Project description:Myeloid-derived cells comprising the tumor stroma represent a heterogeneous population of cells critical to the structure, function and growth of established cancers. We have recently found that engineering tumor-specific CD8+ T cells to secrete IL-12 (IL-12TD) can lead to striking improvements in T-cell activity against established melanomas in murine models. Surprisingly, IL-12-dependent enhancement of CD8+ T-cell anti-tumor function did not occur through direct ligation of receptors on lymphocytes or NK cells. Instead, IL-12 sensitized host bone marrow-derived tumor-stromal cells, partly through interferon-gamma, to indirectly enhance the effects of adoptively-transferred T cells. Direct presentation of antigen by tumor was not necessary, but MHC class I expression on endogenous cells was essential for IL-12 mediated anti-tumor enhancements. Upon successful treatment with IL-12TD cells, we observed the selective elimination of tumor-infiltrating CD11b+ F4/80+ macrophages, CD11b+/ClassII+/CD11c+ dendritic cells and CD11b+/Ly6C+/Ly6G- but not CD11b+/Ly6C+/Ly6G+ myeloid-derived suppressor cells within regressing lesions. These results are consistent with a model whereby IL-12 triggers the maturation of myeloid-derived cells into competent antigen cross-presenting cells. Licensed recognition of these antigens by effector T cells may in turn trigger the collapse of the tumor stroma and aid in the regression of large vascularized lesions. Samples were collected at 3 days and 7 days from tumors treated in-vivo with no treatment, Mock pmel-1 CD8+ cell treatment, or IL-12 pmel-1 CD8+ cell treatment. There were 4 biological replicates of each sample type. There were a total of 24 samples.
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: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:Translational research is commonly performed in the C57B6/J mouse strain, chosen for its genetic homogeneity and phenotypic uniformity. Here, we evaluate the suitability of the white-footed deer mouse (Peromyscus leucopus) as a model organism for aging research, offering a comparative analysis against C57B6/J and diversity outbred (DO) Mus musculus strains. Our study includes comparisons of body composition, skeletal muscle function, and cardiovascular parameters, shedding light on potential applications and limitations of P. leucopus in aging studies. Notably, P. leucopus exhibits distinct body composition characteristics, emphasizing reduced muscle force exertion and a unique metabolism, particularly in fat mass. Cardiovascular assessments showed changes in arterial stiffness, challenging conventional assumptions and highlighting the need for a nuanced interpretation of aging-related phenotypes. Our study also highlights inherent challenges associated with maintaining and phenotyping P. leucopus cohorts. Behavioral considerations, including anxiety-induced responses during handling and phenotyping assessment, pose obstacles in acquiring meaningful data. Moreover, the unique anatomy of P. leucopus necessitates careful adaptation of protocols designed for Mus musculus. While showcasing potential benefits, further extensive analyses across broader age ranges and larger cohorts are necessary to establish the reliability of P. leucopus as a robust and translatable model for aging studies.