Project description:Anti-viral CD8 T cell responses are characterized by an initial activation/priming of T lymphocytes followed by a massive proliferation, subset differentiation, population contraction and the development of a stable memory pool. The transcription factor BATF3 has been shown to play a central role in the development of conventional dendritic cells (cDC1), which in turn are critical for the optimal priming of CD8 T cells. Here we show that BATF3 is expressed within the first days after priming but has long-lasting T cell intrinsic effects. We found that T cells that lack Batf3 show a normal expansion and differentiation, yet succumbed to an aggravated contraction and had a diminished memory response. Vice versa BATF3-overexpression in CD8 T cells promoted their survival and transition to memory. Mechanistically, BATF3 regulates T cell apoptosis and longevity via the proapoptotic factor BIM. By programing CD8 T cell survival and memory, BATF3 is a promising molecule to optimize adoptive T cell therapy in patients.
Project description:Anti-viral CD8 T cell responses are characterized by an initial activation/priming of T lymphocytes followed by a massive proliferation, subset differentiation, population contraction and the development of a stable memory pool. The transcription factor BATF3 has been shown to play a central role in the development of conventional dendritic cells (cDC1), which in turn are critical for the optimal priming of CD8 T cells. Here we show that BATF3 is expressed within the first days after priming but has long-lasting T cell intrinsic effects. We found that T cells that lack Batf3 show a normal expansion and differentiation, yet succumbed to an aggravated contraction and had a diminished memory response. Vice versa BATF3-overexpression in CD8 T cells promoted their survival and transition to memory. Mechanistically, BATF3 regulates T cell apoptosis and longevity via the proapoptotic factor BIM. By programing CD8 T cell survival and memory, BATF3 is a promising molecule to optimize adoptive T cell therapy in patients.
Project description:The transcription factors Batf3 and IRF8 are required for development of CD8α+ conventional dendritic cells (cDCs), but the basis for their actions was unclear. Here, we identify two novel Zbtb46+ progenitors that separately generate CD8α+ and CD4+ cDCs and arise directly from the common DC progenitor (CDP). Irf8 expression in the CDP depends on prior PU.1-dependent autoactivation, and specification of pre-CD8 DC progenitors requires IRF8 but not Batf3. However, upon pre-CD8 DC specification, Irf8 autoactivation becomes Batf3-dependent at a CD8α+ cDC-specific enhancer containing multiple AP1-IRF composite elements (AICEs) within the Irf8 superenhancer. CDPs from Batf3-/- mice that specify toward pre-CD8 DCs fail to complete CD8α+ cDC development due to decay of Irf8 autoactivation, and divert to the CD4+ cDC lineage. Examination of histone modifications (H3K27ac and H3K4me1) and 2 transcription factors (Batf3 and Irf8) and the p300 co-factor binding in 3 different dendritic cell subsets
Project description:Memory CD8+ T cells are an essential component of protective immunity. Signaling via mechanistic target of rapamycin (mTOR) has been implicated in the regulation of the differentiation of effector and memory T cells. However, little is understood about the mechanisms that control mTOR activity, or the effector pathways regulated by mTOR, in this process. We describe here that tuberous sclerosis 1 (Tsc1), a regulator of mTOR signaling, plays a crucial role in promoting the differentiation and function of memory CD8+ T cells in response to Listeria monocytogenes infection. Mice with specific deletion of Tsc1 in antigen-experienced CD8+ T cells evoked normal effector responses, but were markedly impaired in the generation of memory T cells and their recall responses to antigen re-exposure in a cell-intrinsic manner. Tsc1 deficiency suppressed the generation of memory-precursor effector cells (MPECs) while promoting short-lived effector cell (SLEC) differentiation. Functional genomic analysis indicated that Tsc1 coordinated gene expression programs underlying immune function, transcriptional regulation and cell metabolism. Furthermore, Tsc1 deletion led to excessive mTORC1 activity and dysregulated cellular metabolism including glycolytic and oxidative metabolism. These findings establish a Tsc1-mediated checkpoint in linking immune signaling and cell metabolism to orchestrate memory CD8+ T cell development and function. We used microarrays to explore the gene expression profiles differentially expressed in OVA-specific CD8+ T-cells from wild-type (WT; Tsc1-fl/fl and cre-negative) and Tsc1-/- (Tsc1-fl/fl and Granzyme B-cre-positive) mice
Project description:Inducing the long-term protection via effector memory CD8+ T cells residing in the peripheral tissues is the ultimate goal of T cell-based vaccination strategies. CD8+ T cell reacting against a particular set of antigenic peptides show propensity to generate stable pools of memory inflating cells with profound protective capacity. While the epitopes that induce memory inflation have been thoroughly characterized and used as excellent constituents of vaccines such as recombinant adenoviruses, the identity of the tissue factors responsible for maintaining memory inflating CD8+ T cells remains elusive. Here, we have used a Cre recombinase-dependent, -galactosidase (gal)–recombinant adenovirus vector that allowed for cell-specific expression of gal epitopes and identification of cell types involved in generation of inflationary responses. While targeting antigen expression to classical hematopoietic antigen presenting cells was insufficient to activate gal-specific CD8+ T cells, expressing the antigen exclusively in CCL19-producing fibroblastic stromal cells (FSCs) induced robust anti-gal CD8+ T cell response. Using bone marrow chimera mice to abolish the expression of major histocompatibility complex I (MHC-I) and Basic Leucine Zipper ATF-Like Transcription Factor 3 (BATF3) in hematopoietic cells we demonstrated that CCL19-expressing FCS function as antigen libraries, gradually releasing the antigen to CD103+ DCs to maintain gal-specific memory inflating population. Moreover, targeted ablation of CCL19-producing cells revealed that pulmonary fibroblastic stromal cells act as the principal organizer of the nurturing niches that support the metabolic conversion in CD8+ T cells necessary for the generation of long-lasting protective inflationary responses. Overall, our data reveal a hitherto unknown function of CCL19-expressiong fibroblastic stromal in supporting the metabolic fitness of CD8+ T cells, thereby promoting the generation of tissue-specific and long-lasting protective CD8+ T cell responses.
