In vitro effects of vitamin C and selenium on NK activity of patients with beta-thalassemia major

Proliferation capability of natural killer cells upon cytokines stimulation correlated negatively with serum lactate dehydrogenase level in coronary artery disease patients

Background

Natural killer (NK) cells are proposed to participate in coronary artery disease (CAD) development. However, little is known about how CAD patients' NK cells respond to different stimulatory factors in terms of proliferation capability.

Methods and results

Twenty-nine CAD patients' peripheral blood NK cells were isolated and individually treated with IL-2, IL-12, IL-15, IL-18, IL-21, cortisone acetate, hydrocortisone, or ascorbic acid for 36 hours, followed by cell cycle analysis using flow cytometry. The ratio of S and G2/M phase cell number to total cell number was defined as a proliferation index (PrI) and used for proliferative capability indication. The results showed that these eight factors resulted in different life cycle changes in the 29 NK cell samples. Remarkably, 28 out of 29 NK cell samples showed an obvious increase in PrI upon ascorbic acid treatment. The serum lactate dehydrogenase (LDH) level of the 29 CAD patients was measured. The results showed a negative correlation between serum LDH level and the CAD patients' NK cell PrI upon stimulation of interleukins, but not the non-interleukin stimulators. Consistently, a retrospective analysis of 46 CAD patients and 32 healthy donors showed that the circulating NK cell number negatively correlated with the serum LDH level in CAD patients. Unexpectedly, addition of LDH to NK cells significantly enhanced the production of IFN-γ, IL-10 and TNF-α, suggesting a strong regulatory role on NK cell's function.

Conclusion

Ascorbic acid could promote the proliferation of the CAD patients' NK cells; LDH serum level may function as an indicator for NK cell proliferation capability and an immune-regulatory factor.

Ascorbic acid modulates immune responses through Jumonji-C domain containing histone demethylases and Ten eleven translocation (TET) methylcytosine dioxygenase

Ascorbic acid is a redox regulator in many physiological processes. Besides its antioxidant activity, many intriguing functions of ascorbic acid in the expression of immunoregulatory genes have been suggested. Ascorbic acid acts as a co-factor for the Fe+2 -containing α-ketoglutarate-dependent Jumonji-C domain-containing histone demethylases (JHDM) and Ten eleven translocation (TET) methylcytosine dioxygenasemediated epigenetic modulation. By influencing JHDM and TET, ascorbic acid facilitates the differentiation of double negative (CD4- CD8- ) T cells to double positive (CD4+ CD8+ ) T cells and of T-helper cells to different effector subsets. Ascorbic acid modulates plasma cell differentiation and promotes early differentiation of hematopoietic stem cells (HSCs) to NK cells. These findings indicate that ascorbic acid plays a significant role in regulating both innate and adaptive immune cells, opening up new research areas in Immunonutrition. Being a water-soluble vitamin and a safe micro-nutrient, ascorbic acid can be used as an adjunct therapy for many disorders of the immune system.

Pharmacological ascorbate as a novel therapeutic strategy to enhance cancer immunotherapy

Pharmacological ascorbate (i.e., intravenous infusions of vitamin C reaching ~ 20 mM in plasma) is under active investigation as an adjuvant to standard of care anti-cancer treatments due to its dual redox roles as an antioxidant in normal tissues and as a prooxidant in malignant tissues. Immune checkpoint inhibitors (ICIs) are highly promising therapies for many cancer patients but face several challenges including low response rates, primary or acquired resistance, and toxicity. Ascorbate modulates both innate and adaptive immune functions and plays a key role in maintaining the balance between pro and anti-inflammatory states. Furthermore, the success of pharmacological ascorbate as a radiosensitizer and a chemosensitizer in pre-clinical studies and early phase clinical trials suggests that it may also enhance the efficacy and expand the benefits of ICIs.

