Cancer Immunology, Immunotherapy最新文献

Drugs or cellular products that bind to gp100 are being investigated for treatment of cutaneous melanoma. The relative specificity of gp100 expression in melanocytes makes it an attractive target to harness for therapeutic intent. For example, Tebentafusp, a bispecific gp100 peptide-HLA-directed CD3 T cell engager, has generated significant enthusiasm in recent years due to its success in improving outcomes for uveal melanoma and is being studied in cutaneous melanoma. However, the extent and intensity of gp100 expression in advanced cutaneous melanoma has not been well studied. Here, we interrogated a large cohort of primary and metastatic melanomas for gp100 expression by immunohistochemistry. Expression in metastatic samples was globally higher and almost uniformly positive, however the degree of intensity was variable. Using a quantitative immunofluorescence method, we confirmed the variability in expression. As gp100-binding drugs are assessed in clinical trials, the association between activity of the drugs and the level of gp100 expression should be studied in order to potentially improve patient selection.

Purpose: Immune checkpoint inhibitors have revolutionized the treatment of renal cell carcinoma (RCC), but many patients do not respond to therapy and the majority develop resistant disease over time. Thus, there is increasing need for alternative immunomodulating agents. The co-inhibitory molecule T-cell immunoglobulin and ITIM domain (TIGIT) may play a role in resistance to approved immune checkpoint inhibitors and is being investigated as a potential therapeutic target. The purpose of this study was to quantify TIGIT positivity in tumor-infiltrating T cells in RCC.

Methods: We employed tissue microarrays containing specimens from primary RCC tumors, adjacent normal renal tissue, and RCC metastases to quantify TIGIT within tumor-infiltrating CD3⁺ T cells using quantitative immunofluorescent analysis. We also compared these results to TIGIT⁺ CD3⁺ levels in four other tumor types (melanoma, non-small cell lung, cervical, and head and neck cancers).

Results: We did not observe significant differences in TIGIT positivity between primary RCC tumors and patient-matched metastatic samples. We found that the degree of TIGIT positivity in RCC is comparable to that in lung cancer but lower than that in melanoma, cervical, and head and neck cancers. Correlation analysis comparing TIGIT positivity to previously published, patient-matched spatial proteomic data by our group revealed a negative association between TIGIT and the checkpoint proteins PD-1 and LAG3.

Conclusion: Our findings support careful evaluation of TIGIT expression on T cells in primary or metastatic RCC specimens for patients who may be treated with TIGIT-targeting antibodies, as increased TIGIT positivity might be associated with a greater likelihood of response to therapy.

Objective: Most recurrent glioblastoma (rGBM) patients do not benefit from immune checkpoint inhibition, emphasizing the necessity for response biomarkers. This study evaluates whether tumor in situ fluid (TISF) circulating tumor DNA (ctDNA) could serve as a biomarker for response to low-dose bevacizumab (Bev) plus anti-PD-1 therapy in rGBM patients, aiming to enhance systemic responses to immunotherapy.

Methods: In this phase II trial, 32 GBM patients with first recurrence after standard therapy were enrolled and then received tislelizumab plus low-dose Bev each cycle. TISF samples were analyzed for ctDNA using a 551-gene panel before each treatment.

Results: The median progression-free survival (mPFS) and overall survival (mOS) were 8.2 months (95% CI, 5.2-11.1) and 14.3 months (95% CI, 6.5-22.1), respectively. The 12-month OS was 43.8%, and the objective response rate was 56.3%. Patients with more than 20% reduction in the mutant allele fraction and tumor mutational burden after treatment were significantly associated with better prognosis compared to baseline TISF-ctDNA. Among detectable gene mutations, patients with MUC16 mutation, EGFR mutation & amplification, SRSF2 amplification, and H3F3B amplification were significantly associated with worse prognosis.

Conclusions: Low-dose Bev plus anti-PD-1 therapy significantly improves OS in rGBM patients, offering guiding significance for future individualized treatment strategies. TISF-ctDNA can monitor rGBM patients' response to combination therapy and guide treatment.

Clinical trial registration: This trial is registered with ClinicalTrials.gov, NCT05540275.

