Adoptive NK cell therapy: a potential revolutionary approach in longevity therapeutics.

The aging process intricately involves immune system dynamics, with a crucial role in managing senescent cells (SNCs) and their senescence-associated secretory phenotypes (SASPs). Unfortunately, immunosenescence, a progressively dysregulated immunity with age, hampers effective SNC elimination, leading to accumulation, coupled with the release of SASPs, which, in turn, inhibits immunity and heightened susceptibility to aging-associated diseases (AADs). Natural killer (NK) cells, integral to the innate immune system, play a pivotal role in addressing SNCs swiftly. These cells also coordinate with other components of both innate and adaptive immunity to surveil and eliminate these cells. Accordingly, preserving NK cell function during aging is crucial for evading AADs and promoting healthy aging. Alternatively, NK-cell-based therapies present promising avenues for addressing the challenges associated with aging. Notable, recent studies in adoptive NK cell therapy have shown promise in rejuvenating immunosenescence, eliminating SNCs, and alleviating SASPs. This progress provides the proof-concept of adoptive NK cell therapy for senotherapy and holds promise as an emerging revolution in longevity therapeutics.

The value of combined MRI, enhanced CT and 18F-FDG PET/CT in the diagnosis of recurrence and metastasis after surgery for ovarian cancer.

OBJECTIVE: The purpose of this article was to investigate the value of combined MRI, enhanced CT and 18F-FDG PET/CT in the diagnosis of recurrence and metastasis after surgery for ovarian cancer. METHODS: Ninety-five ovarian cancer patients were selected as the study subjects, all of them underwent surgical treatment, and MRI, enhanced CT and 18F-FDG PET/CT were performed on all of them in the postoperative follow-up, and the pathological results after the second operation were used as the diagnostic "gold standard". The diagnostic value (sensitivity, specificity, accuracy, negative predictive value and positive predictive value) of the three examination methods alone or in combination for the diagnosis of postoperative recurrence and metastasis of ovarian cancer was compared, and the detection rate was calculated when the lesion was the unit of study, so as to compare the efficacy of the three methods in the diagnosis of postoperative recurrent metastatic lesions of ovarian cancer. RESULTS: The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the combined group were higher than those of MRI and enhanced CT for recurrence and metastasis of ovarian cancer after surgery, and the specificity, accuracy and positive predictive value of the combined group were higher than those of the 18F-FDG PET/CT group, and those of the 18F-FDG PET/CT group were higher than those of the enhanced CT group (all P < 0.05). When the postoperative recurrent metastatic lesions of ovarian cancer were used as the study unit, the detection rate of lesions in the combined group was higher than that of the three examinations detected individually, and the detection rate of lesions in 18F-FDG PET/CT was higher than that of enhanced CT and MRI (P < 0.05). CONCLUSION: The combination of MRI, enhanced CT and 18F-FDG PET/CT can accurately diagnose recurrence and metastasis of ovarian cancer after surgery, detect recurrent metastatic lesions as early as possible, and improve patients' prognosis.

Harnessing NK Cells to Control Metastasis.

In recent years, tumor immunotherapy has produced remarkable results in tumor treatment. Nevertheless, its effects are severely limited in patients with low or absent pre-existing T cell immunity. Accordingly, metastasis remains the major cause of tumor-associated death. On the other hand, natural killer (NK) cells have the unique ability to recognize and rapidly act against tumor cells and surveil tumor cell dissemination. The role of NK cells in metastasis prevention is undisputable as an increase in the number of these cells mostly leads to a favorable prognosis. Hence, it is reasonable to consider that successful metastasis involves evasion of NK-cell-mediated immunosurveillance. Therefore, harnessing NK cells to control metastasis is promising. Circulating tumor cells (CTCs) are the seeds for distant metastasis, and the number of CTCs detected in the blood of patients with tumor is associated with a worse prognosis, whereas NK cells can eliminate highly motile CTCs especially in the blood. Here, we review the role of NK cells during metastasis, particularly the specific interactions of NK cells with CTCs, which may provide essential clues on how to harness the power of NK cells against tumor metastasis. As a result, a new way to prevent or treat metastatic tumor may be developed.