The Variable Nature of Vitamin C—Does It Help When Dealing with Coronavirus?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still spreading worldwide. For this reason, new treatment methods are constantly being researched. Consequently, new and already-known preparations are being investigated to potentially reduce the severe course of coronavirus disease 2019 (COVID-19). SARS-CoV-2 infection induces the production of pro-inflammatory cytokines and acute serum biomarkers in the host organism. In addition to antiviral drugs, there are other substances being used in the treatment of COVID-19, e.g., those with antioxidant properties, such as vitamin C (VC). Exciting aspects of the use of VC in antiviral therapy are its antioxidant and pro-oxidative abilities. In this review, we summarized both the positive effects of using VC in treating infections caused by SARS-CoV-2 in the light of the available research. We have tried to answer the question as to whether the use of high doses of VC brings the expected benefits in the treatment of COVID-19 and whether such treatment is the correct therapeutic choice. Each case requires individual assessment to determine whether the positives outweigh the negatives, especially in the light of populational studies concerning the genetic differentiation of genes encoding the solute carriers responsible forVC adsorption. Few data are available on the influence of VC on the course of SARS-CoV-2 infection. Deducing from already-published data, high-dose intravenous vitamin C (HDIVC) does not significantly lower the mortality or length of hospitalization. However, some data prove, among other things, its impact on the serum levels of inflammatory markers. Finally, the non-positive effect of VC administration is mainly neutral, but the negative effect is that it can result in urinary stones or nephropathies.

Vitamin C, From Supplement to Treatment: A Re-Emerging Adjunct for Cancer Immunotherapy?

Vitamin C (VitC), in addition to its role as a general antioxidant, has long been considered to possess direct anti-cancer activity at high doses. VitC acts through oxidant and epigenetic mechanisms, which at high doses can exert direct killing of tumor cells in vitro and delay tumor growth in vivo. Recently, it has also been shown that pharmacologic-dose VitC can contribute to control of tumors by modulating the immune system, and studies have been done interrogating the role of physiologic-dose VitC on novel adoptive cellular therapies (ACTs). In this review, we discuss the effects of VitC on anti-tumor immune cells, as well as the mechanisms underlying those effects. We address important unanswered questions concerning both VitC and ACTs, and outline challenges and opportunities facing the use of VitC in the clinical setting as an adjunct to immune-based anti-cancer therapies.

Pathomechanisms of Immunological Disturbances in β-Thalassemia

Thalassemia, a chronic disease with chronic anemia, is caused by mutations in the β-globin gene, leading to reduced levels or complete deficiency of β-globin chain synthesis. Patients with β-thalassemia display variable clinical severity which ranges from asymptomatic features to severe transfusion-dependent anemia and complications in multiple organs. They not only are at increased risk of blood-borne infections resulting from multiple transfusions, but they also show enhanced susceptibility to infections as a consequence of coexistent immune deficiency. Enhanced susceptibility to infections in β-thalassemia patients is associated with the interplay of several complex biological processes. β-thalassemia-related abnormalities of the innate immune system include decreased levels of complement, properdin, and lysozyme, reduced absorption and phagocytic ability of polymorphonuclear neutrophils, disturbed chemotaxis, and altered intracellular metabolism processes. According to available literature data, immunological abnormalities observed in patients with thalassemia can be caused by both the disease itself as well as therapies. The most important factors promoting such alterations involve iron overload, phenotypical and functional abnormalities of immune system cells resulting from chronic inflammation oxidative stress, multiple blood transfusion, iron chelation therapy, and splenectomy. Unravelling the mechanisms underlying immune deficiency in β-thalassemia patients may enable the designing of appropriate therapies for this group of patients.

Vitamin and mineral supplementation for β-thalassemia during COVID-19 pandemic

AIM

Low levels of immune-related micronutrients have been identified in β-thalassemia samples. Moreover, the excess amount of iron, contributing to oxidative stress in the pathogenesis of the disease, alters the immune system in β-thalassemia, which is important during the COVID-19 pandemic.

MATERIALS & METHODS

Searches of PUBMED and EMBASE were conducted to identify the level and supplementation of micronutrients in β-thalassemia, published from 2001-May 2020.