Project description:Inducing the long-term protection via effector memory CD8+ T cells residing in the peripheral tissues is the ultimate goal of T cell-based vaccination strategies. CD8+ T cell reacting against a particular set of antigenic peptides show propensity to generate stable pools of memory inflating cells with profound protective capacity. While the epitopes that induce memory inflation have been thoroughly characterized and used as excellent constituents of vaccines such as recombinant adenoviruses, the identity of the tissue factors responsible for maintaining memory inflating CD8+ T cells remains elusive. Here, we have used a Cre recombinase-dependent, -galactosidase (gal)–recombinant adenovirus vector that allowed for cell-specific expression of gal epitopes and identification of cell types involved in generation of inflationary responses. While targeting antigen expression to classical hematopoietic antigen presenting cells was insufficient to activate gal-specific CD8+ T cells, expressing the antigen exclusively in CCL19-producing fibroblastic stromal cells (FSCs) induced robust anti-gal CD8+ T cell response. Using bone marrow chimera mice to abolish the expression of major histocompatibility complex I (MHC-I) and Basic Leucine Zipper ATF-Like Transcription Factor 3 (BATF3) in hematopoietic cells we demonstrated that CCL19-expressing FCS function as antigen libraries, gradually releasing the antigen to CD103+ DCs to maintain gal-specific memory inflating population. Moreover, targeted ablation of CCL19-producing cells revealed that pulmonary fibroblastic stromal cells act as the principal organizer of the nurturing niches that support the metabolic conversion in CD8+ T cells necessary for the generation of long-lasting protective inflationary responses. Overall, our data reveal a hitherto unknown function of CCL19-expressiong fibroblastic stromal in supporting the metabolic fitness of CD8+ T cells, thereby promoting the generation of tissue-specific and long-lasting protective CD8+ T cell responses.
Project description:We use RNAseq to investigate the transcriptome of resident memory CD8 T cells (TRM) infiltrating human lung cancer. CD103+CD8+ T cells and KLRG1+CD8+ T cells (population paired) were sorted by flow cytometry from 7 primary non-small cell lung cancers to elucidate the genetic programs that underlie their immune functions. We compared the RNA expression profile of these two CD8 T cell populations to better describe CD103+CD8+ T cells, which correspond to TRM, and study their role in antitumor immunity.
Project description:During a T cell response, naïve CD8 T cells differentiate into effector cells. Subsequently, a subset of effector cells termed memory precursor effector cells (MPECs) further differentiates into functionally mature memory CD8 T cells. The transcriptional network underlying this carefully scripted process is not well understood. Here, we report that the transcription factor FoxO1 plays an integral role in facilitating effector to memory transition and functional maturation of memory CD4 and CD8 T cells. We find that FoxO1 is not required for differentiation of effector cells, but in the absence of FoxO1, memory CD8 T cells displayed features of scenescence and progressive attrition in polyfunctionality, which in turn led to impared recall responses and poor protective immunity. These data suggest that FoxO1 is essential for active maintenance of functional CD8 T cell memory and protective immunity. Under competing conditions in bone marrow Single-cell suspensions from splenocytes of eight samples WT (control) and FoxO1-/- (experimental) LCMV-immune mice were prepared using standard procedures. CD8 T cells were then isoloated using Thy1.2 (CD90.2) (30-H12) microbeads (Miltenyi Biotec). Cells were then stained with anti-CD8, anti-CD44 and Db/NP396 MHC class I tetramer. Activated (CD8+CD44hi), naive (CD8+CD44lo), and virus-specific CD8 T cells were sorted using FACSAria II instrument (BD Biosciences). The purity of the cells was >95%. Total RNA was extracted from the sorted cells by Trizol Reagent. RNA samples were reverse transcribed and Cy3-labeled cDNAs were hyrbidized to Agilent whole Mouse Genome Oligo Microarrays. Fluorscence signals were detected using Agilent's Microarray Scanner system, data was analyzed using the Rosetta Resolver gene expression data analysis system and genes with a fold change < and p-values <0.01 were identified. Microarray data discussed in the paper is focused on virus-specific memory CD8 T cells from samples WT_Tet_2 vs KO_Tet_2.
Project description:The transcription factors Batf3 and IRF8 are required for development of CD8α+ conventional dendritic cells (cDCs), but the basis for their actions was unclear. Here, we identify two novel Zbtb46+ progenitors that separately generate CD8α+ and CD4+ cDCs and arise directly from the common DC progenitor (CDP). Irf8 expression in the CDP depends on prior PU.1-dependent autoactivation, and specification of pre-CD8 DC progenitors requires IRF8 but not Batf3. However, upon pre-CD8 DC specification, Irf8 autoactivation becomes Batf3-dependent at a CD8α+ cDC-specific enhancer containing multiple AP1-IRF composite elements (AICEs) within the Irf8 superenhancer. CDPs from Batf3-/- mice that specify toward pre-CD8 DCs fail to complete CD8α+ cDC development due to decay of Irf8 autoactivation, and divert to the CD4+ cDC lineage.