Memory T cells are a highly heterogeneous collection of antigen-experienced cells that undergo dynamic adaptations upon antigen re-encounter and environmental signals. This heterogeneity hinders studies on memory T cell durability and age-related dysfunction. Using chronic Epstein-Barr virus (EBV) infection and barcode-enabled antigen tracing, we assess the influence of age on memory states at the level of single antigen-specific CD8+ T cells. In young adults (<40 years), EBV-specific CD8+ T cells recognizing different antigenic peptides assume divergent preferred differentiation phenotypes. In older adults (>65-years), antigen-specific cells show largely distinct phenotypic and transcriptomic aging trajectories. Common to many albeit not all antigen-specific populations are maintained TCR diversity, gained natural killer cell-like, innate signatures and lost stem-like features while no evidence is seen for cellular senescence or exhaustion. TCR avidity contributes to these phenotypic differences and aging-related changes. Collectively, our data uncover divergent antigen-guided aging shifts in memory T cell phenotypes, which are informative for antigen selection in optimizing vaccine design and adoptive T cell therapy.

Memory T cells are a highly dynamic and heterogeneous population that is maintained by cytokine-driven homeostatic proliferation interspersed with episodes of antigen-mediated expansion and contraction which affect their functional state and their durability. This heterogeneity complicates studies on the impact of aging on global human memory cells, specifically, it is unclear how aging drives memory T cell dysfunction. Here, we used chronic infection with Epstein-Barr virus (EBV) to assess the influence of age on memory states at the level of antigen-specific CD8 + T cells. We find that in young adults (<40 years), EBV-specific CD8 + T cells assume preferred differentiation states depending on their peptide specificity. By age >65-years, different T cell specificities had undergone largely distinct aging trajectories, which had in common a loss in adaptive and a gain in innate immunity signatures. No evidence was seen for cellular senescence or exhaustion. While naïve/stem-like EBV-specific T cells disappeared with age, T cell diversity of EBV-specific memory cells did not change or even increased. In summary, by controlling for antigen specificity we uncover age-associated shifts in gene expression and TCR diversity that have implications for optimizing vaccination strategies and adoptive T cell therapy.

The human adult immune system maintains normal T cell counts and compensates for T cell loss throughout life, mainly through peripheral homeostatic proliferation after the ability of the thymus to generate new T cells has rapidly declined at adolescence. This process is mainly driven by STAT5-activating cytokines, most importantly IL-7, and is very effective in maintaining a large naive CD4+ T cell compartment into older age. Here, we describe that naive CD4+ T cells undergo adaptations to optimize IL-7 responses by upregulating the guanine-nucleotide exchange factor PREX1 in older age. PREX1 promotes nuclear translocation of phosphorylated STAT5, thereby supporting homeostatic proliferation in response to IL-7. Through the same mechanism, increased expression of PREX1 also biases naive cells to differentiate into effector T cells. These findings are consistent with the concept that primarily beneficial adaptations during aging, i.e., improved homeostasis, account for unfavorable functions of the aged immune system, in this case biased differentiation.

<p>Supplementary Figure S1: Time-course expression analysis of LNCaP cells reveals dynamic and heterogeneous responses to androgen stimulation. Supplementary Figure S2: Cell cycle progression of LNCaP cells treated with or without R1881 after cell synchronization by double thymidine block (DTB). Supplementary Figure S3: The summary of aligned and unaligned single-cell RNA-seq reads counts. Supplementary Figure S4: Correlation of single-cell RNA-seq ensemble reads with representative bulk RNA-seq reads. Supplementary Figure S5: Venn diagrams illustrating the comparison of differentially expressed genes found in single- and bulk-cell LNCaP experiments. Supplementary Figure S6: The Mclust algorithm defines likely subgroups using a "model-based" approach. Supplementary Figure S7: Each cell within each subcluster exhibits a similar gene expression profile. Supplementary Figure S8: Gleason score and biochemical recurrence status compared to each subcluster''s gene expression profile. Supplementary Figure S9: Differential expression of 10 genes in LNCaP''s 8.1 subpopulation of cells. Supplementary Figure S10: High single-cell expression of 10 genes in PC3 similar to 12hr-R1881 LNCaP cells.</p>

