Cancer Immunology, Immunotherapy最新文献

Background: Tumor-reactive T cells play a crucial role in anti-tumor responses, but T cells induced by DNA vaccination are time-consuming processes and exhibit limited anti-tumor efficacy. Therefore, we evaluated the anti-tumor effectiveness of reactive T cells elicited by electroporation (EP)-mediated DNA vaccine targeting epidermal growth factor receptor variant III (pEGFRvIII plasmid), in conjunction with adoptive cell therapy (ACT), involving the transfer of lymphocytes from a pEGFRvIII EP-vaccinated healthy donor.

Methods: The validation of the established pEGFRvIII plasmid and EGFRvIII-positive cell model was confirmed through immunofluorescence and western blot analysis. Flow cytometry and cytotoxicity assays were performed to evaluate the functionality of antigen-specific reactive T cells induced by EP-mediated pEGFRvIII vaccines, ACT, or their combination. The anti-tumor effectiveness of EP-mediated pEGFRvIII vaccines alone or combined with ACT was evaluated in the B16F10-EGFRvIII tumor model.

Results: EP-mediated pEGFRvIII vaccines elicited serum antibodies and a robust cellular immune response in both healthy and tumor-bearing mice. However, this response only marginally inhibited early-stage tumor growth in established tumor models. EP-mediated pEGFRvIII vaccination followed by adoptive transfer of lymphocytes from vaccinated healthy donors led to notable anti-tumor efficacy, attributed to the synergistic action of antigen-specific CD4⁺ Th1 cells supplemented by ACT and antigen-specific CD8⁺ T cells elicited by the EP-mediated DNA vaccination.

Conclusions: Our preclinical studies results demonstrate an enhanced anti-tumor efficacy of EP-mediated DNA vaccination boosted with adoptively transferred, vaccinated healthy donor-derived allogeneic lymphocytes.

Introduction: This study assesses the effectiveness of durvalumab with platinum and gemcitabine for biliary tract cancers (BTC). It aims to confirm the TOPAZ-1 trial results in a real-world context and explore the link between BTC molecular profiles and patient outcomes.

Methods: A retrospective analysis was conducted on 102 BTC patients treated with durvalumab, platinum, and gemcitabine at five cancer centers in Austria and one in Germany from 2022 to 2024. Molecular profiling used targeted DNA and RNA assays. Clinical endpoints, including progression-free survival (PFS) and overall survival (OS), were assessed using log-rank tests and Cox regression, with correlations to second-line molecular-targeted therapies.

Results: Among 102 patients, 60.8% had intrahepatic cholangiocarcinoma. The treatment achieved a disease control rate of 71.57% and an overall response rate of 35.11%. Median PFS was 6.51 months, and OS was 13.61 months. Patients under 65 had significantly better OS. Alterations in chromatin remodeling or homologous recombination repair genes were not predictive of survival benefit (HR: 0.45; p = 0.851 and HR: 1.63; p = 0.26, respectively). Patients with molecular-informed second-line therapy showed a trend toward survival benefit (HR: 0.23; p = 0.052).

Conclusion: This study confirms the phase 3 trial results of durvalumab with platinum and gemcitabine, providing a substantial real-world dataset with detailed molecular characterization. No specific patient subgroup showed a markedly better response to durvalumab based on conventional NGS panels. Further research is needed to explore the link between immunotherapy responses and molecular subgroups.

The hemagglutinating virus of Japan envelope (HVJ-E) is an inactivated Sendai virus particle with antitumor effect and inducing antitumor immunity. However, its dosage and efficacy have not been verified. We conducted a phase I clinical study on chemotherapy-resistant malignant pleural mesothelioma (MPM) aiming to determine the recommended dosage for a phase II study through dose-limiting toxicity and evaluate HVJ-E's preliminary efficacy. HVJ-E was administered intratumorally and subcutaneously to the patients with chemotherapy-resistant MPM. While no serious adverse events occurred, known adverse events of HVJ-E were observed. In the preliminary antitumor efficacy using modified response evaluation criteria in solid tumors (RECIST) criteria, three low-dose patients exhibited progressive disease, while all high-dose patients achieved stable disease, yielding disease control rates (DCRs) of 0% and 100%, respectively. Furthermore, the dose-dependent effect of HVJ-E revealed on DCR modified by RECIST and the baseline changes in target lesion size (by CT and SUL-peak; p < 0.05). Comparing targeted lesions receiving intratumoral HVJ-E with non-injected ones, while no clear difference existed at the end of the study, follow-up cases suggested stronger antitumor effects with intratumoral administration. Our findings suggest that HVJ-E could be safely administered to patients with chemotherapy-resistant MPM at both study doses. HVJ-E exhibited some antitumor activity against chemotherapy-resistant MPM, and higher doses tended to have stronger antitumor effects than lower doses. Consequently, a phase II clinical trial with higher HVJ-E doses has been conducted for MPM treatment. Trial registration number: UMIN Clinical Trials Registry (#UMIN000019345).