Transforming growth factor β (TGFβ) is present in blood of patients who do not respond to anti-programmed cell death (ligand) 1 [PD-(L)1] treatment, and through synergy with vascular endothelial growth factor (VEGF), it helps to create an environment that promotes tumor immune evasion and immune tolerance. Therefore, simultaneous inhibition of TGFβ/VEGF is more effective than targeting TGFβ alone. In this study, the dual inhibitory mechanism of TU2218 was identified through in vitro analysis mimicking the tumor microenvironment, and its antitumor effects were analyzed using mouse syngeneic tumor models. TU2218 directly restored the activity of damaged cytotoxic T lymphocytes (CTLs) and natural killer cells inhibited by TGFβ and suppressed the activity and viability of regulatory T cells. The inactivation of endothelial cells induced by VEGF stimulation was completely ameliorated by TU2218, an effect not observed with vactosertib, which inhibits only TGFβ signaling. The combination of TU2218 and anti-PD1 therapy had a significantly greater antitumor effect than either drug alone in the poorly immunogenic B16F10 syngeneic tumor model. The mechanism of tumor reduction was confirmed by flow cytometry, which showed upregulated VCAM-1 expression in vascular cells and increased influx of CD8 + CTLs into the tumor. As another strategy, combination of anti-CTLA4 therapy and TU2218 resulted in high complete regression (CR) rates in CT26 and WEHI-164 tumor models. In particular, immunological memory generated by the combination of anti-CTLA4 and TU2218 in the CT26 model prevented the development of tumors after additional tumor cell transplantation, suggesting that the TU2218-based combination has therapeutic potential in immunotherapy.

Background: The efficacy of antibody-targeted therapy of solid cancers is limited by the lack of consistent tumour-associated antigen expression. However, tumour-associated antigens shared with non-malignant cells may still be targeted using conditionally activated-antibodies, or by chimeric antigen receptor (CAR) T cells or CAR NK cells activated either by the tumour microenvironment or following 'unlocking' via multiple antigen-recognition. In this study, we have focused on tissue factor (TF; CD142), a type I membrane protein present on a range of solid tumours as a basis for future development of conditionally-activated BiTE or CAR T cells. TF is frequently upregulated on multiple solid tumours providing a selective advantage for growth, immune evasion and metastasis, as well as contributing to the pathology of thrombosis via the extrinsic coagulation pathway.

Methods: Two well-characterised anti-TF monoclonal antibodies (mAb) were cloned into expression or transposon vectors to produce single chain (scFv) BiTE for assessment as CAR and CD28-CD3-based CAR or CD3-based BiTE. The affinities of both scFv formats for TF were determined by surface plasmon resonance. Jurkat cell line-based assays were used to confirm the activity of the BiTE or CAR constructs.

Results: The anti-TF mAb hATR-5 and TF8-5G9 mAb were shown to maintain their nanomolar affinities following conversion into a single chain (scFv) format and could be utilised as CD28-CD3-based CAR or CD3-based BiTE format.

Conclusion: Because of the broad expression of TF on a range of solid cancers, anti-TF antibody formats provide a useful addition for the development of conditionally activated biologics for antibody and cellular-based therapy.

Patients with recurrent or metastatic head and neck cancers (R/M HNCs) are prone to developing resistance after immunotherapy. This retrospective real-world study aims to investigate whether the addition of anlotinib can reverse resistance to PD-1 inhibitors (PD-1i) and evaluate the efficacy and safety of this combination in R/M HNCs. Main outcomes included objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), duration of response (DOR), and safety. Potential biomarkers included PD-L1 expression, lipid index, and genomic profiling. Twenty-one patients with R/M HNCs were included, including 11 nasopharyngeal carcinoma (NPC), five head and neck squamous cell carcinoma (HNSCC), three salivary gland cancers (SGC), and two nasal cavity or paranasal sinus cancers (NC/PNC). Among all patients, ORR was 47.6% (95% CI: 28.6-66.7), with 2 (9.5%) complete response; DCR was 100%. At the median follow-up of 17.1 months, the median PFS and OS were 14.3 months (95% CI: 5.9-NR) and 16.7 months (95% CI:8.4-NR), respectively. The median DOR was 11.2 months (95% CI: 10.1-NR). As per different diseases, the ORR was 45.5% for NPC, 60.0% for HNSCC, 66.7% for SGC, and 50.0% for NC/PNC. Most treatment-related adverse events (TRAEs) were grade 1 or 2 (88.9%). The most common grades 3-4 TRAE was hypertension (28.6%), and two treatment-related deaths occurred due to bleeding. Therefore, adding anlotinib to the original PD-1i could reverse PD-1 blockade resistance, with a favorable response rate, prolonged survival, and acceptable toxicity, indicating the potential as a second-line and subsequent therapy choice in R/M HNCs.

CD27 belongs to the tumor necrosis factor receptor superfamily and acts as a co-stimulatory molecule, modulating T and B cell responses. CD27 stimulation enhances T cell survival and effector functions, thus providing opportunities to develop therapeutic strategies. The current study aims to investigate the role of endogenous CD27 signaling in tumor growth and metastasis. CD8 + T cell-specific CD27 knockout (CD8Cre-CD27fl) mice were developed, while global CD27 knockout (KO) mice were also used in our studies. Flow cytometry analyses confirmed that CD27 was deleted specifically from CD8 + T cells without affecting CD4 + T cells, B cells, and HSPCs in the CD8Cre-CD27fl mice, while CD27 was deleted from all cell types in global CD27 KO mice. Tumor growth and metastasis studies were performed by injecting B16-F10 melanoma cells subcutaneously (right flank) or intravenously into the mice. We have found that global CD27 KO mice succumbed to significantly accelerated tumor growth compared to WT controls. In addition, global CD27 KO mice showed a significantly higher burden of metastatic tumor nests in the lungs compared to WT controls. However, there was no significant difference in tumor growth curves, survival, metastatic tumor nest counts between the CD8Cre-CD27fl mice and WT controls. These results suggest that endogenous CD27 signaling inhibits tumor growth and metastasis via CD8 + T cell-independent mechanisms in this commonly used melanoma model, presumably through stimulating antitumor activities of other types of immune cells.