RESULTS

The review found six observational and five interventional studies supporting the importance of supplementing vitamins and minerals among patients with β-thalassemia.

CONCLUSION

Supplementation of immune-related vitamins and minerals might bring benefits to the immune system, especially in reducing oxidative stress in β-thalassemia.

Immunomodulatory and Antimicrobial Effects of Vitamin C

Humans have lost their vitamin C-synthesizing capacities during evolution. Therefore, the uptake of this essential compound from external sources is mandatory in order to prevent vitamin C-deficient conditions resulting in severe morbidities such as scurvy. The potent antioxidant, immunomodulatory, and antiinfectious effects of vitamin C are known since the 1930s. We here (i) review the impact of vitamin C on innate and adaptive immune functions, (ii) provide an overview of its antimicrobial, antibacterial, antiviral, antiparasitic, and antifungal properties, and finally, (iii) discuss vitamin C as an adjunct treatment option for the combat of human infections by bacteria, particularly by emerging multidrug-resistant species.

Influence of Vitamin C on Lymphocytes: An Overview

Vitamin C or ascorbic acid (AA) is implicated in many biological processes and has been proposed as a supplement for various conditions, including cancer. In this review, we discuss the effects of AA on the development and function of lymphocytes. This is important in the light of cancer treatment, as the immune system needs to regenerate following chemotherapy or stem cell transplantation, while cancer patients are often AA-deficient. We focus on lymphocytes, as these white blood cells are the slowest to restore, rendering patients susceptible to often lethal infections. T lymphocytes mediate cellular immunity and have been most extensively studied in the context of AA biology. In vitro studies demonstrate that T cell development requires AA, while AA also enhances T cell proliferation and may influence T cell function. There are limited and opposing data on the effects of AA on B lymphocytes that mediate humoral immunity. However, AA enhances the proliferation of NK cells, a group of cytotoxic innate lymphocytes. The influence of AA on natural killer (NK) cell function is less clear. In summary, an increasing body of evidence indicates that AA positively influences lymphocyte development and function. Since AA is a safe and cheap nutritional supplement, it is worthwhile to further explore its potential benefits for immune reconstitution of cancer patients treated with immunotoxic drugs.

Quantitative assessment of metal dysregulation in β-thalassemia patients in comparison with healthy controls by ICP-MS and chemometric analyses

β-Thalassemia is one of the most common inherited disorders and is widely distributed throughout the world. Owing to severe deficiencies in red blood cell production, blood transfusion is required to correct anemia for normal growth and development but causes additional complications owing to iron overload. The aim of this study is to quantify the biometal dysregulations in β-thalassemia patients as compared with healthy controls. A total of 17 elements were analyzed in serum samples of β-thalassemia patients and healthy controls using ICP-MS followed by chemometric analyses. Out of these analyzed elements, 14 showed a significant difference between healthy and disease groups at p < 0.05 and fold change >3. A PLS-DA model revealed an excellent separation with 89.8% sensitivity and 97.2% specificity and the overall accuracy of the model was 92.2%. This metallomic study revealed that there is major difference in metallomic profiling of β-thalassemia patients specifically in Co, Mn, Ni, V and Ba, whereas the fold changes in Co, Mn, V and Ba were found to be greater than that in Fe, providing evidence that, in addition to Fe, other metals are also altered significantly and therefore chelation therapy for other metals may also needed in β-thalassemia patients.