Exploring the Utility of NK Cells in COVID-19.

Coronavirus disease 2019 (COVID-19) can manifest as acute respiratory distress syndrome and is associated with substantial morbidity and mortality. Extensive data now indicate that immune responses to SARS-CoV-2 infection determine the COVID-19 disease course. A wide range of immunomodulatory agents have been tested for the treatment of COVID-19. Natural killer (NK) cells play an important role in antiviral innate immunity, and anti-SARS-CoV-2 activity and antifibrotic activity are particularly critical for COVID-19 control. Notably, SARS-CoV-2 clearance rate, antibody response, and disease progression in COVID-19 correlate with NK cell status, and NK cell dysfunction is linked with increased SARS-CoV-2 susceptibility. Thus, NK cells function as the key element in the switch from effective to harmful immune responses in COVID-19. However, dysregulation of NK cells has been observed in COVID-19 patients, exhibiting depletion and dysfunction, which correlate with COVID-19 severity; this dysregulation perhaps contributes to disease progression. Given these findings, NK-cell-based therapies with anti-SARS-CoV-2 activity, antifibrotic activity, and strong safety profiles for cancers may encourage the rapid application of functional NK cells as a potential therapeutic strategy to eliminate SARS-CoV-2-infected cells at an early stage, facilitate immune-immune cell interactions, and favor inflammatory processes that prevent and/or reverse over-inflammation and inhibit fibrosis progression, thereby helping in the fight against COVID-19. However, our understanding of the role of NK cells in COVID-19 remains incomplete, and further research on the involvement of NK cells in the pathogenesis of COVID-19 is needed. The rationale of NK-cell-based therapies for COVID-19 has to be based on the timing of therapeutic interventions and disease severity, which may be determined by the balance between beneficial antiviral and potential detrimental pathologic actions. NK cells would be more effective early in SARS-CoV-2 infection and prevent the progression of COVID-19. Immunomodulation by NK cells towards regulatory functions could be useful as an adjunct therapy to prevent the progression of COVID-19.

Immunosurveillance of Cancer and Viral Infections with Regard to Alterations of Human NK Cells Originating from Lifestyle and Aging.

Natural killer (NK) cells are cytotoxic immune cells with an innate capacity for eliminating cancer cells and virus- infected cells. NK cells are critical effector cells in the immunosurveillance of cancer and viral infections. Patients with low NK cell activity or NK cell deficiencies are predisposed to increased risks of cancer and severe viral infections. However, functional alterations of human NK cells are associated with lifestyles and aging. Personal lifestyles, such as cigarette smoking, alcohol consumption, stress, obesity, and aging are correlated with NK cell dysfunction, whereas adequate sleep, moderate exercise, forest bathing, and listening to music are associated with functional healthy NK cells. Therefore, adherence to a healthy lifestyle is essential and will be favorable for immunosurveillance of cancer and viral infections with healthy NK cells.

Effective induction of melanoma-antigen-specific CD8+ T cells via Vγ9γδT cell expansion by CD56(high+) Interferon-α-induced dendritic cells.

Dendritic cells (DCs) can be differentiated from CD14+ monocytes in the presence of interferon-α (IFNα) and granulocyte/macrophage-colony stimulating factor (GM-CSF) in vitro and are known as IFN-DCs. Circulating blood CD56+ cells expressing high levels of CD14, HLA-DR and CD86 have been shown to spontaneously differentiate into DC-like cells in vitro after their isolation from blood. We show here that IFN-DCs expressing high levels of CD56 (hereafter, CD56(high+) IFN-DCs) can be differentiated in vitro from monocytes obtained as adherent cells from healthy donors and patients with metastatic melanoma. These cells expressed high levels of CD14, HLA-DR and CD86 and possessed many pseudopodia. These CD56(high+) IFN-DCs may be an in vitro counterpart of the circulating CD56+ CD14+ CD86+ HLA-DR+ cells in blood. Conventional mature DCs differentiated from monocytes as adherent cells in the presence of GM-CSF, IL-4 and TNF-α (hereafter, mIL-4DCs) did not express CD56 or CD14. In contrast to mIL-4DCs, the CD56(high+) IFN-DCs exhibited a stronger capacity to stimulate autologous CD56+ Vγ9γδT cells highly producing IFNγ in the presence of zoledronate and IL-2. The CD56(high+) IFN-DCs possessing HLA-A*0201 effectively induced Mart-1-modified melanoma peptide (A27L)-specific CD8+ T cells through preferential expansion of CD56+ Vγ9γδT cells in the presence of A27L, zoledronate and IL-2. Vaccination with CD56(high+) IFN-DCs copulsed with tumor antigens and zoledronate may orchestrate the induction of various CD56+ immune cells possessing high effector functions, resulting in strong immunological responses against tumor cells. This study may be relevant to the design of future clinical trials of CD56(high+) IFN-DCs-based immunotherapies for patients with melanoma.

