IL-2/IL-7-inducible factors pioneer the path to T cell differentiation in advance of lineage-defining factors

Lactobacillus plantarum isolated from kimchi regulates inflammation by increasing interleukin-10 secretion by antigen-presenting cells, leading to diminishing of STAT5 phosphorylation in Th2 cells

The relationship between allergic inflammation and gut microbiota has been elucidated, and the effect of probiotics on immune disorders has been studied as well. Identifying the role of probiotics in individual diseases and immune responses and selecting and applying specific microorganisms based on these findings can be an effective strategy for using probiotics. Herein, lactobacilli isolated from kimchi were investigated in depth, focusing on their immune regulatory effects and the mechanisms involved. Lactic acid bacteria (LAB) effectively diminished the increased secretion of T helper 2 cytokines, such as IL-4, IL-5, and IL-13, from ovalbumin (OVA)-sensitized mouse splenocytes. The gene expression of GATA3, IL-4, IL-5, IL-9, and IL-13 was confirmed to be regulated by LAB. LAB also suppressed IL-2 production and STAT5 phosphorylation. An IL-10-neutralizing antibody attenuated these effects, indicating that LAB-induced upregulation of IL-10 in antigen-presenting cells was responsible at least partially for the increased IL-2 production and STAT5 phosphorylation in CD4+ T cells. In conclusion, the current study identified one immunomodulatory mechanism that allows LAB to regulate allergic immune reactions and the potential of LAB from kimchi to modulate various immune reactions.

Advances in IL-7 Research on Tumour Therapy

Interleukin-7 (IL-7) is a versatile cytokine that plays a crucial role in regulating the immune system's homeostasis. It is involved in the development, proliferation, and differentiation of B and T cells, as well as being essential for the differentiation and survival of naïve T cells and the production and maintenance of memory T cells. Given its potent biological functions, IL-7 is considered to have the potential to be widely used in the field of anti-tumour immunotherapy. Notably, IL-7 can improve the tumour microenvironment by promoting the development of Th17 cells, which can in turn promote the recruitment of effector T cells and NK cells. In addition, IL-7 can also down-regulate the expression of tumour growth factor-β and inhibit immunosuppression to promote anti-tumour efficacy, suggesting potential clinical applications for anti-tumour immunotherapy. This review aims to discuss the origin of IL-7 and its receptor IL-7R, its anti-tumour mechanism, and the recent advances in the application of IL-7 in tumour therapy.

Double-edged sword of JAK/STAT signaling pathway in viral infections: novel insights into virotherapy

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) is an intricate signaling cascade composed of various cytokines, interferons (IFN, growth factors, and other molecules. This pathway provides a delicate mechanism through which extracellular factors adjust gene expression, thereby acting as a substantial basis for environmental signals to influence cell growth and differentiation. The interactions between the JAK/STAT cascade and antiviral IFNs are critical to the host's immune response against viral microorganisms. Recently, with the emergence of therapeutic classes that target JAKs, the significance of this  cascade has been recognized in an unprecedented way. Despite the functions of the JAK/STAT pathway in adjusting immune responses against viral pathogens, a vast body of evidence proposes the role of this cascade in the replication and pathogenesis of viral pathogens. In this article, we review the structure of the JAK/STAT signaling cascade and its role in immuno-inflammatory responses. We also highlight the paradoxical effects of this pathway in the pathogenesis of viral infections. Video Abstract.

Characterizing control of memory CD8 T cell differentiation by BTB-ZF transcription factor Zbtb20

Members of the BTB-ZF transcription factor family regulate the immune system. Our laboratory identified that family member Zbtb20 contributes to the differentiation, recall responses, and metabolism of CD8 T cells. Here, we report a characterization of the transcriptional and epigenetic signatures controlled by Zbtb20 at single-cell resolution during the effector and memory phases of the CD8 T cell response. Without Zbtb20, transcriptional programs associated with memory CD8 T cell formation were up-regulated throughout the CD8 T response. A signature of open chromatin was associated with genes controlling T cell activation, consistent with the known impact on differentiation. In addition, memory CD8 T cells lacking Zbtb20 were characterized by open chromatin regions with overrepresentation of AP-1 transcription factor motifs and elevated RNA- and protein-level expressions of the corresponding AP-1 components. Finally, we describe motifs and genomic annotations from the DNA targets of Zbtb20 in CD8 T cells identified by cleavage under targets and release under nuclease (CUT&RUN). Together, these data establish the transcriptional and epigenetic networks contributing to the control of CD8 T cell responses by Zbtb20.

