scholarly journals The Role of the Status of Selected Micronutrients in Shaping the Immune Function

2019 ◽  
Vol 19 (8) ◽  
pp. 1100-1115 ◽  
Author(s):  
Ibrahim Elmadfa ◽  
Alexa L. Meyer
Keyword(s):  
T Cells ◽  
Cellular Immunity ◽  
Viral Infections ◽  
Cell Signalling ◽  
The Elderly ◽  
Immune Defence ◽  
Th1 Cell ◽  
Special Effects ◽  
T Cell Subpopulations

Objective: This narrative review gives an overview on the essential role of adequate nutrition to an optimally functioning immune defence. Micronutrients act as regulators of the immune response, with the focus of this review on the immunomodulatory effects of the trace elements iron, zinc and selenium, and the vitamins A, D, E, C, B6 and B12 and folic acid. Results: Iron deficiency especially impairs the Th1 cell-borne cellular immunity. T lymphocytes are also most affected by a deficiency of zinc, needed for their maturation and the balance between the different T cell subpopulations and acting as a redox signal in the regulation of many enzymes. Selenium is also involved in redox reactions as the glutathione peroxidases and other redox enzymes are selenoproteins. Selenium status has shown special effects on cellular immunity and resistance to viral infections. : Vitamin A in the form of retinoic acid induces a humoral Th2 cell response via antigen-presenting cells and is involved in maintaining intestinal immune defence and tolerance through its nuclear receptor RAR and via kinase signalling cascades. Immune tolerance is particularly promoted by vitamin D acting through dendritic cells to stimulate the differentiation of regulatory T cells. Vitamin E has antiinflammatory effects and stimulates naïve T cells especially in the elderly. Besides its antioxidative properties, vitamin C has effects on cell signalling and epigenetic regulation. The B vitamins are required for cytotoxic cellular immunity and modulateT cell responses. : A diverse diet and regular exposure to sunlight are the best sources for a balanced nutrient supply to maintain an optimal immune defence.

scholarly journals Protective to a T: The Role of T Cells during Zika Virus Infection

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 820 ◽  
Author(s):  
Ryan D. Pardy ◽  
Martin J. Richer
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Zika Virus ◽  
Viral Infections ◽  
Cross Reactivity ◽  
Negative Effects ◽  
Cell Responses ◽  
Recent Emergence ◽  
Human Infections

CD4 and CD8 T cells are an important part of the host’s capacity to defend itself against viral infections. During flavivirus infections, T cells have been implicated in both protective and pathogenic responses. Given the recent emergence of Zika virus (ZIKV) as a prominent global health threat, the question remains as to how T cells contribute to anti-ZIKV immunity. Furthermore, high homology between ZIKV and other, co-circulating flaviviruses opens the possibility of positive or negative effects of cross-reactivity due to pre-existing immunity. In this review, we will discuss the CD4 and CD8 T cell responses to ZIKV, and the lessons we have learned from both mouse and human infections. In addition, we will consider the possibility of whether T cells, in the context of flavivirus-naïve and flavivirus-immune subjects, play a role in promoting ZIKV pathogenesis during infection.

scholarly journals SARS-CoV-2-specific T cells in infection and vaccination

2021 ◽  
Vol 18 (10) ◽  
pp. 2307-2312 ◽  
Author(s):  
Antonio Bertoletti ◽  
Nina Le Bert ◽  
Martin Qui ◽  
Anthony T. Tan
Keyword(s):  
T Cells ◽  
Adaptive Immunity ◽  
Viral Infections ◽  
Infected Cells

AbstractDuring viral infections, antibodies and T cells act together to prevent pathogen spread and remove virus-infected cells. Virus-specific adaptive immunity can, however, also trigger pathological processes characterized by localized or systemic inflammatory events. The protective and/or pathological role of virus-specific T cells in SARS-CoV-2 infection has been the focus of many studies in COVID-19 patients and in vaccinated individuals. Here, we review the works that have elucidated the function of SARS-CoV-2-specific T cells in patients and in vaccinated individuals. Understanding whether SARS-CoV-2-specific T cells are more linked to protection or pathogenesis is pivotal to define future therapeutic and prophylactic strategies to manage the current pandemic.

scholarly journals Immunosenescence: a key player in cancer development

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Jingyao Lian ◽  
Ying Yue ◽  
Weina Yu ◽  
Yi Zhang
Keyword(s):  
T Cells ◽  
Cytotoxic T Lymphocyte ◽  
Malignant Tumors ◽  
Killer Cell ◽  
Antibody Therapy ◽  
The Elderly ◽  
Mtor Inhibition ◽  
Interleukin 7 ◽  
The Many

