Oncoimmunology最新文献

Biomarkers for cancer immunotherapy are an unmet medical need. The group of Daniela Thommen at the NKI recently reported on novel methodologies based on short-term cultures of patient-derived tumor fragments whose cytokine concentrations in the supernatants and activation markers on infiltrating T cells were associated with clinical response to PD-1 blockade. We set up a similar culture technology with tumor-derived fragments using mouse tumors transplanted into syngeneic immunocompetent mice to test an agonist anti-CD137 mAb and its combinations with anti-PD-1 and/or anti-TGF-β. Increases in IFNγ concentrations in the tissue culture supernatants were detected upon in-culture activation with the anti-CD137 and anti-PD-1 mAb combinations or concanavalin A as a positive control. No other cytokine from a wide array was informative of stimulation with these mAbs. Interestingly, increases in Ki67 and other activation markers were substantiated in lymphocytes from cell suspensions gathered at the end of 72 h cultures. In mice bearing bilateral tumors in which one was excised prior to in vivo anti-CD137 + anti-PD-1 treatment to perform the fragment culture evaluation, no association was found between IFNγ production from the fragments and the in vivo therapeutic outcome in the non-resected contralateral tumors. The experimental system permitted freezing and thawing of the fragments with similar functional outcomes. Using a series of patient-derived tumor fragments from excised solid malignancies, we showed IFNγ production in a fraction of the studied cases, that was conserved in frozen/thawed fragments. The small tumor fragment culture technique seems suitable to preclinically explore immunotherapy combinations.

Immune checkpoint (IC) blockade and adoptive transfer of tumor-specific T-cells (ACT) are two major strategies to treat metastatic melanoma. Their combination can potentiate T-cell activation in the suppressive tumor microenvironment, but the autoimmune adverse effects associated with systemic injection of IC blockers persist with this strategy. ACT of tumor-reactive T-cells defective for IC expression would overcome this issue. For this purpose, PD-1 and TIGIT appear to be relevant candidates, because their co-expression on highly tumor-reactive lymphocytes limits their therapeutic efficacy within the tumor microenvironme,nt. Our study compares the consequences of PDCD1 or TIGIT genetic deletion on anti-tumor properties and T-cell fitness of melanoma-specific T lymphocytes. Transcriptomic analyses revealed down-regulation of cell cycle-related genes in PD-1^KO T-cells, consistent with biological observations, whereas proliferative pathways were preserved in TIGIT^KO T-cells. Functional analyses showed that PD-1^KO and TIGIT^KO T-cells displayed superior antitumor reactivity than their wild-type counterpart in vitro and in a preclinical melanoma model using immunodeficient mice. Interestingly, it appears that TIGIT^KO T-cells were more effective at inhibiting tumor cell proliferation in vivo, and persist longer within tumors than PD-1^KO T-cells, consistent with the absence of impact of TIGIT deletion on T-cell fitness. Taken together, these results suggest that TIGIT deletion, over PD-1 deletion, in melanoma-specific T-cells is a compelling option for future immunotherapeutic strategies.

TCRαβ+ CD4- CD8- double-negative T (DNT) cells are minor populations in peripheral blood, and their roles have mostly been discussed in inflammation and autoimmunity. However, the functions of DNT cells in tumor microenvironment remain to be elucidated. We investigated their characteristics, possible origins and functions in colorectal cancer tissues as well as their corresponding tumor-draining lymph nodes. We found a significant enrichment of DNT cells in tumor tissues compared with their corresponding lymph nodes, especially in tumors with lower T cell infiltration. T cell receptor (TCR) sequence analysis of CD4+ T, CD8+ T and DNT cells indicated that TCR sequences detected in DNT cells were found in CD8+ T cells, but rarely in CD4+ T cells, suggesting that a part of DNT cells was likely to be originated from CD8+ T cells. Through a single-cell transcriptomic analysis of DNT cells, we found that a DNT cell cluster, which showed similar phenotypes to central memory CD8+ T cells with low expression of effector and exhaustion markers, revealed some specific gene expression patterns, including higher GZMK expression. Moreover, in flow cytometry analysis, we found that DNT cells lost production of cytotoxic mediators. These findings imply that DNT cells might function as negative regulators of anti-tumor immune responses in tumor microenvironment.

