Cancer immunology research最新文献

Neoantigen-specific T cells recognize tumor cells and are critical for cancer immunotherapies to be effective. However, the transcriptional program controlling the cell-fate decisions by neoantigen-specific T cells is incompletely understood. Here, using joint single-cell transcriptome and T-cell receptor (TCR) profiling, we mapped the clonal expansion and differentiation of neoantigen-specific CD8+ T cells in the tumor and draining lymph node in mouse prostate cancer. Neoantigen-specific CD8+ tumor-infiltrating lymphocytes (TILs) upregulated gene signatures of T-cell activation and exhaustion compared to those recognizing other tumor antigens. In the tumor-draining lymph node, we identified TCF1+TOX- TSCM, TCF1+TOX+ TPEX, and TCF1-TOX+ effector-like TEX subsets among neoantigen-specific CD8+ T cells. Divergent neoantigen-specific CD8+ T-cell clones with balanced distribution across multiple differentiation fates underwent significantly greater expansion compared to clones biased towards TEX, TPEX, or TSCM. The TPEX subset had greatest clonal diversity and likely represented the root of neoantigen-specific CD8+ T-cell differentiation, whereas highly clonally expanded effector-like TEX cells were positioned at the branch point where neoantigen-specific clones exited the lymph node and differentiated into TEX TILs. TSCM differentiation of neoantigen-specific CD8+ T-cell clones in the lymph node negatively correlated with exhaustion and clonal expansion of the same clones in the tumor. In addition, the gene signature of neoantigen-specific clones biased toward tumor infiltration relative to lymph-node residence predicted a poorer response to immune checkpoint inhibitors by cancer patients. In conclusion, we have identified a transcriptional program that controls the cell-fate choices by neoantigen-specific CD8+ T cells and correlates with clinical outcomes in cancer patients.

Natural killer (NK) cells play a critical role in anti-cancer immunity through their direct cytotoxicity and production of cytokines, such as Flt3L. NK cell production of Flt3L controls conventional type I dendritic cell (cDC1) abundance in the tumor and promotes protective immune responses. Here, we show that NK cell production of Flt3l in the tumor is regulated by activation, and that activation by IL-2 and IL-15 uniquely induced Flt3L expression in NK cells. In melanoma, IL-2 signaling in NK cells led to increased Flt3L production, which boosted cDC1 abundance in the tumor and improved anti-PD-1 immunotherapy response. Further, NK cell subsets differentially regulated Flt3L in the tumor, with CD11b-CD27+ NK cells in mouse tumors enriched for IL-2-family signaling and upregulated Flt3l upon activation. Consistently, human CD56brightCD16- NK cells more strongly correlated with cDC1 and FLT3LG expression than other NK cell subsets across multiple human melanoma datasets and cancer indications. This mechanistic study of NK cell regulation of FLT3LG and control of the NK cell-cDC1 axis provides insights and strategies for the development of more effective cancer immunotherapies.

Pancreatic adenocarcinoma (PDAC) has a dismal survival rate due to limited effective therapies. Although studies have focused on the influence of innate immune cells on adaptive immune cell functions, few have explored interactions between innate immune cells, which modulate the PDAC tumor microenvironment (TME). Macrophages are responsible for the clearance of neutrophil-mediated inflammation in physiologic, resolving immune responses; however, both of these cell types coexist in the TME, suggesting a failure of macrophages to clear neutrophils in PDAC. We sought to determine how neutrophil extracellular traps (NET), neutrophil release of decondensed chromatin, and intracellular contents affect monocyte/macrophage populations in the PDAC TME. Utilizing samples from patients with PDAC, we demonstrated elevated levels of the monocyte chemokine CCL2 in plasma, as well as elevated NET citrullinated histone H3 and the pan-macrophage marker CD68 in the PDAC TME via fluorescent IHC. To determine how NETs affected macrophage populations in the PDAC TME, we targeted NETs with DNase I treatment to digest extracellular DNA released from NETs or with genetic knockout of PAD4, an enzyme required for NET formation. NET depletion resulted in an elevation in the pan-macrophage marker F4/80. The depletion led to an increased T-cell stimulatory signal, CD80, whereas the protumor macrophage marker CD206 was decreased. We further demonstrated that macrophages in the NET-deficient PDAC TME may be recruited through the CCL2/CCR2 axis, and CCL2 was released from tumor cells and macrophages in the presence of IFNγ. Taken together, our findings reveal that inhibition of NETs can prime the innate immune response toward an antitumor phenotype.

Recent studies have explored the composition of the tumor microenvironment (TME) in diffuse large B-cell lymphoma (DLBCL) However, cell-to-cell interactions, along with the spatial organization of DLBCL TME and their impact on patient outcomes, have remained poorly characterized. We applied multiplex immunofluorescence, cell phenotyping, and neighborhood analysis to investigate 1,218,756 single cells in 99 samples from patients with primary DLBCL. We identified 17 cell phenotypes and 10 recurrent cellular neighborhoods (RCN) across samples, subdividing DLBCLs into immune-poor areas and areas with diverse immune cell infiltrates. Avoidance of B cells and PD-1+ T cells was associated with less aggressive clinical characteristics and favorable survival. Likewise, the proximity of CD8+ T cell-rich and immune-poor RCNs translated to favorable patient outcomes, and the proximity of PD-L1+ B cell-rich and CD8+ T cell-rich RCNs to unfavorable patient outcomes. Our findings provide insights into the spatial interactions and organization of DLBCL TME with implications for patient outcomes.

