Cancer immunology research最新文献

Tertiary lymphoid structures (TLS) in cancer are considered ectopic hotspots for immune activation that are similar to lymphoid follicles in secondary lymphoid organs (SLO). This study elucidates shared and TLS/SLO-specific features in pancreatic ductal adenocarcinoma (PDAC). TLS abundance was related to superior survival and T-cell abundance in 110 treatment-naïve PDAC samples, underlining their clinical relevance. Immunofluorescence microscopy identified structural homologies between TLSs and SLOs. In RNA expression analyses of laser-microdissected TLSs and paired SLOs, we observed largely overlapping expression patterns of immune-related gene clusters but distinct expression patterns of T-cell and complement-associated genes. Immune cells in TLS expressed essential markers of germinal center formation. Increased activation of tumor-draining lymph nodes in patients with high numbers of TLSs highlights the relevance of these tumor-related structures to systemic immune response. In line with this, we identified an overlap of expanded B-cell receptor clonotypes in TLSs and SLOs, which suggests a vivid cross-talk between the two compartments. We conclude that combined therapeutic approaches exploiting TLS-mediated antitumor immune responses may improve susceptibility of PDAC to immunotherapy.

Despite advances in cancer immunotherapy, such as targeting the PD-1/PD-L1 axis, a substantial number of patients harbor tumors that are resistant or relapse. Selective engagement of T-cell co-stimulatory molecules with bispecific antibodies may offer novel therapeutic options by enhancing signal 1-driven activation occurring via T-cell receptor engagement. In this study, we report the development and preclinical characterization of NI-3201, a PD-L1×CD28 bispecific antibody generated on the κλ-body platform that was designed to promote T-cell activity and antitumor function through a dual mechanism of action. We confirmed that NI-3201 blocks the PD-L1/PD-1 immune checkpoint pathway and conditionally provides T-cell co-stimulation via CD28 (signal 2) when engaging PD-L1+ tumors or immune cells. In systems with signal 1-primed T cells, NI-3201 enhanced potent effector functionality: in vitro through antigen-specific recall assays with cytomegalovirus-specific T cells and in vivo by inducing tumor regression and immunologic memory in tumor-associated antigen-expressing MC38 syngeneic mouse models. When T-cell engagers were used to provide synthetic signal 1, the combination with NI-3201 resulted in synergistic T cell-dependent cytotoxicity and potent antitumor activity in two humanized mouse tumor models. Nonhuman primate safety assessments showed favorable tolerability and pharmacokinetics at pharmacologically active doses. Quantitative systems pharmacology modeling predicted that NI-3201 exposure results in antitumor activity in patients, but this remains to be investigated. Overall, this study suggests that by combining PD-L1 blockade with safe and effective CD28 co-stimulation, NI-3201 has the potential to improve cancer immunotherapy outcomes, and the clinical development of NI-3201 for PD-L1+ solid tumors is planned.

The term cancer immunoediting describes the dual role by which the immune system can suppress and promote tumor growth and is divided into three phases: elimination, equilibrium, and escape. The role of NK cells has mainly been attributed to the elimination phase. Here, we show that NK cells play a role in all three phases of cancer immunoediting. Extended co-culturing of DNA-barcoded mouse BCR/ABLp185+ B-cell acute lymphoblastic leukemia (B-ALL) cells with NK cells allowed for a quantitative measure of NK cell-mediated immunoediting. Although most tumor cell clones were efficiently eliminated by NK cells, a certain fraction of tumor cells harbored an intrinsic primary resistance. Furthermore, DNA barcoding revealed tumor cell clones with secondary resistance, which stochastically acquired resistance to NK cells. NK cell-mediated cytotoxicity put a selective pressure on B-ALL cells, which led to an outgrowth of primary and secondary resistant tumor cell clones, which were characterized by an IFNγ signature. Besides well-known regulators of immune evasion, our analysis of NK cell-resistant tumor cells revealed the upregulation of genes, including lymphocyte antigen 6 complex, locus A (Ly6a), which we found to promote leukemic cell resistance to NK cells. Translation of our findings to the human system showed that high expression of LY6E on tumor cells impaired their physical interaction with NK cells and led to worse prognosis in patients with leukemia. Our results demonstrate that tumor cells are actively edited by NK cells during the equilibrium phase and use different avenues to escape NK cell-mediated eradication.

