WO2013132256A1 - Compositions and methods for treating viral-mediated infection and disease in immunocompromised individuals - Google Patents

Abstract

Described herein is a method of treating viral infection and resulting diseases in immunocompromised patients, the method comprising administering to the patient a cellular composition comprising activated NK cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low.

Description

COMPOSITIONS AND METHODS FOR TREATING VIRAL-MEDIATED INFECTION AND DISEASE IN IMMUNOCOMPROMISED INDIVIDUALS

FIELD OF INVENTION

[0001] Activated natural killer cell compositions are provided for treating acute or chronic viral infections and diseases resulting therefrom in immunocompromised individuals.

BACKGROUND OF THE INVENTION

[0002] Viruses are biological agents that replicate their genomic material (either DNA or RNA) using the cellular machinery of other organisms. Infection with a virus can be acute or chronic and can result in disease. Examples of diseases caused by viral infections include smallpox, herpes, hepatitis, cancer (e.g., hepatocellularcarcinoma resulting from infection with hepatitis C virus, cervical cancer arising from infection with papilloma virus, nasopharyngeal cancer arising from infection from Epstein Barr virus, etc.), measles, flu, encephalitis, acquired immunodeficiency syndrome (AIDS) and severe acute respiratory syndrome (SARS).

[0003] Certain types of viral infections can lead to substantial morbidity and mortality in immunocompromised individuals in particular, e.g. patients with weakened immune systems due to AIDS, organ transplantation, bone marrow transplantation, chemotherapy, or other medicines that suppress the immune system. For example, cytomegalovirus (CMV) infection in such immunocompromised patients can result in viral attack on specific organs, leading to blindness or visual impairment in the eye, pneumonia and/or hypoxia in the lungs, diarrhea and/or ulcerations in the gastrointenstinal tract, and encephalitis and/or seizures in the brain. Likewise, reactivation of a human herpesvirus 6 (HHV-6) infection in immunosuppressed individuals can lead to graft rejection, often in consort with other betaherpesviridae. Also in HIV/AIDS, HHV-6 re-activations can cause disseminated infections leading to end organ disease and death.

[0004] Similarly, hematopoietic stem cell transplant (HSCT) recipients as well as solid organ transplant (SOT) recipients are at significant risk of developing post-transplant

lymphoproliferative disorder (PTLD) upon infection by Epstein-Barr virus (EBV). In immunocompetent patients, EBV causes infectious mononucleosis, characterized by a proliferation of B-lymphocytes that is usually kept in check by suppressor T cells.

Unfortunately, however, conventional immunosuppressants used in organ transplantation {e.g. calcineurin inhibitors such as tacrolimus and cyclosporine) inhibit T cell function and can prevent control of the B cell proliferation, resulting in uncontrolled lymphoproliferation. For immunocompromised patients in particular, therefore, there is a significant unmet need for effective anti-viral therapies. Indeed, even a ubiquitous adenovirus can cause disseminated infection and death in such patients. (Pham et al (2003) Am. J. Clin. Pathol. 120:575-583)

[0005] Strategies for treating viral infections often focus on ways to enhance immunity. For instance, the most common method for treating viral infection involves prophylactic vaccines that induce immune-based memory responses. In response to viral infection or prophylactic vaccination, CD4+ T cells become activated and initiate a T-helper type I (TH1) response and the subsequent cascade required for cell-mediated immunity. That is, following their expansion by specific growth factors like IL-2, T helper cells stimulate killer CD8+ T-cells to kill virally infected host cells in an antigen specific manner. Additionally, B cells may produce antibodies specific for the viral antigens. Unfortunately, however, the antigen specificity of these vaccination approaches limits their usefulness since the protection provided is specific, and with viruses constantly mutating to yield new strains a vaccine efficacious against a certain viral strain is unlikely to provide protection against a new strain. Moreover, such prophylactic approaches are of little value in cases of acute infection and/or in immunocompromised patients incapable of mounting a robust T cell response due to disease impact or ongoing pharmacologic therapy.

[0006] A variety of adoptive T cell strategies have been evaluated as potential solutions for this class of patients. With this approach, allogeneic or autologous viral-specific cytotoxic T lymphocytes (CTLs) are prepared ex vivo and administered to immunocompromised patients as a means for reconstituting a virus-specific immune response in vivo. (Savoldo et al. (2006) Blood 108:2942-2949 (EBV-specific CTLs); Ulrike et al. (2013) Blood 121 :207-18 (human herpesvirus 6 (HHV6) CTLs). Unfortunately, however, although somewhat helpful as a prophylactic therapy in the context of HSCT, this approach has not been as useful with SOT, and long-term viral- specific immunity is not sustained in patients who continue to receive immunosuppression. (Heslop (2005) Hematology 260-266). Moreover, the generation of autologous viral specific CTLs is also time- and labor-intensive, requires specialized facilities, and has yet to progress beyond investigational trials. Accordingly, there remains a significant and unmet need for improved therapies in the treatment of viral infections and resulting diseases in

immunocompromised patients. SUMMARY OF THE INVENTION

[0007] The present invention addresses the aforementioned problems in the art with more effective, less toxic and more commercially practicable methods for treating viral infections and the diseases resulting therefrom. Cellular compositions comprising activated natural killer (NK) cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low are shown herein to provide protection and have remarkable efficacy against infection from several different viruses. Furthermore, the cellular compositions provided herein may be administered to patients in need without regard to allogeneic boundaries, including immunocompromised patients, thereby providing a universal cellular therapy for viral infections with more widespread applicability and manageable toxicity.

[0008] In one aspect, methods for treating a patient suffering from a viral infection are provided, comprising administering to an infected patient in need thereof a cellular composition comprising activated NK cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low. The subject activated NK cells may be autologous or allogeneic to the patient, or may include a mixture of NK cells that are allogeneic to each other. The NK cells may also be preserved, e.g., by cryopreservation, refrigeration and the like, prior to administration. In one embodiment, the composition is co-administered with one or more inactivated virus antigens. In preferred embodiments, the patient is infected with, e.g., a herpes virus or an adenovirus.

[0009] The subject methods find particular use in the treatment of immunocompromised individuals, i.e. those having reduced immune function due to the adverse immunological impact of an existing disease, age and/or ongoing pharmacologic therapy, e.g. patients with weakened immune systems due to HIV/AIDS, solid organ transplantation (SOT), hematopoietic stem cell transplantation (HSCT), chemotherapy, or other medicines that suppress the immune system. In one embodiment, the patient is an HSCT or SOT recipient. In another embodiment, the patient is an AIDS patient. In another embodiment, the patient is undergoing chemotherapy and/or radiotherapy. As noted above, acute or chronic viral infections in such patients can lead to organ damage, lymphoproliferative disorders and even death.

[0010] The subject virus may be a DNA virus, e.g.₃ from Herpesviridae, Adenoviridae, Hepadnaviridae,Parvoviridae, and the like, or an RNA virus, e.g., from Picornaviridae, Paramyxoviridae, Flaviviridae, Hepviridae and the like. In preferred embodiments, the virus is a herpesvirus, an adenovirus, a retrovirus, or combinations thereof. In one embodiment, the virus is a herpesvirus selected from the group consisting of herpes simplex type I (HSV-I) virus, herpes simplex type II (HSV-II) virus, human herpesvirus 6 (HHV-6), varicella zoster virus (VZV), cytomegalovirus (CMV), and Epstein-Barr virus (EBV). In another embodiment, the virus is an adenovirus. In a further embodiment, the virus is a retrovirus selected from the group consisting of HIV-I and HIV-II.

[0011] In one embodiment, the present invention provides a composition comprising activated Natural Killer ("NK") cells having the phenotype CD69+CD25+CD15+CD16^low for use in treating a viral infection. In another embodiment, the present invention provides the use of activated Natural Killer ("NK") cells having the phenotype CD69+CD25+CD15+CD16^low in the manufacture of a cellular composition for treating a viral infection.

[0012] In a further embodiment, the subject NK cells are administered simultaneously with or sequentially (e.g., prior to or subsequent to) another treatment for the underlying viral infection and/or for the disease resulting therefrom (e.g., surgical resection of a tumor, wart, etc., radiation therapy, chemotherapy, immunotherapy, supportive therapy, etc.). In one embodiment, supportive therapy comprises the co-administration of one or more therapeutic agents selected from the group consisting of a chemotherapeutic agent, an immunotherapeutic agent, a painkiller, a diuretic, an antidiuretic, an antiviral, an antibiotic, a nutritional supplement, an anti- anemia therapeutic, a blood clotting therapeutic, a bone therapeutic, a psychological therapeutic, and combinations thereof.

BRIEF DESCRIPTION OF THE FIGURES

[0013] Figure 1 illustrates the gamma interferon secretion levels of primed CD69⁺CD25⁺ CDl5⁺CD16^low NK cells from normal healthy donors (n=24) and from patients in the first 6 months post allogeneic stem cell transplant (n=34) in response to CMV-infected target cells, in both CMV-negative and CMV-positive individuals..

[0014] Figure 2 shows the lytic capability of NK cells from CMV-naive donors against infected MRC5 target cells with (red bars) and without priming (pink bars)at an effector to target cell ratio of 5:1 . The primed CD69⁺CD25⁺CD15⁺ CD16^low K cells were also tested for their ability to lyse non-infected MRC5 (open bars). DETAILED DESCRIPTION

[0015] Described herein is a method of treating, e.g., ablating, curing, inhibiting, reducing, or delaying the onset of a viral infection or symptoms thereof, comprising administering a cellular composition comprising activated NK cells having durable anti-viral activity. In preferred embodiments, cellular compositions comprising activated CD69⁺CD25⁺

CD15⁺CD16^l0W NK cells are employed either alone or in combination with other conventional anti-viral therapies.

