Project description:Pathogen-associated molecular patterns decisively influence antiviral immune responses, whereas the contribution of endogenous signals of tissue damage, also known as “damage-associated molecular patterns” or “alarmins”, remains ill-defined. We show that interleukin-33 (IL-33), an alarmin released from necrotic cells, is necessary for potent CD8+ T cell (CTL) responses to replicating, prototypic RNA and DNA viruses in mice. IL-33 signaled through its receptor on activated CTLs, enhanced clonal expansion in a MyD88-dependent, CTL-intrinsic fashion, determined polyfunctional effector cell differentiation and was necessary for virus control. Moreover, recombinant IL-33 augmented vaccine-induced CTL responses. Radio-resistant cells of the splenic T cell zone produced IL-33, and efficient CTL responses required IL-33 from radio-resistant cells but not from hematopoietic cells. Thus, alarmin release by radio-resistant cells orchestrates protective antiviral CTL responses. 2 groups (wt vs. ST-/- P14 cells), 3 replicates per group.
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: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: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.
Project description:Background: IL-33, a cytokine with pleiotropic functions, is elevated in serum of patients with hepatocellular carcinoma (HCC). This study investigated effects of local IL-33 expression in resected HCC on patient survival and on immunological and molecular tumor microenvironment. Methods: Tissue of resected HCCs was stained for H&E, masson trichrome, alpha smooth muscle actin, IL-33, CD8 and IL-13 and analysed by flow cytometry. Besides histomorphologic evaluation, the immunohistochemical stainings were analysed for the respective cell numbers separately for tumor area, infiltrative margin and distant liver stroma. These findings were correlated with clinical data and patient outcome. Further, gene expression of different HCC risk groups was compared using Micro Arrays. Results: In multivariable analysis, infiltration of HCCs by IL-33+ cells (P=0.032) and CD8+ cells (P=0.014) both independently were associated with prolonged patient survival. Flow cytometry demonstrated that cytotoxically active CD8+CD62L-KLRG1+CD107a+ effectory-memory cells are the main producers of IL-33 in these HCC patients. Using infiltration by IL-33+ and CD8+ cells as two separate factors, a HCC immune score (HCCIS) was designed and evaluated that stratified patient survival (P=0.0004). This HCCIS identified high and low risk patients who differ in gene expression profiles (P<0.001). Conclusion: Infiltration of HCCs by IL-33+ and CD8+ cells is independently associated with prolonged patient survival. We suggest that this is due to an induction of highly effective cytotoxically active CD8+CD62L-KLRG1+CD107a+ effector-memory cells producing IL-33. Based on these two independent factors we established a HCC immune score that provides risk stratification for HCC patients and can be used in the clinical setting. To investigate if HCCIS 0 high risk and HCCIS 2 low risk tumors exhibit a distinct molecular environment and gene expression pattern, RNA from fresh tumor tissue was isolated and analyzed by whole genome Microarray 4 patients with low risk tumors (HCCIS 2) were compared to 4 patients with high risk tumors (HCCIS 0).
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
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:Pathogen-associated molecular patterns decisively influence antiviral immune responses, whereas the contribution of endogenous signals of tissue damage, also known as “damage-associated molecular patterns” or “alarmins”, remains ill-defined. We show that interleukin-33 (IL-33), an alarmin released from necrotic cells, is necessary for potent CD8+ T cell (CTL) responses to replicating, prototypic RNA and DNA viruses in mice. IL-33 signaled through its receptor on activated CTLs, enhanced clonal expansion in a MyD88-dependent, CTL-intrinsic fashion, determined polyfunctional effector cell differentiation and was necessary for virus control. Moreover, recombinant IL-33 augmented vaccine-induced CTL responses. Radio-resistant cells of the splenic T cell zone produced IL-33, and efficient CTL responses required IL-33 from radio-resistant cells but not from hematopoietic cells. Thus, alarmin release by radio-resistant cells orchestrates protective antiviral CTL responses.
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.