Functional co-delivery nanoliposomes based on improving hypoxia for increasing photoimmunotherapy efficacy of cold tumors.

Cold tumors lack T cells infiltration and have low immunogenicity, resulting insufficient immunotherapy response. Therefore, how to realize the transformation from cold tumor to hot tumor is an urgent problem to be solved. Photodynamic therapy can induce immunogenic death of tumor cells (ICD) and activate T lymphocytes to produce tumor immune response. However, hypoxia in the cold tumor microenvironment limits the effectiveness of photodynamic therapy. So in this article, MET-HMME/CAT-HMME@Nlip as a functional co-delivery nanoliposomes was constructed based on overcoming the above problems. Firstly, the oxygen-deficient state could be improved by the following two ways, one is catalase loaded in CAT-HMME@Nlip can decompose high concentration hydrogen peroxide to produce oxygen, and the other is metformin loaded in MET-HMME@Nlip can decrease oxygen consumption by inhibiting of mitochondrial respiration. And then with the increase of substrate oxygen concentration, the sensitivity of photodynamic therapy can be greatly improved and the anti-tumor immune response by PDT-induced ICD can also be enhanced obviously. In addition, metformin could act as a small molecule immune checkpoint inhibitor to reduce the expression of PD-L1 on the surface of tumor cells, thereby effectively improving the specific killing ability of cytotoxic T cells to tumor cells which could not only erasing the primary tumor, but also inhibiting the growth of simulated distant tumors through the immune memory function. This study provides a new idea for improving the clinical treatment effect of hypoxic cold tumors, especially for tumors that could not benefit from immunotherapy due to low or no expression of PD-L1 protein on the surface of tumor cells.

Human/mouse CD137 agonist, JNU-0921, effectively shrinks tumors through enhancing the cytotoxicity of CD8+ T cells in cis and in trans.

Agonistic antibodies against CD137 have been demonstrated to completely regress established tumors through activating T cell immunity. Unfortunately, current CD137 antibodies failed to benefit patients with cancer. Moreover, their antitumor mechanisms in vivo remain to be determined. Here, we report the development of a small molecular CD137 agonist, JNU-0921. JNU-0921 effectively activates both human and mouse CD137 through direct binding their extracellular domains to induce oligomerization and signaling and effectively shrinks tumors in vivo. Mechanistically, JNU-0921 enhances effector and memory function of cytotoxic CD8+ T cells (CTLs) and alleviates their exhaustion. JNU-0921 also skews polarization of helper T cells toward T helper 1 type and enhances their activity to boost CTL function. Meanwhile, JNU-0921 attenuates the inhibitory function of regulatory T cells on CTLs. Our current work shows that JNU-0921 shrinks tumors by enhancing the cytotoxicity of CTLs in cis and in trans and sheds light on strategy for developing CD137 small molecular agonists.

LSD1 inhibition improves efficacy of adoptive T cell therapy by enhancing CD8+ T cell responsiveness.

The lysine-specific histone demethylase 1 A (LSD1) is involved in antitumor immunity; however, its role in shaping CD8 + T cell (CTL) differentiation and function remains largely unexplored. Here, we show that pharmacological inhibition of LSD1 (LSD1i) in CTL in the context of adoptive T cell therapy (ACT) elicits phenotypic and functional alterations, resulting in a robust antitumor immunity in preclinical models in female mice. In addition, the combination of anti-PDL1 treatment with LSD1i-based ACT eradicates the tumor and leads to long-lasting tumor-free survival in a melanoma model, complementing the limited efficacy of the immune or epigenetic therapy alone. Collectively, these results demonstrate that LSD1 modulation improves antitumoral responses generated by ACT and anti-PDL1 therapy, providing the foundation for their clinical evaluation.

Cytotoxic T cells drive doxorubicin-induced cardiac fibrosis and systolic dysfunction.

Doxorubicin, the most prescribed chemotherapeutic drug, causes dose-dependent cardiotoxicity and heart failure. However, our understanding of the immune response elicited by doxorubicin is limited. Here we show that an aberrant CD8+ T cell immune response following doxorubicin-induced cardiac injury drives adverse remodeling and cardiomyopathy. Doxorubicin treatment in non-tumor-bearing mice increased circulating and cardiac IFNγ+CD8+ T cells and activated effector CD8+ T cells in lymphoid tissues. Moreover, doxorubicin promoted cardiac CD8+ T cell infiltration and depletion of CD8+ T cells in doxorubicin-treated mice decreased cardiac fibrosis and improved systolic function. Doxorubicin treatment induced ICAM-1 expression by cardiac fibroblasts resulting in enhanced CD8+ T cell adhesion and transformation, contact-dependent CD8+ degranulation and release of granzyme B. Canine lymphoma patients and human patients with hematopoietic malignancies showed increased circulating CD8+ T cells after doxorubicin treatment. In human cancer patients, T cells expressed IFNγ and CXCR3, and plasma levels of the CXCR3 ligands CXCL9 and CXCL10 correlated with decreased systolic function.

