T follicular helper (Tfh) cells are fundamental for B cell selection and antibody maturation in germinal centers. Circulating Tfh (cTfh) cells constitute a minor proportion of the CD4+ T cells in peripheral blood, but their clonotypic relationship to Tfh populations resident in lymph nodes and the extent to which they differ from non-Tfh CD4+ cells have been unclear. Using donor-matched blood and tonsil samples, we investigate T cell receptor (TCR) sharing between tonsillar Tfh cells and peripheral Tfh and non-Tfh cell populations. TCR transcript sequencing reveals considerable clonal overlap between peripheral and tonsillar Tfh cell subsets as well as a clear distinction between Tfh and non-Tfh cells. Furthermore, influenza-specific cTfh cell clones derived from blood can be found in the repertoire of tonsillar Tfh cells. Therefore, human blood samples can be used to gain insight into the specificity of Tfh responses occurring in lymphoid tissues, provided that cTfh subsets are studied.
- MeSH
- Clone Cells cytology MeSH
- CD4-Positive T-Lymphocytes immunology MeSH
- Tissue Donors MeSH
- Adult MeSH
- T Follicular Helper Cells immunology MeSH
- Hemagglutinin Glycoproteins, Influenza Virus immunology MeSH
- Palatine Tonsil immunology MeSH
- Middle Aged MeSH
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Computer Simulation MeSH
- Lymphocyte Subsets immunology MeSH
- Receptors, CXCR3 metabolism MeSH
- Cell Size MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
- Research Support, N.I.H., Intramural MeSH
The importance of cellular metabolic adaptation in inducing robust T cell responses is well established. However, the mechanism by which T cells link information regarding nutrient supply to clonal expansion and effector function is still enigmatic. Herein, we report that the metabolic sensor adenosine monophosphate-activated protein kinase (AMPK) is a critical link between cellular energy demand and translational activity and, thus, orchestrates optimal expansion of T cells in vivo. AMPK deficiency did not affect T cell fate decision, activation, or T effector cell generation; however, the magnitude of T cell responses in murine in vivo models of T cell activation was markedly reduced. This impairment was global, as all T helper cell subsets were similarly sensitive to loss of AMPK which resulted in reduced T cell accumulation in peripheral organs and reduced disease severity in pathophysiologically as diverse models as T cell transfer colitis and allergic airway inflammation. T cell receptor repertoire analysis confirmed similar clonotype frequencies in different lymphoid organs, thereby supporting the concept of a quantitative impairment in clonal expansion rather than a skewed qualitative immune response. In line with these findings, in-depth metabolic analysis revealed a decrease in T cell oxidative metabolism, and gene set enrichment analysis indicated a major reduction in ribosomal biogenesis and mRNA translation in AMPK-deficient T cells. We, thus, provide evidence that through its interference with these delicate processes, AMPK orchestrates the quantitative, but not the qualitative, manifestation of primary T cell responses in vivo.
- MeSH
- Adenylate Kinase genetics metabolism MeSH
- Lymphocyte Activation MeSH
- Th17 Cells physiology MeSH
- CD4-Positive T-Lymphocytes MeSH
- DNA-Binding Proteins genetics metabolism MeSH
- Adaptation, Physiological MeSH
- Colitis immunology MeSH
- RNA, Messenger genetics metabolism MeSH
- Mice, Knockout MeSH
- Mice MeSH
- Adoptive Transfer MeSH
- Gene Expression Regulation, Enzymologic MeSH
- T-Lymphocytes, Regulatory physiology MeSH
- T-Lymphocytes, Helper-Inducer physiology MeSH
- Th1 Cells physiology MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
CD4 and CD8 mark helper and cytotoxic T cell lineages, respectively, and serve as coreceptors for MHC-restricted TCR recognition. How coreceptor expression is matched with TCR specificity is central to understanding CD4/CD8 lineage choice, but visualising coreceptor gene activity in individual selection intermediates has been technically challenging. It therefore remains unclear whether the sequence of coreceptor gene expression in selection intermediates follows a stereotypic pattern, or is responsive to signaling. Here we use single cell RNA sequencing (scRNA-seq) to classify mouse thymocyte selection intermediates by coreceptor gene expression. In the unperturbed thymus, Cd4+Cd8a- selection intermediates appear before Cd4-Cd8a+ selection intermediates, but the timing of these subsets is flexible according to the strength of TCR signals. Our data show that selection intermediates discriminate MHC class prior to the loss of coreceptor expression and suggest a model where signal strength informs the timing of coreceptor gene activity and ultimately CD4/CD8 lineage choice.
