Gene expression profiling: human CD8+CD45RO+ memory T cells in IL23 responsive and nonresponsive individuals
ABSTRACT: The interleukin-23 (IL-23) pathway plays a critical role in the pathogenesis of multiple chronic inflammatory disorders, however, inter-individual variability in IL-23-induced signal transduction in circulating human lymphocytes has not been well-defined. In this study, we observed marked, reproducible inter-individual differences in IL-23 responsiveness (measured by STAT3 phosphorylation) in peripheral blood CD8+CD45RO+ memory T and CD3+CD56+ NKT cells. To define mechanisms that might be contributing to the differential IL-23-induced STAT3 activation between individuals, we examined mRNA expression differences in CD8+CD45RO+ memory T cells between IL-23 responsive and non-responsive individuals. We analyzed unstimulated and IL-23 stimulated FACS sorted CD8+CD45RO+ memory T cells from two individuals demonstrating robust IL-23 responsiveness, and two individuals demonstrating low IL-23 responsiveness, using the Affymetrix Human Exon 1.0 ST platform. Array data was processed by Affymetrix Expression Console software. No techinical replicates were performed.
Project description:The interleukin-23 (IL-23) pathway plays a critical role in the pathogenesis of multiple chronic inflammatory disorders, however, inter-individual variability in IL-23-induced signal transduction in circulating human lymphocytes has not been well-defined. In this study, we observed marked, reproducible inter-individual differences in IL-23 responsiveness (measured by STAT3 phosphorylation) in peripheral blood CD8+CD45RO+ memory T and CD3+CD56+ NKT cells. Age, but not gender, was a significant (Pearson's correlation coefficient, r = -0.37, p = 0.001) source of variability observed in CD8+CD45RO+ memory T cells, with IL-23 responsiveness gradually decreasing with increasing age. Relative to cells from individuals demonstrating low responsiveness to IL-23 stimulation, CD8+CD45RO+ memory T cells from individuals demonstrating high responsiveness to IL-23 stimulation showed increased gene expression for IL-23 receptor (IL-23R), RORC (ROR?t) and CD161 (KLRB1), whereas RORA (ROR?) and STAT3 expression were equivalent. Similar to CD4+ memory T cells, IL-23 responsiveness is confined to the CD161+ subset in CD8+CD45RO+ memory T cells, suggesting a similar CD161+ precursor as has been reported for CD4+ Th17 cells. We observed a very strong positive correlation between IL-23 responsiveness and the fraction of CD161+, CD8+CD45RO+ memory T cells (r = 0.80, p<0.001). Moreover, the fraction of CD161+, CD8+CD45RO+ memory T cells gradually decreases with aging (r = -0.34, p = 0.05). Our data define the inter-individual differences in IL-23 responsiveness in peripheral blood lymphocytes from the general population. Variable expression of CD161, IL-23R and RORC affects IL-23 responsiveness and contributes to the inter-individual susceptibility to IL-23-mediated defenses and inflammatory processes.
Project description:The ability to detect and isolate human CD8 TSP (Side population), Naïve, Effector memory (EM), Central memory (CM) cells allowed us to compare the global gene expression profiles of these cells. Human TSP cells comprise of distinct gene expression profile specifically enriched for genes overexpressed in TRM cells. RNA samples from CD8 TSP (Side population), Naïve, Effector memory (EM), Central memory (CM) cells were amplified, labeled, and hybridized on the Affymetrix Human Genome U133 Plus 2.0 microarray chips. The data were analyzed with GeneSpring GX 12.5 (Agilent Technologies)
Project description:Systemic sclerosis (SSc) is an autoimmune disease characterized by vascular damage, and fibrosis of the skin and internal organs. Because activated and oligoclonally expanded CD8+ T cells can be detected in peripheral blood and lung of SSc patients, effector memory CD8+ T cells may play a critical role for organ involvement in SSc; however, the pathogenic functions of effector memory CD8+ T cells remain incompletely understood. Here we performed DNA microarray analysis of the sort-purified effector memory CD8+ T cells from SSc patients and healthy controls, and showed that the expression of genes related to immune response and cell adhesion, including CD226 (also known as DNAX accessory molecule-1, DNAM-1), was significantly altered. Moreover, detailed analysis of CD226 revealed that CD226highCD8+ T cells were increased in SSc patients (mean, 50.7%) compared with healthy controls (32.9%) and were appreciably associated with the severity of skin sclerosis and interstitial lung disease. Further, CD226highCD8+ T cells from SSc patients produced abundant IL-13 and were positively correlated with the cytotoxic capacity of CD8+ T cells against HUVECs. Finally, the neutralization of CD226 impaired IL-13 production and cytolysis against HUVECs. These findings indicate that upregulated CD226 expression on CD8+ T cells reflects disease severity and are involved in SSc pathogenesis via the production of profibrotic IL-13 and endothelial cell injury, and that CD226 may be a useful target in the treatment of SSc. We first purified effector memory CD8+ T cells (CD3+CD8+CD45RO+CD62L+ cells) from peripheral blood by cell sorting and subsequently performed cDNA microarray analysis of the sort-purified effector memory CD8+ T cells from 9 SSc patients and 5 healthy controls.
