Project description:Immune checkpoint blockade is able to achieve durable responses in a subset of patients, however we lack a satisfying comprehension of the underlying mechanisms of anti-CTLA-4 and anti-PD-1 induced tumor rejection. To address these issues we utilized mass cytometry to comprehensively profile the effects of checkpoint blockade on tumor immune infiltrates in human melanoma and murine tumor models. These analyses reveal a spectrum of tumor infiltrating T cell populations that are highly similar between tumor models and indicate that checkpoint blockade targets only specific subsets of tumor infiltrating T cell populations. Anti-PD-1 predominantly induces the expansion of specific tumor infiltrating exhausted-like CD8 T cell subsets. In contrast, anti-CTLA-4 induces the expansion of an ICOS+ Th1-like CD4 effector population in addition to engaging specific subsets of exhausted-like CD8 T cells. Thus, our findings indicate that anti-CTLA-4 and anti-PD-1 checkpoint blockade induced immune responses are driven by distinct cellular mechanisms.
Project description:Immune checkpoint blockade is able to achieve durable responses in a subset of patients, however we lack a satisfying comprehension of the underlying mechanisms of anti-CTLA-4 and anti-PD-1 induced tumor rejection. To address these issues we utilized mass cytometry to comprehensively profile the effects of checkpoint blockade on tumor immune infiltrates in human melanoma and murine tumor models. These analyses reveal a spectrum of tumor infiltrating T cell populations that are highly similar between tumor models and indicate that checkpoint blockade targets only specific subsets of tumor infiltrating T cell populations. Anti-PD-1 predominantly induces the expansion of specific tumor infiltrating exhausted-like CD8 T cell subsets. In contrast, anti-CTLA-4 induces the expansion of an ICOS+ Th1-like CD4 effector population in addition to engaging specific subsets of exhausted-like CD8 T cells. Thus, our findings indicate that anti-CTLA-4 and anti-PD-1 checkpoint blockade induced immune responses are driven by distinct cellular mechanisms.
Project description:Transcriptome analysis of human peripheral blood monocytes Combination therapy concurrently targeting PD-1 and CTLA-4 immune checkpoints leads to remarkable antitumor effects. Although both PD-1 and CTLA-4 dampen the T cell activation, the in vivo effects of these drugs in humans remain to be clearly defined. To better understand biologic effects of therapy, we analyzed blood/tumor tissue from patients undergoing single or combination immune checkpoint blockade. We show that blockade of CTLA-4, PD-1, or combination of the two leads to distinct genomic (changes in gene-expression profile) and functional signatures in vivo in purified human T cells and monocytes. RNA extracted from freshly isolated monocytes from peripheral blood of patients treated with either antiâPD-1 (n = 6), antiâCTLA-4 (n = 5), Combo therapy with antiâPD-1 and antiâCTLA-4 concurrently (Combo, n = 6), and Seq antiâPD-1 in patients with prior antiâCTLA-4 (Seq, n = 3) was analyzed using the Affymetrix GeneChip Human Transcriptome 2.0 exon array. No techinical replicates were performed.
Project description:Transcriptome analysis of human peripheral blood T cells Combination therapy concurrently targeting PD-1 and CTLA-4 immune checkpoints leads to remarkable antitumor effects. Although both PD-1 and CTLA-4 dampen the T cell activation, the in vivo effects of these drugs in humans remain to be clearly defined. To better understand biologic effects of therapy, we analyzed blood/tumor tissue from patients undergoing single or combination immune checkpoint blockade. We show that blockade of CTLA-4, PD-1, or combination of the two leads to distinct genomic (changes in gene-expression profile) andfunctional signatures in vivo in purified human T cells. RNA extracted from freshly isolated T cells from peripheral blood of patients treated with either antiâ??PD-1 (n = 6), antiâ??CTLA-4 (n = 5), Combo therapy with antiâ??PD-1 and antiâ??CTLA-4 concurrently (Combo, n = 6), and Seq antiâ??PD-1 in patients with prior antiâ??CTLA-4 (Seq, n = 3) was analyzed using the Affymetrix GeneChip Human Transcriptome 2.0 exon array. No techinical replicates were performed.
Project description:Goal: determine how transcriptome of immune cells within the tumor microenvironment changes as a function of CD40 agonist and/or immune checkpoint blockade (anti-PD-1 AND anti-CTLA-4; "ICB") therapy
Project description:<p>Blockade of T cell coinhibitory molecules such as CTLA-4 and PD-1, can activate T cell antitumor response. Although these immune checkpoint blockades (CTLA-4 blockade and PD-1 blockade) have shown durable response, response rate is modest. Therefore, there is a need to find stable biomarkers predictive of response to immune checkpoint blockades and to understand underlying resistance mechanisms. We collected longitudinal tumor biopsies from a cohort of metastatic melanoma patients treated with sequential immune checkpoint blockades and performed whole exome sequencing of this cohort. The comprehensive genomic characterization of tumors enabled identification of higher copy number loss burden as a resistance mechanism and clonal T cell repertoire as a predictive biomarker.</p>
Project description:Transcriptome analysis of human peripheral blood T cells Combination therapy concurrently targeting PD-1 and CTLA-4 immune checkpoints leads to remarkable antitumor effects. Although both PD-1 and CTLA-4 dampen the T cell activation, the in vivo effects of these drugs in humans remain to be clearly defined. To better understand biologic effects of therapy, we analyzed blood/tumor tissue from patients undergoing single or combination immune checkpoint blockade. We show that blockade of CTLA-4, PD-1, or combination of the two leads to distinct genomic (changes in gene-expression profile) andfunctional signatures in vivo in purified human T cells.
Project description:Transcriptome analysis of human peripheral blood monocytes Combination therapy concurrently targeting PD-1 and CTLA-4 immune checkpoints leads to remarkable antitumor effects. Although both PD-1 and CTLA-4 dampen the T cell activation, the in vivo effects of these drugs in humans remain to be clearly defined. To better understand biologic effects of therapy, we analyzed blood/tumor tissue from patients undergoing single or combination immune checkpoint blockade. We show that blockade of CTLA-4, PD-1, or combination of the two leads to distinct genomic (changes in gene-expression profile) and functional signatures in vivo in purified human T cells and monocytes.