Ex vivo-expanded natural killer cells kill cancer cells more effectively than ex vivo-expanded γδ T cells or αß T cells.

Adoptive immunotherapy of cancer is evolving with the development of novel technologies for generating a large number of activated killer cells such as natural killer (NK) cells, γδ T cells, and αß T cells. We have recently established large-scale culture methods to generate activated NK cells from human peripheral blood, and demonstrated that expanded NK cells have higher cytotoxicity against cancer cells than freshly isolated NK cells. In this study, we compared cultured NK cells with cultured γδ T and αß T cells that were prepared by conventional culture methods regarding the expression of cytotoxic molecules and cytotoxicity against cancer cells. Natural cytotoxicity receptors such as NKp30, NKp44 and NKp46, and perforin were expressed most exclusively on NK cells. Granzyme A, NKG2D, and interferon-γ were dominantly expressed in NK cells and γδ T cells but not in αß T cells. Consistent with the expression profiles of the cytotoxic molecules, cultured NK cells from both healthy volunteers and cancer patients demonstrated significantly higher cytotoxicity against cancer cell lines, including MHC class I-positive cell lines, compared with cultured γδ T cells and cultured αß T cells. Additionally, NK cells, unlike γδ T cells or αß T cells, expressed high levels of CD16, and showed augmented cytotoxicity when co-administered with an anti-CD20 monoclonal antibody drug, rituximab. These results suggest the excellent efficacy of expanded NK cells for cancer treatment.

Efficacy of ex vivo activated and expanded natural killer cells and T lymphocytes for colorectal cancer patients.

Immune cell-based therapies using natural killer (NK) cells and cytotoxic T cells are under constant scrutiny, with the aim to design an effective and reduced-toxicity therapy, which will benefit patients via improved quality of life and improved prognosis. Four patients with stage IV colon cancer were administered 1, 3, 5 and 6 effector cell intravenous infusions, respectively. Peripheral blood was collected from the patients and the ex vivo activation and expansion of NK and T cells was performed in Good Manufacturing Practice-certified clean rooms for ~12-15 days. Immunophenotypic analysis of the peripheral blood mononuclear cells (PBMCs) and expanded NK and T cells was conducted using flow cytometry and the patients were followed up. On average, 4.8×107 initial PBMCs and 2.7×109 total expanded cells were obtained. The intravenous infusions of the expanded cells were not accompanied by adverse reactions. Improved prognosis, reflected by a considerable decrease in the cancer markers, accompanied by an improved quality of life in the patients were observed. In conclusion, potential strategies are currently under development for the large-scale production of effectors cells; therefore, autologous immune enhancement therapy (AIET) may be considered as a viable approach to cancer treatment.

Autologous immune enhancement therapy against an advanced epithelioid sarcoma: A case report.

Rare types of cancer are often not effectively treated by approaches such as chemotherapy and radio-therapy, although their side-effects persist. Immunotherapy has been gaining attention worldwide with growing examples of its anticancer activity demonstrated in vivo. This case report describes a 35-year-old male who suffered from advanced epithelioid sarcoma and underwent 18 cycles of chemotherapy without any significant response, who suffered adverse effects that caused lung collapse. A notable response was observed following the administration of autologous immune enhancement therapy (AIET), which involves a process of isolation, activation and expansion of natural killer (NK) and T cells, which were obtained from the patient's own (autologous) peripheral blood. With the present data and the response of the patient to AIET, it may be proposed that AIET is beneficial for patients suffering from advanced epithelioid sarcoma without producing adverse effects.

