Project description:CD25, the high affinity interleukin-2 (IL-2) receptor alpha-chain, is rapidly upregulated by antigen-specific CD8+ T cells after T cell receptor stimulation. We demonstrated that during an acute viral infection, CD25 expression was dynamic, and a subset of virus-specific CD8+ T cells sustained CD25 expression longer than the rest. Examination of the in vivo fate of effector CD8+ T cells exhibiting differential responsiveness to IL-2 revealed that CD25lo cells, which were relatively less sensitive to IL-2, preferentially upregulated CD127 and CD62L and gave rise to the functional long-lived memory pool. In contrast, CD25hi cells that accumulate enhanced IL-2 signals, proliferated more rapidly, were prone to apoptosis, exhibited a more pronounced effector phenotype, and appeared to be terminally differentiated. Sustained IL-2 receptor signaling resulted in increased CD8+ T cell proliferation, higher granzyme B expression and exaggerated contraction after antigen clearance. These data support the hypothesis that prolonged IL-2 signals during priming promote terminal effector differentiation of CD8+ T cells. Experiment Overall Design: An important question in memory development is understanding the differences between effector CD8 T cells that die versus effector cells that survive and give rise to memory cells. In this study we have performed genomic profiling of terminal effectors and memory precursors as defined by CD25 heterogeneity, towards better understanding the generation of these subsets. The two effector subsets were FACS purified based on the amount of cell surface CD25 expression into CD25lo and CD25hi subsets during the early expansion phase (Days 3-4 post-infection) and analyzed for their gene expression profiles (by genome-wide microarray analyses).
Project description:CD25, the high affinity interleukin-2 (IL-2) receptor alpha-chain, is rapidly upregulated by antigen-specific CD8+ T cells after T cell receptor stimulation. We demonstrated that during an acute viral infection, CD25 expression was dynamic, and a subset of virus-specific CD8+ T cells sustained CD25 expression longer than the rest. Examination of the in vivo fate of effector CD8+ T cells exhibiting differential responsiveness to IL-2 revealed that CD25lo cells, which were relatively less sensitive to IL-2, preferentially upregulated CD127 and CD62L and gave rise to the functional long-lived memory pool. In contrast, CD25hi cells that accumulate enhanced IL-2 signals, proliferated more rapidly, were prone to apoptosis, exhibited a more pronounced effector phenotype, and appeared to be terminally differentiated. Sustained IL-2 receptor signaling resulted in increased CD8+ T cell proliferation, higher granzyme B expression and exaggerated contraction after antigen clearance. These data support the hypothesis that prolonged IL-2 signals during priming promote terminal effector differentiation of CD8+ T cells.
Project description:Interventions: A:CEA-CART
Primary outcome(s): cytokines IL-1beta;cytokine IL-2R;cytokine IL-6;cytokine IL-8;cytokine IL-10;cytokine TNF-alpha;copy numbers of CART in vivo;serum CEA;tumor size
Study Design: Non randomized control
Project description:Much is known concerning the cellular and molecular basis for CD8+ T memory immune responses. Nevertheless, conditions that selectively support memory generation have remained elusive. Here we show that an immunization regimen that delivers TCR signals through a defined antigenic peptide, inflammatory signals through LPS, and growth and differentiation signals through the IL-2R initially favors antigen-specific CD8+ T cells to rapidly and substantially develop into tissue-residing T effector-memory cells by TCR transgenic OVA-specific OT-I CD8+ T cells. Amplified CD8+ T memory development depends upon a critical frequency of antigen-specific T cells and direct responsiveness to IL-2. A homologous prime-boost immunization protocol with transiently enhanced IL-2R signaling in normal mice led to persistent polyclonal antigen-specific CD8+ T cells that supported protective immunity to Listeria monocytogenes. These results identify a general approach for amplified T memory development that may be useful to optimize vaccines aimed at generating robust cell-mediated immunity. Gene expression analysis was performed for OT-I T cells on day 3 and day 5 after activation with ovalbumin and LPS in vivo with and without treatment with IL-2 using an agonists IL-2/anti-IL-2 complexes (IL2/Jes-6.1) OT-I T cells were purified and adoptively transferred into congenic syngenic mice. 24 hours later mice were immunization with ovalbumin and LPS. 24 hr later some mice received agonist IL2/anti-IL2. 