Activated Natural Killer Cells

[0016] NK cells are a subset of peripheral blood lymphocytes defined by the expression of CD56 or CD16 and the absence of the T cell receptor (CD3). They recognize and kill

transformed cell lines, without priming in an MHC-unrestricted fashion.

[0017] NK cells represent the predominant lymphoid cell in the peripheral blood for many months after allogeneic or autologous stem cell transplant and they have a primary role in immunity to pathogens during this period (Reittie et al (1989) Blood 73: 1351-1358; Lowdell et al (1998) Bone Marrow Transplant 21: 679-686). The role of NK cells in engraftment, graft- versus-host disease, anti-leukemia activity and post-transplant infection is reviewed in Lowdell (2003) Transfusion Medicine 13:399-404.

[0018] Human NK cells mediate the lysis of tumor cells and virus-infected cells via natural cytotoxicity and antibody-dependent cellular cytotoxicity (ADCC).

[0019] Human NK are controlled by positive and negative cytolytic signals.

[0020] Inhibitory receptors fall into two groups, those of the Ig-superfamily called Killer Immunoglobulin-like Receptors (KIRs) and those of the lectin family, the KG2, which form dimers with CD94 at the cell surface. KIRs have a 2- or 3-domain extracellular structure and bind to HLA-A, -B or -C. The NKG2/CD94 complexes ligate HLA-E.

[0021] Inhibitory KIRs have up to 4 intracellular domains which contain ITIMs and the best characterized are K1R2DL1, KIR2DL2 and KIR2DL3 which are known to bind HLA-C molecules. KIR2DL2 and KIR2DL3 bind the group 1 HLA-C alleles while K1R2DL1 binds to group 2 alleles. Certain leukemia/lymphoma cells express both group 1 and 2 HLA-C alleles and are known to be resistant to NK-mediated cell lysis.

[0022] With regards to positive activating signals, ADCC is thought to be mediated via CD 16, and a number of triggering receptors responsible for natural cytotoxicity have been identified, including CD2, CD38, CD69, NKRP-1, CD40, B7-2, NK-TR, NKp46, NKp30 and NKp44. In addition, several KIR molecules with short intracytoplasmic tails are also

stimulatory. These KIRs (KIR2DS1, KIR2DS2 and KTR2DS4) are known to bind to HLA-C; their extracellular domains being identical to their related inhibitory KIRs. The activating KIRs lack the ITIMs and instead associate with DAP 12 leading to NK cell activation. The mechanism of control of expression of inhibitory versus activating KTRs remains unknown.

[0023] NK cell compositions suitable for use in the invention will generally include an activated NK cell population that overexpresses CD69 and/or CD25 in comparison to resting NK cells. In preferred embodiments, the subject NK cell population will also express CD 15, and lose expression of CD16. See, e.g., U.S. Patent Publication No. 20080166326 and U.S.

Provisional Application No. 61/224,771, each of which is incorporated by reference herein in its entirety. These activated NK cells exhibit durable lytic (e.g., anti-viral) activity in the absence of continued or repeated contact with an activating agent.

[0024] Certain tumor cells, e.g., CD15⁺ LAK-resistant tumor cells, have the capacity to activate NK cells to exhibit such durable activity. These activated NK cells are capable of lysing "NK-resistant" tumor cell (i.e. tumor cells resistant to lysis with unstimulated NK cells) and virally infected cells. Furthermore, these activated NK cells retain their activated state even after preservation and/or in the absence of continued contact with the activating tumor cells, and thus, do not require reactivation after preservation and before administration. CD15⁺ LAK-resistant tumor cells capable of activating NK cells such that the NK cells retain their activated state after preservation in the absence of the activating tumor cells include CTV-1 cells, MV4-11 cells, SEM cells, sublines thereof, or combinations thereof. In preferred embodiments, the activating agent is a CTV-1 cell, which is commercially available, for example from the Deutsche

Sammlung Mikroorganismen Zellkulturen GmbH (DSMZ). In one embodiment, the activating cell is obtained from a CTV-1 subline. In another embodiment, the activating agent is a MV4-11 cell. This cell line is also commercially available, e.g., from the American Type Culture Collection (ATCC Number CRL-9591) (Lange, et al. (1987) Blood 70:192-199; Santoli, et al. (1987) J Immunol. 139:3348-3354). In another embodiment, the activating agent is an SEM cell. This cell line is also commerically available, e.g., from DSMZ (DSMZ No. ACC456) (Greil, et al. (1994) Br. J. Haemotol. 86:275-83; Reichel, et al. (1998) Oncogene 17:3035-44; Drexler, et al. (2004) Leukemia 18:227-232).

[0025] "CD 15" as used herein refers to the ligand for CD2 that is structurally associated with CD 15 and that is essential to prime resting NK cells. As used herein, "CD 15" may also refer to the product of GeneID:2526, the official name of which is FUT4, and of which is also known as ELFT, FCT3A, FUTIV, and FUC-TIV. The product of GeneID:2526 transfers fucose to N- acetyllactosamine polysaccharides to generate fucosylated carbohydrate structures. It also catalyzes the synthesis of non-sialylated antigen, Lewis x (CD 15). Accordingly, a cell that is "CD15⁺" expresses a ligand for CD2

[0026] The activating agent may consist of or comprise a cell lysate preparation. For example, a cell lysate preparation may be made by standard fixation techniques (such as using paraformaldehyde). Fixation has the advantage that the preparation is stabilized, has a much longer "shelf-life" and is easier to store. A suitable cell lysate preparation may also be made by repeated cycles of freeze-thawing, in combination with DNAse treatment. Such a preparation may be considered to have increased safety as it reduces the likelihood of contamination associated with prions etc.

[0027] In cases where the activating agent is a tumor cell, e.g., a CD15+ LAK-resistant tumor cell, e.g., CTV-1, MV4-11, SEM, sublines thereof, or a combination thereof, the activating agent may be irradiated prior to use, by standard techniques. Lysate preparations have the advantage over preparations comprising intact tumor cells as they avoid the risk of transferring potentially malignant tumor cells to the patient.

[0028] The activating agent may be or comprise an entity (such as a protein) derivable from a tumor cell. The activating agent may, for example, comprise a recombinant protein. The protein may be derivable from, e.g., CTV-1 cells, MV4-11 cells, SEM cells, sublines thereof, or a combination thereof. Additionally, the activating agent may be surface-bound (e.g., to a glass or plastic vial or tube or a bag (e.g., sealed infusion bags, ampoules or vials), freeze-dried, and/or lyophilized according to well-known methods, and may be used to activate an NK cell preparation as described herein in its surface-bound, freeze-dried, and/or lyophilized form.

[0029] The activating agent and the NK cell preparation may be brought together by, for example, co-culturing (where intact tumor cells are used). The "activation time" will depend on the nature of the cell preparation(s) and the contact conditions, but may commonly be 4-24 hours, e.g., 8 hours.

[0030] Pre-incubation of NK cells with an activating agent as described herein, preferably a CD 15+ LAK-resistant tumor cell (such as CTV-1 cells), causes rapid upregulation of CD69 on the NK cells. Virally infected cells that are lysable by activated NK cells as described herein may express CD69 ligand (CD69L), and this expression may absent from cells which are not lysed (such as B cells). The presence of recombinant CD69 may inhibits the capacity of activated NK cells to lyse virally infected cells.

[0031] In addition to CD69, the IL-2 receptor, CD25, is also upregulated on NK cells after contact with CTV-1. In contrast, CD25 is downregulated in conjunction with NK activation by IL-2. Accordingly, in another embodiment the activating agents contemplated for use herein also produce an activated NK cell population that is CD69+ and/or CD25+.

[0032] In a further embodiment, contact with CTV-1 results in the transfer of CD 15 to the activated NK cells (e.g., activated NK cells gain CD 15), and the reduction of CD 16 expression from the NK cell after activation. Accordingly, in further embodiments, the activating agents contemplated for use herein also produce an activated NK cell population that is also CD 15+ and/or CD16^low.

[0033] Prior to administration, the CD69⁺CD25⁺ CD 15⁺CD 16^low NK cells contemplated for use herein may be preserved. The terms "preservation" and "preserved" as used herein refer generally to the continued maintenance of a cellular composition in viable form, and the subject NK cells may be preserved according to any well known method, see, e.g., U.S. Patent Nos. 7,270,946; 7150,991; 6,921,633; Kanias and Acker (2006) Cell Preservation Technology 4:253- 277; etc., each of which is incorporated herein in its entirety by reference. In one embodiment, NK cells are preserved by a method selected from the group consisting of cell culture, refrigeration and cryopreservation. In a preferred embodiment, the preserved population described herein is preserved by cryopreservation. [0034] The cells may be preserved in any cryoprotectant known in the art. For example, the cryoprotectant can be dimethyl sulfoxide (DMSO) or glycerol. In some embodiments, the freezing medium comprises DMSO from about 5-10%, 10-90% serum albumin, and 50-90% culture medium. In some embodiments, the cryopreservation medium will comprise DMSO about 7.5%, about 42.5% serum albumin, and about 50% culture medium. The cells may be preserved in any stabilizer known in the art. For example, the stabilizer may be methyl cellulose or serum. Other additives useful for preserving cells include, by way of example and not limitation, disaccharides such as trehalose (Scheinkonig, C. et al., Bone Marrow Transplant. 34(6):531-6 (2004)), or a plasma volume expander, such as hetastarch (i.e., hydroxyethyl starch). In some embodiments, isotonic buffer solutions, such as phosphate-buffered saline, may be used. An exemplary cryopreservative composition has cell-culture medium with 4% HSA, 7.5% dimethyl sulfoxide (DMSO), and 2% hetastarch. Other compositions and methods for cryopreservation are well known and described in the art (see, e.g., Broxmeyer, H. E. et al., Proc. Natl Acad. Sci. USA 100(2):645-650 (2003)).

