Project description:To identify potential T-cell targets for Triple-Negative Breast Cancer (TNBC) vaccination, we examined the effect of the pro-inflammatory cytokine interferon-γ (IFNγ) on the transcriptome, proteome and immunopeptidome of the TNBC cell line MDA-MB-231. Using high resolution mass spectrometry, we identified a total of 84,131 peptides from 9,647 source proteins presented by human leukocyte antigen (HLA)-I and HLA-II alleles. Treatment with IFNγ resulted in a remarkable remoulding of the immunopeptidome, with only a 34% overlap between untreated and treated cells across the HLA-I immunopeptidome, and expression of HLA-II only on treated cells. IFNγ increased the overall number, diversity and abundance of the immunopeptidome, as well as the proportion of coverage of source antigens. The suite of peptides displayed under conditions of IFNγ treatment included many known tumour associated antigens, with the HLA-II repertoire sampling 265 breast cancer associated antigens absent from those sampled by HLA-I. Quantitative analysis of the transcriptome (10,248 transcripts) and proteome (6783 proteins) of these cells revealed 229 proteins and transcripts were commonly differentially expressed, most of which involved in downstream targets of IFNγ signalling including components of the antigen processing machinery such as tapasin and HLA. However, these changes in protein expression did not explain the dramatic modulation of the immunopeptidome following IFNγ treatment. These results demonstrate the high degree of plasticity in the immunopeptidome TNBC cells following cytokine stimulation and provide evidence that under pro-inflammatory conditions a greater variety of HLA-I and HLA-II vaccine targets are unveiled to the immune system. This has important implications for the development of personalised cancer vaccination strategies.
Project description:Transcriptional response of KBM7 cells to IFN-gamma or TNF-alpha was investigated in control or cells with genetrap insertions in JAK2 or TNFRS1A, respectively. The experiment shows that, as expected, cells lacking JAK2 or TNFRS1A expression display a severly blunted response to the tested cytokines. KBM7 genetrap mutant cells stimulated with TNF-alpha and IFN-gamma Sample WT_1 corresponds with the control sample for the IFN-gamma stimulation; Sample WT_2 corresponds with the control sample for the TNF-alpha stimulation. As the expected differences between the samples was large, only single replicates were performed for each condition
Project description:Activated T cells polarize mesenchymal stromal cells (MSCs) to a proinflammatory Th1 phenotype which likely has an important role in amplifying the immune response in the tumor microenvironment. We investigated the role of interferon gamma (IFN-g) and tumor necrosis factor alpha (TNF-a), two factors produced by activated T cells, in MSC polarization. Gene expression and culture supernatant analysis showed that TNF-a and IFN-g stimulated MSCs expressed distinct sets of proinflammatory factors. The combination of IFN-g and TNF-a was synergistic and induced a transcriptome most similar to that found in MSCs stimulation with activated T cells and similar to that found in the inflamed tumor microenvironment; a Th1 phenotype with the expression of the immunosuppressive factors IL-4, IL-10, CD274/PD-L1 and indoleamine 2,3 dioxygenase (IDO). Single cell qRT-PCR analysis showed that the combination of IFN-g and TNF-a polarized uniformly to this phenotype. The combination of IFN-g and TNF-a results in the synergist uniform polarization of MSCs toward a primarily Th1 phenotype. The stimulation of MSCs by IFN-g and TNF-a released from activated tumor infiltrating T cells is likely responsible for the production of many factors that characterize the tumor microenvironment.
Project description:Transcriptional activation of cultured mouse astrocytes in response to stimulation with CCM (complete cytokine mix: TNF-alpha, IL1-beta and IFN-gamma) at 4hr and 16hr time points.
Project description:In malaria, T cells play a dual role by both restricting parasite growth and mediating immunopathology such as the deadly neuroinflammation called cerebral malaria. During experimental cerebral malaria (ECM), IFN produced by CD4 T cells promotes CD8 T cell sequestration in brain capillaries, resulting in endothelial damage, oedema and death. However the antigen-presenting cells controlling the development of CD4 T cell responses, as well as the antigens recognized by these CD4 T cells, are unknown. Here we used mass spectrometry to characterize the MHC II immunopeptidome presented by dendritic cells during blood stage malaria in C57BL/6 mice. We identified 14 MHC II ligands derived from 13 conserved Plasmodium berghei proteins that we validated in vivo. This work profiles the first MHC II immunopeptidome in a mouse model of blood stage malaria.