Exposure of volunteers to microgravity by dry immersion bed over 21 days results in gene expression changes and adaptation of T cells

The next steps of deep space exploration are manned missions to Moon and Mars. For safe space missions for crew members, it is important to understand the impact of space flight on the immune system. We studied the effects of 21 days dry immersion (DI) exposure on the transcriptomes of T cells isolated from blood samples of eight healthy volunteers. Samples were collected 7 days before DI, at day 7, 14, and 21 during DI, and 7 days after DI. RNA sequencing of CD3+ T cells revealed transcriptional alterations across all time points, with most changes occurring 14 days after DI exposure. At day 21, T cells showed evidence of adaptation with a transcriptional profile resembling that of 7 days before DI. At 7 days after DI, T cells again changed their transcriptional profile. These data suggest that T cells adapt by rewiring their transcriptomes in response to simulated weightlessness and that remodeling cues persist when reexposed to normal gravity.

3D chromatin reprogramming primes human memory TH2 cells for rapid recall and pathogenic dysfunction

Memory T cells provide long-lasting defense responses through their ability to rapidly reactivate, but how they efficiently "recall" an inflammatory transcriptional program remains unclear. Here, we show that human CD4⁺ memory T helper 2 (T_H2) cells carry a chromatin landscape synergistically reprogrammed at both one-dimensional (1D) and 3D levels to accommodate recall responses, which is absent in naive T cells. In memory T_H2 cells, recall genes were epigenetically primed through the maintenance of transcription-permissive chromatin at distal (super)enhancers organized in long-range 3D chromatin hubs. Precise transcriptional control of key recall genes occurred inside dedicated topologically associating domains ("memory TADs"), in which activation-associated promoter-enhancer interactions were preformed and exploited by AP-1 transcription factors to promote rapid transcriptional induction. Resting memory T_H2 cells from patients with asthma showed premature activation of primed recall circuits, linking aberrant transcriptional control of recall responses to chronic inflammation. Together, our results implicate stable multiscale reprogramming of chromatin organization as a key mechanism underlying immunological memory and dysfunction in T cells.

A model of Th2 differentiation based on polarizing cytokine repression

Conventional dendritic cells (cDCs) can integrate multiple stimuli from the environment and provide three separate outputs in terms of antigen presentation, costimulation, and cytokine production; this guides the activation, expansion, and differentiation of distinct functional T helper subsets. Accordingly, the current dogma posits that T helper cell specification requires these three signals in sequence. Data show that T helper 2 (Th2) cell differentiation requires antigen presentation and costimulation from cDCs but does not require polarizing cytokines. In this opinion article, we propose that the 'third signal' driving Th2 cell responses is, in fact, the absence of polarizing cytokines; indeed, the secretion of the latter is actively suppressed in cDCs, concomitant with acquired pro-Th2 functions.

A genome-wide relay of signalling-responsive enhancers drives hematopoietic specification

Developmental control of gene expression critically depends on distal cis-regulatory elements including enhancers which interact with promoters to activate gene expression. To date no global experiments have been conducted that identify their cell type and cell stage-specific activity within one developmental pathway and in a chromatin context. Here, we describe a high-throughput method that identifies thousands of differentially active cis-elements able to stimulate a minimal promoter at five stages of hematopoietic progenitor development from embryonic stem (ES) cells, which can be adapted to any ES cell derived cell type. We show that blood cell-specific gene expression is controlled by the concerted action of thousands of differentiation stage-specific sets of cis-elements which respond to cytokine signals terminating at signalling responsive transcription factors. Our work provides an important resource for studies of hematopoietic specification and highlights the mechanisms of how and where extrinsic signals program a cell type-specific chromatin landscape driving hematopoietic differentiation.