Sea buckthorn (Hippophae rhamnoides L.) oil protects against chronic stress-induced inhibitory function of natural killer cells in rats

Chronic stress can suppress natural killer (NK) cell activity; this may also be related to the effect of stress on the neuroendocrine-immune network. Sea buckthorn (SBT) (Hippophae rhamnoides L.) is a thorny nitrogen fixing deciduous shrub, native to both Europe and Asia. It has been used as a medicinal plant in Tibetan and Mongolian traditional medicines. SBT has multifarious medical properties, including anti-fatigue as well as immunoregulatory effects. This study reports the effects of SBT oil with regard to the cytotoxicity and quantity of NK cells in the blood of a chronic-stress rat model, in addition to its mechanisms on the neuroendocrine-immune network. These results show that SBT oil, given by gavage to rats with chronic stress, could increase the following: body weight, NK cell quantities, and cytotoxicity, as well as the expression of perforin and granzyme B. The results also show that SBT oil in rats with chronic stress could suppress cortisol, ACTH, IL-1β and TNF-α levels, in addition to increasing 5-HT and IFN-γ serum levels. This leads to suggest that SBT oil, in rats with chronic stress, can increase NK cell cytotoxicity by upregulating the expression of perforin and granzyme B, thus causing associated effects of SBT oil on the neuroendocrine-immune network.

Effects of vitamin C on the hypobaric hypoxia-induced immune changes in male rats

Hypobaric hypoxia (HH) induces oxidative stress (OS) and is associated with the generation of reactive oxygen species (ROS). Vitamin C is an efficient antioxidant, and it is used in a high-altitude environment to reduce the OS. The present study explores the role of vitamin C on some HH-induced changes of immune parameters in rats which were exposed to HHc condition at 18,000 ft in a simulated chamber for 8 h/day for 6 days with and without vitamin C administration at three different doses (200, 400, and 600 mg/kg body wt). The phagocytic activity of circulating blood WBC was increased, and the cytotoxic activity of splenic mononuclear cell (MNC) and the delayed type of hypersensitivity (DTH) responses to bovine serum albumin (BSA) were decreased in rats exposed to HHc condition, but these immune changes were blocked after administration of vitamin C at 400 mg/kg body wt. The leukocyte adhesive inhibition index (LAI) was not altered either in HHc condition or after administration of vitamin C in HHc condition. The serum corticosterone (CORT) concentration was increased in rats exposed to HHc condition which was blocked after administration of vitamin C (400 mg/kg body wt). The immune parameters and serum CORT concentration, however, did not show any recovery after administration of vitamin C at the dose of 200 and 600 mg/kg body wt. The present study indicates that administration of vitamin C at a dose of 400 mg/kg body wt may prevent the HH-induced immunological changes but not at the lower dose (200 mg/kg body wt) or higher dose (600 mg/kg body wt) in rats.

Effects of micro environmental factors on natural killer activity (NK) of beta thalassemia major patients

The physiological mechanisms of decreased NK activity of β-Thalassemia major (BTM) patients are unknown. To assess in vitro effects of mononuclear cells and their cytokine secretion on NK activity, we compared activator receptor levels and cytotoxic activity of purified NK cells and NK cells in mononuclear cells (MNC) pools. We collected cell supernatant from unincubated and incubated MNC with K562 cells and measured their secreted cytokines levels. CD16 was lower on the surface of NK cells in MNC pools from BTM patients compared to healthy volunteers. This inhibition does not appear when NK cells were purified. NKp30 levels in NK cells decreased both as purified cells and as part of a pool of MNC in BTM patients. After incubation of MNC pools with K562 target cells, we found that supernatant levels of IL10, TGFβ1 and IL15 cytokines were also significantly higher in BTM patients compared to healthy volunteers.

Protein antioxidants in thalassemia

It is common knowledge that thalassemic patients are under significant oxidative stress. Chronic hemolysis, frequent blood transfusion, and increased intestinal absorption of iron are the main factors that result in iron overload with its subsequent pathophysiologic complications. Iron overload frequently associates with the generation of redox-reactive labile iron, which in turn promotes the production of other reactive oxygen species (ROS). If not neutralized, uncontrolled production of ROS often leads to damage of various intra- and extracellular components such as DNA, proteins, lipids, and small antioxidant molecules among others. A number of endogenous and exogenous defense mechanisms can neutralize and counteract the damaging effects of labile iron and the reactive substances associated with it. Endogenous antioxidant enzymes, such as superoxide dismutase, catalase, glutathione peroxidase, and ferroxidase, may directly or sequentially terminate the activities of ROS. Nonenzymatic endogenous defense mechanisms include metal binding proteins (ceruloplasmin, haptoglobin, albumin, and others) and endogenously produced free radical scavengers (glutathione (GSH), ubiquinols, and uric acid). Exogenous agents that are known to function as antioxidants (vitamins C and E, selenium, and zinc) are mostly diet-derived. In this review, we explore recent findings related to various antioxidative mechanisms operative in thalassemic patients with special emphasis on protein antioxidants.