Autologous immune enhancement therapy: A case report of a stage IV colonic cancer.

Current modalities of cancer treatment, including surgery, chemotherapy and radiotherapy, show marginal therapeutic responses in cancer patients. In adoptive immunotherapy, interleukin-2 (IL-2) activated immune cells demonstrated notable results in patients with advanced malignant disease. The present study reports the efficacy and safety of repetitive infusions of autologous immune enhancement therapy (AIET) in a stage IV colonic cancer patient who had already received first-line chemotherapeutic drugs. Peripheral blood was aspirated from the patient. Specifically, natural killer (NK) cells and T-lymphocytes were isolated from the peripheral blood mononuclear cells (PBMCs). These cells were activated and expanded ex vivo for 14 days and were transfused intravenously to the patient. After six infusions of AIET, the carcinoembryonic antigen (CEA) level was decreased from 901 to 437 U/ml, regression of lesions was noted and there were no adverse reactions during the course of this therapy. Thus, AIET may be a promising anticancer approach to eradicate tumor cells with other conventional therapies.

Analysis of a hollow core photonic bandgap fiber ring resonator based on micro-optical structure.

The fiber ring resonator (FRR) is the key component of resonator fiber optic gyros (R-FOGs). The configuration of a novel hollow core photonic bandgap fiber (HC-PBF) ring resonator is proposed based on the usage of micro-optical structure. The normalized transfer function of such kind of FRR is derived, and the effects of different FRR parameters' on the resonant depth, resonant finesse and sensitivity limited by the shot noise of the detector are simulated. The laboratory sample of integrated HC-PBF ring resonator is fabricated and tested experimentally and the optimal scheme is proposed based on the acquired test data. The experimental setup and results verify the feasibility of the micro-optical coupling structure used in the HC-PBF ring resonator and also support the integration and miniaturization of R-FOGs composed of HC-PBFs.

Synergistic cytotoxicity of ex vivo expanded natural killer cells in combination with monoclonal antibody drugs against cancer cells.

The adoptive transfer of highly cytotoxic natural killer (NK) cells is an emerging tool for cancer immunotherapy. Antibody-dependent cellular cytotoxicity (ADCC) has recently been identified as one of the critical factors for the clinical efficacy of anticancer antibodies, in which NK cells are the major effectors of ADCC. NK cells were expanded from PBMC by a feeder-cell-free expansion method. NK cell expansion efficiency was evaluated within a period of 21 days. The kinetics of NK cell expansion and the expression of activating and inhibitory receptors on NK cells were monitored. NK cells producing IFN-γ and TNF-α were detected by intracellular cytokine staining. The cytotoxicity of expanded NK cells against various cancer cells was compared with that of freshly isolated NK cells. The ADCC functions of expanded NK cells in combination with rituximab against CD20+ lymphoma cell lines were evaluated. Our method efficiently expanded NK cells ex vivo, which showed a much higher activity to induce the expression of activating receptors and to produce IFN-γ and TNF-α as well as cytotoxicity against various cancer cell lines including CD133+ primary cancer cells than freshly isolated NK cells. We observed a synergistic cytotoxicity of our expanded NK cells against CD20+ B lymphoma cell lines as well as higher IFN-γ and TNF-α production when combined with rituximab. Our results suggest that the adoptive transfer of a large number of ex vivo expanded NK cells, particularly in combination with monoclonal antibody drugs, is a useful tool for cancer immunotherapy.

Autologous immune enhancement therapy in recurrent ovarian cancer with metastases: a case report.

