Gene expression signature of naïve and in vitro activated CD8 T cells in response to IL-12 and Type I IFN
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ABSTRACT: Differentiation of naive CD8 T cells into cytotoxic effector cells requires three distinct signals- antigen (signal 1), costimulation -B7-1 (signal 2) and cytokine, either interleukin-12 or interferon-a/b (signal 3). Interaction of naive CD8 T cells with antigen and B7-1 programs cell division and proliferation whereas the presence of cytokines- IL-12 or IFNa/b promote survival, differentiation and memory establishment. In the absence of signal 3, the cells interacting with antigen/B7-1 undergo tolerance induction. The objective of this study was to elucidate the mechanisms how the provision of signal 3 promotes differentiation and averts tolerance induction in CD8 T cells. Trichostatin A is a pharmacological agent that inhibits histone deacetylase activity, hence regulating chromatin structure and gene expression and differentiation in many cell types. Gene signature profiles of IL-12, IFNa/b and trichostatin A stimulated cells were compared to elucidate the molecular mechanisms of gene regulation. Oligonucleotide microarray analysis is carried out to determine the extent and molecular nature of the CD8 T cell differentiation program induced by IL-12 or IFNa/b in concert with antigen and B7-1 signal.
Project description:Differentiation of naive CD8 T cells into cytotoxic effector cells requires three distinct signals- antigen (signal 1), costimulation -B7-1 (signal 2) and cytokine, either interleukin-12 or interferon-a/b (signal 3). Interaction of naive CD8 T cells with antigen and B7-1 programs cell division and proliferation whereas the presence of cytokines- IL-12 or IFNa/b promote survival, differentiation and memory establishment. In the absence of signal 3, the cells interacting with antigen/B7-1 undergo tolerance induction. The objective of this study was to elucidate the mechanisms how the provision of signal 3 promotes differentiation and averts tolerance induction in CD8 T cells. Trichostatin A is a pharmacological agent that inhibits histone deacetylase activity, hence regulating chromatin structure and gene expression and differentiation in many cell types. Gene signature profiles of IL-12, IFNa/b and trichostatin A stimulated cells were compared to elucidate the molecular mechanisms of gene regulation. Oligonucleotide microarray analysis is carried out to determine the extent and molecular nature of the CD8 T cell differentiation program induced by IL-12 or IFNa/b in concert with antigen and B7-1 signal. Experiment Overall Design: The programming for development of function and memory in presence of signal 3 occurs over three days of initial stimulation, and antigen-B7 and IL-12 or IFNa/b must be present for most of this period to achieve maximal responses. We analyzed gene expression in highly purified naive CD8 T cells at 0, 24, 48 and 72h of in vitro culture stimulated with antigen-B7 and with or without IL-12 or IFNa/b to tease apart gene expression profiles of naive, 2-signal and 3-signal stimulated cells over the course of 3-days. Gene expression of cells stimulated with trichostatin A for 72hr were compared with IL-12 or IFNa/b stimulated cells. 20 arrays.
Project description:Differentiation of naive CD8 T cells into cytotoxic effector cells requires three distinct signals- antigen (signal 1), costimulation -B7-1 (signal 2) and cytokine, either interleukin-12, interferon-a/b, or IL-21 (signal 3). Interaction of naive CD8 T cells with antigen and B7-1 programs cell division and proliferation whereas the presence of cytokines- IL-12, IFNa/b or IL-21 promote survival, differentiation and memory establishment. In the absence of signal 3, the cells interacting with antigen/B7-1 undergo tolerance induction. Previous work had analyzed the regulation of mRNA expression changes induced by IL-12 and IFN-a and cells stimulated with antigen, B7-1 and cytokine by comparing mRNA expression levels in naïve CD8 T cells, cells stimulated with 2 signals (antigen and B7-1) (Agarwal, P.A., A. Raghavan, S.L. Nandiwada, J.M. Curtsinger, P.R. Bohjanen, D.L. Mueller and M.F. Mescher. Gene regulation and chromatin remodeling by IL-12 and Type I interferon in programming for CD8 T cell effector function and memory. J. Immunol. 183:1695-1704 (2009). PMCID: PMC2893405). That microarray data was deposited in the NCI GEO database and can be found at http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc_GSE15930. The objective of the current study was to carry out the same analysis to determine IL-21-dependent changes in mRNA expression in CD8 T cells responding to antigen and B7-1-dependent costimulation in the absence or presence of IL-21.