Project description:Effects of IL-4 on CD8 T cells functions are largely unknown. IL-4 induces survival and proliferation of CD8 T cells, but several studies suggest that IL-4 could also affect several functions of CD8 T cells such as cytotoxicity. Our team has shown that IL-4 repress the expression of Ccl5 in vitro. To define more precisely the impact of IL-4 on CD8 T cells, we performed a whole genome expression microarray analysis of naive and memory CD8 T cells cultured in presence or absence of IL-4. This approach allowed us to define the IL4-gene-expression signature on CD8 T cells. 18 samples were processed. Two populations of F5 naive CD8 T cells were FACS-sorted: samples from each population were incubated 20 hours with IL-7 in presence or absence of IL-4. Thus, a total of 6 “Naive” samples were processed. In addition, 4 populations of F5 TIM memory CD8 T cells were FACS-sorted: samples from 2 of these populations were incubated 20 hours in presence of IL-7 and/or IL-4, or in medium alone. Thus, 12 “Memory” samples were processed.
Project description:Peripheral Blood Mononuclear Cells (PBMCs) were isolated from a buffy coat (Australian Blood Bank) using Ficoll methodology. CD4+ T cells were isolated using Dynal Beads kit. Pure CD4+ T cells were then stained using a cocktail of monoclonal antobodies (mAbs), including: anti-CD4PE, CD45RO ECD, CD62L APC-Cy7, CD25 APC, CD127 Pacific Blue. After incubation, cells were washed twice in PBS/FCS (0.2%), and sorted into five different cell subsets: CD4+CD25+CD127low CD62L+CD45RO- (naive regulatory T cells), CD4+CD25+CD127low CD62L+/- CD45RO+ (activated regulatory T cells), CD4+CD25+CD127hi CD62L+/- CD45RO+ (memory T cells), CD4+CD25-CD127low CD62L+/- CD45RO+ (effector T cells) and CD4+CD25-CD127hi CD62L+ CD45RO- (naive T cells).
Project description:The mechanisms regulating memory CD8(+) T cell function and homeostasis during aging are unclear. CD8(+) effector memory T cells that re-express CD45RA increase considerably in older humans and both aging and persistent CMV infection are independent factors in this process. We used MHC class I tetrameric complexes that were mutated in the CD8 binding domain to identify CMV-specific CD8(+) T cells with high Ag-binding avidity. In individuals who were HLA-A*0201, CD8(+) T cells that expressed CD45RA and were specific for the pp65 protein (NLVPMVATV epitope) had lower avidity than those that expressed CD45RO and demonstrated decreased cytokine secretion and cytolytic potential after specific activation. Furthermore, low avidity NLVPMVATV-specific CD8(+) T cells were significantly increased in older individuals. The stimulation of blood leukocytes with CMV lysate induced high levels of IFN-? that in turn induced IL-15 production. Moreover, the addition of IL-15 to CD45RA(-)CD45RO(+) CMV-specific CD8(+) T cells induced CD45RA expression while Ag activated cells remained CD45RO(+). This raises the possibility that non-specific cytokine-driven accumulation of CMV-specific CD8(+)CD45RA(+) T cells with lower Ag-binding avidity may exacerbate the effects of viral reactivation on skewing the T cell repertoire in CMV-infected individuals during aging.