Background: Head and neck squamous cell carcinoma (HNSCC) typically present with a complex anatomical distribution, often accompanied by insidious symptoms. This combination contributes to its high incidence and poor prognosis. It is now understood that the immune features of cellular components within the tumor ecosystem and their complex interactions are critical factors influencing both tumor progression and the effective immune response.

Methods: We obtained single-cell RNA sequencing data of 26,496 cells from three tumor tissues and five normal tissues and performed subsequent analyses. Immunohistochemical staining on tumor sections was used to validate the presence of malignant cells. Additionally, we included bulk RNA sequencing data from 502 HNSCC patients. Kaplan-Meier analysis and the log-rank test were employed to assess predictors of patient outcomes.

Results: We identified three epithelial subclusters exhibiting immune-related features. These subclusters promoted the infiltration of T cells, dendritic cells, and monocytes into the tumor microenvironment. Additionally, cancer-associated fibroblasts displayed tumor-promoting and angiogenesis characteristics, contrasting with the predominant antigen-presenting and inflammatory roles observed in fibroblasts from normal tissues. Furthermore, tumor endothelial subsets exhibited a double-sided effect, promoting tumor progression and enhancing the effectiveness of immune response. Finally, follicular helper T cells and T helper 17 cells were found to be significantly correlated with improved outcomes in HNSCC patients. These CD4⁺ T cell subpopulations could promote the anti-tumor immune response by recruiting and activating B and T cells.

Conclusion: Our findings provide deeper insights into the immune features of the tumor ecosystem and reveal the prognostic significance of follicular helper T cells and T helper 17 cells. These findings may pave the way for the development of therapeutic approaches.

Previous studies have suggested a negative impact of steroids on the efficacy of immune checkpoint inhibitors (ICI), but how this effect is modulated by the dosage and time of administration is yet to be clarified. We have performed a retrospective analysis of 475 patients with advanced solid tumors treated with ICI as monotherapy from 2015 to 2022. Data regarding immune-related adverse events (irAEs) and clinical outcomes were collected. For each patient, the daily steroid dose (in mg/kg of prednisone) was registered until disease progression or death. The impact of cumulative doses on response rates and survival outcomes was analyzed within different periods. The objective response rate (ORR) was significantly lower among patients exposed to steroids within 30 days before the first cycle of ICI (C1) (20.3% vs. 36.7%, p < 0.01) and within the first 90 days of treatment (25.7% vs. 37.7%, p = 0.01). This negative association was confirmed by multivariable analysis. Higher mean steroid doses were observed among non-responders, and cumulative doses were inversely correlated with the disease control rate (DCR) around ICI initiation. Remarkably, poorer outcomes were observed even in patients belonging to the lowest dose quartile compared to the steroid-naïve population. The exposure to steroids after 6 months of ICI was not associated with worse survival outcomes. Our results suggest that the potential impact of steroids on ICI efficacy may be time-dependent, prevailing around ICI initiation, and dose-dependent, with modulation of neutrophil-to-lymphocyte ratio as a possible underlying mechanism.

Chordoma is a rare bone tumor that frequently recurs after surgery, and the prognosis is poor with current treatments. This study aimed to identify potential novel immunotherapeutic targets for chordomas by identifying target proteins in clinical samples as well as tumor microenvironmental factors to enhance efficacy. Fourteen chordoma samples were analyzed by single-cell RNA sequencing, and B7-H3 and IL-7 were identified as potential targets and potentiators, respectively. B7-H3-targeted chimeric antigen receptor T (CAR-T) cells and B7-H3 CAR-T cells expressing IL-7 were synthesized and their anti-tumor activity evaluated in vitro, including in primary chordoma organoid models. The B7-H3 CAR-T/IL-7 therapy showed enhanced cytotoxicity and prolonged duration of action against tumor cells. Additionally, IL-7 modulated favorable subpopulations of cultured CAR-T cells, diminished immune checkpoint expression on T-cell surfaces, and enhanced T-cell functionality. The incorporation of IL-7 molecules into the B7-H3 CAR structure augmented CAR-T-cell function and improved CAR-T-cell efficacy, thus providing a novel dual therapeutic strategy for chordoma treatment.