Project description:Immunotherapy provides an alternative approach for cancer treatment. However, in-depth analyses of the effects of immunotherapy on the tumor microenvironment (TME) have not been conducted in non-melanoma tumors. Here we describe changes in the pancreatic ductal adenocarcinoma (PDAC) TME following immunotherapy treatment, and show for the first time that vaccine-based immunotherapy directly alters the TME, inducing neogenesis of tertiary lymphoid structures that convert immunologically quiescent tumors into immunologically active tumors. Alterations in five pathways important for immune modulation and lymphoid structure development (TH17/Treg, NFkB, Ubiquitin-proteasome, Chemokines/chemokine receptors, and Integrins/adhesion molecules) in vaccine-induced intratumoral lymphoid aggregates were associated with improved post-vaccination responses. Additional studies in other cancers and patients treated with other forms of immunotherapy are warranted to further develop signatures defined in intratumoral lymphoid structures into biomarkers that predict effective anti-tumor immune responses. These signatures may also expose therapeutic targets for promoting more robust antitumor immune responses in the TME.
Project description:Immunotherapy provides an alternative approach for cancer treatment. However, in-depth analyses of the effects of immunotherapy on the tumor microenvironment (TME) have not been conducted in non-melanoma tumors. Here we describe changes in the pancreatic ductal adenocarcinoma (PDAC) TME following immunotherapy treatment, and show for the first time that vaccine-based immunotherapy directly alters the TME, inducing neogenesis of tertiary lymphoid structures that convert immunologically quiescent tumors into immunologically active tumors. Alterations in five pathways important for immune modulation and lymphoid structure development (TH17/Treg, NFkB, Ubiquitin-proteasome, Chemokines/chemokine receptors, and Integrins/adhesion molecules) in vaccine-induced intratumoral lymphoid aggregates were associated with improved post-vaccination responses. Additional studies in other cancers and patients treated with other forms of immunotherapy are warranted to further develop signatures defined in intratumoral lymphoid structures into biomarkers that predict effective anti-tumor immune responses. These signatures may also expose therapeutic targets for promoting more robust antitumor immune responses in the TME. Between July 2008 and September 2012, 59 patients were enrolled into an ongoing study of an irradiated, allogeneic GM-CSF-secreting pancreatic tumor vaccine (GVAX) administered intradermally either alone or in combination with immune modulatory doses of cyclophophamide (Cy) as neoadjuvant and adjuvant treatment for patients with resectable pancreatic ductal adenocarcinoma (PDAC). Patients were randomized 1:1:1 to 3 treatment arms. In Arm A, patients received GVAX alone; in Arm B, patients received GVAX plus a single intravenous dose of Cy at 200 mg/m2 1 day prior to each vaccination; in Arm C, patients received GVAX plus oral Cy at 100 mg once daily for 1 week on and 1 week off. Up to 6 GVAX treatments were administered and all of the patients remained in their initial treatment arms throughout the duration of the study. All 59 of the patients received the 1st GVAX treatment 2 weeks +/-4 days prior to surgery. Formalin-fixed paraffin-embedded (FFPE) tissue blocks of surgically resected PDAC were obtained from the pathology archive. FFPE tissue blocks from each subject were stained by H&E immediately before the vaccine therapy-induced lymphoid aggregates were microdissected . To better understand the functional status of these vaccine therapy induced lymphoid aggregate structures, gene microarray analysis on RNA isolated from microdissected lymphoid aggregates was performed. Gene expression was compared among samples grouped according to patient overall survival, post-vaccination induction of enhanced mesothelin-specific T cell responses in peripheral blood lymphocytes (PBL), and the intratumoral CD8+ T effector to FoxP3+ Treg ratio. Post-vaccination induction of enhanced mesothelin-specific T cell responses has been reported to correlate with longer survival in patients treated with Panc GVAX.
Project description:Gut resident IL10+CX3CR1hi macrophages drive development of mucosal tertiary lymphoid structures that serve as ectopic site of the IgA response to enteric infection.
Project description:Tertiary lymphoid structures (TLS are lymph node-like immune cell clusters that emerge during chronic inflammation in non-lymphoid organs like the kidney, but their origin remains not well understood. Here we show, using conditional deletion strategies of the canonical Notch signaling mediator Rbpj, that loss of endothelial Notch signaling in adult mice induces the spontaneous formation of bona fide TLS in the kidney, liver and lung, based on molecular, cellular and structural criteria. These TLS form in a stereotypical manner around parenchymal arteries, while secondary lymphoid structures remained largely unchanged. This effect is mediated by endothelium of blood vessels, but not lymphatics, since a lymphatic endothelial-specific targeting strategy did not result in TLS formation, and involves loss of arterial specification and concomitant acquisition of a high endothelial cell phenotype, as shown by transcriptional analysis of kidney endothelial cells. This indicates a so far unrecognized role for vascular endothelial cells and Notch signaling in TLS initiation.