Natural killer (NK) cells are frontline defenders against cancer and are capable of recognizing and eliminating tumor cells without prior sensitization or antigen presentation. Due to their unique HLA mismatch tolerance, they are ideal for adoptive cell therapy (ACT) because of their ability to minimize graft-versus-host-disease risk. The therapeutic efficacy of NK cells is limited in part by inhibitory immune checkpoint receptors, which are upregulated upon interaction with cancer cells and the tumor microenvironment. Overexpression of inhibitory receptors reduces NK cell-mediated cytotoxicity by impairing the ability of NK cells to secrete effector cytokines and cytotoxic granules. T-cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT), a well-known checkpoint receptor involved in T-cell exhaustion, has recently been implicated in the exhaustion of NK cells. Overcoming TIGIT-mediated inhibition of NK cells may allow for a more potent antitumor response following ACT. Here, we describe a novel approach to TIGIT inhibition using self-delivering RNAi compounds (INTASYL™) that incorporates the features of RNAi and antisense technology. INTASYL compounds demonstrate potent activity and stability, are rapidly and efficiently taken up by cells, and can be easily incorporated into cell product manufacturing. INTASYL PH-804, which targets TIGIT, suppresses TIGIT mRNA and protein expression in NK cells, resulting in increased cytotoxic capacity and enhanced tumor cell killing in vitro. Delivering PH-804 to NK cells before ACT has emerged as a promising strategy to counter TIGIT inhibition, thereby improving the antitumor response. This approach offers the potential for more potent off-the-shelf products for adoptive cell therapy, particularly for hematological malignancies.

Human lung cancer carries high genetic alterations, expressing high tumor-specific neoantigens. Although orthotopic murine lung cancer models recapitulate many characteristics of human lung cancers, genetically engineered mouse models have fewer somatic mutations than human lung cancer, resulting in scarce immune cell infiltration and deficient immune responses. The endogenous mouse lung cancer model driven by Kras mutation and Trp53 deletion (KP model) has minimal immune infiltration because of a scarcity of neoantigens. Fine-tuning tumor antigenicity to trigger the appropriate level of antitumor immunity would be key to investigating immune responses against human lung cancer. We engineered the KP model to express antigens of OVA peptides (minOVA) as neoantigens along with ZsGreen, a traceable fluorescent conjugate. The KP model expressing minOVA exhibited stronger immunogenicity with higher immune cell infiltration comprised of CD8⁺ T cells and CD11c⁺ dendritic cells (DCs). Consequently, the KP model expressing minOVA exhibits suppressed tumor growth compared to its origin. We further analyzed tumor-infiltrated DCs. The majority of ZsGreen conjugated with minOVA was observed in the conventional type 2 DCs (cDC2), whereas cDC1 has minimal. These data indicate that tumor immunogenicity regulates host immune responses, and tumor neoantigen is mostly recognized by cDC2 cells, which may play a critical role in initiating antitumor immune responses in an orthotopic murine lung cancer model.

Patients with relapsed/refractory (r/r) diffuse large B-cell lymphoma (DLBCL) show varied responses to PD-1 monoclonal antibody (mAb) containing regimens. The mechanisms and predictive biomarkers for the efficacy of this regimen are unclear. This study retrospectively collected r/r DLBCL patients who received PD-1 mAb and rituximab regimens as salvage therapy. Clinical and genomic features were collected, and mechanisms were explored by multiplex immunofluorescence and digital spatial profiling. An artificial neural network (ANN) model was constructed to predict the response. Between October 16th, 2018 and May 4th, 2023, 50 r/r DLBCL patients were collected, 29 were response patients and 21 were non-response patients. CREBBP (p = 0.029) and TP53 (p = 0.015) alterations were statistically higher in non-response patients. Patients with PD-L1 CPS ≥ 5 were correlated with a longer overall survival (OS) than those with PD-L1 CPS < 5 (median OS: not reached vs. 9.7 months, hazard ratio [HR]: 3.8, 95% confidence interval [CI] 0.64-22.44, p = 0.016). Immune-related pathways were activated in response patients. The proportion and spatial organization of tumor-infiltrating immune cells affect the response. PD-L1 CPS level, age, and alterations of TP53, MYD88, CREBBP, EP300, GNA13 were used to build an ANN predictive model that showed high prediction efficiency (training set area under curve [AUC] of 0.97 and test set AUC of 0.94). The proportion and spatial distribution of tumor-infiltrating immune cells may be related to the function of immune-related pathways, thereby influencing the efficacy of PD-1 mAb containing regimens. The ANN predictive model showed potential value in predicting the responses of r/r DLBCL patients received PD-1 mAb and rituximab regimens.