Despite the pivotal role of CTLs in antitumor immunity, a substantial proportion of CTL-rich patients with hepatocellular carcinoma (HCC) experience early relapse or immunotherapy resistance. However, spatial immune variations impacting the heterogeneous clinical outcomes of CTL-rich HCCs remain poorly understood. In this study, we compared the single-cell and spatial landscapes of 20 CTL-rich HCCs with distinct prognoses using multiplexed in situ staining and validated the prognostic value of myeloid spatial patterns in a cohort of 386 patients. Random forest and Cox regression models identified macrophage aggregation as a distinctive spatial pattern characterizing a subset of CTL-rich HCCs with an immunosuppressive microenvironment and poor prognosis. Integrated analysis of single-cell and spatial transcriptomics, combined with in situ staining validation, revealed that spatial aggregation enhanced protumoral macrophage reprogramming in HCCs, marked by lipid metabolism orientation, M2-like polarization, and increased adjacent CTL exhaustion. This spatial effect on macrophage reprogramming was replicated in HCC-conditioned human macrophage cultures, which showed an enhanced capability to suppress CTLs. Notably, increased macrophage aggregation was associated with higher response rates to anti-PD-1 immunotherapy. These findings suggest that the spatial distribution of macrophages is a biomarker of their functional diversities and microenvironment status, which holds prognostic and therapeutic implications.

Many tumor-specific monoclonal antibody therapies stimulate antibody-dependent cellular cytotoxicity (ADCC) by natural killer (NK) cells through FcγRIIIa (CD16). The efficacy of these ADCC-based immunotherapies is potentiated in patients with the common CD16 polymorphic variant F158-V that increases the binding affinity between the receptor and the IgG Fc domain. However, other CD16 variants are less well characterized. Here, we report that CD16 L48-H and L48-R variants both significantly enhance in vitro ADCC responses in primary NK cells and NK-92 cells. During ADCC responses, NK cells expressing CD16 48-H killed and disengaged from target cells faster than those expressing CD16 48-L, resulting in improved serial killing of tumor cells. We found that CD16 48-H also formed an immunologic synapse with a more compact interface, as well as more robust intracellular calcium signaling and quicker polarization of cytolytic vesicles. The ADCC response observed occurs due to increased cytolytic signaling and target cell disengagement, which drives NK cell-mediated serial killing of tumor cells. The L48-H/R polymorphism has potential to benefit patient responses to cancer antibody therapies and may also potentiate antitumor ADCC responses if incorporated into adoptive NK cell therapeutic platforms.

Denosumab, a RANKL inhibitor, is primarily used to prevent osteoclastogenesis in the treatment of conditions such as osteoporosis, bone metastasis, and giant cell tumour of bone (GCTB). RANKL also plays an important role in immunity by activating NF-κB and its target genes, including the osteopontin-coding gene SPP1 (also known as OPN), which is linked to CXCL9:SPP1 macrophage polarization and prognosis. In this study, we explored an additional role of denosumab in enhancing antitumour immunity in patients. Single-cell RNA sequencing was performed on nine human GCTB samples, including six untreated and three treated only with denosumab, to exclude confounding treatment factors linked with bone metastasis samples. We further analysed paired pre- and post-denosumab treated samples from a cohort of nine GCTB patients and conducted a pan-cancer analysis of 34 distinct types of cancers. Our single-cell analysis of GCTB resulted in a comprehensive cell atlas revealing an antitumour role of denosumab in inhibiting SPP1 expression and augmenting active cytotoxic T cell abundance. Furthermore, we validated this immunomodulatory role of denosumab using the paired GCTB samples. Finally, the pan-cancer analysis supported a negative correlation between SPP1 and CD8A levels, with the CD8A:SPP1 ratio correlating with overall survival in 14 cancer types, which was superior to either CD8A or SPP1 alone. Our research provides clinical evidence that denosumab improves antitumour immunity by decreasing SPP1 expression and enhancing cytotoxic T cell activity, serving as a milestone in the development of innovative use of denosumab and offering potential benefits to patients with elevated levels of SPP1.