Role of Metabolism in Adoptive T Cell Therapy: Strategies and Challenges

Significance: Immune cell therapy involves the administration of immune cells into patients, and it has emerged as one of the most common type of immunotherapy for cancer treatment. Knowledge on the biology and metabolism of the adoptively transferred immune cells and the metabolic requirements of different cell types in the tumor is fundamental for the development of immune cell therapy with higher efficacy. Recent Advances: Adoptive T cell therapy has been shown to be effective in limited types of cancer. Different types and generations of adoptive T cell therapies have evolved in the recent decade. This review covers the basic principles and development of these therapies in cancer treatment. Critical Issues: Our review provides an overview on the basic concepts on T cell metabolism and highlights the metabolic requirements of T and adoptively transferred T cells. Future Directions: Integrating the knowledge just cited will facilitate the development of strategies to maximize the expansion of adoptively transferred T cells ex vivo and in vivo and to promote their durability and antitumor effects. Antioxid. Redox Signal. 37, 1303-1324.

CD4+CD8+ T follicular helper cells regulate humoral immunity in chronic inflammatory lesions

T follicular helper (Tfh) cells drive humoral immunity by facilitating B cell responses at the initial and recall phases. Recent studies have indicated the possible involvement of Tfh cells in the process of chronic inflammation. However, the functional role of Tfh cells in persistent immune settings remains unclear. Here, we report that CD4⁺CD8⁺ (double-positive, DP; CD3⁺CD4⁺CD8⁺CXCR5^hiPD-1^hi) Tfh cells, a subset of germinal-center-type Tfh cells, were abundantly present in the fibroinflammatory lesions of patients with immunoglobulin G4-related disease (IgG4-RD). Transcriptome analyses showed that these DP-Tfh cells in the lesions of IgG4-RD preferentially expressed signature genes characteristic of cytotoxic CD8⁺ T cells, such as Eomes, CRTAM, GPR56, and granzymes, in addition to CD70. Scatter diagram analyses to examine the relationships between tissue-resident lymphocytes and various clinical parameters revealed that the levels of DP-Tfh cells were inversely correlated to the levels of serum IgG4 and local IgG4-expressing (IgG4⁺) memory B cells (CD19⁺CD27⁺IgD^-) in patients with IgG4-RD. Cell culture experiments using autologous tonsillar lymphocytes further suggested that DP-Tfh cells possess a poor B-cell helper function and instead regulate memory B cells. Since CD4⁺ (single positive, SP; CD3⁺CD4⁺CD8^-CXCR5^hiPD-1^hi) Tfh cells differentiated into DP-Tfh cells under stimulation with IL-2 and IL-7 as assessed by in vitro experiments, these data imply that SP-Tfh cells are a possible origin of DP-Tfh cells under persistent inflammation. These findings highlight the potential feedback loop mechanism of Tfh cells in immune tolerance under chronic inflammatory conditions. Further studies on DP-Tfh cells may facilitate control of unresolved humoral responses in IgG4-RD pathological inflammation.

Distinct spatial and temporal roles for Th1, Th2, and Th17 cells in asthma

Immune response in the asthmatic respiratory tract is mainly driven by CD4⁺ T helper (Th) cells, represented by Th1, Th2, and Th17 cells, especially Th2 cells. Asthma is a heterogeneous and progressive disease, reflected by distinct phenotypes orchestrated by τh2 or non-Th2 (Th1 and Th17) immune responses at different stages of the disease course. Heterogeneous cytokine expression within the same Th effector state in response to changing conditions in vivo and interlineage relationship among CD4⁺ T cells shape the complex immune networks of the inflammatory airway, making it difficult to find one panacea for all asthmatics. Here, we review the role of three T helper subsets in the pathogenesis of asthma from different stages, highlighting timing is everything in the immune system. We also discuss the dynamic topography of Th subsets and pathogenetic memory Th cells in asthma.

