IL-6R identifies early differentiated human effector memory CD8+ T cells that potently expand and produce IL-2 and IL-13
ABSTRACT: We found a unique subset of effector memory (EM) CD8+ T cells that expressed high levels of IL-6 receptor in human peripheral blood. These cells which also expressed high levels of IL-7Ra (referred to as IL-6R high IL-7Rahigh cells) had the a distinct gene expression profile and cellular characteristics compared to other EM CD8+ T cells. IL-6R high IL-7Ra high cells were early differentiated EM CD8+ T cells with decreased expression of T-bet, KLRG1, perforin and granzyme B. These cells had increased cell proliferation likely secondary to enhanced IL-2 production and high affinity IL-2R expression. IL-6R high IL-7Ra high EM CD8+ T cells exclusively produced high levels of IL-2, IL-5, IL-9 and IL-13 although IFN-r was produced by this cell subset and other EM CD8+ T cells. Of interest, IL-6R high IL-7Ra high EM CD8+ T cells expanded in the peripheral blood of patients with chronic obstructive pulmonary disease (COPD) and asthma where CD8+ T cells, IL-13 and IFN-r are suggested to be involved in the pathogenesis. Being the early-differentiated EM CD8+ T cells with a potent capacity to proliferate, survive and generate multiple cytokines, IL-6R high IL-7Ra high EM CD8+ T cells may serve as a primary reservoir for effector CD8+ T cells which potently expand and produce cytokines upon immune stimulation. Duplicate experiments were performed for each condition. In each condition, we independently prepared total RNA using the RNeasy mini kit (Qiagen) and assessed RNA integrity using Bioanalyzer 2100 (Agilent)- RINs were close to 10 for all samples. RNA was then amplified and hybridized to the Illumina HumanHT-12 v4.0 BeadChip, according to Illumina standard protocols.
Project description:Genome wide DNA methylation profiling of IL-7Ra high and low EM CD8+ T cells. The Illumina Infinium 27k Human DNA methylation Beadchip v1.2 was used to obtain DNA methylation profiles across approximately 27,578 CpGs. Samples included 2 IL-7Ra high EM CD8+ T cells and 2 IL-7Ra high EM CD8+ T cells. Bisulphite converted DNA from the 4 samples were hybridised to the Illumina Infinium 27k Human Methylation Beadchip v1.2
Project description:IL-6 is known to contribute to the differentiation of CD4+ T cells into different subsets of effector T helper cells. Less is known about the potential of IL-6 in regulating CD8+ T cell effector function. Here, we identify IL-6 as a master regulator of IL-21 in effector CD8+ T cells. IL-6 promotes the differentiation of a subset of naive CD8+ T cells that express IL-6R into a unique population of effector CD8+ T cells characterized by the production of high levels of IL-21 and low levels of IFN-γ. Similar to CD4+ T follicular helper (Tfh) cells, IL-21-producing CD8+ T cells generated in the presence of IL-6 directly provide help to B cells to induce isotype switching. CD8+ T cell-derived IL-21 contributes to the production of protective virus-specific IgG antibodies during influenza virus infection. Thus, this study reveals the presence of a new mechanism by which IL-6 regulates antibody production during viral infection, and a novel function of effector CD8+ T cells in the protection against viruses.
Project description:DNA methylation is an epigenetic mechanism that modulates gene expression in mammalian cells including T cells. Memory T cells are heterogeneous populations. Human effector memory (EM) CD8(+) T cells in peripheral blood contain two cell subsets with distinct traits that express low and high levels of the IL-7R?. However, epigenetic mechanisms involved in defining such cellular traits are largely unknown. In this study, we use genome-wide DNA methylation and individual gene expression to show the possible role of DNA methylation in conferring distinct traits of chemotaxis and inflammatory responses in human IL-7R?(low) and IL-7R?(high) EM CD8(+) T cells. In particular, IL-7R?(low) EM CD8(+) T cells had increased expression of CX3CR1 along with decreased DNA methylation in the CX3CR1 gene promoter compared with IL-7R?(high) EM CD8(+) T cells. Altering the DNA methylation status of the CX3CR1 gene promoter changed its activity and gene expression. IL-7R?(low) EM CD8(+) T cells had an increased migratory capacity to the CX3CR1 ligand fractalkine compared with IL-7R?(high) EM CD8(+) T cells, suggesting an important biological outcome of the differential expression of CX3CR1. Moreover, IL-7R?(low) EM CD8(+) T cells induced fractalkine expression on endothelial cells by producing IFN-? and TNF-?, forming an autocrine amplification loop. Overall, our study shows the role of DNA methylation in generating unique cellular traits in human IL-7R?(low) and IL-7R?(high) EM CD8(+) T cells, including differential expression of CX3CR1, as well as potential biological implications of this differential expression.