The advent of syngeneic mouse tumor models provided the scientific foundation for cancer immunotherapies now in widespread use. However, in many respects, these models do not faithfully recapitulate the interactions between cancer cells and the immune systems of human patients who have solid tumors because they represent a very early stage in the immune response to the newly transplanted cancer cells compared with the relatively mature stage found in human patients at the time of treatment. The lack of translatability of syngeneic models is probably responsible for many failed clinical trials conducted at considerable expense, involving far too many patients with cancer who received no benefit. Better mouse models would substantially accelerate the pace of discovery of new immunotherapies. Until these models emerge, a better understanding of the differences between the existing syngeneic models and human cancers may provide a more efficient path for moving experimental drugs into clinical development. To accomplish this, we must consider mice transplanted with syngeneic tumor cells to be in vivo assays, potentially useful for understanding the mechanism of action of immunotherapies rather than disease models.

Immune checkpoint inhibitors (ICIs) have changed the treatment paradigm for many cancers but have not shown benefit in prostate cancer (PCa). Chronic inflammation contributes to the immunosuppressive prostate tumor microenvironment (TME) and is associated with poor response to ICIs. The primary source of inflammatory cytokine production is the inflammasome. Here, we identify PIM kinases as regulators of inflammasome activation in tumor-associated macrophages (TAMs). Analysis of clinical data from a cohort of treatment naïve, hormone-responsive PCa patients revealed that tumors from patients with high PIM1/2/3 displayed an immunosuppressive TME characterized by high inflammation and a high density of repressive immune cells, most notably TAMs. Macrophage-specific knockout of PIM reduced tumor growth in syngeneic models of PCa. Transcriptional analyses indicated that eliminating PIM from macrophages enhanced the adaptive immune response and increased cytotoxic immune cells. Combined treatment with PIM inhibitors and ICIs synergistically reduced tumor growth. Immune profiling revealed that PIM inhibitors sensitized PCa tumors to ICIs by increasing tumor suppressive TAMs and increasing the activation of cytotoxic T cells. Our data implicate macrophage PIM as a driver of inflammation that limits ICI potency and provide preclinical evidence that PIM inhibitors are an effective strategy to improve the ICI efficacy in PCa.

Traditional anti-cancer therapies induce tumor cell death and subsequent release of Damage Associated Molecular Patterns (DAMPs) that activate the innate inflammatory response. Paradoxically, after treatment, macrophages often adopt a pro-wound healing, rather than pro-inflammatory, phenotype and contribute to cancer progression. We found that in areas proximal to DAMP release, tumor cells upregulate the expression of Pros1. Tumor-secreted Pros1 binds to the macrophage Mer receptor, consequently limiting responsiveness to DAMPs by preventing Toll Like Receptor (TLR) signal transduction. Pharmacological inhibition of PTP1b signaling downstream of Mer rescued the pro-inflammatory response, even in the presence of Pros1. Combining PTP inhibition with traditional therapeutics, like chemo- or radiotherapy, rescued the innate immune response to DAMPs, increased immune infiltration, and resulted in a 40-90% reduction in tumor growth in multiple treatment refractory preclinical models. Our findings suggest using PTP1b inhibitors may be a tumor agnostic means of improving the efficacy of some of the most widely used anti-cancer therapeutic agents.