Comparison of the oxidative respiratory burst and mitogen-induced leukocyte responses of camels, goats, sheep, and cows

Background and Aim:

The reports from the Ministry of Agriculture and Fisheries suggest that camels suffer less compared to goats, sheep, and cows from a number of common infectious diseases in Oman. However, there is no immunological evidence to substantiate this claim. This present study is, therefore, an attempt to study the immunological responses of camels, goats, sheep, and cows by comparing their oxidative respiratory burst of peripheral blood leukocytes (PBLs) as a marker of innate immunity occurring during phagocytosis and the mitogenic responses of their peripheral blood mononuclear leukocytes (PBMLs) as a marker of their adaptive immune response.

Materials and Methods:

Ten female adult animals (n = 10) were selected from each species (goats, sheep, and cows). The goats, sheep, and cows were maintained at the Agricultural Experiment Station, while camels were kept at the Royal Camel Corps (RCC). Blood samples were collected from the jugular vein in 7 mL of heparin and ethylenediaminetetraacetic acid vacutainer tubes. The oxidative respiratory burst of PBLs was measured using a chemiluminescence (CL) assay. Reactants consisted of 75 mL of whole blood diluted (1:50), 75 mL of luminol/isoluminol, and 75 mL of zymosan opsonized with non-heat inactivated serum/heat-inactivated serum or non-opsonized zymosan. CL responses were measured as relative light units and expressed as the mean count per minute and peak CL values. The mitogenic response of PBMLs to concanavalin A (Con-A), phytohemagglutinin (PHA), and pokeweed mitogen (PWM) was tested using a WST-8 assay and read spectrophotometrically at 450 nm.

Results:

The present findings showed that camel PBLs generate significantly higher CL responses, both intracellularly as well as extracellularly, with zymosan opsonized with autologous serum. Camel PBLs demonstrated a significantly higher (p = 0.001) response when stimulated with zymosan opsonized with heat-inactivated serum compared to those of goat, sheep, and cow lymphocytes from camels exhibited significantly higher (p = 0.001) stimulation indices (SI) with Con-A, PHA, and PWM.

Conclusion:

The present study suggests that camels are capable of mounting both superior innate as well as adaptive immune responses and provide immunological evidence supporting the belief of some authors, who have proposed that camels are less susceptible to a number of common infectious diseases than other domesticated ruminants.

Effects of the Zbtb1 Gene on Chromatin Spatial Structure and Lymphatic Development: Combined Analysis of Hi-C, ATAC-Seq and RNA-Seq

Zbtb1 (zinc finger and BTB domain containing 1) is a member of mammalian zbtb gene family. A series of bioinformatics analysis was carried out for the EL4 cell and the Zbtb1-deficient EL4 cell by Hi-C, ATAC-seq and RNA-seq techniques. Finally, Hi-C results showed that the intensity of chromatin interaction in the deletion group decreased with distance, the degree of chromosome interaction decreased significantly, the AB division region changed significantly, and the compactness of TAD structure decreased; The results of ATAC-seq showed that the open area and degree of chromatin in the deletion group decreased; 7778 differentially expressed mRNAs were found by RNA-seq. Our experimental results for the first time expounded the significance of Zbtb1 gene for T cell development, lymphocyte production and apoptosis from the aspects of chromosome spatial structure and chromatin opening degree, and provided relevant theoretical basis and data support for the in-depth study of related Zbtb1 genes in the future.

Partial STAT5 signaling is sufficient for CD4+ T cell priming but not memory formation

Signal transducer and activator of transcription 5 (STAT5) plays an important role in regulating gene expression in response to cytokines of the common (γc) chain family. In this capacity, STAT5 promotes CD8⁺ effector and memory T cell survival and regulatory T cell development. However, its function in conventional CD4⁺ T cells is less clear. In this study, the requirement of intact STAT5 signaling for CD4⁺ effector and memory T cell generation and maintenance was investigated by using DO11.10 TCR transgenic T cells that are genetically deficient in STAT5A or B, as well as by transducing DO11 T cells with a dominant-negative STAT5 to temporally block STAT5 function. We found that the presence of STAT5A or B alone was sufficient for primary CD4⁺ effector T cell generation, but not for establishing a long-lived memory cell population. Similarly, blocking STAT5 signaling during priming did not prevent initial T cell activation, but inhibited the generation of memory cells. Surprisingly, blocking STAT5 post-priming did not impact the long-term survival of CD4⁺ memory T cells in vivo. Mechanistically, intact STAT5B, but not STAT5A, was required for IL-7Rα re-expression in activated T cells, which is an important cytokine receptor for CD4⁺ memory generation. These data show that fully functional STAT5 is essential to deliver an early, non-redundant signal for memory programming during the primary CD4⁺ T cell response, while partial STAT5 signaling is sufficient for effector differentiation. Our results have implications for the precise use of STAT5 inhibitors to timely inhibit memory T cell responses.