Current therapeutic modalities for ovarian cancer such as chemotherapy, radiotherapy and surgery have been reported to yield only marginal success in improving survival rates of patients and have associated adverse effects. We report here a case of recurrent stage IV ovarian cancer, treated with cell-based autologous immune enhancement therapy (AIET) along with chemotherapy and followed up for 18 months. A 54-year-old female was diagnosed with a recurrence of ovarian carcinoma 1 year after initial surgical removal followed by chemotherapy for stage IIIC ovarian carcinoma. When diagnosed in 2010 with recurrence, she had liver and spleen metastases with a CA-125 level of 243 U/ml and a stage IV clinical status. Six infusions of AIET using autologous in vitro expanded and activated natural killer (NK) cells (CD3-CD56+) and activated T lymphocytes (CD3+CD56+) were administered in combination with 6 cycles of chemotherapy with carboplatin and doxorubicin. Following this treatment, CA-125 decreased to 4.7 U/ml along with regression of the metastatic lesions and an improved quality of life. No adverse reactions were reported after the AIET transfusions. Eighteen months of follow-up revealed a static nonprogressive disease. Combining AIET with chemotherapy and other conventional treatments has been found to be effective in our experience, as reported earlier, even in patients with advanced ovarian cancer, and we recommend this strategy be considered in treating similar cases.

A comparative analysis of in vitro expansion of natural killer cells of a patient with autoimmune haemolytic anaemia and ovarian cancer with patients with other solid tumours.

The functional profile of natural killer (NK) cells has been reported to be lower in auto-immune haemolytic anaemia (AIHA). In this study, we report a comparative analysis of peripheral blood mononuclear cells (PBMNCs) and the in vitro expansion of NK cells in a patient with AIHA and cancer, with that of other cancer patients without AIHA. PBMNCs and in vitro NK-cell expansion of a 64-year old female patient with ovarian cancer and AIHA was compared with that of four other patients with cancer without AIHA who underwent autologous immune enhancement therapy (AIET). The NK cells were cultured using autologous plasma without feeder layers. The quantities of PBMNCs, NK cells and CD3-CD56+ cells were compared. The average quantity of PBMNCs per ml in Cases I to V were 10.71, 39.2, 49.26, 65.16 and 49.33×10(4), respectively, and the average maximum count of NK cells was 3.9, 1730.03, 1824.16, 1058.61 and 761×10(6), respectively. The average percentage of CD3-CD56+ cells in Cases I to V following in vitro expansion was 1.2, 65.7, 28.63, 65.9 and 40%, respectively. In the present study, probably the first in the literature, the in vitro expansion of NK cells was found to be significantly lower in the AIHA patient. Previously, only a lower NK-cell functional profile was reported. Further studies are required to establish the association between AIHA and NK-cell profile and in vitro expansion, and to find common antibodies between red blood cells (RBCs) and NK cells.

Refractory lung metastasis from breast cancer treated with multidisciplinary therapy including an immunological approach.

A suggestive case of metastatic disease from breast cancer is reported. The HER-2-positive tumor was refractory to several agents, including anti-HER-2 therapy, trastuzumab, and lapatinib. After re-induction of trastuzumab in combination with activated natural killer (NK) cell injection therapy, tumor markers decreased, and finally a synergistic effect of taxane and capecitabine led to treatment response. This case suggests that multidisciplinary therapy including an immunological approach might be a breakthrough in the treatment of refractory disease.

Natural killer activity of peripheral-blood mononuclear cells in breast cancer patients.

Natural killer (NK) activity of immune cells plays a central role in host defense against cancer and virus-infected cells. Natural cytotoxic activity of peripheral-blood mononuclear cells was assessed by a Calcein-AM release assay in 89 subjects. In the present study, we here demonstrated that NK activities of peripheral-blood mononuclear cells (PBMCs) from breast cancer patients were significantly lower as compared with that of healthy individuals. There were significant differences in the NK activities of PBMCs from HER2-negative breast cancer patients as compared with HER2-positive patients. Our results suggest that NK activity of PBMCs is lower in breast cancer indicating a role for immunological natural host defense mechanisms against cancer.

Potential role of NK cells in the induction of immune responses: implications for NK cell-based immunotherapy for cancers and viral infections.

Natural killer (NK) cells recognize tumor cells and virus-infected cells and attack without being sensitized to antigens. The development of the antitumor/antivirus activities of NK cells is controlled by multiple mechanisms such as direct cytotoxic activity against target cells, antibody-dependent cell-mediated cytotoxicity, secretion of Th1-type cytokines, and interactions with dendritic cells. The development of these activities plays a significant role in both innate and adaptive immunities. Considering the recent progress made in elucidating the molecular and cellular biology of NK cells, we summarize the current situation and discuss future possibilities with regard to NK cell-based adoptive immunotherapy.