The biotechnological development of monoclonal antibodies and their immunotherapeutic use in oncology have grown exponentially in the last decade, becoming the first-line therapy for some types of cancer. Their mechanism of action is based on the ability to regulate the immune system or by interacting with targets that are either overexpressed in tumor cells, released into the extracellular milieu or involved in processes that favor tumor growth. In addition, the intrinsic characteristics of each subclass of antibodies provide specific effector functions against the tumor by activating antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity, and antibody-dependent cellular phagocytosis, among other mechanisms. The rational design and engineering of monoclonal antibodies have improved their pharmacokinetic and pharmacodynamic features, thus optimizing the therapeutic regimens administered to cancer patients and improving their clinical outcomes. The selection of the immunoglobulin G subclass, modifications to its crystallizable region (Fc), and conjugation of radioactive substances or antineoplastic drugs may all improve the antitumor effects of therapeutic antibodies. This review aims to provide insights into the immunological and pharmacological aspects of therapeutic antibodies used in oncology, with a rational approach at molecular modifications that can be introduced into these biological tools, improving their efficacy in the treatment of cancer.

Neoantigen vaccines represent an emerging and promising strategy in the field of tumor immunotherapy. Despite their potential, designing an effective neoantigen vaccine remains a challenge due to the current limitations in predicting CD4⁺ T cell epitopes with high accuracy. Here, we introduce a novel approach to neoantigen vaccine design that does not rely on computational prediction of CD4⁺ T cell epitopes. Utilizing nitrated helper T cell epitope containing p-nitrophenylalanine, termed "NitraTh epitope," we have successfully engineered a series of tumor neoantigen vaccines capable of eliciting robust neoantigen-specific immune responses. With the help of NitraTh epitope, even mutations with low predicted affinity for MHC class I molecules were successfully induced to elicit neoantigen-specific responses. In H22 cell allograft and patient-derived xenograft (PDX) liver cancer mouse models, the NitraTh epitope-based neoantigen vaccines significantly suppressed tumor progression. More strikingly, through single-cell sequencing we found that the NitraTh epitope-based neoantigen vaccines regulate macrophage reprogramming and modulate macrophages to decrease the levels of the immunosuppressive molecule prostaglandin E2 (PGE2), which in turn reshapes the tumor immunosuppressive microenvironment. In summary, NitraTh epitope-based neoantigen vaccines possess the dual effects of potently activating neoantigen-specific immunity and alleviating immunosuppression, potentially providing a new paradigm for the design of tumor neoantigen vaccines.

Recent advances in cancer immunotherapy, particularly the success of immune checkpoint inhibitors, have reignited interest in targeted monoclonal antibodies for immunotherapy. Antibody therapies aim to minimize on-target, off-tumor toxicity by targeting antigens overexpressed on tumor cells but not on healthy cells. Despite considerable efforts, some therapeutic antibodies have been linked to dose-limiting side effects. Our hypothesis suggests that the efficacy of IgG leads to a lower target expression threshold for tumor cell killing, contributing to these side effects. Earlier, therapeutic IgG antibodies were reformatted into the IgA isotype. Unlike IgG, which primarily engages Fc gamma receptors (FcγR) to induce antibody-dependent cellular cytotoxicity (ADCC) by NK cells and antibody-dependent cellular phagocytosis (ADCP) by monocytes/macrophages, IgA antibodies activate neutrophils through the Fc alpha receptor I (CD89, FcαRI). In previous studies, it appeared that IgA may require a higher target expression threshold for effective killing, and we aimed to investigate this in our current study. Moreover, we investigated how blocking the myeloid checkpoint CD47/SIRPα axis affect the target expression threshold. Using a tetracycline-inducible expression system, we regulated target expression in different cell lines. Our findings from ADCC assays indicate that IgA-mediated PMN ADCC requires a higher antigen expression level than IgG-mediated PBMC ADCC. Furthermore, blocking CD47 enhanced IgA-mediated ADCC, lowering the antigen threshold. Validated in two in vivo models, our results show that IgA significantly reduces tumor growth in high-antigen-expressing tumors without affecting low-antigen-expressing healthy tissues. This suggests IgA-based immunotherapy could potentially minimize on-target, off-tumor side effects, improving treatment efficacy and patient safety.