Abstract Immunosenescence is a process of immune dysfunction that occurs with age and includes remodeling of lymphoid organs, leading to changes in the immune function of the elderly, which is closely related to the development of infections, autoimmune diseases, and malignant tumors. T cell–output decline is an important feature of immunosenescence as well as the production of senescence-associated secretory phenotype, increased glycolysis, and reactive oxygen species. Senescent T cells exhibit abnormal phenotypes, including downregulation of CD27, CD28, and upregulation of CD57, killer cell lectin-like receptor subfamily G, Tim-3, Tight, and cytotoxic T-lymphocyte-associated protein 4, which are tightly related to malignant tumors. The role of immunosenescence in tumors is sophisticated: the many factors involved include cAMP, glucose competition, and oncogenic stress in the tumor microenvironment, which can induce the senescence of T cells, macrophages, natural killer cells, and dendritic cells. Accordingly, these senescent immune cells could also affect tumor progression. In addition, the effect of immunosenescence on the response to immune checkpoint blocking antibody therapy so far is ambiguous due to the low participation of elderly cancer patients in clinical trials. Furthermore, many other senescence-related interventions could be possible with genetic and pharmacological methods, including mTOR inhibition, interleukin-7 recombination, and NAD+ activation. Overall, this review aims to highlight the characteristics of immunosenescence and its impact on malignant tumors and immunotherapy, especially the future directions of tumor treatment through senescence-focused strategies.

scholarly journals CD8+T Cells Can Mediate Short-Term Protection against Heterotypic Dengue Virus Reinfection in Mice

2015 ◽  
Vol 89 (12) ◽  
pp. 6494-6505 ◽  
Author(s):  
Raphaël M. Zellweger ◽  
William W. Tang ◽  
William E. Eddy ◽  
Kevin King ◽  
Marisa C. Sanchez ◽  
...  
Keyword(s):  
T Cells ◽  
Dengue Virus ◽  
Cellular Immunity ◽  
Vaccine Design ◽  
Neutralizing Antibody ◽  
Cross Protection ◽  
Denv Serotypes ◽  
Transient Period ◽  
Protection Period

ABSTRACTDengue virus (DENV) is a major public health threat worldwide. Infection with one of the four serotypes of DENV results in a transient period of protection against reinfection with all serotypes (cross-protection), followed by lifelong immunity to the infecting serotype. While a protective role for neutralizing antibody responses is well established, the contribution of T cells to reinfection is less clear, especially during heterotypic reinfection. This study investigates the role of T cells during homotypic and heterotypic DENV reinfection. Mice were sequentially infected with homotypic or heterotypic DENV serotypes, and T cell subsets were depleted before the second infection to assess the role of DENV-primed T cells during reinfection. Mice primed nonlethally with DENV were protected against reinfection with either a homotypic or heterotypic serotype 2 weeks later. Homotypic priming induced a robust neutralizing antibody response, whereas heterotypic priming elicited binding, but nonneutralizing antibodies. CD8+T cells were required for protection against heterotypic, but not homotypic, reinfection. These results suggest that T cells can contribute crucially to protection against heterotypic reinfection in situations where humoral responses alone may not be protective. Our findings have important implications for vaccine design, as they suggest that inducing both humoral and cellular responses during vaccination may maximize protective efficacy across all DENV serotypes.IMPORTANCEDengue virus is present in more than 120 countries in tropical and subtropical regions. Infection with dengue virus can be asymptomatic, but it can also progress into the potentially lethal severe dengue disease. There are four closely related dengue virus serotypes. Infection with one serotype results in a transient period of resistance against all serotypes (cross-protection), followed by lifelong resistance to the infecting serotype, but not the other ones. The duration and mechanisms of the transient cross-protection period remain elusive. This study investigates the contribution of cellular immunity to cross-protection using mouse models of DENV infection. Our results demonstrate that cellular immunity is crucial to mediate cross-protection against reinfection with a different serotype, but not for protection against reinfection with the same serotype. A better understanding of the mediators responsible for the cross-protection period is important for vaccine design, as an ideal vaccine against dengue virus should efficiently protect against all serotypes.

scholarly journals Antioxidant Treatment Reduces Expansion and Contraction of Antigen-Specific CD8+ T Cells during Primary but Not Secondary Viral Infection

2004 ◽  
Vol 78 (20) ◽  
pp. 11246-11257 ◽  
Author(s):  
Nathan G. Laniewski ◽  
Jason M. Grayson
Keyword(s):  
T Cells ◽  
Viral Infection ◽  
Large Scale ◽  
Viral Infections ◽  
Lymphocytic Choriomeningitis ◽  
T Cell Response ◽  
Oxygen Intermediates ◽  
Mimetic Compound