Project description:The IL-7 receptor alpha (IL-7R?) is the high affinity receptor for IL-7 which is essential for T cell homeostasis. We recently reported an age-associated expansion of human effector memory (EM) CD8(+) T cells expressing IL-7R? low (IL-7R?(low)), which could be detrimental to hosts by occupying "immunological space". We investigated the potential mechanisms for this phenomenon, focusing on cytomegalovirus (CMV) infection and INF-?. In the elderly (age ? 65), CMV infection was associated with a decreased frequency of naïve CD8(+) T cells as well as with an increased frequency of total EM and IL-7R?(low) EM CD8(+) T cells. However, in the young (age ? 40), this viral infection was associated only with an increased frequency of IL-7R?(low) EM CD8(+) T cells. There was no association found between CMV immune status and plasma levels of IFN-?. In CMV-infected young and elderly people, INF-? levels had no correlation with the frequency of IL-7R?(low) EM CD8(+) T cells although this cytokine levels correlated with the frequency of IL-7R?(low) CD45RA(+) EM CD8(+) T cells in CMV-uninfected elderly people. Our findings suggest that the effect of CMV infection on the frequency of CD8(+) T cell subsets may begin with IL-7R?(low) EM CD8(+) T cells and spread to other subsets with aging. Also, IFN-? could be associated with the expansion of IL-7R?(low) CD45RA(+) EM CD8(+) T cells in the CMV-uninfected elderly.
Project description:Cytokine receptors can be markers defining different T-cell subsets and considered as therapeutic targets. The association of IL-6 and IL-6 receptor α (IL-6Rα) with asthma was reported, suggesting their involvement in asthma.To determine whether and how IL-6Rα defines a distinct effector memory (EM) CD8+ T-cell population in health and disease.EM CD8+ T cells expressing IL-6Rα (IL-6Rα(high)) were identified in human peripheral blood and analyzed for function, gene, and transcription factor expression. The relationship of these cells with asthma was determined using blood and sputum.A unique population of IL-6Rα(high) EM CD8+ T cells was found in peripheral blood. These cells that potently proliferated, survived, and produced high levels of the Th2-type cytokines IL-5 and IL-13 had increased levels of GATA3 and decreased levels of T-bet and Blimp-1 in comparison with other EM CD8+ T cells. In fact, GATA3 was required for IL-6Rα expression. Patients with asthma had an increased frequency of IL-6Rα(high) EM CD8+ T cells in peripheral blood compared with healthy control subjects. Also, IL-6Rα(high) EM CD8+ T cells exclusively produced IL-5 and IL-13 in response to asthma-associated respiratory syncytial virus and bacterial superantigens.Human IL-6Rα(high) EM CD8+ T cells is a unique cell subset that may serve as a reservoir for effector CD8+ T cells, particularly the ones producing Th2-type cytokines, and expand in asthma.
Project description:We propose a novel role for interleukin (IL) 6 in inducing rapid spontaneous proliferation (SP) of naive CD8(+) T cells, which is a crucial step in the differentiation of colitogenic CD8(+) T cells. Homeostasis of T cells is regulated by two distinct modes of cell proliferation: major histocompatibility complex/antigen-driven rapid SP and IL-7/IL-15-dependent slow homeostatic proliferation. Using our novel model of CD8(+) T cell-dependent colitis, we found that SP of naive CD8(+) T cells is essential for inducing pathogenic cytokine-producing effector T cells. The rapid SP was predominantly induced in mesenteric lymph nodes (LNs) but not in peripheral LNs under the influence of intestinal flora and IL-6. Indeed, this SP was markedly inhibited by treatment with anti-IL-6 receptor monoclonal antibody (IL-6R mAb) or antibiotic-induced flora depletion, but not by anti-IL-7R mAb and/or in IL-15-deficient conditions. Concomitantly with the inhibition of SP, anti-IL-6R mAb significantly inhibited the induction of CD8(+) T cell-dependent autoimmune colitis. Notably, the transfer of naive CD8(+) T cells derived from IL-17(-/-) mice did not induce autoimmune colitis. Thus, we conclude that IL-6 signaling is crucial for SP under lymphopenic conditions, which subsequently caused severe IL-17-producing CD8(+) T cell-mediated autoimmune colitis. We suggest that anti-IL-6R mAb may become a promising strategy for the therapy of colitis.