[0035] Prior to freezing, the cells may be portioned into several separate containers to create a cell bank. The cells may be preserved, for example, in a glass or plastic vial or tube or a bag. When the cells are needed for future use, a portion of the cryopreserved cells (from one or more containers) may be selected from the cell bank, thawed and used.

[0036] In one embodiment, the NK cells may be preserved in a cryocyte bag (e.g., the NK cells that exhibit durable activity may be frozen a cell density of 1-2 X 107 cells/mL in a 20 mL bag) in a medium (e.g., a medium comprising X-vivo 10 (VWR, West Chester, PA), dimethyl sulfoxide (DMSO), and human serum albumin (HSA) at a ratio of 45(X vivo

10): 10(DMSO):45(HSA)) and vacuum-wrapped in nitrogen vapor at or below -135°C in a monitored nitrogen refrigerator.

Diseases

[0037] The methods described herein are directed toward the treatment of an infection by a virus and/or the disease caused by the underlying infection, preferably as occurring in

immunocompromised patients. Infection or diseases that may be treated as described herein include, but are not limited to, those caused by herpesviruses, adenoviruses and retroviruses. [0038] In one embodiment the infection or disease that is treated by the methods described herein is caused by a herpes virus. At least five of the human herpes viruses, including herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), cytomegalovirus (CMV), Epstein-Barr virus (EBV), and varicella zoster virus (VZV) are known to infect and cause lesions in tissues of certain infected individuals. Infection with the herpes virus is categorized into one of several distinct disorders based on the site of infection. For instance, together, these viruses are the leading cause of infectious blindness in the developed world. Oral herpes, the visible symptoms of which are referred to as cold sores, infects the face and mouth. Infection of the genitals, commonly known as, genital herpes is another common form of herpes. Other disorders such as herpetic whitlow, herpes gladiatorum, ocular herpes (keratitis), cerebral herpes infection encephalitis, Mollaret's meningitis, and neonatal herpes are all caused by herpes simplex viruses. Herpes simplex is most easily transmitted by direct contact with a lesion or the body fluid of an infected individual. Transmission may also occur through skin-to-skin contact during periods of asymptomatic shedding.

[0039] HSV-1 primarily infects the oral cavity, while HSV-2 primarily infects genital sites. However, any area of the body, including the eye, skin and brain, can be infected with either type of HSV. Generally, HSV is transmitted to a non-infected individual by direct contact with the infected site of the infected individual.

[0040] VZV, which is transmitted by the respiratory route, is the cause of chickenpox, a disease which is characterized by a maculopapular rash on the skin of the infected individual. As the clinical infection resolves, the virus enters a state of latency in the ganglia, only to reoccur in some individuals as herpes zoster or "shingles". The reoccurring skin lesions remain closely associated with the dermatome, causing intense pain and itching in the afflicted individual.

Although usually a relatively benign and self-limiting illness, varicella can be much more severe when it occurs in immunocompromised patients, and in pediatric patients in particular, as these individuals are at much higher risk of pneumonia and disseminated disease with visceral involvement in spite of antiviral therapy. Accordingly, constant vigilance is necessary by such patients to avoid contact with infected individuals.

[0041] CMV is more ubiquitous and may be transmitted in bodily fluids. The exact site of latency of CMV has not been precisely identified, but is thought to be leukocytes of the infected host. Although CMV does not cause vesicular lesions, it does cause a rash. Human CMVs (HCMV) are a group of related herpes viruses. After a primary infection, the viruses remain in the body in a latent state. Physical or psychic stress can cause reactivation of latent HCMV. Similar to EBV infections, the cell-mediated immune response plays an important role in the control and defense against the HCMV infection. In adults having a functional immune system, the infection has an uneventful course, at most showing non-specific symptoms, such as exhaustion and a slight increase in body temperature. Infections in young children are often expressed as severe respiratory infection, and in older children and adults, they are expressed as anicteric hepatitis and mononucleosis. All of these problems are of course greatly exacerbated in immunocompromised patients, with pulmonary diseases and retinitis also associated with HCMV infections.

[0042] Epstein-Barr virus, frequently referred to as EBV, is a member of the herpesvirus family and one of the most common human viruses. The virus occurs worldwide, and most people become infected with EBV sometime during their lives. Many children become infected with EBV, and these infections usually cause no symptoms or are indistinguishable from the other mild, brief illnesses of childhood. When infection with EBV occurs during adolescence or young adulthood, it can cause infectious mononucleosis. EBV also establishes a lifelong dormant infection in some cells of the body's immune system. A late event in a very few carriers of this virus is the emergence of Burkitt's lymphoma and nasopharyngeal carcinoma, two rare cancers that are not normally found in the United States. EBV appears to play an important role in these malignancies, but is probably not the sole cause of disease. More significantly, as noted above, such infections can lead to lymphoproliferative disorders in immunocomprised patients, including in particular those on lifelong immunosuppressive therapy after organ transplantation.

[0043] No treatment that can eradicate herpes virus from the body currently exists. Antiviral medications can reduce the frequency, duration, and severity of outbreaks. Antiviral drugs also reduce asymptomatic shedding. Antivirals used against herpes viruses work by interfering with viral replication, effectively slowing the replication rate of the virus and providing a greater opportunity for the immune response to intervene. Antiviral medicaments for controlling herpes simplex outbreaks, include aciclovir (Zovirax), valaciclovir (Valtrex), famciclovir (Famvir), and penciclovir. Topical lotions, gels and creams for application to the skin include Docosanol (Avanir Pharmaceuticals), Tromantadine, and Zilactin.. [0044] Various substances are employed for treatment against HCMV. For example, Foscarnet is an antiviral substance which exhibits selective activity, as established in cell cultures, against human herpes viruses, such as herpes simplex, VZV, EBV and CMV, as well as hepatitis viruses. The antiviral activity is based on the inhibition of viral enzymes, such as DNA polymerases and reverse transcriptases. The activated NK cell compositions as described herein may be used alone in the treatment of an infection with a herpes virus, and may act to eradicate latent viruses and/or lyse actively infected cells. Furthermore, the activated NK compositions as described herein may be used in combination with any other known treatment for infection with a herpes virus and/or the disease resulting therefrom.

[0045] The methods described herein may also find advantageous use in the treatment of an infection by RNA viruses, including but not limited to retroviruses such as human

immunodeficiency virus type I (HIV-I), human immunodeficiency virus type II (HIV-II), human T-cell lymphotropic virus type I (HTLV-I), and human T-cell lymphotropic virus type II (HTLV- II). In another embodiment of the invention, the infection or disease that is treated by the methods of the present invention is caused by a human immunodeficiency virus (human immunodeficiency virus type I (HIV-I), or human immunodeficiency virus type II (HIV-II); e.g., the related disease is acquired immunodeficiency syndrome (AIDS).

[0046] According to an embodiment of the invention, the methods described herein are useful in treating AIDS or HIV infections, including in particular secondary or combination viral infections. HIV stands for human immunodeficiency virus, the virus that presumably causes AIDS. HIV is different from many other viruses because it attacks the immune system, and specifically white blood cell (T cells or CD4 cells) that are important for the immune system to fight disease. In a specific embodiment, treatment is by administering into a subject infected with HIV or a subject at risk for HIV infection a cellular composition comprising activated Natural Killer (NK) cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low.

[0047] In another embodiment, the cellular composition comprising activated NK cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low may be administered in conjunction with, or supplementary to, the customary treatments of AIDS or HIV infection. Historically, the recognized treatment for HIV infection is nucleoside analogs, inhibitors of HIV reverse transcriptase (RT). Intervention with these antiretroviral agents has led to a decline in the number of reported AIDS cases and has been shown to decrease morbidity and mortality associated with advanced AIDS. Prolonged treatment with these reverse transcriptase inhibitors eventually leads to the emergence of viral strains resistant to their antiviral effects. Recently, inhibitors of HIV protease have emerged as a new class of HIV chemotherapy. HIV protease is an essential enzyme for viral infectivity and replication. Protease inhibitors have exhibited greater potency against HIV in vitro than nucleoside analogs targeting HIV-1 RT. Inhibition of HIV protease disrupts the creation of mature, infectious virus particles from chronically infected cells. This enzyme has become a viable target for therapeutic intervention and a candidate for combination therapy.

[0048] Knowledge of the structure of the HIV protease also has led to the development of novel inhibitors, such as saquinovir, ritonavir, indinivir and nelfmavir. NNRTIs (non-nucleoside reverse transcriptase inhibitors) have recently gained an increasingly important role in the therapy of HIV infection. Several NNRTIs have proceeded onto clinical development (i.e., tivirapine, loviride, MKC-422, HBY-097, DMP 266). Nevirapine and delaviridine have already been authorized for clinical use. Every step in the life cycle of HIV replication is a potential target for drug development.

[0049] Many of the antiretroviral drugs currently used in chemotherapy either are derived directly from natural products, or are synthetics based on a natural product model. The rationale behind the inclusion of deoxynucleoside as a natural based antiviral drugs originated in a series of publications dating back as early as 1950, wherein the discovery and isolation of thymine pentofuranoside from the air-dried sponges (Cryptotethia crypta) of the Bahamas was reported. A significant number of nucleosides were made with regular bases but modified sugars, or both acyclic and cyclic derivatives, including AZT and acyclovir. The natural spongy-derived product led to the first generation, and subsequent second—third generations of nucleosides (AZT, DDI, DDC, D4T, 3TC) antivirals specific inhibitors of HIV-1 RT.