Project description:Inflammasomes are multi-protein complexes that control the production of pro-inflammatory cytokines such as IL-1beta. Inflammasomes play an important role in the control of immunity to tumors and infections, and also in autoimmune diseases, but the mechanisms controlling the activation of human inflammasomes are largely unknown. We found that human activated CD4+CD45RO+ memory T-cells specifically suppress P2X7R-mediated NLRP3 inflammasome activation, without affecting P2X7R-independent NLRP3 or NLRP1 inflammasome activation. The concomitant increase in pro-IL-1β production induced by activated memory T-cells concealed this effect. Priming with IFNβ decreased pro-IL-1β production in addition to NLRP3 inflammasome inhibition and thus unmasked the inhibitory effect on NLRP3 inflammasome activation. IFNβ did not suppress NLRP3 inflammasome activation by acting directly on monocytes. The inhibition of pro-IL-1β production and suppression of NLRP3 inflammasome activation by IFNβ-primed human CD4+CD45RO+ memory T-cells is partly mediated by soluble FasL and is associated with down-regulated P2X7R mRNA expression and reduced response to ATP in monocytes. CD4+CD45RO+ memory T-cells from multiple sclerosis (MS) patients showed a reduced ability to suppress NLRP3 inflammasome activation, however their suppressive ability was recovered following in vivo treatment with IFNβ. Thus, our data demonstrate that human P2X7R-mediated NLRP3 inflammasome activation is regulated by activated CD4+CD45RO+ memory T cells, and provide new information on the mechanisms mediating the therapeutic effects of IFNβ in MS. Memory T-cells were cultured in the presence of monocytes with and without Interferon-beta, resorted and expression profile was determined
Project description:The SNP (c.1142G > A;p.R381Q) in the IL-23 receptor (IL23R) confers protection from multiple inflammatory diseases, representing one of the most significant human genetic polymorphisms in autoimmunity. We, therefore, sought to define the functional consequences of this clinically significant variant. We find that CD4+CD45RO+ and CD8+ T cells from healthy R381Q IL23R carriers show decreased IL-23-dependent IL-17 and IL-22 production relative to WT IL23R individuals. This was associated with a lower percentage of circulating Th17 and Tc17 cells. Furthermore, CD8+ T cells from R381Q IL23R individuals showed decreased IL-23-dependent expansion and signal transducer and activator of transcription 3 (STAT3) activation compared with WT CD8+ T cells. Importantly, cells transfected with the IL23R glutamine variant show decreased IL-23-mediated signaling compared with the IL23R arginine allele. Our results show that the R381Q IL23R variant leads to selective, potentially desirable, loss of function alterations in primary human CD4+ and CD8+ T cells, resulting in highly significant protection against autoimmunity.
Project description:Patients with rheumatoid arthritis (RA) were treated with a cellular vaccine, which consisted of autologous collagen-reactive T-cells. This study showed that antigen-specific proliferative activity of the peripheral blood mononuclear cells was significantly downregulated after T-cell vaccination in RA patients. T-cell vaccination resulted in a statistically significant decrease in plasma IFNγ levels and a concomitant increase in IL-4 levels in treated patients. Accordingly, following T-cell vaccination the number of IFNγ-producing CD4(+) and CD8(+) T-cells was decreased by 1.6-1.8-fold, which was paralleled by 1.7-fold increases in IL-4-producing CD4(+) T-cells. In addition, the present study showed 5-7-fold increase in the CD8(+)CD45RO(+)CD62L(-) effector memory T-cells and central memory T-cells (both CD4(+) CD45RO(+)CD62L(+) T-cells and CD8(+)CD45RO(+)CD62L(+) T-cells) in RA patients, as compared with healthy individuals. We observed significant reduction in CD4(+) and CD8(+) central memory T-cells, as well as reduction in CD8(+) effector memory T-cells in vaccinated patients in the course of the treatment. We also demonstrated that CD4(+)CD25(+)FoxP3(+) regulatory T-cell levels were significantly up-regulated in the peripheral blood of RA patients following T-cell vaccination. However, CD4(+)CD25(-)FoxP3(+) Т-cell levels did not significantly change during the entire T-cell vaccination course. In conclusion, the T-cell immunotherapy regimen used resulted in the clinical improvement, which was achieved in 87% patients.
Project description:An early-differentiated CD8+ memory T cell subset with stem cell-like properties (TSCM) can be identified within the naïve-like T cell population by the expression of CD95/Fas. Based on experiments including exon- and gene-level expression analysis, we provide evidence that this subset of antigen-specific cells represents an early precursor of conventional central (TCM) and effector (TEM) memory CD8+ T cells with enhanced self-renewal capacity and proliferative potential. We identified 900 genes differentially expressed between major T cell subsets defined along with memory T cell commitment. Based on the analysis of these genes, CD95+ naïve T cells (TSCM) cluster closer to the CD8+ T memory compartment than to classical (CD95-) naïve T (TN) cells, and display an intermittent phenotype between classical TN and TCM cells in terms of all major T cell differentiation markers analyzed. Three healthy human blood donors provided lymphocyte-enriched apheresis blood for this study after informed consent. From all samples, total RNA was isolated using an RNEasy Micro kit (Qiagen), processed by Ambion’s WT expression kit, fragmented and labeled with a WT Terminal Labeling Kit (Affymetrix), hybridized to WT Human Gene 1.0 ST arrays (Affymetrix) and stained on a Genechip Fluidics Station 450 (Affymetrix), all according to the respective manufacturer's instructions. Samples represent "exon-level" and "gene-level" analyses.