Project description:Glioblastomas (GBM) are aggressive primary brain tumors with an inherent resistance to T cell-centric immunotherapy imparted to their low mutational burden and immunosuppressive tumor microenvironment (TME). Examination of the GBM TME dynamics following fractionated RT revealed a 10-fold increase in T cell content, an enrichment also observed by spatial imaging mass cytometry in matched primary and recurrent human GBM. Implementation of a-PD-1 treatment at the peak of T cell infiltration results in a modest, albeit distinct survival benefit compared to concurrent a-PD-1 administration in GBM-bearing mice. CD103+ Tregs presenting increased cholesterol pathway activity are recruited to the GBM TME in response to a-PD-1 therapy, suggestive of their ability to restrain the response to immune checkpoint blockade. Targeting of Tregs elicits the formation of tertiary lymphoid structures, enhanced CD8 T cell content and activation and enables the therapeutic efficacy of radio-immunotherapy. These results support the rational design of therapeutic regimens limiting the induction of immunosuppressive feedback pathways in order to unleash the efficacy of T-cell centric immunotherapy in glioblastoma.
Project description:Objective: To better understand the immune microenvironment of pancreatic ductal adenocarcinomas (PDACs), here we explored the relevance of T and B cell compartmentalization into tertiary lymphoid structures (TLSs) for the generation of local antitumor immunity. Design: We characterized the functional states and spatial organization of PDAC-infiltrating T and B cells using single-cell RNA sequencing (scRNA-seq), flow cytometry, multicolor immunofluorescence, gene expression profiling of microdissected TLSs, as well as in vitro assays. Additionally, we performed a pan-cancer analysis of tumor-infiltrating T cells using scRNA-seq and single-cell T cell receptor sequencing (scTCR-seq) datasets from 8 cancer types. To evaluate the clinical relevance of our findings we used PDAC bulk RNA-seq data from The Cancer Genome Atlas and the PRINCE chemoimmunotherapy trial. Results: We found that a subset of PDACs harbors fully developed TLSs where B cells proliferate and differentiate to plasma cells. These mature TLSs also support T cell activity and are enriched with tumor-reactive T cells. Importantly, we showed that chronically activated, tumor-reactive T cells exposed to fibroblast-derived TGF-β may act as TLS organizers by producing the B cell chemoattractant CXCL13. Identification of highly similar subsets of clonally expanded CXCL13+ tumor-infiltrating T cells across multiple cancer types further indicated a conserved link between tumor-antigen recognition and the allocation of B cells within sheltered hubs in the tumor microenvironment. Finally, we showed that the expression of a gene signature reflecting mature TLSs was enriched in pre-treatment biopsies from PDAC patients with longer survival after receiving different chemoimmunotherapy regimens. Conclusion: We provided a framework for understanding the biological role of PDAC-associated TLSs and revealed their potential to guide the selection of patients for future immunotherapy trials.
Project description:Utilizing surgical and chemical skin sensory denervation methods, we show that afferent neurons support the growth of melanoma tumors in vivo. We demonstrate that sensory innervation limits the activation of effective anti-tumor immune response. Specifically, sensory ablation led to improved leukocyte recruitment and infiltration into tumors, decreased intratumoral lymphoid and myeloid immunosuppressive cells, and the activation of T effector cells within the TME. We found that cutaneous sensory nerves hinder the maturation of intratumoral high endothelial venules and the formation of mature tertriary lymphoid-like structures containing organized clusters of CD4+ T cells and B cells. Denervation further increased T cell clonality and expanded the B cell repertoire in the TME. Importantly, CD8a depletion prevented the denervation-dependent anti-tumor effects. Finally, we observed that the gene signatures associated with immune function and sensory innervation were inversely correlated in human primary cutaneous melanomas, and the latter was a negative prognostic marker of the overall survival in the examined cohort. Our results suggest that tumor-associated sensory neurons negatively regulate the development of effective anti-tumor immune responses, thereby defining a novel target for therapeutic intervention in the cancer setting.
Project description:The presence of intratumoral tertiary lymphoid structures (TLS) is associated with positive clinical outcomes and responses to immunotherapy in cancer. Here, we used spatial transcriptomics to examine the nature of B cell responses within TLS in renal cell carcinoma (RCC). B cells were enriched in TLS, and therein, we could identify all B cell maturation stages toward plasma cell (PC) formation. B cell repertoire analysis revealed clonal diversification, selection, expansion in TLS, and the presence of fully mature clonotypes at distance. In TLS+ tumors, IgG- and IgA-producing PCs disseminated into the tumor beds along fibroblastic tracks. TLS+ tumors exhibited high frequencies of IgG-producing PCs and IgG-stained and apoptotic malignant cells, suggestive of anti-tumor effector activity. Therapeutic responses and progression-free survival correlated with IgG-stained tumor cells in RCC patients treated with immune checkpoint inhibitors. Thus, intratumoral TLS sustains B cell maturation and antibody production that is associated with response to immunotherapy, potentially via direct anti-tumor effects.