[0050] A number of non-nucleoside agents (NNRTIs) have been discovered from natural products that inhibit RT allosterically. NNRTIs have considerable structural diversity but share certain common characteristics in their inhibitory profiles. Among NNRTIs isolated from natural products include: calanoid A from calophylum langirum; Triterpines from Maporonea African a. There are publications on natural HIV integrase inhibitors from the marine ascidian alkaloids, the lamellarin. The activated NK cell compositions as described herein may be used in combination with any other known treatment for HIV infection and/or AIDS.

[0051] A cellular composition comprising activated NK cells having the phenotype

CD69⁺CD25⁺CD15⁺CD16^low may also be used in treating liver specific diseases, in particular liver disease where viral infection is in part an etiologic agent. In particular the cellular compositions described herein may be used to treat a mammal with an infection with a virus selected from the group consisting of hepatitis A, hepatitis B, hepatitis C.

[0052] Hepatitis A is caused by the hepatitis A virus (HA V) and produces a self-limited disease that does not result in chronic infection or chronic liver disease. HAV infection is primarily transmitted by the fecal-oral route, by either person-to-person contact or through consumption of contaminated food or water. Hepatitis B is a caused by hepatitis B virus (HB V) and can cause acute illness, leading to chronic or lifelong infection, cirrhosis (scarring) of the liver, liver cancer, liver failure, and death. HB V is transmitted through percutaneous (puncture through the skin) or mucosal contact with infectious blood or body fluids. Hepatitis C is caused by the hepatitis C virus (HCV) that sometimes results in an acute illness, but most often becomes a silent, chronic infection that can lead to cirrhosis, liver failure, liver cancer, and death. Chronic HCV infection develops in a majority of HCV-infected persons. HCV is spread by contact with the blood of an infected person.

[0053] Presently, the most effective HCV therapy employs a combination of alpha-interferon and RIBAVIRIN®. Recent clinical results demonstrate that pegylated alpha-interferon is superior to unmodified alpha-interferon as monotherapy. However, even with experimental therapeutic regimens involving combinations of pegylated alpha-interferon and ribavirin, a substantial fraction of patients do not have a sustained reduction in viral load.

[0054] When liver disease is inflammatory and continuing for at least six months, it is generally considered chronic hepatitis. Hepatitis C virus (HCV) patients actively infected will be positive for HCV-RNA in their blood, which is detectable by reverse transcritptase/polymerase chain reaction (RT-PCR) assays. The methods of the present invention will slow the progression of the liver disease. Clinically, diagnostic tests for HCV include serologic assays for antibodies and molecular tests for viral particles. Enzyme immunoassays are available (Vrielink et al.

(1997) Transfusion 37:845-849), but may require confirmation using additional tests such as an immunoblot assay (Pawlotsky et al. (1998) Hepatology 27:1700-1702). Qualitative and quantitative assays generally use polymerase chain reaction techniques, and are preferred for assessing viremia and treatment response (Poynard et al. (1998) Lancet 352:1426-1432;

McHutchinson et al. (1998) N. Engl. J. Med. 339:1485-1492). Several commercial tests are available, such as, quantitative RT-PCR (Amplicor HCV Monitor.TM., Roche Molecular Systems, Branchburg, N.J.) and a branched DNA (deoxyribonucleic acid) signal amplification assay (Quantiplex.TM. HCV RNA Assay [bDNA], Chiron Corp., Emeryville, Calif.). A nonspecific laboratory test for liver inflammation or necrosis measures alanine aminotransferase level (ALT) and is inexpensive and readily available (National Institutes of Health Consensus Development Conference Panel (1997) Hepatology 26 (Suppl. 1):2S-10S). Histologic evaluation of liver biopsy is generally considered the most accurate means for determining hepatitis progression (Yano et al. (1996) Hepatology 23:1334-1340). For a review of clinical tests for HCV, see, Lauer et al. (2001) N. Engl. J. Med. 345:41-52.

[0055] There are several in vivo models for testing HBV and HCV that are known to those skilled in art. For example, the effects of a cellular composition comprising activated NK cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^lowon mammals infected with HBV can be assessed using a woodchuck model. Briefly, woodchucks chronically infected with woodchuck hepatitis virus (WHV) develop hepatitis and hepatocellular carcinoma that is similar to disease in humans chronically infected with HBV. The model has been used for the preclinical assessment of antiviral activity. A chronically infected WHV strain has been established and neonates are inoculated with serum to provide animals for studying the effects of certain compounds using this model. (For a review, see, Tannant et al.(2001) ILAR J. 42:89-102). Chimpanzees may also be used to evaluate the effect of activated NK cells having the phenotype

CD69⁺CD25⁺CD15⁺CD16^low on HBV infected mammals. Using chimpanzees, characterization of HBV was made and these studies demonstrated that the chimpanzee disease was remarkably similar to the disease in humans (Barker et al. (1975) J. Infect. Dis. 132:451-458 and Tabor et al. (1983) J. Infect. Dis. 147:531-534). The chimpanzee model has been used in evaluating vaccines (Prince et al. (1997) In: Vaccines 97 Cold Spring Harbor Laboratory Press). Therapies for HIV are routinely tested using non-human primates infected with simian immunodeficiency viruses (for a review, see, Hirsch et al. (2000) Adv. Pharmcol. 49:437-477 and athanson et al. (1999) AIDS 13:S13-S120). For a review of use of non-human primates in HIV, hepatitis, malaria, respiratory syncytial virus, and other diseases, see, Sibal et al. (2001) ILAR J. 42:74-84.

[0056] In another embodiment of the invention, the infection or disease that is treated by the methods of the present invention is caused by a human papilloma virus (HPV). HPVs establish productive infections only in keratinocytes of the skin or mucous membranes. While the majority of the known types of HPV cause no symptoms in most people, some types can cause warts (verrucae), while others can lead to cancers of the cervix, vulva, vagina, penis, oropharynx and anus. HPV may also cause epidermodysplasia verruciformis in immunocompromised individuals. The virus, unchecked by the immune system, causes the overproduction of keratin by skin cells, resulting in lesions resembling warts or cutaneous horns

[0057] Other examples of the types of viral infections for which activated NK cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low may be used in treating include, but are not limited to pox viruses such as Variola (small pox) virus; Orthomyxoviruses (e.g., Influenza viruses); Paramyxoviruses (e.g., Measles virus); Rabies virus; Coronaviruses (which may cause Severe Acute Respiratory Syndrome (SARS)); Rhinovirus, Respiratory Syncytial Virus, Norovirus, West Nile Virus, Yellow Fever, Rift Vallley Virus, Lassa Fever Virus, Ebola Virus,

Lymphocytic Choriomeningitis Virus, which replicates in tissues including liver, and the like.

[0058] Moreover, examples of the types of diseases for which a cellular composition comprising activated NK cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low may be used include, but are not limited to: acquired immunodeficiency syndrome (AIDS); hepatitis;

gastroenteritis; hemorrhagic diseases; enteritis; carditis; encephalitis; paralysis; bronchiolitis; upper and lower respiratory disease; respiratory papillomatosis; arthritis; disseminated disease, hepatocellular carcinoma resulting from, e.g., chronic Hepatitis C infection, severe acute respiratory syndrome (SARS), glioblastoma multiforme associated with CMV infection, cervical carcinoma associated with HPV infection, PTLD, Burkitt's lymphoma or nasopharyngeal carcinoma resulting from, e.g., EBV infection, etc. In addition, viral disease in other tissues may be treated with a cellular composition comprising activated NK cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^l0W, for example viral meningitis, and HIV-related disease.

[0059] Animal models that are used to test for efficacy in specific viruses are known. For example, Dengue Virus can be tested using a model as such as described in Huang et al. (2000) J. Gen. Virol. 81(Pt 9):2177-82. West Nile Virus can be tested using the model as described in Xiao et al. (2001) Emerg. Infect. Dis. 7:714-21 or Mashimo et al. (2002) Proc. Natl. Acad. Sci. USA 99: 11311-6. Venezuelan equine encephalitis virus model is described in Jackson et al. (1991) Veterinary Pathology 28: 410-418; Vogel et al. (1996) Arch. Pathol. Lab. Med. 120:164- 72; Lukaszewski and Brooks (2000) J. of Virology 74:5006-5015. Rhinoviruses models are described in Yin and Lomax (1986) J. Gen. Virol. 67:2335-40, 1986. Models for respiratory syncytial virus are described in Byrd and Prince (1997) Clin. Infect. Dis. 25: 1363-8. A transgenic model for testing the activity of a therapeutic sample is described in the following examples and described in Morrey, et al. (1998) Antiviral Ther. 3:59-68. Other models are known in the art and it is well within the skill of those ordinarily skilled in the art to know how to use such models.

Methods of Treatment

[0060] One advantage that the activated NK cells as described herein have over antigen- specific lymphocytes in antiviral immunity is that there is no "lag" phase of clonal expansion for these NK cells to be successful as effectors, as there is with antigen-specific T and B

lymphocytes. Thus, the activated NK cells as described herein may be effective early in the course of viral infection, and may limit or prevent the spread of infection during this early stage as well as expose viral antigens for the recruitment and expansion of antigen-specific lymphocytes.

[0061] Accordingly, provided is a method of treating a viral infection in a patient in need thereof comprising administering to the patient a cellular composition comprising activated Natural Killer ("NK") cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low. The method described herein is directed toward the treatment of a viral infection and/or the disease resulting therefrom. Common viral infections that may be treated with a cellular composition comprising activated NK cells as described herein include infection with viruses selected from the group consisting of hepatitis type A virus, hepatitis type B virus, hepatitis type C virus, etc.;

parvoviruses, such as adeno-associated virus and cytomegalovirus; papovaviruses such as papilloma virus, polyoma viruses, and SV40; adenoviruses; herpes viruses such as herpes simplex type I (HSV-I), herpes simplex type II (HSV-II), and Epstem-Barr virus; poxviruses, such as variola (smallpox) and vaccinia virus; RNA viruses, including but not limited to human immunodeficiency virus type I (H1V-I), human immunodeficiency virus type II (HIV-II), human T-cell lymphotropic virus type I (HTLV-I), and human T-cell lymphotropic virus type II (HTLV- II); influenza virus; measles virus; rabies virus; Sendai virus; picornaviruses such as

poliomyelitis virus; coxsackieviruses; rhinoviruses; reoviruses; togaviruses such as rubella virus (German measles) and Semliki forest virus; arboviruses; rinderpest; echovirus; rotavirus;

respiratory syncytial virus; echinovirus; huntavirus; mumps virus; measles virus; rubella virus; polio virus; coronavirus; and combinations thereof.