ABSTRACT During many viral infections, antigen-specific CD8+ T cells undergo large-scale expansion. After viral clearance, the vast majority of effector CD8+ T cells undergo apoptosis. Previous studies have implicated reactive oxygen intermediates (ROI) in lymphocyte apoptosis. The purpose of the experiments presented here was to determine the role of ROI in the expansion and contraction of CD8+ T cells in vivo during a physiological response such as viral infection. Mice were infected with lymphocytic choriomeningitis virus (LCMV) and treated with Mn(III)tetrakis(4-benzoic acid)porphyrin chloride (MnTBAP), a metalloporphyrin-mimetic compound with superoxide dismutase activity, from days 0 to 8 postinfection. At the peak of CD8+-T-cell response, on day 8 postinfection, the numbers of antigen-specific cells were 10-fold lower in MnTBAP-treated mice than in control mice. From days 8 to 30, a contraction phase ensued where the numbers of antigen-specific CD8+ T cells declined 25-fold in vehicle-treated mice compared to a 3.5-fold decrease in MnTBAP-treated mice. Differences in contraction appeared to be due to greater proliferation in drug-treated mice. By day 38, the numbers of antigen-specific CD8+ memory T cells were equivalent for the two groups. The administration of MnTBAP during secondary viral infection had no effect on the expansion of antigen-specific CD8+ secondary effector T cells. These data suggest that ROI production is critical for the massive expansion and contraction of antigen-specific CD8+ T cells during primary, but not secondary, viral infection.

scholarly journals A possible role of immunopathogenesis in COVID-19 progression

2020 ◽  
Author(s):  
Moritz Anft ◽  
Krystallenia Paniskaki ◽  
Arturo Blazquez-Navarro ◽  
Adrian Doevelaar ◽  
Felix S. Seibert ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Humoral Immunity ◽  
Viral Infections ◽  
Cell Subset ◽  
T Cell Response ◽  
T Cell Subsets ◽  
Clear Correlation

AbstractBackgroundThe efficacy of the humoral and cellular immunity determines the outcome of viral infections. An appropriate immune response mediates protection, whereas an overwhelming immune response has been associated with immune-mediated pathogenesis in viral infections. The current study explored the general and SARS-CoV-2 specific cellular and humoral immune status in patients with different COVID-19 severities.MethodsIn this prospective study, we included 53 patients with moderate, severe, and critical COVID-19 manifestations comparing their quantitative, phenotypic, and functional characteristics of circulating immune cells, SARS-CoV-2 antigen specific T-cells, and humoral immunity.ResultsSignificantly diminished frequencies of CD8+T-cells, CD4+ and CD8+T-cell subsets with activated differentiated memory/effector phenotype and migratory capacity were found in circulation in patients with severe and/or critical COVID-19 as compared to patients with moderate disease. Importantly, the improvement of the clinical courses from severe to moderate was accompanied by an improvement in the T-cell subset alterations. Furthermore, we surprisingly observed a detectable SARS-CoV-2-reactive T-cell response in all three groups after stimulation with SARS-CoV-2 S-protein overlapping peptide pool already at the first visit. Of note, patients with a critical COVID-19 demonstrated a stronger response of SARS-CoV-2-reactive T-cells producing Th1 associated inflammatory cytokines. Furthermore, clear correlation between antibody titers and SARS-CoV-2-reactive CD4+ frequencies underscore the role of specific immunity in disease progression.ConclusionOur data demonstrate that depletion of activated memory phenotype circulating T-cells and a strong SARS-CoV-2-specific cellular and humoral immunity are associated with COVID-19 disease severity. This counter-intuitive finding may have important implications for diagnostic, therapeutic and prophylactic COVID-19 management.

scholarly journals Interleukin-6: Molecule in the Intersection of Cancer, Ageing and COVID-19

2020 ◽  
Vol 21 (21) ◽  
pp. 7937
Author(s):  
Jan Brábek ◽  
Milan Jakubek ◽  
Fréderic Vellieux ◽  
Jiří Novotný ◽  
Michal Kolář ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Malignant Disease ◽  
Viral Infections ◽  
Fatal Outcome ◽  
The Elderly ◽  
Premetastatic Niche ◽  
Fundamental Factor ◽  
Pathological Conditions ◽  
New Strategies

Interleukin-6 (IL-6) is a cytokine with multifaceted effects playing a remarkable role in the initiation of the immune response. The increased level of this cytokine in the elderly seems to be associated with the chronic inflammatory setting of the microenvironment in aged individuals. IL-6 also represents one of the main signals in communication between cancer cells and their non-malignant neighbours within the tumour niche. IL-6 also participates in the development of a premetastatic niche and in the adjustment of the metabolism in terminal-stage patients suffering from a malignant disease. IL-6 is a fundamental factor of the cytokine storm in patients with severe COVID-19, where it is responsible for the fatal outcome of the disease. A better understanding of the role of IL-6 under physiological as well as pathological conditions and the preparation of new strategies for the therapeutic control of the IL-6 axis may help to manage the problems associated with the elderly, cancer, and serious viral infections.