ALK5/VEGFR2 dual inhibitor TU2218 alone or in combination with immune checkpoint inhibitors enhances immune-mediated antitumor effects.

Transforming growth factor ß (TGFß) 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 TGFß/VEGF is more effective than targeting TGFß 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 TGFß 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 TGFß 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.

Multi-modal Ca2+ nanogenerator via reversing T cell exhaustion for enhanced chemo-immunotherapy.

Chemo-immunotherapy holds the advantage of specific antitumor effects by activating cytotoxic lymphocyte cells (CTLs) immune response. However, multiple barriers have limited the outcomes partly due to tumor-cell-mediated exhaustion of CTLs in the immunosuppressive tumor microenvironment (iTME). Here, we rationally designed a simple-yet-versatile Ca2+ nanogenerator to modulate iTME for enhancing 2-deoxyglucose (2-DG) mediated chemo-immunotherapy. Briefly, after 2-DG chemotherapy, CaO2 nanoparticles coated with EL4 cell membrane (denoted as CaNP@ECM) could preferentially accumulate in tumor tissue via adhesion between LFA-1 on EL4 cell membrane and ICAM-1 on inflamed endothelial cell in tumor tissues and display a series of benefits for CTLs: i) Increasing glucose availability of CTLs while reducing lactic acid secretion through Ca2+ overloading mediated inhibition of tumor cell glycolysis, as well as relieving hypoxia; ii) Reversing CTLs exhaustion via TGF-ß1 scavenging and PD-L1 blockade through PD-1 and TGF-ß1R on EL4 cell membrane; iii) Boosting tumor immunotherapy via immunologic death (ICD) of tumor cells induced by Ca2+ overloading. We demonstrate that the multi-modal Ca2+ nanogenerator rescues T cells from exhaustion and inhibits tumor growth both in vitro and in vivo. More importantly, the study also facilitate the development of glucose metabolism inhibition-based tumor immunotherapy via Ca2+ overloading.

Photodynamic Therapy Synergizes CD47 Blockade Strategy for Enhanced Antitumor Therapy.

The antitumor strategies based on innate immunity activation have become favored by researchers in recent years. In particular, strategies targeting antiphagocytic signaling blockade to enhance phagocytosis have been widely reported. For example, the addition of prophagocytic signals such as calreticulin could make the strategy significantly more effective. In this study, an antitumor strategy that combines photodynamic therapy (PDT) with CD47 blockade has been reported. This approach promotes the maturation of dendritic cells and the presentation of tumor antigens by PDT-mediated tumor immunogenic cell death, as well as the enhancement of cytotoxic T lymphocyte infiltration in tumor areas and the phagocytic activity of phagocytes. Furthermore, the downregulation and blockage of CD47 protein could further promote phagocytic activity, strengthen the innate immune system, and ultimately elevate the antitumor efficacy and inhibit tumor metastasis.

Ultra-pH-sensitive nanoparticle of gambogenic acid for tumor targeting therapy via anti-vascular strategy plus immunotherapy.

Although the combination of anti-vascular strategy plus immunotherapy has emerged as the optimal first-line treatment of hepatocellular carcinoma, lack of tumor targeting leads to low antitumor efficacy and serious side effect. Here, we report an ultra-pH-sensitive nanoparticle of gambogenic acid (GNA) encapsulated by poly(ethylene glycol)-poly(2-azepane ethyl methacrylate) (PEG-PAEMA) for tumor-targeting combined therapy of anti-vascular strategy plus immunotherapy. PEG-PAEMA-GNA nanoparticle was quite stable at pH 7.4 for 30 d. In contrast, it exerted size shrinkage, charge reversal and the release of GNA at pH 6.7 within 24 h. Moreover, PEG-PAEMA-GNA significantly enhanced the anti-vascular activity, membrane-disruptive capability and pro-apoptosis when pH changed from 7.4 to 6.7. Western blot analysis exhibits that PEG-PAEMA and its GNA nanoparticle facilitated the phosphorylation of STING protein. In vivo assays show that PEG-PAEMA-GNA not only displayed much higher tumor inhibition of 92 % than 37 % of free GNA, but also inhibited tumor vasculature, promoted the maturation of dendritic cells and recruited more cytotoxic t-lymphocytes for sufficient anti-vascular therapy and immunotherapy. All these results demonstrate that PEG-PAEMA-GNA displayed tumor-targeting combined treatment of anti-vascular therapy and immunotherapy. This study offers a simple and novel method for the combination of anti-vascular therapy and immunotherapy with high selectivity towards tumor.