[0062] In one embodiment, the activated NK cell compositions are used to treat an infection from a herpesvirus. In another embodiment, the activated NK cells are used to treat infection from HIV and/or AIDS, including secondary infections with, e.g. a herpesvirus or adenovirus. In another embodiment, the activated NK cell compositions are used to treat an infection from HBV, HCB, and/or hepatitis or other chronic liver diseases. In another embodiment, the activated NK cell compositions are used to treat infection with an adenovirus. In another embodiment, the activated NK cell compositions are used to treat infection with a coronavirus or SA S.

[0063] The administered NK cells may be autologous or allogeneic NK cells. Additionally, the administered NK cells may be from a single donor or may be pooled from multiple donors (e.g., 2 or more donors).

[0064] "Autologous" NK cells are cells derived from the patient, e.g., the virally infected host. "Allogeneic" NK cells are derived from another, non-genetically identical individual. If the NK cells are derived from an identical twin, they may be termed "syngeneic".

[0065] Donor NK cells may be HLA-KIR matched or mismatched. The present inventors have shown that the degree of matching between the NK cells and target infected cells is of no significance.

[0066] Accordingly, the CD69⁺CD25⁺ CD 15⁺CD 16^low NK cells may comprise or consist essentially of autologous and/or allogeneic NK cells with respect to the recipient. In other words, autologous NK cells may be obtained from peripheral blood of the recipient. Allogeneic NK cells may be HLA mismatched. Allogenic NK may be obtained from peripheral blood from a donor individual, or multiple donors. [0067] Peripheral blood mononuclear cells may be collected by standard techniques (e.g. conventional apheresis). To minimize the possibility of graft versus host disease and immune mediated aplasia, allogeneic cells may be depleted of T cells. For example, the cell preparation may be depleted of CD3+ T-cells using microbeads conjugated with monoclonal mouse anti- human CD3 antibody and a cell selection device (such as the Miltenyi Biotec CliniMACS.RTM. cell selection device).

[0068] However, NK cells produced by such "negative selection" procedures alone do not have a high degree of purity and may be contaminated with T and B cells. Although not necessary in the autologous setting, removal of such cells is advantageous in the allogeneic settings contemplated herein. In order to reduce contamination, it is possible to obtain an NK cell preparation by direct immunomagnetic separation, for example on the basis of CD56 expression. To further reduce T cell contamination, the product may be depleted for CD3+ cells (for example using CD3 FITC and anti-FITC beads).

[0069] Prior to activation by the activating agent, the NK cell preparation may comprise at least 80%, at least 90%, at least 95% or at least 98% CD56+ cells. In another embodiment, prior to activation by the activating agent, the NK cell preparation may comprise less than 15%, less than 10%, less than 5% or less than 3% CD3+ cells. A skilled artisan will recognize that in an autologous setting, T cell content is irrelevant, and as such, non-selected NK cells may be used.

[0070] The administered pharmaceutical compositions will often further comprise one or more buffers (e.g., neutral buffered saline or phosphate buffered saline), carbohydrates (e.g., glucose, mannose, sucrose or dextrans), mannitol, proteins, polypeptides or amino acids such as glycine, antioxidants (e.g., ascorbic acid, sodium metabisulfite, butylated hydroxytoluene, butylated hydroxyanisole, etc.), bacteriostats, chelating agents such as EDTA or glutathione, solutes that render the formulation isotonic, hypotonic or weakly hypertonic with the blood of a recipient, suspending agents, thickening agents, preservatives, flavoring agents, sweetening agents, and coloring compounds as appropriate.

[0071] While any suitable carrier known to those of ordinary skill in the art may be employed in the compositions, the type of carrier will typically vary depending on the mode of administration. The therapeutic compositions may be formulated for any appropriate manner of administration, including for example, oral, nasal, mucosal, rectal, vaginal, topical, intravenous, intraperitoneal, intradermal, subcutaneous, and intramuscular administration.

[0072] For parenteral administration, the compositions can be administered as injectable dosages of a solution or suspension of the activated CD69⁺CD25⁺ CD15⁺CD16^low NK cells in a physiologically acceptable diluent with a pharmaceutical carrier that can be a sterile liquid such as sterile pyrogen free water, oils, saline, glycerol, polyethylene glycol or ethanol. Additionally, auxiliary substances, such as wetting or emulsifying agents, surfactants, pH buffering substances and the like can be present in compositions. Other components of pharmaceutical compositions are those of petroleum, animal, vegetable, or synthetic origin, for example, non-aqueous solutions of peanut oil, soybean oil, corn oil, cottonseed oil, ethyl oleate, and isopropyl myristate.

[0073] The activated NK cells described herein may be preserved in unit-dose or multi-dose containers, such as sealed infusion bags, ampoules or vials. Such containers are typically sealed in such a way to preserve the sterility and stability of the formulation until use. In general, formulations may be preserved as suspensions, solutions or emulsions in oily or aqueous vehicles, as indicated above. Alternatively, a pharmaceutical composition may be preserved in a freeze-dried condition requiring only the addition of a sterile liquid carrier immediately prior to use. In one embodiment, pharmaceutical compositions comprising the NK cells cryopreserved in a suitable cryopreservation medium are employed, which can be thawed and resuspended as needed for administration to a patient. If a preserved cell population of the subject CD69⁺CD25⁺ CD15⁺CD16^low NK cells is to be used, such a population does not require reactivation by subsequent contact with the activating agent prior to medical use.

[00741 The amount administered to the host will vary depending upon what is being administered, the purpose of the administration, such as prophylaxis or therapy, the state of the host, the manner of administration, the number of administrations, interval between

administrations, and the like. These can be determined empirically by those skilled in the art and may be adjusted for the extent of the therapeutic response. Factors to consider in determining an appropriate dose include, but is not limited to, size and weight of the patient, the age and sex of the patient, the severity of the symptom, the stage of the disease, method of delivery of the agent, half-life of the agents, and efficacy of the agents. Stage of the disease to consider includes whether the disease is acute or chronic, relapsing or remitting phase, and the progressiveness of the disease.

[0075] Determining the dosages and times of administration for a therapeutically effective amount are well within the skill of the ordinary person in the art. For example, an initial effective dose can be estimated from cell culture or other in vitro assays. A dose can then be formulated in animal models to generate a circulating concentration or tissue concentration, including that of the IC₅₀ as determined by the cell culture assays.

[0076] In addition, toxicity and therapeutic efficacy are generally determined by cell culture assays and/or using experimental animals, typically by determining a LD₅₀ (lethal dose to 50% of the test population) and ED₅₀ (therapeutically effectiveness in 50% of the test population).

Guidance is found in standard reference works, for example, Goodman & Gilman's The

Pharmacological Basis of Therapeutics, 10^th Ed. (Hardman, J. G. et al., eds.) McGraw-Hill, New York, N.Y. (2001).

[0077] For the purposes of this invention, the methods of administration are chosen depending on the condition being treated and the pharmaceutical composition. Administration of the subject CD69⁺CD25⁺CD15⁺CD16^lowNK cells can be done in a variety of ways, including, but not limited to, subcutaneously, intravenously, intraperitoneally, intramuscularly, and possibly direct injection to specified organs such as e.g., brain, spleen or bone marrow, although systemic administration is preferred. Administration of the pharmaceutical compositions may be through a single route or concurrently by several routes.

[0078] The compositions may be administered once per day, a few or several times per day, or even multiple times per day, depending upon, among other things, the indication being treated and the judgment of the prescribing physician.

[0079] Prior to treatment with the composition, the patient may receive some additional treatment, for example, to relieve sequelae of the viral infection. For methods employing allogeneic activated NK cell populations in particular, obtaining appropriate immunosuppression of the patient prior to administration of the subject NK cells may be advantageous. This may be achieved, for example, either indirectly by chemotherapy or directly by immune suppressive therapy. [0080] It is possible to obtain virally infected cells from patients at time of diagnosis and to cryopreserve these as viable single cell suspensions. It is thus possible for a composition according to the invention to be tested in vitro against the patient's own virally infected cells. This could be done before embarking on a treatment regime, to gauge the suitability of the approach. The correlation of the results of the in vitro study and the corresponding clinical response to treatment may also be investigated.

[0081] Accordingly, the number of cells needed for achieving a therapeutic effect may be determined empirically in accordance with conventional procedures for the particular purpose. Generally, for administering the cells for therapeutic purposes, the cells are given at a pharmacologically effective dose. "Pharmacologically effective amount" or "pharmacologically effective dose" refers to an amount sufficient to produce the desired physiological effect or amount capable of achieving the desired result, particularly for treating the disorder or disease condition, including reducing or eliminating one or more symptoms or manifestations of the disorder or disease. As an illustration, administration of cells to a patient suffering from viral infection provides a therapeutic benefit not only when the underlying condition is eradicated or ameliorated, but also when the patient reports a decrease in the severity or duration of the symptoms associated with the disease, e.g., a decrease in the number of infected cells, an increase in progression free survival, etc. Therapeutic benefit also includes halting or slowing the progression of the underlying disease or disorder, regardless of whether improvement is realized. Pharmacologically effective dose, as defined above, will also apply to therapeutic compounds used in combination with the cells, as further described below.