Immune checkpoint inhibitors (ICIs) are linked to diverse immune-related adverse events (irAEs). Rare irAEs surface first in clinical practice. Here, we systematically studied the rare irAE, cytokine-release syndrome (CRS), in a cohort of 2672 patients treated with ICIs at Karolinska University Hospital in Stockholm, Sweden. We find that the risk of ICI-induced CRS - defined as fever, negative microbiological findings and absence of other probable causes within 30 days after ICI treatment - is approximately 1%, higher than previously reported. ICI-induced CRS was often mild and rechallenge with ICIs after mild CRS was generally safe. However, two out of 28 patients experienced high-grade CRS, and one was fatal. While C-reactive protein (CRP) and procalcitonin were not discriminative of fatal CRS, our data suggest that the quick Sequential Organ Failure Assessment (qSOFA) score might identify high-risk patients. These data provide a framework for CRS risk assessment and motivate multicenter studies to improve early CRS diagnosis.

Gut microbiota impacts responses to immune checkpoint inhibitors (ICI). A high level of Faecalibacterium prausnitzii have been associated with a positive response to ICI in multiple cancer types. Here, based on fecal shotgun metagenomics data, we show in two independent cohorts of patients with non-small cell lung cancer and advanced melanoma that a high level of F. prausnitzii at baseline is positively associated with a better clinical response to ICI. In MCA205 tumor-bearing mice, administration of F. prausnitzii strain EXL01, already in clinical development for Inflammatory Bowel Disease, restores the anti-tumor response to ICI in the context of antibiotic-induced microbiota perturbation at clinical and tumor transcriptomics level. In vitro, EXL01 strain enhances T cell activation in the presence of ICI. Interestingly, oral administration of EXL01 strain did not induce any change in fecal microbiota diversity or composition, suggesting a direct effect on immune cells in the small intestine. F. prausnitzii strain EXL01 will be evaluated as an adjuvant to ICI in multiple cancers in the near future.

The randomized METIMMOX trial (NCT03388190) examined if patients with previously untreated, unresectable abdominal metastases from microsatellite-stable (MSS) colorectal cancer (CRC) might benefit from potentially immunogenic, short-course oxaliplatin-based chemotherapy alternating with immune checkpoint blockade (ICB). Three of 38 patients assigned to this experimental treatment had metastases from BRAF-mutant MSS-CRC, in general a poor-prognostic subgroup explored here. The ≥70-year-old females presented with ascending colon adenocarcinomas with intermediate tumor mutational burden (6.2-11.8 mutations per megabase). All experienced early disappearance of the primary tumor followed by complete response of all overt metastatic disease, resulting in progression-free survival as long as 20-35 months. However, they encountered recurrence at previously unaffected sites and ultimately sanctuary organs, or as intrahepatic tumor evolution reflected in the terminal loss of initially induced T-cell clonality in liver metastases. Yet, the remarkable first-line responses to short-course oxaliplatin-based chemotherapy alternating with ICB may offer a novel therapeutic option to a particularly hard-to-treat MSS-CRC subgroup.

Isolation of tumor-specific T cells and their antigen receptors (TCRs) from malignant pleural effusions (MPE) may facilitate the development of TCR-transduced adoptive cellular immunotherapy products for advanced lung cancer patients. However, the characteristics and markers of tumor-specific T-cells in MPE are largely undefined. To this end, to establish the phenotypes and antigen specificities of CD8⁺ T cells, we performed single-cell RNA and TCR sequencing of samples from three advanced lung cancer patients. Dimensionality reduction on a total of 4,983 CD8⁺ T cells revealed 10 clusters including naïve, memory, and exhausted phenotypes. We focused particularly on exhausted T cell clusters and tested their TCR reactivity against neoantigens predicted from autologous cancer cell lines. Four different TCRs specific for the same neoantigen and one orphan TCR specific for the autologous cell line were identified from one of the patients. Differential gene expression analysis in tumor-specific T cells relative to the other T cells identified CXCL13, as a candidate gene expressed by tumor-specific T cells. In addition to expressing CXCL13, tumor-specific T cells were present in a higher proportion of T cells co-expressing PDCD1(PD-1)/TNFRSF9(4-1BB). Furthermore, flow cytometric analyses in advanced lung cancer patients with MPE documented that those with high PD-1/4-1BB expression have a better prognosis in the subset of 57 adenocarcinoma patients (p = .039). These data suggest that PD-1/4-1BB co-expression might identify tumor-specific CD8⁺ T cells in MPE, which are associated with patients' prognosis. (233 words).