PDF file - 1049K, Supplementary Figure S1. Summarized sequencing reads and coverage of MBDCap-seq Supplementary Figure S2. Reproducibility test of MBDCap-seq Supplementary Figure S3. Validation of MBDCap-seq by MassARRAY analysis Supplementary Figure S4. Distribution of differentially methylated regions (DMRs) in endometrial tumors relative to normal control Supplementary Figure S5. Network analysis of differential methylation loci by using Steiner-tree analysis Supplementary Figure S6. DNA methylation distribution in early and late stage of the TCGA endometrial cancer cohort Supplementary Figure S7. Relative expression of BMP genes with EGF treatment in the presence or absence of PI3K/AKT and Raf (MAPK) inhibitors in endometrial cancer cells Supplementary Figure S8. Induction of invasion by EGF in AN3CA and HEC1A cell lines Supplementary Figure S9. Knockdown expression of BMP4 and BMP7 in RL95-2 cells Supplementary Figure S10. Relative expression of BMPs and BMPRs in normal endometrial cell and endometrial cancer cell lines Supplementary Figure S11. Microfluidics-based PCR analysis of EMT gene panel in RL95-2 cells with or without EGF treatment Supplementary Figure S12. Knockdown expression of EpCAM by different shRNA sequences in RL95-2 cells Supplementary Figure S13. Proposed model for EpICD mediated regulation of BMP genes by EGF Supplementary Table 1. Characteristics of endometrial cancer patients Supplemental Table 2. Summary of sequencing reads in endometrial tumors an normal controls Supplementary Table 3. Differentially methylated promoter CpG islands in recurrent relative to non-recurrent tumors Supplementary Table 4. List of primer sequences Supplementary Table 5. List of siRNA and shRNA sequences

Supplementary Table S3: P values for significant differences between 0, 6, 12, 24, 36, and 72 hour R1881-treated LNCaP cells

Naive CD4+ T cells are more resistant to age-related loss than naive CD8+ T cells, suggesting mechanisms that preferentially protect naive CD4+ T cells during aging. Here, we show that TRIB2 is more abundant in naive CD4+ than CD8+ T cells and counteracts quiescence exit by suppressing AKT activation. TRIB2 deficiency increases AKT activity and accelerates proliferation and differentiation in response to interleukin-7 (IL-7) in humans and during lymphopenia in mice. TRIB2 transcription is controlled by the lineage-determining transcription factors ThPOK and RUNX3. Ablation of Zbtb7b (encoding ThPOK) and Cbfb (obligatory RUNT cofactor) attenuates the difference in lymphopenia-induced proliferation between naive CD4+ and CD8+ cells. In older adults, ThPOK and TRIB2 expression wanes in naive CD4+ T cells, causing loss of naivety. These findings assign TRIB2 a key role in regulating T cell homeostasis and provide a model to explain the lesser resilience of CD8+ T cells to undergo changes with age.

Chronic systemic inflammation is one of the hallmarks of the aging immune system. Here we show that activated T cells from older adults contribute to inflammaging by releasing mitochondrial DNA (mtDNA) into their environment due to an increased expression of the cytokine-inducible SH2-containing protein (CISH). CISH targets ATP6V1A, an essential component of the proton pump V-ATPase, for proteasomal degradation, thereby impairing lysosomal function. Impaired lysosomal activity caused intracellular accumulation of multivesicular bodies and amphisomes and the export of their cargos, including mtDNA. CISH silencing in T cells from older adults restored lysosomal activity and prevented amphisomal release. In antigen-specific responses in vivo, CISH-deficient CD4 + T cells released less mtDNA and induced fewer inflammatory cytokines. Attenuating CISH expression may present a promising strategy to reduce inflammation in an immune response of older individuals.