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:IFNα-mediated gene expression pattern. Direct effects of IFNα on human CD8 T cells without any other concomitant signal. This analysis examined the direct effects of IFNa on human CD8 T cells without any other concomitant signal. Total human CD8 T cells were magnetically sorted from peripheral blood by negative selection. In order to minimize the presence of antigen-experienced cells, total human CD8 T cells were depleted of CD45RO+ cells by labelling with anti-CD45RO magnetic bead. In both steps of cellular sorting, negative selection were preferred to positive selection to avoid direct labelling of CD8 T cell surface molecules could interfere with downstream IFNa-mediated signalling. Magnetically sorted untouched human CD8+CD45R0- T cells from three different donors were unstimulated or stimulated with IFNa2b or IFNa5 and cells were harvested 7 hours later. mRNAs from the 3 subjects were pooled and analyzed using Affymetrix human HG-U133A 2.0 array gene chips Fold-change ≥ 2 criterion was used to identify genes which expression differed between treatment and control (unstimulated cells). Keywords: Gene expression pattern analysis Magnetically sorted untouched CD8+CD45R0-T cells mRNA pooled sample from three different donors unstimulated or stimulated with IFN alfa 2b or IFN alfa 5 for 7 hours.
Project description:The expansion, trafficking and functional effectiveness of adoptively transferred CD8+ T-cells play a critical role in mediating effective anti-tumor immunity. However, the mechanisms which program the highly proliferative and functional state of CD8+ T-cells are not completely understood. We hypothesized that IL-12, a cytokine commonly induced by TLR activation, could enhance T-cell priming by altering responsiveness to antigen and cytokines. Priming of tumor specific CD8+ T-cells in the presence of IL-12 induced the acquisition of a 'polyfunctional' effector response and increased the generation of memory cells. Moreover, IL-12 priming also promoted high levels of the IL-2 receptor alpha-chain (CD25) and robust IL-2 mediated activation of STAT5. This sensitivity to IL-2 translated into enhanced in vivo proliferation of adoptively transferred CD8+ T-cells. Furthermore, real-time, in vivo imaging of T-cell trafficking confirmed the ability of IL-12 priming to drive in vivo proliferation. IL-12 priming enhanced the anti-tumor function of adoptively transferred cells by reducing established subcutaneous tumor burden, and significantly increasing survival in an established intracranial tumor model. Finally, IL-12 priming of human PBMCs generates tumor specific T-cells phenotypically and functionally similar to IL-12 primed Pmel-1 T-cells. These results highlight IL-12 as an important mediator of CD8+ T-cell effector function and anti-tumor immunity. We primed Pmel-1 TCR transgenic CD8+ T-cells with cognate antigen and either IL-2 or IL-12 and compared their gene expression profiles. This was used to identify pathways or genes necessary for anti-tumor activity in vivo. RNA was isolated from Pmel-1 T-cells primed with antigen and cytokine for 6 days and hybridized to Affymetrix arrays.
Project description:CD8+ cytotoxic T lymphocytes (CTLs) play a major role in defense against intracellular pathogens, and their functions are specified by antigen recognition and innate cytokines. While effector CTLs eliminate the infection, a small population of memory cells are retained that yields more rapid and robust response upon re-infection. Antigen presenting cells secrete an array of innate cytokines including IL-12 and IFN-α after recognition of pathogens. Both IL-12 and IFN-α have been shown to act as the third signal regulating the development of CTLs. We have shown that these two cytokines have a non-redundant effect in generation of human effector CTL. IL-12 alone is sufficient for effector CTL genesis marked by IFN-γ and TNF-α production, as well as increased cytolytic activity. Even in the presence of IFN-α, IL-12 programs CTLs that express the chemokine receptor CXCR3 and effector cytokines. Using microarray analysis we have investigated how IL-12 and IFN-α differentially regulate the genetic programming pathways that give rise to effector CTLs among multiple human donors. We have also analyzed the gene expression patterns of cells sorted from healthy human peripheral blood that display surface markers of effector memory CTL (designated as ex vivo) samples. 5 healthy human donor samples were used for the in vitro cultures. For each donor the CFSE labeled cells (CD8+CD45RA+) were cultured in the presence of neutralized, IL-12, IFN-a, and IL-12+IFN-a conditions and plate-bound anti-CD3+anti-CD28 for 3.5 days. Total RNA from CFSEhi (Undiv) and CFSElo (Div) sorted cells were used for Illumina Bead Array. 4 healthy human donor samples were used for the ex vivo samples. Total RNA was collected from FACS sorted CD8+CCR7hiCXCR3lo and CD8+CCR7loCXCR3hi cells without any stimulation.