Prostate cancer (PCa) is characterized as a "cold tumor" with limited immune responses, rendering the tumor resistant to immune checkpoint inhibitors (ICI). Therapeutic messenger RNA (mRNA) vaccines have emerged as a promising strategy to overcome this challenge by enhancing immune reactivity and significantly boosting anti-tumor efficacy. In our study, we synthesized Tetra, an mRNA vaccine mixed with multiple tumor-associated antigens, and ImmunER, an immune-enhancing adjuvant, aiming to induce potent anti-tumor immunity. ImmunER exhibited the capacity to promote dendritic cells (DCs) maturation, enhance DCs migration, and improve antigen presentation at both cellular and animal levels. Moreover, Tetra, in combination with ImmunER, induced a transformation of bone marrow-derived dendritic cells (BMDCs) to cDC1-CCL22 and up-regulated the JAK-STAT1 pathway, promoting the release of IL-12, TNF-α, and other cytokines. This cascade led to enhanced proliferation and activation of T cells, resulting in effective killing of tumor cells. In vivo experiments further revealed that Tetra + ImmunER increased CD8⁺T cell infiltration and activation in RM-1-PSMA tumor tissues. In summary, our findings underscore the promising potential of the integrated Tetra and ImmunER mRNA-LNP therapy for robust anti-tumor immunity in PCa.

The role of CD161⁺CD127⁺CD8⁺ T cells in non-small cell lung cancer (NSCLC) patients with diabetes remains unexplored. This study determined the prevalence, phenotype, and function of CD8⁺ T cell subsets in NSCLC with diabetes. We recruited NSCLC patients (n = 436) treated with anti-PD-1 immunotherapy as first-line treatment. The progression-free survival (PFS), overall survival (OS), T cells infiltration, and peripheral blood immunological characteristics were analyzed in NSCLC patients with or without diabetes. NSCLC patients with diabetes exhibited shorter PFS and OS (p = 0.0069 and p = 0.012, respectively) and significantly lower CD8⁺ T cells infiltration. Mass cytometry by time-of-flight (CyTOF) showed a higher percentage of CD161⁺CD127⁺CD8⁺ T cells among CD8⁺T cells in NSCLC with diabetes before anti-PD-1 treatment (p = 0.0071) than that in NSCLC without diabetes and this trend continued after anti-PD-1 treatment (p = 0.0393). Flow cytometry and multiple-immunofluorescence confirmed that NSCLC with diabetes had significantly higher CD161⁺CD127⁺CD8⁺ T cells to CD8⁺T cells ratios than NSCLC patients without diabetes. The RNA-sequencing analysis revealed immune-cytotoxic genes were reduced in the CD161⁺CD127⁺CD8⁺ T cell subset compared to CD161⁺CD127^-CD8⁺ T cells in NSCLC with diabetes. CD161⁺CD127⁺CD8⁺ T cells exhibited more T cell-exhausted phenotypes in NSCLC with diabetes. NSCLC patients with diabetes with ≥ 6.3% CD161⁺CD127⁺CD8⁺ T cells to CD8⁺T cells ratios showed worse PFS. These findings indicate that diabetes is a risk factor for NSCLC patients who undergo anti-PD-1 immunotherapy.CD161⁺CD127⁺CD8⁺ T cells could be a key indicator of a poor prognosis in NSCLC with diabetes. Our findings would help in advancing anti-PD-1 therapy in NSCLC patients with diabetes.

Deregulation or loss of the human leukocyte antigen class I (HLA-I) molecules on tumor cells leading to inhibition of CD8⁺ T cell recognition is an important tumor immune escape strategy, which could be caused by a posttranscriptional control of molecules in the HLA-I pathway mediated by RNA-binding proteins (RBPs). So far, there exists only limited information about the interaction of RBPs with HLA-I-associated molecules, but own work demonstrated a binding of the heterogeneous ribonucleoprotein C (hnRNP C) to the 3' untranslated region (UTR) of the TAP-associated glycoprotein tapasin (tpn). In this study, in silico analysis of pan-cancer TCGA datasets revealed that hnRNP C is higher expressed in tumor specimens compared to corresponding normal tissues, which is negatively correlated to tpn expression, T cell infiltration and the overall survival of tumor patients. Functional analysis demonstrated an upregulation of tpn expression upon siRNA-mediated downregulation of hnRNP C, which is accompanied by an increased HLA-I surface expression. Thus, hnRNP C has been identified to target tpn and its inhibition could improve the HLA-I surface expression on melanoma cells suggesting its use as a possible biomarker for T-cell-based tumor immunotherapies.