Potential role of natural killer cells in controlling growth and infiltration of AIDS-associated primary effusion lymphoma cells.

Natural killer (NK) cells are an important component of the innate immune response against microbial infections and tumors. Direct involvement of NK cells in tumor growth and infiltration has not yet been demonstrated clearly. Primary effusion lymphoma (PEL) cells were able to produce tumors and ascites very efficiently with infiltration of cells in various organs of T-, B- and NK-cell knock-out NOD/SCID/gammac(null) (NOG) mice within 3 weeks. In contrast, PEL cells formed small tumors at inoculated sites in T- and B-cell knock-out NOD/SCID mice with NK-cells while completely failing to infiltrate into various organs. Immunosupression of NOD/SCID by treatment with an antimurine TM-beta1 antibody, which transiently abrogates NK cell activity in vivo, resulted in enhanced tumorigenicity and organ infiltration in comparison with non-treated NOD/SCID mice. Activated human NK cells inhibited tumor growth and infiltration in NOG mice. Our results suggest that NK cells play an important role in growth and infiltration of PEL cells, and activated NK cells could be a promising immunotherapeutic tool against tumor or virus-infected cells either alone or in combination with conventional therapy. The rapid and efficient engraftment of PEL cells in NOG mice also suggests that this new animal model could provide a unique opportunity to understand and investigate the mechanism of pathogenesis and malignant cell growth.

Predominance of three NF-kappaB binding sites in the long terminal repeat region of HIV Type 1 subtype C isolates from Zambia.

Human immunodeficiency virus type-1 (HIV-1) is a leading cause of mortality and morbidity in the world, with almost 46 million people infected globally. HIV-1 subtype C accounts for 55% of these infections. In Zambia, the majority of HIV-1 infections are subtype C. However, to its north most countries have non-subtype C as the most predominant HIV-1 subtype while to its south most of them are predominantly subtype C. The aim of this study was to determine the subtype distribution and to analyze the long terminal repeat (LTR) region of HIV-1 isolates from the northern part of Zambia. We amplified as well as directly sequenced the LTR, gag, and env regions of 78 HIV-1 peripheral blood samples from adult Zambians. Our results show 95% (74/78) of our isolates were HIV-1 subtype C. Furthermore, of the subtype C samples analyzed across the LTR, 61% (25/41) carried 3 NF-kappaB signature binding site sequences.

Antithetical effects of hemicellulase-treated Agaricus blazei on the maturation of murine bone-marrow-derived dendritic cells.

We report the effects of hemicellulase-treated Agaricus blazei (ABH) on the maturation of bone-marrow-derived dendritic cells (BMDCs). ABH activated immature BMDCs, inducing up-regulation of surface molecules, such as CD40, CD80 and major histocompatibility complex class I antigens, as well as inducing allogeneic T-cell proliferation and T helper type 1 cell development. However, unlike lipopolysaccharide (LPS), ABH did not stimulate the BMDCs to produce proinflammatory cytokines, such as interleukin-12 (IL-12) p40, tumour necrosis factor-alpha, or IL-1beta. In addition, ABH suppressed LPS-induced DC responses. Pretreatment of DCs with ABH markedly reduced the levels of LPS-induced cytokine secretion, while only slightly decreasing up-regulation of the surface molecules involved in maturation. ABH also had a significant impact on peptidoglycan-induced or CpG oligodeoxynucleotide-induced IL-12p40 production in DCs. The inhibition of LPS-induced responses was not associated with a cytotoxic effect of ABH nor with an anti-inflammatory effect of IL-10. However, ABH decreased NF-kappaB-induced reporter gene expression in LPS-stimulated J774.1 cells. Interestingly, DCs preincubated with ABH and then stimulated with LPS augmented T helper type 1 responses in culture with allogeneic T cells as compared to LPS-stimulated but non-ABH-pretreated DCs. These observations suggest that ABH regulates DC-mediated responses.