Chemotherapy-induced high expression of IL23A enhances efficacy of anti-PD-1 therapy in TNBC by co-activating the PI3K-AKT signaling pathway of CTLs.

Treatment of advanced triple-negative breast cancer (TNBC) is a great challenge in clinical practice. The immune checkpoints are a category of immunosuppressive molecules that cancer could hijack and impede anti-tumor immunity. Targeting immune checkpoints, such as anti-programmed cell death 1 (PD-1) therapy, is a promising therapeutic strategy in TNBC. The efficacy and safety of PD-1 monoclonal antibody (mAb) with chemotherapy have been validated in TNBC patients. However, the precise mechanisms underlying the synergistic effect of chemotherapy and anti-PD-1 therapy have not been elucidated, causing the TNBC patients that might benefit from this combination regimen not to be well selected. In the present work, we found that IL-23, an immunological cytokine, is significantly upregulated after chemotherapy in TNBC cells and plays a vital role in enhancing the anti-tumor immune response of cytotoxic T cells (CTLs), especially in combination with PD-1 mAb. In addition, the combination of IL-23 and PD-1 mAb could synergistically inhibit the expression of Phosphoinositide-3-Kinase Regulatory Subunit 1 (PIK3R1), which is a regulatory subunit of PI3K and inhibit p110 activity, and promote phosphorylation of AKT in TNBC-specific CTLs. Our findings might provide a molecular marker that could be used to predict the effects of combination chemotherapy therapy and PD-1 mAb in TNBC.

Nucleotide metabolism in cancer cells fuels a UDP-driven macrophage cross-talk, promoting immunosuppression and immunotherapy resistance.

Many individuals with cancer are resistant to immunotherapies. Here, we identify the gene encoding the pyrimidine salvage pathway enzyme cytidine deaminase (CDA) among the top upregulated metabolic genes in several immunotherapy-resistant tumors. We show that CDA in cancer cells contributes to the uridine diphosphate (UDP) pool. Extracellular UDP hijacks immunosuppressive tumor-associated macrophages (TAMs) through its receptor P2Y6. Pharmacologic or genetic inhibition of CDA in cancer cells (or P2Y6 in TAMs) disrupts TAM-mediated immunosuppression, promoting cytotoxic T cell entry and susceptibility to anti-programmed cell death protein 1 (anti-PD-1) treatment in resistant pancreatic ductal adenocarcinoma (PDAC) and melanoma models. Conversely, CDA overexpression in CDA-depleted PDACs or anti-PD-1-responsive colorectal tumors or systemic UDP administration (re)establishes resistance. In individuals with PDAC, high CDA levels in cancer cells correlate with increased TAMs, lower cytotoxic T cells and possibly anti-PD-1 resistance. In a pan-cancer single-cell atlas, CDAhigh cancer cells match with T cell cytotoxicity dysfunction and P2RY6high TAMs. Overall, we suggest CDA and P2Y6 as potential targets for cancer immunotherapy.

A dual-enzyme-like photosensitive nanozyme for remodeling the tumor immunosuppressive microenvironment to enhance immunotherapy.

In "immune-cold" tumors, the upregulation of immunosuppressive cells and insufficient infiltration of lymphocytes contribute to the resistance against immune therapy. Herein, we have developed a dual-enzyme-like photosensitive nanozyme (PBAF) to remodel the tumor immunosuppressive microenvironment (TIME) and induce the tumor infiltration of cytotoxic T lymphocytes (CTLs). Specifically, PBAF exhibits peroxidase (POD)-like activity and glutathione oxidase (GSHOx)-like activity and can be stimulated by 750 nm laser, promoting oxidative stress at the tumor site. Consequently, this process further leads to the reconstruction of TIME in animal experiments, inducing tumor-associated macrophages (TAMs) toward the immunostimulatory M1 phenotype, eliminating myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs). Simultaneously, PBAF also promotes dendritic cells (DCs) maturation to enhance CTLs infiltration into the tumor. The remodeled TIME and enhanced immune responses by PBAF demonstrate significant post-administration inhibition of recurrence and metastasis in the treatment of malignant tumors.