3 and 5 days after immunization, the activated OT-I T cells were purifed by FACS and total RNA was isolated for genome wide expression analysis using Affymetrix Mouse Gene ST1.0 arrays
Project description:Much is known concerning the cellular and molecular basis for CD8+ T memory immune responses. Nevertheless, conditions that selectively support memory generation have remained elusive. Here we show that an immunization regimen that delivers TCR signals through a defined antigenic peptide, inflammatory signals through LPS, and growth and differentiation signals through the IL-2R initially favors antigen-specific CD8+ T cells to rapidly and substantially develop into tissue-residing T effector-memory cells by TCR transgenic OVA-specific OT-I CD8+ T cells. Amplified CD8+ T memory development depends upon a critical frequency of antigen-specific T cells and direct responsiveness to IL-2. A homologous prime-boost immunization protocol with transiently enhanced IL-2R signaling in normal mice led to persistent polyclonal antigen-specific CD8+ T cells that supported protective immunity to Listeria monocytogenes. These results identify a general approach for amplified T memory development that may be useful to optimize vaccines aimed at generating robust cell-mediated immunity. Gene expression analysis was performed for OT-I T cells on day 3 and day 5 after activation with ovalbumin and LPS in vivo with and without treatment with IL-2 using an agonists IL-2/anti-IL-2 complexes (IL2/Jes-6.1)
Project description:STAT5 proteins are vital for lymphocyte development and function. Tyrosine phosphorylation of a C-terminal tyrosine is the key event in cytokine activation of STAT5A and STAT5B. However, the role of STAT5 tyrosine phosphorylation has not been assessed in vivo. Here we generated Stat5a and Stat5b tyrosine mutant knock-in (KI) mice and found that these animals had greatly reduced CD8+ T cell numbers. These cells exhibited profoundly diminished proliferation in response to IL-2, correlating with greatly reduced IL-2-induced pRB and a block in the G1-->S phase transition. The mutant cells also exhibited decreased IL-2-mediated activation of pERK and pAKT, which can in part be attributed to diminished IL-2-induced expression of IL-2R-beta and IL-2R-gamma. Our findings highlight that the tyrosine phosphorylation of both STAT5A and STAT5B is essential for maximal IL-2 signaling and elucidate the molecular basis for achieving an optimal mitogenic effect of IL-2 on CD8+ T cells.
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:STAT5 proteins are vital for lymphocyte development and function. Tyrosine phosphorylation of a C-terminal tyrosine is the key event in cytokine activation of STAT5A and STAT5B. However, the role of STAT5 tyrosine phosphorylation has not been assessed in vivo. Here we generated Stat5a and Stat5b tyrosine mutant knock-in (KI) mice and found that these animals had greatly reduced CD8+ T cell numbers. These cells exhibited profoundly diminished proliferation in response to IL-2, correlating with greatly reduced IL-2-induced pRB and a block in the G1-->S phase transition. The mutant cells also exhibited decreased IL-2-mediated activation of pERK and pAKT, which can in part be attributed to diminished IL-2-induced expression of IL-2R-beta and IL-2R-gamma. Our findings highlight that the tyrosine phosphorylation of both STAT5A and STAT5B is essential for maximal IL-2 signaling and elucidate the molecular basis for achieving an optimal mitogenic effect of IL-2 on CD8+ T cells. [doi:10.25345/C5833N851] [dataset license: CC0 1.0 Universal (CC0 1.0)]
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: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.