Potential Application of Low-Intensity Pulsed Ultrasound in Delaying Aging for Mice

INTRODUCTION

The low-intensity pulsed ultrasound (LIPUS) is one of the popular treatment modalities allowing to boost the proliferation, differentiation, and migratory activity of cells, which might be a powerful strategy for anti-aging. Seeking a novel setup for LIPUS would benefit the development of ultrasound therapeutics.

METHODS

Here, we proposed a novel underwater exposure setup of LIPUS. C57BL/6 mice were reared in the designated age-groups, which consisted of a middle-aged group (12-14 months) and an old-age group (20-23 months). The age-related changes of body composition, imbalance of energy supply and demand, imbalance of signal network maintaining internal stability, and representative phenotypes of neurodegeneration and neuroplasticity with the presence and absence of underwater LIPUS in middle-aged and aged groups were evaluated.

RESULTS

The results showed that there were obvious aging changes, imbalance of energy supply and demand, imbalance of signal network maintaining homeostasis, neurodegeneration, and damage of neural plasticity in the middle-aged and aged group with or without the LIPUS. Although middle-aged group and aged group responded differently to LIPUS, they mostly generated positive results in relieving bone loss, improving ovarian structure, regulated immune system, and enhanced endurance ability, which should have declined over age.

DISCUSSION

These findings indicate that underwater extracorporeal LIPUS exposure could be employed as single or combined anti-aging strategies that generated positive outcomes against the process of aging.

Logic and lineage impacts on functional transcription factor deployment for T-cell fate commitment

Transcription factors are the major agents that read the regulatory sequence information in the genome to initiate changes in expression of specific genes, both in development and in physiological activation responses. Their actions depend on site-specific DNA binding and are largely guided by their individual DNA target sequence specificities. However, their action is far more conditional in a real developmental context than would be expected for simple reading of local genomic DNA sequence, which is common to all cells in the organism. They are constrained by slow-changing chromatin states and by interactions with other transcription factors, which affect their occupancy patterns of potential sites across the genome. These mechanisms lead to emergent discontinuities in function even for transcription factors with minimally changing expression. This is well revealed by diverse lineages of blood cells developing throughout life from hematopoietic stem cells, which use overlapping combinations of transcription factors to drive strongly divergent gene regulation programs. Here, using development of T lymphocytes from hematopoietic multipotent progenitor cells as a focus, recent evidence is reviewed on how binding specificity and dynamics, transcription factor cooperativity, and chromatin state changes impact the effective regulatory functions of key transcription factors including PU.1, Runx1, Notch-RBPJ, and Bcl11b.

Natural Killer cells and monoclonal antibodies: Two partners for successful antibody dependent cytotoxicity against tumor cells

Monoclonal antibodies targeting tumors are one of the most important discoveries in the field of cancer. Although several effective antibodies have been developed, a relapse may occur. One of their mechanisms of action is Antibody Dependent Cell Cytotoxicity (ADCC), by engaging the Fc γ receptor CD16 expressing Natural Killer cells, innate lymphoid cells involved in cancer immunosurveillance and able to kill tumor cells. A lack of NK cells observed in many cancers may therefore be a cause of the low efficacy of antibodies observed in some clinical situations. Here we review clear evidences of the essential partnership between NK cells and antibodies showed in vitro, in vivo, and in clinical trials in different indications, describe the hurdles and ways to enhance ADCC and the evolution of monoclonal antibody therapy. NK cell adoptive immunotherapy combined with monoclonal antibodies may overcome the resistance to the treatment and enhance their efficacy.