- MeSH
- Lymphocyte Activation genetics MeSH
- Principal Component Analysis MeSH
- Cell Differentiation immunology MeSH
- Cell Lineage immunology MeSH
- CD4-Positive T-Lymphocytes cytology immunology MeSH
- CD8-Positive T-Lymphocytes cytology immunology MeSH
- Cytokines metabolism MeSH
- DNA-Binding Proteins metabolism MeSH
- Histocompatibility Antigens metabolism MeSH
- RNA, Messenger genetics metabolism MeSH
- Mice, Inbred C57BL MeSH
- Core Binding Factor Alpha 3 Subunit metabolism MeSH
- Receptors, Antigen, T-Cell metabolism MeSH
- Gene Expression Regulation MeSH
- Signal Transduction MeSH
- Thymus Gland cytology immunology MeSH
- Transcription Factors metabolism MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
Mutations in the gene encoding for filaggrin (FLG) are major predisposing factors for atopic dermatitis (AD). Besides genetic predisposition, immunological dysregulations considerably contribute to its pathophysiology. For example, thymic stromal lymphopoietin (TSLP) is highly expressed in lesional atopic skin and significantly contributes to the pathogenesis of AD by activating dendritic cells that then initiate downstream effects on, for example, T cells. However, little is known about the direct interplay between TSLP, filaggrin-deficient skin and other immune cells such as T lymphocytes. In the present study, FLG knockdown skin equivalents, characterised by intrinsically high TSLP levels, were exposed to activated CD4+ T cells. T cell exposure resulted in an inflammatory phenotype of the skin equivalents. Furthermore, a distinct shift from a Th1/Th17 to a Th2/Th22 profile was observed following exposure of T cells to filaggrin-deficient skin equivalents. Interestingly, TSLP directly stimulated T cell migration exclusively in filaggrin-deficient skin equivalents even in the absence of dendritic cells, indicating a hitherto unknown role of TSLP in the pathogenesis of AD.
- MeSH
- Lymphocyte Activation MeSH
- Th17 Cells immunology metabolism MeSH
- CD4-Positive T-Lymphocytes immunology metabolism MeSH
- Cytokines metabolism MeSH
- Dendritic Cells immunology metabolism MeSH
- Gene Expression MeSH
- Skin immunology metabolism MeSH
- Humans MeSH
- Lipid Metabolism MeSH
- Cell Movement immunology MeSH
- Intermediate Filament Proteins deficiency MeSH
- Tight Junction Proteins genetics metabolism MeSH
- T-Lymphocyte Subsets immunology metabolism MeSH
- Th1 Cells immunology metabolism MeSH
- Th2 Cells immunology metabolism MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
A low-molecular-weight (under 10 kDa) dialysable leukocyte extract (called transfer factor, TF) has been shown to be a prospective substance to improve or modulate immune response in autoimmunity, inflammation, infectious diseases or cancers. However, the use of TF has been limited by the absence of any data on the mechanism of its action. Here we show that TF prepared from peripheral blood leukocytes of healthy human donors displays multiple regulatory effects on individual parameters of the immune system. TF decreases proliferation of T and B lymphocytes and partially alters the production of cytokines and nitric oxide by activated macrophages. TF also inhibits production of T helper 1 (Th1) cytokines interleukin 2 (IL-2) and interferon γ, slightly stimulates production of Th2 cytokine IL-10 and considerably enhances the secretion of IL-17 by activated mouse spleen T cells. At the molecular level, TF enhances expression of genes for transcription factor RORγt and for IL-17. The enhanced expression of the RORgt gene corresponds with an increase in the number of RORγt⁺CD4⁺ Th17 cells and with enhanced IL-17 production. In contrast, the expression of the Foxp3 gene and the proportion of CD4⁺CD25⁺Foxp3⁺ regulatory T cells are not significantly changed in the presence of TF. These results suggest that the activation of pro-inflammatory Th17 cells, which have multiple immunoregulatory properties, could be the main mechanism of the immunomodulatory action of a low-molecular-weight leukocyte extract.
