like) containing proper ingredients, as necessary.

(57) The pharmaceutical composition according to the present invention may be administered in conventional ways through routes of intravenous, intraarterial, intraperitoneal, intramuscular, intrasternal administration, and the like.

(58) An effective amount of the CIK cells included in the pharmaceutical composition of the present invention refers to an amount required to achieve an effect of preventing or treating a virus-mediated disease. Therefore, the effective amount may be adjusted according to various factors including the type of a disease, the severity of a disease, the types and contents of other components included in the composition, and the age, weight, general health conditions, gender and diet of a patient, an administration time, a route of administration, a treatment period, drugs to be used in combination, and the like. For example, when administered once to several times a day, the CIK cells of the present invention may be administered, in the case of adults, at a dose of 1×10.sup.6 cells/kg to 1×10.sup.11 cells/kg, for example, a dose of 1×10.sup.6 cells/kg to 1×10.sup.8 cells/kg, but the present invention is not limited thereto.

(59) Accordingly, the present invention provides a method for treating a virus-mediated disease, which includes administering the virus antigen CIK cells to a subject in need thereof.

(60) Also, the present invention provides a kit for preparing the virus antigen-specific cytokine-induced killer cells (CIK cells), which includes IFN-γ, an anti-CD3 antibody, IL-2, and a virus antigen peptide mixture.

(61) According to the present invention, because a large amount of the CIK cells are induced and proliferated from a small amount of the peripheral blood mononuclear cells without using expensive equipment or various expensive cytokines, the efficiency and effectiveness of prevention and treatment of the virus-mediated disease using the CIK cells may be remarkably enhanced.

MODE FOR INVENTION

(62) These and other advantages and features of the present invention and methods of achieving them will become apparent from the following description of preferred embodiments, with reference to the accompanying drawings. However, the present invention is not limited to the following examples but may be embodied in various forms. That is, these examples are provided so that the disclosure of the present invention will be through and complete, and the scope of the invention will be fully disclosed to those of ordinary skill in the art to which this invention belongs. This invention should be defined based on the scope of the appended claims.

Example 1: Preparation of CMV Antigen-Specific Dual Activated T Cells

(63) Mononuclear cells were isolated from human peripheral blood by means of Ficoll density-gradient centrifugation, and then treated with 1,000 U/mL of an interferon gamma recombinant protein and 1 μg/mL of PepTivator (Miltenyi Biotec, Bergisch Gladbach, Germany) for cytomegalovirus (CMV) antigen pp65. After 4 days, the mononuclear cells were treated with 300 U/mL of an interleukin-2 (IL-2) recombinant protein, and cultured for 21 days to produce CMV antigen-specific dual activated T cells. IL-2 was added at a dose of 300 U/mL once every 2 to 3 days.

Comparative Example 1: Preparation of CIK Cells

(64) Mononuclear cells were isolated from human peripheral blood by means of Ficoll density-gradient centrifugation, and then treated with 1,000 U/mL of an interferon gamma recombinant protein. After 24 hours, the mononuclear cells were treated with 50 ng/mL of an anti-CD3 antibody and 300 U/mL of an interleukin-2 (IL-2) recombinant protein, and cultured for 21 days to produce normal CIK cells. IL-2 was added at a dose of 300 U/mL once every 2 to 3 days.

Experimental Example 1: Measurement of CMV Antigen-Specific T Cells and NK Cells

(65) Surfaces of the dual activated T cells and the CIK cells were stained with fluorescence-conjugated antibodies against CD3 and CD8, which are T cell markers of the dual activated T cells and the CIK cell induced in the example and comparative example, and CD56, which is an NK cell marker, and then measured using flow cytometry. To measure the CMV antigen-specific dual activated T cells, the cell surfaces were stained with a fluorescent antibody bound to an antigen pp65/MHC complex, and measured using flow cytometry. In this case, the T cells binding to the pp65/MHC complex may be referred to as the CMV antigen pp65-specific dual activated T cells. The results of measurements using flow cytometry are shown in FIG. 2, and the results of measuring the CMV antigen-specific T cells using a pentamer assay are shown in FIG. 3.

(66) As shown in FIGS. 2 and 3, it can be seen that a significantly high amount of the CMV-pp65 antigen-specific dual activated T cells was measured in the case of the experimental group in which the cells were treated with PepTivator, compared to the control in which the cells were not treated with PepTivator.

Experimental Example 2: Phenotypic Analysis of CMV-Specific Dual Activated T Cells

(67) The dual activated T cells and CIK cells produced in the example and comparative example were cultured, and the phenotypes of the cells were compared on day 21 of the culture. The results are shown in FIG. 4.