Role of T cell subpopulations in mice infected with Angiostrongylus cantonensis

1996 ◽  
Vol 70 (3) ◽  
pp. 211-214 ◽  
Author(s):  
J.D. Lee ◽  
J.J. Wang ◽  
J.H. Chang ◽  
L.Y. Chung ◽  
E.R. Chen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Angiostrongylus Cantonensis ◽  
T Helper ◽  
The Third ◽  
Cell Subpopulations ◽  
T Cell Subpopulations

AbstractWhen C57BL/6 mice were infected with Angiostrongylus cantonensis, the percentage of T helper (CD4+) cells and T supressor (CD8+) cells in peripheral blood increased weekly until the third and seventh week respectively, and then gradually decreased. C57BL/6 mice were depleted of CD4+ and CD8+ T cells by in vivo injection of anti-CD4 and anti-CD8 monoclonal antibodies, respectively, and then infected with A. cantonensis. There were significantly more and less worms recovered in the mice depleted of CD4+ and CD8+ T cells respectively than in undepleted mice. Discrete subpopulations of T cells from mice exposed to A. cantonensis for 3 weeks or 7 weeks were adoptively transferred to syngeneic recipients which were then given a challenge infection. Protection was mediated by a CD4+ T cell population present in mice after 3 weeks of infection but was not demonstrable with cells taken 7 weeks after infection. When CD4+ T cells obtained from 3-week infected mice were mixed with 5% CD8+ T cells obtained from mice infected for 7 weeks, no significant transfer of resistance was observed. Thus, immune responses to A. cantonensis in mice were regulated by discrete subpopulations of T lymphocytes.

The role of CD4 and CD8 T cells in viral infections

1991 ◽  
Vol 3 (4) ◽  
pp. 471-475 ◽  
Author(s):  
Ulrich H Koszinowski ◽  
Matthias J Reddehase ◽  
Stipan Jonjic
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Viral Infections

scholarly journals Role of the cellular immunity in the formation of the immune response in coronavirus infections

2021 ◽  
Vol 23 (6) ◽  
pp. 1229-1238
Author(s):  
I. A. Ivanova ◽  
N. D. Omelchenko ◽  
A. V. Filippenko ◽  
A. A. Trufanova ◽  
A. K. Noskov
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Cellular Immunity ◽  
Memory T Cells ◽  
Adaptive Immune Response ◽  
Cell Immune Response ◽  
Adaptive Immune ◽  
Specific Memory ◽  
Causative Agents

The data obtained during previous epidemics caused by coronaviruses, and current pandemic indicate that assessing the role of certain immune interactions between these viruses and the microorganism is the main pre-requisite for development of diagnostic test systems as well as effective medical drugs and preventive measures. The review summarizes the results of studying patho– and immunogenesis of SARSCoV, MERS-CoV, and SARS-CoV-2 infections. These coronaviruses were proven to suppress development of adaptive immune response at the stage of its induction, affecting the number and functional activity of lymphocytes, effectors of cellular immunity, causing impairment of lymphopoiesis, apoptosis and «depletion» of these cells, thus leading to longer duration of the disease and increased viral load. Information about the role of cellular immunity in development of immune response to coronaviruses is presented. It was proven that the causative agents of SARS, MERS and COVID-19 trigger adaptive immune response in the microorganism according to both humoral and cellular types. Moreover, the synthesis of specific immunoglobulins does not yet point to presence of protective immune response. Activation of the cellular link of immunity is also important. A high degree of antigenic epitope homology in SARS-CoV, MERS-CoV and SARS-CoV-2 is described, thus suggesting an opportunity for cross-immunity to coronaviruses. The review addresses issues related to the terms of specific memory immune cells to SARS-CoV, MERS-CoV and SARS-CoV-2, and their role in providing long-term protection against these infections. Given that specific antibodies to SARS and MERS pathogens persisted for a year, were often not detected or briefly registered in patients with mild and asymptomatic infections, we can talk about important role of the cellular immune response in providing immunity to these coronaviruses. It was shown that, in contrast to antibodies, the antigen-specific memory T cells were registered in patients with SARS virus for 4 to 11 years, and Middle East Respiratory Syndrome – up to two years. Further research is needed to determine presence and number of memory T cells in COVID-19. A comparative analysis of data obtained during previous epidemics with respect to formation of adaptive immunity to coronaviruses. Description of proteins and epitopes recognized by human T lymphocytes will be useful in monitoring immune responses in COVID-19 patients, as well as in developing informative tests to study T cell immune response to SARS-CoV-2 and new preventive drugs.

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