- MeSH
- Adjuvants, Immunologic pharmacology MeSH
- Lymphocyte Activation drug effects MeSH
- B-Lymphocytes drug effects MeSH
- Cell Division drug effects MeSH
- CD4-Positive T-Lymphocytes drug effects metabolism MeSH
- Forkhead Transcription Factors biosynthesis genetics MeSH
- Interferon-gamma biosynthesis genetics MeSH
- Interleukin-17 biosynthesis genetics MeSH
- Interleukins biosynthesis genetics MeSH
- Nuclear Receptor Subfamily 1, Group F, Member 3 analysis biosynthesis genetics MeSH
- Concanavalin A pharmacology MeSH
- Cells, Cultured MeSH
- Real-Time Polymerase Chain Reaction MeSH
- Molecular Weight MeSH
- Mice, Inbred BALB C MeSH
- Mice MeSH
- Nitric Oxide biosynthesis MeSH
- Macrophages, Peritoneal drug effects metabolism MeSH
- Lymphocyte Subsets drug effects metabolism MeSH
- Drug Evaluation, Preclinical MeSH
- Gene Expression Regulation drug effects MeSH
- Spleen cytology MeSH
- Transfer Factor pharmacology MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The role of the immune system as an integral component of the inflammatory response in the pathophysiology of migraine remains unclear. The aim of this study was to evaluate the differences in immune system parameters (acquired immunity parameters) in patients with episodic migraine (EM) and in healthy controls. In EM patients, we aimed to determine whether the changes found in peripheral blood parameters were related to migraine severity according to the standardised MIDAS and HIT-6 tests. Forty-nine patients with EM and 50 healthy controls were included in this study. The authors compared different lymphocyte parameters obtained by multicolor flow cytometry in the EM and control groups by performing statistical tests. The relationship between the changes in peripheral blood parameters and migraine severity in EM patients was investigated using correlation and regression analysis. EM patients showed higher values than healthy controls, especially in nine parameters: relative count of lymphocytes, relative and absolute counts of CD3 T cells, relative and absolute counts of CD8 suppressor cytotoxic T cells, relative and absolute counts of CD4 + TEMRA (terminally differentiated helper T lymphocytes), absolute count of CD8 naïve T cells, and absolute count of CD19 switched memory B cells. Among the lymphocyte parameters, CD4 + TEM (effector memory helper T lymphocytes) and CD8 + TEMRA (terminally differentiated cytotoxic T lymphocytes) were statistically significantly associated with HIT-6. Patients with a CD4 + TEM value below 15 had a high probability (90%) that the HIT-6 value would be higher than 60. The results of this study show that EM patients have changes in immune system parameters measured in the peripheral blood. Changes in the abundance of CD4 + TEM could be used as a biomarker for disease severity.
- MeSH
- Biomarkers MeSH
- Adult MeSH
- Immune System immunology metabolism MeSH
- Immunophenotyping MeSH
- Comorbidity MeSH
- Middle Aged MeSH
- Humans MeSH
- Migraine Disorders diagnosis etiology metabolism MeSH
- Adolescent MeSH
- Young Adult MeSH
- Disease Susceptibility * MeSH
- Flow Cytometry MeSH
- Aged MeSH
- Case-Control Studies MeSH
- Severity of Illness Index MeSH
- T-Lymphocyte Subsets immunology metabolism MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Adolescent MeSH
- Young Adult MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Aim: The development of type 2 diabetes (T2DM) is associated with disturbances of immune status that may be reflected by alterations of the profile of circulating immune cells. In order to study whether there exists genetic predisposition to these alterations, we investigated the relative content of circulating monocyte and lymphocyte subpopulations at fasting condition and upon stimulation by short-term hyperinsulinemia in nondiabetic first-degree relatives (FDR) of T2DM patients and in control subjects. Materials and Methods: 19 nondiabetic (FDR) and 19 control subjects without a family history of diabetes (all men) matched for age and BMI underwent 2-hour hyperinsulinemic-euglycemic clamp. Blood samples taken before and at the end of the clamp were used for the flow cytometry analysis of lymphocyte and monocyte populations and for the assessment of cytokine levels. Results: At fasting conditions, FDR showed a higher CD4/CD8 ratio of peripheral lymphocytes, a higher percentage of Th17 lymphocytes, and a lower content of intermediate monocytes when compared to controls. The CD4/CD8 ratio correlated with fat mass, insulin, and HOMA-IR in the entire group of subjects. Hyperinsulinemia decreased a relative content of peripheral CD4+ and increased a relative content of CD8+ T lymphocytes, thus decreasing the CD4/CD8 ratio by 18-22% in both groups of subjects. In FDR but not in controls, the decrease of CD4+ T lymphocyte content was partially based on the decrease of TH2 and TH17 lymphocyte subpopulations. In control subjects but not in FDR, the number of intermediate monocytes has declined in response to hyperinsulinemia. Conclusion: The alterations of the CD4/CD8 lymphocyte ratio, relative content of TH17 cells, and intermediate monocytes in FDR are features of genetic predisposition to T2DM and may play a role in pathogenesis of T2DM. Short-term hyperinsulinemia affected mostly the immune cell populations deregulated in FDR subjects, which suggests important interplay between immune system homeostasis and insulin levels.