Project description:Engineered cytokine-based approaches for immunotherapy of cancer are poised to enter the clinic, with IL-12 being at the forefront. However, little is known about potential mechanisms of resistance to cytokine therapies. We found that orthotopic murine lung tumors were resistant to systemically delivered IL-12 fused to murine serum albumin (MSA, IL12-MSA) due to low IL-12R expression on tumor-reactive CD8+ T cells. IL2-MSA increased binding of IL12-MSA by tumor-reactive CD8+ T cells, and combined administration of IL12-MSA and IL2-MSA led to enhanced tumor-reactive CD8+ T cell effector differentiation, decreased numbers of tumor-infiltrating CD4+ regulatory T (Treg) cells, and increased survival of lung tumor-bearing mice. Predictably, the combination of IL-2 and IL-12 at therapeutic doses led to significant dose-limiting toxicity. Administering IL-12 and IL-2 analogs with preferential binding to cells expressing IL12rb1 and CD25, respectively, led to a significant extension of survival in mice with lung tumors while abrogating dose-limiting toxicity. These findings suggest that IL-12 and IL-2 represent a rational approach to combination cytokine therapy whose dose-limiting toxicity can be overcome with engineered cytokine variants.
Project description:IL-2 inducible tyrosine kinase (Itk) is a Tec family non-receptor tyrosine kinase that is known to regulate T cell receptor signal strength (TcR) and T cell development and differentiation. TcR signal strength and antigen affinity are parameters known to regulate the development of CD8+ T cell memory. However, the intersection between TcR signal strength and antigen affinity on CD8+ memory T cell development remains unclear. Therefore, we compared the transcriptomes of WT and Itk-/- OT-1/Rag-/- CD8+ T cells at day 0 and day 7 following infection with Listeria monocytogenes expressing the SIINFEKL (N4) or SIITFEKL (T4) OVA peptide variant (different affinities for TcR) by RNA sequencing.
Project description:IFNα-mediated gene expression pattern. Direct effects of IFNα on human CD8 T cells without any other concomitant signal. This analysis examined the direct effects of IFNa on human CD8 T cells without any other concomitant signal. Total human CD8 T cells were magnetically sorted from peripheral blood by negative selection. In order to minimize the presence of antigen-experienced cells, total human CD8 T cells were depleted of CD45RO+ cells by labelling with anti-CD45RO magnetic bead. In both steps of cellular sorting, negative selection were preferred to positive selection to avoid direct labelling of CD8 T cell surface molecules could interfere with downstream IFNa-mediated signalling. Magnetically sorted untouched human CD8+CD45R0- T cells from three different donors were unstimulated or stimulated with IFNa2b or IFNa5 and cells were harvested 7 hours later. mRNAs from the 3 subjects were pooled and analyzed using Affymetrix human HG-U133A 2.0 array gene chips Fold-change ≥ 2 criterion was used to identify genes which expression differed between treatment and control (unstimulated cells). Keywords: Gene expression pattern analysis
Project description:The differentiation of naive CD8+ T cells into effector cells is important for establishing immunity. However, the effect of heterogeneous naive CD8+ T cell populations is not fully understood. Here, we demonstrate that steady-state naive CD8+ T cells are composed of functionally heterogeneous subpopulations that differ in their ability to differentiate into type 17 cytotoxic effector cells (Tc17) in inflammatory disease models. The differential ability of Tc17 differentiation was not related to T-cell receptor (TCR) diversity and antigen specificity but was inversely correlated with self-reactivity acquired during development. Mechanistically, this phenomenon was linked to differential levels of intrinsic TCR sensitivity and basal SMAD3 expression, generating a wide spectrum of Tc17 differentiation potential within naive CD8+ T cell populations. These findings suggest that developmental self-reactivity can determine the fate of naive CD8+ T cells to generate functionally distinct effector populations and achieve immense diversity and complexity in antigen-specific T-cell immune responses.