NK cell maturation and function in C57BL/6 mice are altered by caloric restriction

NK cells are a heterogenous population of innate lymphocytes with diverse functional attributes critical for early protection from viral infections. We have previously reported a decrease in influenza-induced NK cell cytotoxicity in 6-mo-old C57BL/6 calorically restricted (CR) mice. In the current study, we extend our findings on the influence of CR on NK cell phenotype and function in the absence of infection. We demonstrate that reduced mature NK cell subsets result in increased frequencies of CD127(+) NK cells in CR mice, skewing the function of the total NK cell pool. NK cells from CR mice produced TNF-α and GM-CSF at a higher level, whereas IFN-γ production was impaired following IL-2 plus IL-12 or anti-NK1.1 stimulation. NK cells from CR mice were highly responsive to stimulation with YAC-1 cells such that CD27(-)CD11b(+) NK cells from CR mice produced granzyme B and degranulated at a higher frequency than CD27(-)CD11b(+) NK cells from ad libitum fed mice. CR has been shown to be a potent dietary intervention, yet the mechanisms by which the CR increases life span have yet to be fully understood. To our knowledge, these findings are the first in-depth analysis of the effects of caloric intake on NK cell phenotype and function and provide important implications regarding potential ways in which CR alters NK cell function prior to infection or cancer.

Decreased IFN-γ and IL-12 levels in panic disorder

OBJECTIVE

The aim of this study is to assess the measures of proinflammatory cytokines in patients with panic disorder in comparison with the healthy subjects.

METHODS

Twenty three patients with panic disorder with or without agoraphobia and twenty three controls were recruited for the study. Plasma samples of all subjects were analyzed for TNF-α, IFN-γ, IL-1β, IL-2, IL-6, and IL-12 concentrations and NK-cell activity is measured in the peripheral blood samples of the subjects.

RESULTS

We found significant differences on the mean values of IL-12 (p=0.01) and IFN-γ (p=0.02) between the panic disorder and control groups. In a logistic regression analysis, IFN-γ values were significant statistical predictors of the presence of panic disorder (B=-0.07, SE=0.03, p=0.04).

CONCLUSION

The most important implication of our results is to suggest a relation between panic disorder and low levels of IFN-γ, compatible with the results of the animal studies showing that IFN-γ plays a role by acting to regulate the development of anxiety-like behaviors.

Correlation of oxidative stress with serum trace element levels and antioxidant enzyme status in Beta thalassemia major patients: a review of the literature

Beta thalassemia major is an inherited disease resulting from reduction or total lack of beta globin chains. Patients with this disease need repeated blood transfusion for survival. This may cause oxidative stress and tissue injury due to iron overload, altered antioxidant enzymes, and other essential trace element levels. The aim of this review is to scrutinize the relationship between oxidative stress and serum trace elements, degree of damage caused by oxidative stress, and the role of antioxidant enzymes in beta thalassemia major patients. The findings indicate that oxidative stress in patients with beta thalassemia major is mainly caused by tissue injury due to over production of free radical by secondary iron overload, alteration in serum trace elements and antioxidant enzymes level. The role of trace elements like selenium, copper, iron, and zinc in beta thalassemia major patients reveals a significant change of these trace elements. Studies published on the status of antioxidant enzymes like catalase, superoxide dismutase, glutathione, and glutathione S-transferase in beta thalassemia patients also showed variable results. The administration of selective antioxidants along with essential trace elements and minerals to reduce the extent of oxidative damage and related complications in beta thalassemia major still need further evaluation.