The transcriptional regulation of normal and malignant blood cell development

Development of multicellular organisms requires the differential usage of our genetic information to change one cell fate into another. This process drives the appearance of different cell types that come together to form specialized tissues sustaining a healthy organism. In the last decade, by moving away from studying single genes toward a global view of gene expression control, a revolution has taken place in our understanding of how genes work together and how cells communicate to translate the information encoded in the genome into a body plan. The development of hematopoietic cells has long served as a paradigm of development in general. In this review, we highlight how transcription factors and chromatin components work together to shape the gene regulatory networks controlling gene expression in the hematopoietic system and to drive blood cell differentiation. In addition, we outline how this process goes astray in blood cancers. We also touch upon emerging concepts that place these processes firmly into their associated subnuclear structures adding another layer of the control of differential gene expression.

Remodeling the chromatin landscape in T lymphocytes by a division of labor among transcription factors

An extraordinary degree of condensation is required to fit the eukaryotic genome inside the nucleus. This compaction is attained by first coiling the DNA around structures called nucleosomes. Mammalian genomes are further folded into sophisticated three-dimensional (3D) configurations, enabling the genetic code to dictate a diverse range of cell fates. Recent advances in molecular and computational technologies have enabled the query of higher-order chromatin architecture at an unprecedented resolution and scale. In T lymphocytes, similar to other developmental programs, the hierarchical genome organization is shaped by a highly coordinated division of labor among different classes of sequence-specific transcription factors. In this review, we will summarize the general principles of 1D and 3D genome organization, introduce the common experimental and computational techniques to measure the multilayer chromatin organization, and discuss the pervasive role of transcription factors on chromatin organization in T lymphocytes.

Stable Epigenetic Programming of Effector and Central Memory CD4 T Cells Occurs Within 7 Days of Antigen Exposure In Vivo

T cell immunological memory is established within days of an infection, but little is known about the in vivo changes in gene regulatory networks accounting for their ability to respond more efficiently to secondary infections. To decipher the timing and nature of immunological memory we performed genome-wide analyses of epigenetic and transcriptional changes in a mouse model generating antigen-specific T cells. Epigenetic reprogramming for Th differentiation and memory T cell formation was already established by the peak of the T cell response after 7 days. The Th memory T cell program was associated with a gain of open chromatin regions, enriched for RUNX, ETS and T-bet motifs, which remained stable for 56 days. The epigenetic programs for both effector memory, associated with T-bet, and central memory, associated with TCF-1, were established in parallel. Memory T cell-specific regulatory elements were associated with greatly enhanced inducible Th1-biased responses during secondary exposures to antigen. Furthermore, memory T cells responded in vivo to re-exposure to antigen by rapidly reprograming the entire ETS factor gene regulatory network, by suppressing Ets1 and activating Etv6 expression. These data show that gene regulatory networks are epigenetically reprogrammed towards memory during infection, and undergo substantial changes upon re-stimulation.

IL-2/IL-7-inducible factors pioneer the path to T cell differentiation in advance of lineage-defining factors

When dormant naïve T cells first become activated by antigen-presenting cells, they express the autocrine growth factor IL-2 which transforms them into rapidly dividing effector T cells. During this process, hundreds of genes undergo epigenetic reprogramming for efficient activation, and also for potential reactivation after they return to quiescence as memory T cells. However, the relative contributions of IL-2 and T cell receptor signaling to this process are unknown. Here, we show that IL-2 signaling is required to maintain open chromatin at hundreds of gene regulatory elements, many of which control subsequent stimulus-dependent alternative pathways of T cell differentiation. We demonstrate that IL-2 activates binding of AP-1 and STAT5 at sites that can subsequently bind lineage-determining transcription factors, depending upon what other external factors exist in the local T cell environment. Once established, priming can also be maintained by the stroma-derived homeostatic cytokine IL-7, and priming diminishes if Il7r is subsequently deleted in vivo. Hence, IL-2 is not just a growth factor; it lays the foundation for T cell differentiation and immunological memory.