- MeSH
- Th17 Cells metabolism MeSH
- Diabetes Mellitus, Type 2 blood metabolism pathology MeSH
- Adult MeSH
- Hyperinsulinism blood metabolism pathology MeSH
- Body Mass Index MeSH
- Insulin Resistance physiology MeSH
- Blood Glucose metabolism MeSH
- Humans MeSH
- Monocytes metabolism MeSH
- Fasting blood MeSH
- Lymphocyte Subsets metabolism MeSH
- CD4-CD8 Ratio MeSH
- Th2 Cells metabolism MeSH
- Check Tag
- Adult MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
Myeloid-derived suppressor cells (MDSC) represent a heterogeneous group of immature myeloid cells with immunoregulatory function in cancer and autoimmune diseases. In humans, two subsets of MDSC were determined based on the characteristic surface markers, monocytic MDSC (M-MDSC) and granulocytic MDSC (G-MDSC). Expansion of MDSC has been reported in some murine models and patients with autoimmune diseases and their immune-suppressive properties were characterized. However, the exact role of MDSC in the pathogenesis of autoimmune diseases is more complex and/or controversial. In type 1 diabetes mellitus (T1D), the increased frequency of MDSC was found in the blood of T1D patients but their suppressor capacity was diminished. In our study, we assessed the role of M-MDSC in the pathogenesis of T1D and showed for the first time the increased frequency of M-MDSC not only in the blood of T1D patients but also in their at-risk relatives compared to healthy donors. T1D patients with inadequate long term metabolic control showed an elevation of M-MDSC compared to patients with better disease control. Furthermore, we described the positive correlation between the percentage of M-MDSC and Th17 cells and IFN-γ producing T cells in T1D patients and their at-risk relatives. Finally, we found that the ability of M-MDSC to suppress autologous T cells is efficient only at the high MDSC: T cells ratio and dependent on cell-cell-contact and TGF-β production. Our data show that the engagement of MDSC in the pathogenesis of T1D is evident, yet not entirely explored and more experiments are required to clarify whether MDSC are beneficial or harmful in T1D.
- MeSH
- Th17 Cells immunology MeSH
- Diabetes Mellitus, Type 1 blood immunology MeSH
- Child MeSH
- Interferon-gamma metabolism MeSH
- Humans MeSH
- Adolescent MeSH
- Myeloid-Derived Suppressor Cells immunology MeSH
- CD4 Lymphocyte Count MeSH
- T-Lymphocytes, Regulatory immunology MeSH
- Check Tag
- Child MeSH
- Humans MeSH
- Adolescent MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Imunitní systém prodělává v průběhu života zásadní změny, které reflektují odlišné potřeby jedince v různých údobích života. Nejvýznamnější ontogenetickou dynamiku vykazuje specifická, buňkami zprostředkovaná, imunita. v časných fázích života dominuje aktivita subsetu Th2 pomocných T-lymfocytů. V dospělosti dochází k přesmyku vedoucí k převaze subsetu Thl T-lymfocytů. Pro stán je opět charakteristický návrat k převaze aktivit subsetu Th2 T-Iymfocytů. Až překvapivě efektivní je imunitní systém osob, které se dožily vysokého věku 90-100 let. Zatím nelze doložit, zda je tento fakt příčinou nebo důsledkem dlouhověkosti. Z experimentu na zvířecích modelech vyplývá, že modulací imunitního systému lze prodlužovat věk i zvyšovat kvahtu života. Pro fyziologické změny imunitlího systému, které lze identifikovat u starých hdí, se zavádí termín imunosenescence.
The immune system is undergoing a lot of substantial changes during life which reflect different demands of every individual in different periods of life. The most important ontogenetical dynamies is typical for specific cell-mediated immunity. The activity of Th2 subset of helper inducer CD4+ T cells is upregulated during early period of life. There is the shift from Th2 subset reactivity to predominant Thl subset eactivity during early adulthood. The return back to the predominant Th2 reactivity is typical for the late period of life. The immune system of earderly people who are 90-100 years old is supprisingly well preserved. It is not possible to say now if this fact is either the cause or the consequence of successful senescence. The term immunosenescence is now coined to describe the physiological changes of the immune system in elderly people.