<p>Supplementary Table S2: qPCR primer for subcluster E genes</p>

This article describes the systematic design of an electronic recording peak expiratory flow (PEF) meter to provide accurate data for the diagnosis of occupational asthma. Traditional diagnosis of asthma relies on accurate data of PEF tests performed by the patients in their own homes and places of work. Unfortunately there are high error rates in data produced and recorded by the patient, most of these are transcription errors and some patients falsify their records. The PEF measurement itself is not effort independent, the data produced depending on the way in which the patient performs the test. Patients are taught how to perform the test giving maximal effort to the expiration being measured. If the measurement is performed incorrectly then errors will occur. Accurate data can be produced if an electronically recording PEF instrument is developed, thus freeing the patient from the task of recording the test data. It should also be capable of determining whether the PEF measurement has been correctly performed. A requirement specification for a recording PEF meter was produced. A commercially available electronic PEF meter was modified to provide the functions required for accurate serial recording of the measurements produced by the patients. This is now being used in three hospitals in the West Midlands for investigations into the diagnosis of occupational asthma. In investigating current methods of measuring PEF and other pulmonary quantities a greater understanding was obtained of the limitations of current methods of measurement, and quantities being measured. It is now possible to define the quantities that need to be measured for accurate pulmonary diagnosis and the requirements of future instrumentation to make these necessary measurements. We are now in the process of developing this new instrumentation.

<p>Supplementary Table S4: List of genes most highly associated with each subcluster</p>

<p>Supplementary Table S1: qPCR Primers for androgen responsive genes</p>

Deaf and hearing-impaired people all around the globe choose to communicate through sign language. When utilised in a computer vision or other approach, recognition of sign language can have varied degrees of success. Sign language is claimed to contain a systematic collection of motions, each with its own mean- ing. Some studies have proven to be successful in identifying sign language, but commercialization is prohibitively expensive. Researchers are now paying greater emphasis to building commercially viable Sign Language Recognition systems. Researchers conduct their studies in a variety of methods. It all be- gins with the data collection methods. Because of the high cost of a decent device, the data collecting technique varies, but a low-cost approach is required for the Sign Language Recognition System to be commercialised. The method- ologies utilised to create Sign Language Recognition differ from one researcher to the next. In comparison to other approaches, each method has its own set of restrictions. The purpose of this work is to examine several ways to sign language recognition and determine the most effective method that has been adopted by researchers.

[This corrects the article DOI: 10.3389/fimmu.2020.585168.].

Immune aging combines cellular defects in adaptive immunity with the activation of pathways causing a low-inflammatory state. Here we examined the influence of age on the kinetic changes in the epigenomic and transcriptional landscape induced by T cell receptor (TCR) stimulation in naive CD4 + T cells. Despite attenuated TCR signaling in older adults, TCR activation accelerated remodeling of the epigenome and induced transcription factor networks favoring effector cell differentiation. We identified increased phosphorylation of STAT5, at least in part due to aberrant IL-2 receptor and lower HELIOS expression, as upstream regulators. Human HELIOS-deficient, naive CD4 + T cells, when transferred into human-synovium-mouse chimeras, infiltrated tissues more efficiently. Inhibition of IL-2 or STAT5 activity in T cell responses of older adults restored the epigenetic response pattern to the one seen in young adults. In summary, reduced HELIOS expression in non-regulatory naive CD4 + T cells in older adults directs T cell fate decisions toward inflammatory effector cells that infiltrate tissue.

Healthy immune aging is in part determined by how well the sizes of naïve T cell compartments are being maintained with advancing age. Throughout adult life, replenishment largely derives from homeostatic proliferation of existing naïve and memory T cell populations. However, while the subpopulation composition of CD4 T cells is relatively stable, the CD8 T cell compartment undergoes more drastic changes with loss of naïve CD8 T cells and accumulation of effector T cells, suggesting that CD4 T cells are more resilient to resist age-associated changes. To determine the epigenetic basis for these differences in behaviors, we compared chromatin accessibility maps of CD4 and CD8 T cell subsets from young and old individuals and related the results to the expressed transcriptome. The dominant age-associated signatures resembled hallmarks of differentiation, which were more pronounced for CD8 naïve and memory than the corresponding CD4 T cell subsets, indicating that CD8 T cells are less able to keep cellular quiescence upon homeostatic proliferation. In parallel, CD8 T cells from old adults, irrespective of their differentiation state, displayed greater reduced accessibility to genes of basic cell biological function, including genes encoding ribosomal proteins. One possible mechanism is the reduced expression of the transcription factors YY1 and NRF1. Our data suggest that chromatin accessibility signatures can be identified that distinguish CD4 and CD8 T cells from old adults and that may confer the higher resilience of CD4 T cells to aging.