[0082] Preferably, the effect will result in a quantifiable change of at least about 10%, preferably at least 20%, 30%, 50%, 70%, or even 90% or more. Therapeutic benefit also includes halting or slowing the progression of the underlying disease or disorder, regardless of whether improvement is realized. When the NK cells that exhibit durable activity is used in combination with other treatment protocols, an effective amount is in ratio to a combination of components and the effect is not limited to individual components alone.

[0083] A pharmacologically effective amount of NK cells that will treat or reduce a viral infection and/or disease resulting therefrom will modulate the symptoms typically by at least about 10%; usually by at least about 20%; preferably at least about 30%; or more preferably at least about 50%. Such will result in, e.g., statistically significant and quantifiable changes in the numbers of cells being affected. This may be a decrease in the numbers of cells infected with the virus, etc.

[0084] The activated NK cell compositions described herein may be combined with other treatments for the viral infection and/or the disease resulting therefrom, e.g., surgical resection (e.g., of cancerous growths, herpetic lesions, warts resulting from papilloma virus), radiation therapy, chemotherapy, immunotherapy, and supportive therapy (e.g., painkillers, diuretics, antidiuretics, antivirals, antibiotics, nutritional supplements, anemia therapeutics, blood clotting therapeutics, bone therapeutics, and psychiatric and psychological therapeutics). Such other antiviral treatments may be provided sequentially (e.g., before or after) or simultaneously with the administration of the NK cells.

[0085] In one embodiment, the activated NK cell compositions described herein are coadministered (sequentially or simultaneously) with one or more viral antigens and/or one or more additional therapeutic agents (e.g., chemotherapeutic agent, immunotherapeutic agent, supportive therapeutic agent, or combinations thereof). Listed below are non-limiting examples of well-known therapeutic agents used in anti- viral treatments.

[0086] The activated NK cell compositions described herein can be used in combination with antiviral agents, including those described above. Some of the more common treatments for viral infection include drugs that inhibit viral replication such as ACYCLOVIR™. In addition, the combined use of some of these agents form the basis for highly active antiretroviral therapy (HAART) used for the treatment of AIDS. Examples in which the combination of

immunotherapy (i.e., cytokines) and antiviral drugs shows improved efficacy include the use of interferon plus RIBAVIRIN™ for the treatment of chronic hepatitis C infection (Maddrey (1999) Semin. Liver. Dis. 19 Suppl 1:67-75) and the combined use of IL-2 and HAART (Ross, et al, ibid.).

[0087] In particular, the activated NK cell compositions described herein may be useful in monotherapy or combination therapy with IFN-a, e.g., PEGASYS® or PEG-INTRON® (with or without a nucleoside analog, such as RIBAVIRTN™, lamivudine, entecavir, emtricitabine, telbivudine and tenofovir) or with a nucleoside analog, such as RIBAVIRIN™, lamivudine, entecavir, emtricitabine, telbivudine and tenofovir in patients who do not respond well to IFN therapy.

[0088] The activated NK cell compositions described herein may be used in combination with other immunotherapies including adoptive T cell therapies, cytokine administration, immunoglobulin transfer, and various co-stimulatory molecules. In addition to antiviral drugs, the activated NK cell compositions can be used in combination with any other immunotherapy that is intended to stimulate the immune system. Thus, activated NK cell compositions described herein may be used with other cytokines such as Interferon, 1L-21, or IL-2. The activated NK cell compositions described herein may also be added to methods of passive immunization that involve immunoglobulin transfer, one example being the use of antibodies to treat RSV infection in high risk patients. In addition, the activated NK cell compositions may be used with additional co-stimulatory molecules such as 4- IBB ligand that recognize various cell surface molecules like CD 137 (Tan, j T et al., J. Immunol. 163:4859-68, 1999).

[0089] Since the activated NK cell compositions described herein may also be used to treat diseases resulting from the viral infection, e.g., cancer, the subject methods may also be used with additional therapeutic agents, e.g., chemotherapeutics, used to treat the resulting disease.

[0090] Chemotherapeutic agents described herein as having anti-cancer activity (e.g., compounds that induce apoptosis, compounds that reduce lifespan or compounds that render cells sensitive to stress) include: aminoglutethimide, amsacrine, anastrozole, asparaginase, beg, bicalutamide, bleomycin, buserelin, busulfan, campothecin, capecitabine, carboplatin, carmustine, chlorambucil, cisplatin, cladribine, clodronate, colchicine, cyclophosphamide, cyproterone, cytarabine, dacarbazine, dactinomycin, daunorubicin, dienestrol, diethylstilbestrol, docetaxel, doxorubicin, epirubicin, estradiol, estramustine, etoposide, exemestane, filgrastim, fludarabine, fludrocortisone, fluorouracil, fluoxymesterone, flutamide, gemcitabine, genistein, goserelin, hydroxyurea, idarubicin, ifosfamide, imatimib, interferon, irinotecan, ironotecan, letrozole, leucovorin, leuprolide, levamisole, lomustine, mechlorethamine,

medroxyprogesterone, megestrol, melphalan, mercaptopurine, mesna, methotrexate, mitomycin, mitotane, mitoxantrone, nilutamide, nocodazole, octreotide, oxaliplatin, paclitaxel, pamidronate, pentostatin, plicamycin, porfimer, procarbazine, ratitrexed, rituximab, streptozocin, suramin, tamoxifen, temozolomide, teniposide, testosterone, thioguanine, thiotepa, titanocene dichloride, topotecan, trastuzumab, tretinoin, vinblastine, vincristine, vindesine, and vinorelbine.

[0091] These chemotherapeutic agents may be categorized by their mechanism of action into, for example, following groups: anti-metabolites/anti-cancer agents, such as pyrimidine analogs (5-fluorouracil, floxuridine, capecitabine, gemcitabine and cytarabine) and purine analogs, folate antagonists and related inhibitors (mercaptopurine, thioguanine, pentostatin and 2-chlorodeoxyadenosine (cladribine)); antiproliferative/antimitotic agents including natural products such as vinca alkaloids (vinblastine, vincristine, and vinorelbine), microtubule disruptors such as taxane (paclitaxel, docetaxel), vincristin, vinblastin, nocodazole, epothilones and navelbine, epidipodophyllotoxins (teniposide), DNA damaging agents (actinomycin, amsacrine, anthracyclines, bleomycin, busulfan, camptothecin, carboplatin, chlorambucil, cisplatin, cyclophosphamide, Cytoxan, dactinomycin, daunorubicin, docetaxel, doxorubicin, epirubicin, hexamethylmelamineoxaliplatin, iphosphamide, melphalan, merchlorethamine, mitomycin, mitoxantrone, nitrosourea, paclitaxel, plicamycin, procarbazine, teniposide, triethylenethiophosphoramide and etoposide (VP16)); antibiotics such as dactinomycin

(actinomycin D), daunorubicin, doxorubicin (adriamycin), idarubicin, anthracyclines, mitoxantrone, bleomycins, plicamycin (mithramycin) and mitomycin; enzymes (L-asparaginase which systemically metabolizes L-asparagine and deprives cells which do not have the capacity to synthesize their own asparagine); antiplatelet agents; antiproliferative/antimitotic alkylating agents such as nitrogen mustards (mechlorethamine, cyclophosphamide and analogs, melphalan, chlorambucil), ethylenimines and methylmelamines (hexamethylmelamine and thiotepa), alkyl sulfonates-busulfan, nitrosoureas (carmustine BC U) and analogs, streptozocin), trazenes- dacarbazinine (DTIC); antiproliferative/antimitotic antimetabolites such as folic acid analogs (methotrexate); platinum coordination complexes (cisplatin, carboplatin), procarbazine, hydroxyurea, mitotane, aminoglutethimide; hormones, hormone analogs (estrogen, tamoxifen, goserelin, bicalutamide, nilutamide) and aromatase inhibitors (letrozole, anastrozole);

anticoagulants (heparin, synthetic heparin salts and other inhibitors of thrombin); fibrinolytic agents (such as tissue plasminogen activator, streptokinase and urokinase), aspirin, COX-2 inhibitors, dipyridamole, ticlopidine, clopidogrel, abciximab; antimigratory agents; antisecretory agents (breveldin); immunosuppressives (cyclosporine, tacrolimus (FK-506), sirolimus

(rapamycin), azathioprine, mycophenolate mofetil); anti-angiogenic compounds (TNP-470, genistein) and growth factor inhibitors (vascular endothelial growth factor (VEGF) inhibitors, fibroblast growth factor (FGF) inhibitors, epidermal growth factor (EGF) inhibitors); angiotensin receptor blocker; nitric oxide donors; anti-sense oligonucleotides; antibodies (trastuzumab); cell cycle inhibitors and differentiation inducers (tretinoin); mTOR inhibitors, topoisomerase inhibitors (doxorubicin (adriamycin)), amsacrine, camptothecin, daunorubicin, dactinomycin, eniposide, epirubicin, etoposide, idarubicin, irinotecan (CPT-11) and mitoxantrone, topotecan, irinotecan), corticosteroids (cortisone, dexamethasone, hydrocortisone, methylpednisolone, prednisone, and prenisolone); growth factor signal transduction kinase inhibitors; mitochondrial dysfunction inducers and caspase activators; chromatin disruptors; and proteasome inhibitors such as bortezomib.