(68) As shown in FIG. 4, it can be seen that the two types of the cells had similar phenotypes regardless of the addition of PepTivator for pp65. It can be seen that the dual activated T cells and CIK cells cultured for 21 days were all CD3-positive T cells, most of which were CD8-positive CTL cells, and approximately 15% of the final product had an NK/T cell phenotype in which CD3 and CD56 were expressed at the same time.

Experimental Example 3: Measurement of CMV-Specific IFN-Gamma Secretion Ability

(69) The cells produced in the example and comparative example were collected, and stimulated with PepTivator for antigen pp65, and a level of IFN-gamma specifically secreted accordingly was then measured. The results are shown in FIG. 5.

(70) As shown in FIG. 5, it can be seen that both the dual activated T cells and CIK cells did not secrete IFN-gamma when the cells were not treated with PepTivator, but a secretion rate of IFN-gamma in the dual activated T cells was remarkably increased when the cells were treated with PepTivator.

Experimental Example 4: Analysis of Killing Effect on Tumor Cells

(71) The cells produced in the example and comparative example were collected, and co-cultured with chronic myeloid leukemia-derived K562 cells for 4 hours, and a killing effect on the K562 cells was then measured. The results are shown in FIG. 6.

(72) As shown in FIG. 6, it can be seen that all the dual activated T cells and CIK cells had an MHC-independent killing effect on the K562 cells, and the dual activated T cells treated with the pp65 PepTivator during the culture process had an improved killing effect, compared to the CIK cells.

Example 2: Preparation of CMV Antigen-Specific CIK Cells

(73) Mononuclear cells were isolated from human peripheral blood by means of Ficoll density-gradient centrifugation, and then treated with 1,000 U/mL of an interferon gamma recombinant protein and 1 μg/mL of PepTivator (Miltenyi Biotec, Bergisch Gladbach, Germany) for cytomegalovirus (CMV) antigen pp65. After 24 hours, the mononuclear cells were treated with 50 ng/mL of an anti-CD3 antibody and 300 U/mL of an interleukin-2 (IL-2) recombinant protein, and cultured for 21 days to produce CMV antigen-specific CIK cells. IL-2 was added at a dose of 300 U/mL once every 2 to 3 days. The culture process is schematically shown in FIG. 1.

Experimental Example 5: Measurement of CMV Antigen-Specific CIK Cells and NK Cells

(74) Surfaces of the CIK cells were stained with fluorescence-conjugated antibodies against CD3 and CD8, which are T cell markers of the CIK cells induced in Example 2 and Comparative Example 1, and CD56, which is an NK cell marker, and then measured using flow cytometry. To measure the CMV antigen-specific T cells, the cell surfaces were stained with a fluorescent antibody bound to an antigen pp65/MHC complex, and measured using flow cytometry. In this case, the T cells binding to the pp65/MHC complex may be referred to as the CMV antigen pp65-specific T cells. The results of measurements using flow cytometry are shown in FIG. 7.

(75) As shown in FIG. 7, it can be seen that a significantly high amount of the CMV-pp65 antigen-specific T cells were measured in the case of the experimental group in which the cells were treated with PepTivator, compared to the control in which the cells were not treated with PepTivator.

Experimental Example 6: Phenotypic Analysis of CMV-Specific CIK Cells

(76) The CIK cells produced in Example 2 and Comparative Example 1 were cultured, and the phenotypes of the CIK cells were compared on day 21 of the culture. The results are shown in FIG. 8.

(77) As shown in FIG. 8, it can be seen that the CIK cells had similar phenotypes regardless of the addition of PepTivator for pp65. It can be seen that all the CIK cells cultured for 21 days were CD3-positive T cells, most of which were CD8-positive CTL cells, and approximately 15% of the final product had an NK/T cell phenotype in which CD3 and CD56 were expressed at the same time.

Experimental Example 7: Measurement of Antigen Pp65-Specific Cells of CMV-Specific CIK Cells

(78) The CIK cells produced in Example 2 and Comparative Example 1 were collected to measure the antigen pp65-specific T cells using a pentamer assay. The results are shown in FIG. 9.

(79) As shown in FIG. 9, it was observed that a trace (0.1% or less) of CMV-specific T cells were present in peripheral blood prior to culturing. That is, it can be seen that such CMV-specific T cells were able to be amplified during the culture process. As shown in FIG. 9, it can be seen that there was little change in amplification of the CMV-specific T cells in the case of the control in which the T cells were not treated with the PepTivator, but the CMV-specific T cells were amplified approximately 9-fold in the experimental groups in which the T cells were treated with the PepTivator, compared to the control.