The effectiveness of T cell-based immunotherapy depends on durable T-cell responses that can efficiently eliminate tumor cells. NKG7 was discovered three decades ago as a protein associated with lytic granules. However, only studies published over the past 5 years have contributed substantially to our understanding of NKG7 in T-cell biology. NKG7 has been recognized as an important T-cell functional marker in responses to immune checkpoint inhibitor therapy and in the prognosis of certain cancers. Besides its role in the generation, trafficking, and release of lytic granules, which is critical for efficient T-cell cytotoxicity against tumor cells, NKG7 has been identified as a key negative regulator of mTORC1 activity. By restraining mTORC1 activity, NKG7 promotes T-cell longevity and memory generation after infection. Importantly, NKG7 upregulation has demonstrated therapeutic potential in preclinical T-cell therapy for cancer. Collectively, NKG7 is emerging as a promising biomarker and therapeutic addition to T cell-based immunotherapies.

Tumor-associated macrophages (TAM) and regulatory T cells (Treg) are major immune components of the tumor microenvironment, promoting tumor growth and limiting the efficacy of chemotherapy in almost all cancer indications. Although Tregs are well known for their immunosuppressive activity toward the adaptive immune system, less is known about their regulatory activity toward the innate compartment. In this study, we have shown that in human and mouse lung cancer, chemotherapy transiently reduced Treg number and switched the mononuclear phagocyte (MP) landscape toward not only a proinflammatory signature but also an increased TGFβ-expressing TAM accumulation over time. Preventing Treg recovery further increased the recruitment of monocytes and limited TGFβ expression upon TAM differentiation, demonstrating that Tregs dampen the proinflammatory status of the MP compartment induced by chemotherapy and promote tumor relapse. Anti-TNFR2 antibody treatment during the Treg recovery phase affected the direct interaction between Tregs and MPs, increased the proinflammatory signature of the MPs, and improved survival in the mouse model. Targeting the cross-talk between tumor-associated Tregs and the MP compartment limits the reconstitution of an anti-inflammatory environment following chemotherapy and improves therapeutic outcome.

T-cell therapies have transformed cancer treatment. Although surface glycans have been shown to play critical roles in regulating T-cell development and function, whether and how the glycome influences T cell-mediated tumor immunity remains an area of active investigation. In this study, we show that the intratumoral T-cell glycome is altered early in human colorectal cancer, with substantial changes in branched N-glycans. We demonstrated that CD8+ T cells expressing β1,6-GlcNAc-branched N-glycans adopted an exhausted phenotype, marked by increased PD1 and Tim3 expression. CRISPR-Cas9 deletion of key branching glycosyltransferase genes revealed that Mgat5 played a prominent role in T-cell exhaustion. In culture-based assays and tumor studies, Mgat5 deletion in CD8+ T cells resulted in improved cancer cell killing. These findings prompted the assessment of whether MGAT5 deletion in anti-CD19 chimeric antigen receptor (CAR) T cells could enable this therapeutic modality in a solid tumor setting. We showed that MGAT5 knockout anti-CD19-CAR T cells inhibited the growth of CD19-transduced tumors. Together, these findings show that MGAT5-mediated branched N-glycans regulate CD8+ T-cell function in cancer and provide a strategy to enhance the antitumor activity of native and CAR T cells.

There are limited therapeutic options for patients with advanced sarcomas, which leads to dismal outcomes for children and adults. Although chimeric antigen receptor (CAR) T cells hold promise for treating advanced sarcomas, this approach is constrained by a paucity of effective targets. Our previous clinical study identified endoglin (ENG/CD105), a TGFβ coreceptor, as a target of the endogenous immune response in a patient with sarcoma who exhibited an exceptional response to HER2-targeted CAR T-cell therapy. ENG is expressed on various sarcomas, cancer-associated fibroblasts, and neoangiogenic vessels and therefore offers comprehensive tumor targeting. Furthermore, ENG knockout in sarcoma cells reduces their invasiveness, highlighting its potential as a therapeutic target. Accordingly, we designed a second-generation human ENG-targeting CAR molecule signaling through the CD28 endodomain and retrovirally transduced primary human T cells with this CAR. ENG CAR T cells exhibited strong antigen-specific cytokine release, robust proliferation, memory formation, and cytotoxic function against various sarcoma cell lines. Their cytotoxicity remained unaffected by the presence of soluble ENG or its natural ligand, bone morphogenetic protein-9. Furthermore, ENG CAR T cells disrupted multicellular tumor spheroids in vitro, overcoming tumor compactness and the stromal barrier created by cancer-associated fibroblasts, which are critical challenges in sarcoma CAR T-cell therapy. In orthotopic xenograft models of sarcomas, ENG CAR T-cell treatment resulted in control of tumor growth and metastasis, leading to survival extension. In summary, our study describes the involvement of ENG in sarcoma metastasis and validates our human ENG CAR T cells as a potential therapeutic for advanced sarcomas.