[0092] In one embodiment, an additional therapeutic agent as described herein may be a kinase inhibitor. Protein kinases are a family of enzymes that catalyse the phosphorylation of specific residues in proteins. In general, protein kinases fall into several groups; those that preferentially phosphorylate serine and/or threonine residues, those which preferentially phosphorylate tyrosine residues and those that phosphorylate both tyrosine and Ser/Thr residues. Protein kinases are key elements in signal transduction pathways responsible for transducing extracellular signals, including the action of cytokines on their receptors, to the nuclei, triggering various biological events. The many roles of protein kinases in normal cell physiology include cell cycle control and cell growth, differentiation, apoptosis, cell mobility and mitogenesis. Kinases such as c-Src, c-Abl, mitogen activated protein (MAP) kinase, phosphotidylinositol-3- kinase (PI3K) AKT, and the epidermal growth factor (EGF) receptor are commonly activated in cancer cells, and are known to contribute to tumorigenesis. Many of these occur in the same signaling pathway. For example, HER-kinase family members (HERIEGFR, HER3, and HER4) transmit signals through MAP kinase and PI3 kinase to promote cell proliferation. Logically, a number of kinase inhibitors are currently being developed for anti-cancer therapy, in particular tyrosine kinase inhibitors (TKIs): cyclin-dependent kinase inhibitors, aurora kinase inhibitors, cell cycle checkpoint inhibitors, epidermal growth factor receptor (EGFR) inhibitors, FMS-like tyrosine kinase inhibitors, platelet-derived growth factor receptor (PDGFR) inhibitors, kinase insert domain inhibitors, inhibitors targeting the PDK/Akt/mTOR pathway, inhibitors targeting the Ras-Raf-MEK-ERK (ERK) pathway, vascular endothelial growth factor receptor (VEGFR) kinase inhibitors, c-kit inhibitors and serine/threonine kinase inhibitors. [0093] Kinase inhibitors useful in the method of the present invention include, but are not limited to, Lapatinib, AZD 2171, ETI 8OCH₃, Indirubin-3'-oxime, NSC-154020, PD 169316, Quercetin, Roscovitine, Triciribine, ZD 1839, 5-Iodotubercidin, Adaphostin, Aloisine,

Alsterpaullone, Aminogenistein, API-2, Apigenin, Arctigenin, ARRY-334543, Axitinib (AG- 013736), AY-22989, AZD 2171, Bisindolylmaleimide IX, CCl-779, Chelerythrine, DMPQ, DRB, Edelfosine, ENMD-981693, Erbstatin analog, Erlotinib, Fasudil, Gefitinib (ZD 1839), H-7, H-8, H-89, HA-100, HA-1004, HA-1077, HA-1100, Hydroxyfasudil, Kenpaullone, KN-62, KY12420, LFM-A13, Luteolin, LY294002, LY-294002, Mallotoxin, ML-9, MLN608, NSC- 226080, NSC-231634, NSC-664704, NSC-680410, NU6102, Olomoucine, Oxindole I, PD 153035, PD 98059, Phloridzin, Piceatannol, Picropodophyllin, PKI, PP1, PP2,

PTK787/ZK222584, PTK787/ZK-222584, Purvalanol A, Rapamune, Rapamycin, Ro 31-8220, Rottlerin, SB202190, SB203580, Sirolimus, SL327, SP600125, Staurosporine, STI-571 (also known as Imatinib and Gleevic), SU1498, SU4312, SU5416, SU5416 (Semaxanib), SU6656, SU6668, syk inhibitor, TBB, TCN, Tyrphostin AG 1024, Tyrphostin AG 490, Tyrphostin AG 825, Tyrphostin AG 957, U0126, W-7, Wortmannin, Y-27632, Zactima (ZD6474), ZM 252868. Recently approved tyrosine kinase inhibitors for cancer therapy include, for example, Sorafenib and Sunitinib.

[0094] Kinase inhibitors currently under clinical investigation for use in anti-cancer therapies and/or novel indications are, for example, MK0457, VX-680, ZD6474, MLN8054, AZD2171, SNS-032, PTK787/ZK222584, Sorafinib (BAY43-9006), SU5416, SU6668 AMG706, Zactima (ZD6474), MP-412, Dasatinib, CEP-701, (Lestaurtinib), XL647, XL999, Tykerb, (Lapatinib), MLN518, (formerly known as CT53518), PKC412, ST1571, AMN107, AEE 788, OSI-930, OSI- 817, Sunitinib maleate (Sutent SUl 1248), Vatalanib (PTK787/ZK 222584), SNS-032, SNS-314 and Axitinib (AG-013736). Gefitinib and Erlotinib are two orally available EGFR-TKIs.

[0095] An additional therapeutic agent as described herein may also be an

immunotherapeutic, e.g., an antibody, another immune cell composition, vaccines and small molecules that may act synergistically with active immunotherapy approaches.

[0096] In one embodiment, the immunotherapeutic may be an antibody, which may be a monoclonal or a polyclonal antibody or a fragment thereof, preferably a monoclonal antibody. Humanized and/or chimeric antibodies are included. The antibody may be conjugated or non- conjugated and may be directed at any target antigen of interest, in particular tumor-associated antigens. Examples of antibodies therapeutically active against neoplasia include, but are not limited to, anti-cancer antibodies such as 1D09C3, Abciximab, Alemtuzumab, Apolizumab, Avastin, Basiliximab, Bevacizumab, Cantuzumab, Cetuximab, Dacliximab, Eculizumab, Epratuzumab, Gemtuzumab Ozogamicin, Ibritumomab Tiuxetan, Infliximab, Labetuzumab, Mapatumumab, Matuzumab, Mepolizumab, Muromonab-Cd3, Nimotuzumab, Oregovomab, Palivizumab, Panitumumab, Panorex, Pertuzumab, Rituximab, Tositumomab, and Trastuzumab. Preferred therapeutic antibodies for use in the method of the present invention include anti-CD20 antibodies (e.g., Rituxan™, Bexxar^1M, Zevalin™), anti-Her2/neu antibodies (e.g., Herceptin™), anti-CD33 antibodies (e.g., Mylotarg™), anti-CD52 antibodies (e.g., Campath™), anti-CD22 antibodies, anti-CD25 antibodies, anti-CTLA-4 antibodies, anti-EGF-R antibodies (e.g.

Erbitux™), anti-VEGF antibodies (e.g. Avastin™, VEGF Trap) anti-HLA-DRlO.beta.

antibodies, anti-MUCl antibodies, anti-CD40 antibodies (e.g. CP-870,893), anti-Treg cell antibodies (e.g. MDX-010, CP-675,206), anti-GITR antibodies, anti-CCL22 antibodies, and the like.

[0097] Immunotherapeutic small molecules include peptide-based therapeutic vaccines. Small molecules may also, for example, act in such a way by: (1) reducing regulatory T cells in the periphery and in the tumor lesions; (2) by improving activation of professional APCs and/or helper and/or killer T cells and/or (3) by biasing the immune response towards a THl-type immune response cytokine profile including e.g., IFN-γ, IL-2 upregulation. Nonlimiting examples of such small molecules include 1-MT, ABH, AMD3100, AZD2171, BEC, Celebrex, CP-547632, CPA-7, cyclophosphamide, JSI-124, loxoribine, LY580276, NCX-4016, nor- NOHA, pazopanib, rofecoxib, S-27609, SB-505124, SD-208, Sildenafil, Tadalafil, Vardenafil, XL-999, ZD2171, and imides such as lenalidomide or thalidomide.

[0098] All patents and patent publications referred to herein are hereby incorporated by reference.

[0099] Certain modifications and improvements will occur to those skilled in the art upon a reading of the foregoing description. It should be understood that all such modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the following claims. EXAMPLES

[00100] Example 1 : Anti-CMV lytic activity by primed CD69⁺CD25⁺ CD15⁺CD16^low NK cells from CMV-naive healthy individuals

[00101] CMV is a common human pathogen which, once encountered, leads to a lifelong infection which is maintained in a latent state by a substantial T cell mediated immune response. This is relatively benign except in condition of immunodeficiency or immune incompetence such as post transplant patients where CMV reactivation can cause retinitis, pneumonitis and even death. The most extreme setting is after allogeneic haematopoietic stem cell transplantation. When the immunodepleted recipient is CMV-seropositive but the stem cell donor is naive to CMV, the endogenous CMV in the recipient is under no immune control by the donor immune system. Commonly 90% of such cases result in CMV reactivation which may or may not respond to anti viral chemotherapy. Even if responsive to Foscarnet or Ganciclovir the CMV is not eradicated and the patient experiences repeated CMV reactivation episodes until T cell immunity is established over a six to twelve month period. Anti-viral chemotherapy is expensive and associated with severe side effects including bone marrow suppression which further delays the development of protective immunity.

[00102] We have investigated whether CD69⁺CD25⁺ CD 15⁺CD 16^low NK cells can lyse CMV- infected target cells and secrete appropriate cytokines to medicate protective immunity against CMV. It is established that CMV-specific T cells secreting gamma interferon from a CMV- seropositive donor are capable of controlling CMV reactivation in the post transplant setting. As shown in Figure 1, primed CD69⁺CD25⁺CD15⁺CD16^low NK cells from normal healthy donors (n=24) and from patients in the first 6 months post allogeneic stem cell transplant (n=34) can secrete gamma interferon in response to CMV-infected target cells, and this is independent of prior exposure to CMV.

[00103] Furthermore, as shown in Figure 2, the CD69⁺CD25⁺ CD 15⁺CD 16^low NK cells from CMV-naive healthy donors are able to lyse CMV-infected target cells which are resistant to NK cells from the same donors which are not appropriately primed. In this study NK cells from 5 healthy CMV naive donors were tested with (red bars) and without priming (pink bars) for their ability to lyse infected MRC5 target cells at an effector to target cell ratio of 5:1. The primed CD69⁺CD25⁺CD15⁺ CD16^low K cells were also tested for their ability to lyse non-infected MRC5 (open bars).