BACKGROUND:Rheumatoid arthritis (RA) is an inflammatory disease that manifests as a preclinical stage of systemic autoimmunity followed by chronic progressive synovitis. Disease-associated genetic SNP variants predominantly map to non-coding, regulatory regions of functional importance in CD4 T cells, implicating these cells as key regulators. A better understanding of the epigenome of CD4 T cells holds the promise of providing information on the interaction between genetic susceptibility and exogenous factors.METHODS:We mapped regions of chromatin accessibility using ATAC-seq in peripheral CD4 T cell subsets of patients with RA (n=18) and compared them to T cells from patients with psoriatic arthritis (n=11) and age-matched healthy controls (n=10). Transcripts of selected genes were quantified using qPCR.FINDINGS:RA-associated epigenetic signatures were identified that in part overlapped between central and effector memory CD4 T cells and that were to a lesser extent already present in naïve cells. Sites more accessible in RA were highly enriched for the motif of the transcription factor (TF) CTCF suggesting differences in the three-dimensional chromatin structure. Unexpectedly, sites with reduced chromatin accessibility were enriched for motifs of TFs pertinent for T cell function. Most strikingly, super-enhancers encompassing RA-associated SNPs were less accessible. Analysis of selected transcripts and published DNA methylation patterns were consistent with this finding. The preferential loss in accessibility at these super-enhancers was seen in patients with high and low disease activity and on a variety of immunosuppressive treatment modalities.INTERPRETATION:Disease-associated genes are epigenetically less poised to respond in CD4 T cells from patients with established RA.FUNDING:This work was supported by I01 BX001669 from the Veterans Administration.

Combination therapy with PD-1 blockade and IL-2 is highly effective during chronic lymphocytic choriomeningitis virus infection1. Here we examine the underlying basis for this synergy. We show that PD-1 + IL-2 combination therapy, in contrast to PD-1 monotherapy, substantially changes the differentiation program of the PD-1+TCF1+ stem-like CD8+ T cells and results in the generation of transcriptionally and epigenetically distinct effector CD8+ T cells that resemble highly functional effector CD8+ T cells seen after an acute viral infection. The generation of these qualitatively superior CD8+ T cells that mediate viral control underlies the synergy between PD-1 and IL-2. Our results show that the PD-1+TCF1+ stem-like CD8+ T cells, also referred to as precursors of exhausted CD8+ T cells, are not fate-locked into the exhaustion program and their differentiation trajectory can be changed by IL-2 signals. These virus-specific effector CD8+ T cells emerging from the stem-like CD8+ T cells after combination therapy expressed increased levels of the high-affinity IL-2 trimeric (CD25-CD122-CD132) receptor. This was not seen after PD-1 blockade alone. Finally, we show that CD25 engagement with IL-2 has an important role in the observed synergy between IL-2 cytokine and PD-1 blockade. Either blocking CD25 with an antibody or using a mutated version of IL-2 that does not bind to CD25 but still binds to CD122 and CD132 almost completely abrogated the synergistic effects observed after PD-1 + IL-2 combination therapy. There is considerable interest in PD-1 + IL-2 combination therapy for patients with cancer2,3, and our fundamental studies defining the underlying mechanisms of how IL-2 synergizes with PD-1 blockade should inform these human translational studies.

With increasing age, individuals are more vulnerable to viral infections such as with influenza or the SARS-CoV-2 virus. One age-associated defect in human T cells is the reduced expression of miR-181a. miR-181ab1 deficiency in peripheral murine T cells causes delayed viral clearance after infection, resembling human immune aging. Here we show that naive T cells from older individuals as well as miR-181ab1-deficient murine T cells develop excessive replication stress after activation, due to reduced histone expression and delayed S-phase cell cycle progression. Reduced histone expression was caused by the miR-181a target SIRT1 that directly repressed transcription of histone genes by binding to their promoters and reducing histone acetylation. Inhibition of SIRT1 activity or SIRT1 silencing increased histone expression, restored cell cycle progression, diminished the replication-stress response, and reduced the production of inflammatory mediators in replicating T cells from old individuals. Correspondingly, treatment with SIRT1 inhibitors improved viral clearance in mice with miR-181a-deficient T cells after LCMV infection. In conclusion, SIRT1 inhibition may be beneficial to treat systemic viral infection in older individuals by targeting antigen-specific T cells that develop replication stress due to miR-181a deficiency.