Project description:The effector functions of CD8(+) T cells are influenced by tissue inflammatory microenvironments. IL-33, a member of the IL-1 family, acts as a danger signal after its release during cell necrosis. The IL-33/ST2 axis has been implicated in various Th2 responses. Its role in CD8(+) T-cell-mediated immune response is, however, not known. Here we find that type 1 cytotoxic T (Tc1) cells cultured in vitro unexpectedly express high levels of the IL-33 receptor ST2. Interestingly, the expression of ST2 in Tc1 cells is dependent on T-bet, a master Th1/Tc1 transcription factor. In addition, IL-33 enhances TCR-triggered IFN-? production. IL-33 together with IL-12 can stimulate IFN-? production in Tc1 cells. Moreover, IL-33 synergizes with IL-12 to promote CD8(+) T-cell effector function. The synergistic effect of IL-33 and IL-12 is partly mediated by Gadd45b. Together, these in vitro data establish a novel role of IL-33 in promoting effector type 1 adaptive immune responses.
Project description:Recent work suggests that IL-2 and IL-15 induce distinctive levels of signaling through common receptor subunits and that such varied signaling directs the fate of Ag-activated CD8(+) T cells. In this study, we directly examined proximal signaling by IL-2 and IL-15 and CD8(+) T cell primary and memory responses as a consequence of varied CD122-dependent signaling. Initially, IL-2 and IL-15 induced similar p-STAT5 and p-S6 activation, but these activities were only sustained by IL-2. Transient IL-15-dependent signaling is due to limited expression of IL-15R?. To investigate the outcome of varied CD122 signaling for CD8(+) T cell responses in vivo, OT-I T cells were used from mouse models where CD122 signals were attenuated by mutations within the cytoplasmic tail of CD122 or intrinsic survival function was provided in the absence of CD122 expression by transgenic Bcl-2. In the absence of CD122 signaling, generally normal primary response occurred, but the primed CD8(+) T cells were not maintained. In marked contrast, weak CD122 signaling supported development and survival of T central-memory (T(CM)) but not T effector-memory (T(EM)) cells. Transgenic expression of Bcl-2 in CD122(-/-) CD8(+) T cells also supported the survival and persistence of T(CM) cells but did not rescue T(EM) development. These data indicate that weak CD122 signals readily support T(CM) development largely through providing survival signals. However, stronger signals, independent of Bcl-2, are required for T(EM) development. Our findings are consistent with a model whereby low, intermediate, and high CD122 signaling support T(CM) memory survival, T(EM) programming, and terminal T effector cell differentiation, respectively.
Project description:It is known that human IL-7R low and high EM CD8+ T cells have a difference in the expression of some co-stimulatory, effector and cytotoxic molecules. However, their global gene expression profiles have not been characterized. We thus analyzed global gene expression by IL-7R low and high EM CD8+ T cells in healthy human peripheral blood. Overall design: Total RNA from the 6 samples were hybridized to the Illumina HumanHT-12 V4.0 expression beadchip
Project description:Recent evidence has suggested that IL-10-producing effector CD8+ T cells play an important role in regulating excessive inflammation during acute viral infections. However, the cellular and molecular cues regulating the development of IL-10-producing effector CD8+ T cells are not completely defined. Here, we show that type I interferons (IFNs) are required for the development of IL-10-producing effector CD8+ T cells during influenza virus infection in mice. We find that type I IFNs can enhance IL-27 production by lung APCs, thereby facilitating IL-10-producing CD8+ T-cell development through a CD8+ T-cell-nonautonomous way. Surprisingly, we also demonstrate that direct type I IFN signaling in CD8+ T cells is required for the maximal generation of IL-10-producing CD8+ T cells. Type I IFN signaling in CD8+ T cells, in cooperation with IL-27 and IL-2 signaling, promotes and sustains the expression of IFN regulatory factor 4 (IRF4) and B-lymphocyte-induced maturation protein-1 (Blimp-1), two transcription factors required for the production of IL-10 by effector CD8+ T cells. Our data reveal a critical role of the innate antiviral effector cytokines in regulating the production of a regulatory cytokine by effector CD8+ T cells during respiratory virus infection.