A Safety Evaluation of Intravenous Administration of ex vivo Expanded Human Peripheral Blood-Derived NK Cells: A Preclinical Study

The use of natural killer (NK) cells in the treatment of various cancers is emerging as a promising approach in adoptive immunotherapy. However, the safety of ex vivo activated and expanded cells in in vivo conditions remain unknown. In this study, the toxicity of NK cells was evaluated at different doses, with 5 × 106, 20 × 106 and 50 × 106 cells injected intravenously into pre-irradiated (30Gy) immunodeficient mice twice a week for three weeks and the mice were followed-up on for 90 days. Throughout the study, no mortality, abnormal clinical signs, or behavioural changes related to the testing material were observed in either the treated or control groups of mice. There were no significant variations in food and water consumption between both genders in the NK cell treated and control groups. However, certain significant changes were observed between the groups in the clinical biochemistry and urine analysis reports. As autopsy showed no significant variations in absolute and relative organ weights between the groups, except for the livers of the treated mice. The histopathological analysis also demonstrated that there were no significant abnormalities in most of the organs of both genders, except for the liver. Some necrotic lesions were observed in the livers of both the treated and control mice, and these lesions may be due to the effects of irradiation or could be common in NOD.SCID mice. The findings of this study indicate that intravenous administration of NK cells is safe and does not cause any adverse effects up to the dose of 50 × 106 cells/mouse.

Mesenchymal stem cell therapy for advanced liver cirrhosis: A case report

Mesenchymal stem cell (MSC) transplant may offer an alternative to liver transplantation in patients with end‐stage liver disease. However, its efficacy remains uncertain. MSC was performed on a 50‐year‐old male with decompensated (Child‐Turcotte‐Pugh grade C) alcoholic liver cirrhosis due to an absence of donors for adult‐deceased and living‐related liver transplantation. Autologous bone marrow‐derived MSCs were harvested from the patient and cultured using standard protocols. The MSCs were subsequently re‐administrated into the liver via hepatic intra‐arterial infusion on two separate occasions. After infusion, there was an improvement in biochemical parameters (serum total bilirubin, serum albumin), and a reduction of diuretic use for ascites for up to 8 weeks. However, all biochemical and clinical parameters deteriorated on long‐term follow‐up without any further infusions. The patient eventually succumbed to his disease. MSC transplantation may have a clinical benefit on adult patients with end‐stage liver cirrhosis, but this appears to be transitory.

Impaired redox environment modulates cardiogenic and ion-channel gene expression in cardiac-resident and non-resident mesenchymal stem cells

Redox homeostasis plays a crucial role in the regulation of self-renewal and differentiation of stem cells. However, the behavioral actions of mesenchymal stem cells in redox imbalance state remain elusive. In the present study, the effect of redox imbalance that was induced by either hydrogen peroxide (H₂O₂) or ascorbic acid on human cardiac-resident (hC-MSCs) and non-resident (umbilical cord) mesenchymal stem cells (hUC-MSCs) was evaluated. Both cells were sensitive and responsive when exposed to either H₂O₂ or ascorbic acid at a concentration of 400 µmol/L. Ascorbic acid pre-treated cells remarkably ameliorated the reactive oxygen species level when treated with H₂O₂. The endogenous antioxidative enzyme gene (Sod1, Sod2, TRXR1 and Gpx1) expressions were escalated in both MSCs in response to reactive oxygen species elevation. In contrast, ascorbic acid pre-treated hUC-MSCs attenuated considerable anti-oxidative gene (TRXR1 and Gpx1) expressions, but not the hC-MSCs. Similarly, the cardiogenic gene (Nkx 2.5, Gata4, Mlc2a and β-MHC) and ion-channel gene ( I_KDR, I_KCa, I_to and I_Na.TTX) expressions were significantly increased in both MSCs on the oxidative state. On the contrary, reduced environment could not alter the ion-channel gene expression and negatively regulated the cardiogenic gene expressions except for troponin-1 in both cells. In conclusion, redox imbalance potently alters the cardiac-resident and non-resident MSCs stemness, cardiogenic, and ion-channel gene expressions. In comparison with cardiac-resident MSC, non-resident umbilical cord-MSC has great potential to tolerate the redox imbalance and positively respond to cardiac regeneration. Impact statement Human mesenchymal stem cells (h-MSCs) are highly promising candidates for tissue repair in cardiovascular diseases. However, the retention of cells in the infarcted area has been a major challenge due to its poor viability and/or low survival rate after transplantation. The regenerative potential of mesenchymal stem cells (MSCs) repudiate and enter into premature senescence via oxidative stress. Thus, various strategies have been attempted to improve the MSC survival in 'toxic' conditions. Similarly, we investigated the response of cardiac resident MSC (hC-MSCs) and non-resident MSCs against the oxidative stress induced by H₂O₂. Supplementation of ascorbic acid (AA) into MSCs culture profoundly rescued the stem cells from oxidative stress induced by H₂O₂. Our data showed that the pre-treatment of AA is able to inhibit the cell death and thus preserving the viability and differentiation potential of MSCs.

Generation and characterization of human cardiac resident and non-resident mesenchymal stem cell

Despite the surgical and other insertional interventions, the complete recuperation of myocardial disorders is still elusive due to the insufficiency of functioning myocardiocytes. Thus, the use of stem cells to regenerate the affected region of heart becomes a prime important. In line with this human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) have gained considerable interest due to their potential use for mesodermal cell based replacement therapy and tissue engineering. Since MSCs are harvested from various organs and anatomical locations of same organism, thus the cardiac regenerative potential of human cardiac-derived MSCs (hC-MSCs) and human umbilical cord Wharton's Jelly derived MSC (hUC-MSCs) were tested concurrently. At in vitro culture, both hUC-MSCs and hC-MSCs assumed spindle shape morphology with expression of typical MSC markers namely CD105, CD73, CD90 and CD44. Although, hUC-MSCs and hC-MSCs are identical in term of morphology and immunophenotype, yet hUC-MSCs harbored a higher cell growth as compared to the hC-MSCs. The inherent cardiac regenerative potential of both cells were further investigated with mRNA expression of ion channels. The RT-PCR results demonstrated that both MSCs were expressing a notable level of delayed rectifier-like K(+) current (I KDR ) ion channel, yet the relative expression level was considerably varied between hUC-MSCs and hC-MSCs that Kv1.1(39 ± 0.6 vs 31 ± 0.8), Kv2.1 (6 ± 0.2 vs 21 ± 0.12), Kv1.5 (7.4 ± 0.1 vs 6.8 ± 0.06) and Kv7.3 (27 ± 0.8 vs 13.8 ± 0.6). Similarly, the Ca2(+)-activated K(+) current (I KCa ) channel encoding gene, transient outward K(+) current (I to ) and TTX-sensitive transient inward sodium current (I Na.TTX ) encoding gene (Kv4.2, Kv4.3 and hNE-Na) expressions were detected in both groups as well. Despite the morphological and phenotypical similarity, the present study also confirms the existence of multiple functional ion channel currents IKDR, IKCa, Ito, and INa.TTX in undifferentiated hUC-MSCs as of hC-MSCs. Thus, the hUC-MSCs can be exploited as a potential candidate for future cardiac regeneration.

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.