[00104] As shown in Figure 2, CMV infected MRC remain resistant to lysis by resting NK cells even at the height of viral replication on day +3 post in vitro infection. In contrast, primed CD69⁺CD25⁺CD15⁺CD16^low NK cells led to specific lysis of infected MRC5 without concomitant increase in lysis of uninfected target cells.

[00105] CMV is a typical herpes virus with a lifelong latency under appropriate immune control in immunocompetent hosts. We believe that it is a predictor of broader anti-viral activity medicated by CD69⁺CD25⁺CD15⁺CD16^low NK cells since the triggering ligands for NK cells are not antigen specific but are molecules such as heat shock proteins, MICA, MICB, ULBPs etc which are upregulated by many virsues, including those outside the herpes family.

[00106] Example 2- Inhibition of HIV Replication in Fresh Human PBMCs

[00107] Human immunodeficiency virus (HIV) is a pathogenic retrovirus that infects cells of the immune system. CD4 T cells and monocytes are the primary infected cell types. To test the ability of activated NK cells as described herein to inhibit HIV replication in vitro, PBMCs from normal donors are infected with the HIV virus in the presence of activated NK cells having the phenotype CD69 ' CD25⁺CD 15⁺CD 16^low.

[00108] Fresh human peripheral blood mononuclear cells (PBMCs) are isolated from whole blood obtained from screened donors who were seronegative for HIV and HBV. Peripheral blood cells are pelleted/washed 2-3 times by low speed centrifugation and resuspended in PBS to remove contaminating platelets. The washed blood cells are diluted 1 :1 with Dulbecco's phosphate buffered saline (D-PBS) and layered over 14 mL of Lymphocyte Separation Medium ((LSM; Cellgro.TM. by Mediatech, Inc. Herndon, Va.); density 1.078+/-0.002 g/ml) in a 50 mL centrifuge tube and centrifuged for 30 minutes at 600XG. Banded PBMCs are gently aspirated from the resulting interface and subsequently washed twice in PBS by low speed centrifugation. After the final wash, cells are counted by trypan blue exclusion and resuspended at 1X10⁷ cells/mL in PMI 1640 supplemented with 15% Fetal Bovine Serum (FBS), 2 mM L-glutamine, 4 μg/mL PHA-P. The cells are incubated for 48-72 hours at 37° C. After incubation, PBMCs are centrifuged and resuspended in RPMI 1640 with 15% FBS, 2 mM L-glutamine, 100 U/mL penicillin, 100 μg/mL streptomycin, 10 μg/mL gentamycin, and 20 U/mL recombinant human IL-2. PBMCs will be maintained in the medium at a concentration of 1-2X10⁶ cells/mL with biweekly medium changes until used in the assay protocol. Monocytes are depleted from the culture as the result of adherence to the tissue culture flask.

[00109] For the standard PBMC assay, PHA-P stimulated cells from at least two normal donors are pooled, diluted in fresh medium to a final concentration of 1X10⁶ cells/mL, and plated in the interior wells of a 96 well round bottom microplate at 50 μΙΛνεΙΙ (5X10⁴ cells/well). Test dilutions were prepared at a 2X concentration in microtiter tubes and 100 ϋ of each concentration was placed in appropriate wells in a standard format. Activated NK cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low are added. 50 μΐ, of a predetermined dilution of virus stock is placed in each test well (final MOl of 0.1). Wells with only PMBCs and virus added were used for virus control. Separate plates are prepared identically without virus for drug cytotoxicity studies using an MTS assay system. The PBMC cultures are maintained for seven days following infection, at which time cell-free supernatant samples are collected and assayed for reverse transcriptase activity and p24 antigen levels.

[00110] A decrease in reverse transcriptase activity or p24 antigen levels in samples with activated NK cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^{lo v} would be indicators of antiviral activity and would demonstrate that this cellular composition may have therapeutic value in treating HIV and AIDS.

[00111] Example 3 - Inhibition of GBV-B Replication in Marmoset Liver Cells

[00112] HCV is a member of the Flaviviridae family of RNA viruses. HCV does not replicate well in either ex- vivo or in vitro cultures and therefore, there are no satisfactory systems to test the anti-HCV activity of molecules in vitro. GB virus B (GBV-B) is an attractive surrogate model for use in the development of anti-HCV antiviral agents since it has a relatively high level of sequence identity with HCV and is a hepatotropic virus. To date, the virus can only be grown in the primary hepatocytes of certain non-human primates. This is accomplished by either isolating hepatocytes in vitro and infecting them with GBV-B, or by isolating hepatocytes from GBV-B infected marmosets and directly using them with antiviral compounds.

[00113] The effects of activated NK cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low are assayed on GBV-B extracellular RNA production by TaqMan RT-PCR and on cytotoxicity using CellTiter96® reagent (Promega, Madison, Wis.). Untreated cultures will serve as the cell and virus controls. Both RIBAVIRIN® (200 μg/ml at the highest test concentration) and IFN-a (5000 IU/ml at the highest test) will be included as positive controls. Primary hepatocyte cultures are isolated and plated out on collagen-coated plates. The next day the cultures are treated with the test samples (activated NK cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low IFNa, or RIBAVIRIN®) for 24 hr before being exposed to GBV-B virions or treated directly with test samples when using in vivo infected hepatocytes. Test samples and media are added the next day, and replaced three days later. Three to four days later (at day 6-7 post test sample addition) the supernatant is collected and the cell numbers quantitated with CellTiter96®. Viral RNA is extracted from the supernatant and quantified with triplicate replicates in a quantitative TaqMan RT-PCR assay using an in vitro transcribed RNA containing the RT-PCR target as a standard. The average of replicate samples is computed. Inhibition of virus production is assessed by plotting the average RNA and cell number values of the triplicate samples relative to the untreated virus and cell controls. The inhibitory concentration of drug resulting in 50% inhibition of GBV-B RNA production (IC50) and the toxic concentration resulting in destruction of 50% of cell numbers relative to control values (TC50) are calculated by interpolation from graphs created with the data.

[00114] Inhibition of the GBV-B RNA production by activated NK cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low is an indication of the antiviral properties of the cellular composition on this Hepatitis C-like virus on hepatocytes, the primary organ of infection of Hepatitis C, and positive results suggest that activated NK cells having the phenotype

CD69⁺CD25⁺CD15⁺CD16^l0W may be useful in treating HCV infections in humans.

[00115] Example 4 - Inhibition of HBV Replication in WHO Cells

[00116] Chronic hepatitis B (HBV) is one of the most common and severe viral infections of humans belonging to the Hepadnaviridae family of viruses. To test the antiviral activities of activated NK cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low against HBV, the cells will be tested against HBV in an in vitro infection system using a variant of the human liver line HepG2.

[00117] WT10 cells are a derivative of the human liver cell line HepG2 2.2.15. WT10 cells are stably transfected with the HBV genome, enabling stable expression of HBV transcripts in the cell line (Fu and Cheng, Antimicrobial Agents Chemother, 44(12):3402-3407, 2000). In the WT10 assay the drug in question and a 3TC control will be assayed at five concentrations each, diluted in a half-log series. The endpoints are TaqMan PCR for extracellular HBV DNA (IC50) and cell numbers using CellTiter96 reagent (TC50). The assay is similar to that described by Korba et al. Antiviral Res. 15(3):217-228, 1991 and Korba et al, Antiviral Res. 19(l):55-70, 1992. Briefly, WTl 0 cells are plated in 96-well microtiter plates. After 16-24 hours the confluent monolayer of HepG2-2.2.15 cells is washed and the medium is replaced with complete medium containing varying concentrations of a test samples in triplicate. 3TC is used as the positive control, while media alone is added to cells as a negative control (virus control, VC). Three days later the culture medium is replaced with fresh medium containing the appropriately diluted test samples. Six days following the initial addition of activated NK cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low, the cell culture supernatant is collected, treated with pronase and DNAse, and used in a real-time quantitative TaqMan PCR assay. The PCR-amplified HBV DNA is detected in real-time by monitoring increases in fluorescence signals that result from the exonucleolytic degradation of a quenched fluorescent probe molecule that hybridizes to the amplified HBV DNA. For each PCR amplification, a standard curve is simultaneously generated using dilutions of purified HBV DNA. Antiviral activity is calculated from the reduction in HBV DNA levels (IC50). A dye uptake assay is then employed to measure cell viability which is used to calculate toxicity (TC50). The therapeutic index (TI) is calculated as TC50/1C50.

[00118] Inhibition of Hepatis B viral replication in WT10 cells after incubation with activated NK cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low will demonstrate antiviral activity of activated NK cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low against HBV grown in liver cell lines and provide evidence of therapeutic value for treating HBV in human patients.

Claims

Claims:

1. A method for treating a viral infection in a patient in need thereof comprising administering to the patient a cellular composition comprising activated Natural Killer ("NK") cells having the phenotype CD69⁺CD25⁺CD15⁺CD16^low.

2. The method according to claim 1, wherein said patient is immunocompromised.

3. The method according to claim 1, wherein said activated NK cells are autologous to the patient.

4. The method according to claim 1, wherein said activated NK cells are allogeneic to the patient.

5. The method according to claim 4, wherein said method further comprises

immunosuppressing the patient prior to administration of said allogeneic NK cells.

6. The method according to claim 5, wherein the immunosuppression is accomplished by chemotherapy and/or radiation therapy.

7. The method according to any one of claims 1-6, wherein the virus is selected from the group consisting of a herpes virus, an adenovirus, a retrovirus, or combinations thereof.

8. The method according to claim 7, wherein the virus is a herpes virus

9. The method according to claim 8, wherein the herpes virus is selected from the group consisting of human herpesvirus 6, vari cella zoster virus, cytomegalovirus and Epstein Ban- virus.

10. The method according to claim 7, wherein the virus is an adenovirus.