Biosynthetic MnSe nanobomb with low Mn content activates the cGAS-STING pathway and induces immunogenic cell death to enhance antitumour immunity.

Triple-negative breast cancer (TNBC) is a relatively "cold" tumour with low immunogenicity compared to other tumour types. Especially, the immune checkpoint inhibitors to treat metastatic TNBC only shows the modest immune response rates. Here, we used Chlorella vulgaris as a bioreactor to synthesize an efficient nanobomb (Bio-MnSe) aimed at eliciting systemic anti-tumour immune response. Despite possessing extremely low Mn content, Bio-MnSe effectively produced more ROS and activated stronger cGAS-STING signal pathway compared to pure Se nanoparticles and free Mn2+ ions, promoting the infiltration of natural killer (NK) cells, cytotoxic T lymphocytes (CTLs) in tumour, effectively turning "cold" tumour into "hot" tumour, and achieving strong antitumour immunotherapy. Additionally, the use of αPD-L1 as an immune checkpoint antagonist further increased the anti-tumour immune response of Bio-MnSe, resulting in enhanced anti-tumour effects. Doxorubicin (Dox), an immunogenic cell death (ICD) inducer, was combined with Bio-MnSe to form Bio-MnSe@Dox. This Bio-MnSe@Dox not only directly damaged tumour cells and induced tumour ICD but also promoted dendritic cell maturation, cytotoxic T lymphocyte infiltration, and NK cell recruitment, synergistically intensifying anti-tumour immune responses and suppressing tumour relapse and lung metastasis. Collectively, our findings propose an effective strategy for transforming 'cold' tumours to 'hot' ones, thereby advancing the development of anti-tumour immune drugs. STATEMENT OF SIGNIFICANCE: A biogenic MnSe (Bio-MnSe) nanocomposite was synthesized using Chlorella vulgaris as a bioreactor for enhanced immunotherapy of TNBC. Bio-MnSe demonstrated a stronger ability to activate the cGAS-STING signalling pathway and generate more ROS compared to pure Se nanoparticles and free Mn2+ ions. Apoptotic cells induced by Bio-MnSe released a significant amount of interferon, leading to the activation of T and natural killer (NK) cells, ultimately transforming immunologically 'cold' breast tumours to 'hot' tumours and enhancing the tumour's response to immune checkpoint inhibitors. The combination of Bio-MnSe with Dox or αPD-L1 further enhanced the anti-tumour immune response, fostering dendritic cell maturation, infiltration of cytotoxic T lymphocytes, and recruitment of NK cells, thereby enhancing the anti-tumour immunotherapy of TNBC.

Adjuvant COX inhibition augments STING signaling and cytolytic T cell infiltration in irradiated 4T1 tumors.

Immune therapy is the new frontier of cancer treatment. Therapeutic radiation is a known inducer of immune response and can be limited by immunosuppressive mediators including cyclooxygenase-2 (COX2) that is highly expressed in aggressive triple negative breast cancer (TNBC). A clinical cohort of TNBC tumors revealed poor radiation therapeutic efficacy in tumors expressing high COX2. Herein, we show that radiation combined with adjuvant NSAID (indomethacin) treatment provides a powerful combination to reduce both primary tumor growth and lung metastasis in aggressive 4T1 TNBC tumors, which occurs in part through increased antitumor immune response. Spatial immunological changes including augmented lymphoid infiltration into the tumor epithelium and locally increased cGAS/STING1 and type I IFN gene expression were observed in radiation-indomethacin-treated 4T1 tumors. Thus, radiation and adjuvant NSAID treatment shifts "immune desert phenotypes" toward antitumor M1/TH1 immune mediators in these immunologically challenging tumors. Importantly, radiation-indomethacin combination treatment improved local control of the primary lesion, reduced metastatic burden, and increased median survival when compared with radiation treatment alone. These results show that clinically available NSAIDs can improve radiation therapeutic efficacy through increased antitumor immune response and augmented local generation of cGAS/STING1 and type I IFNs.

Dynamics of pulmonary mucosal cytotoxic CD8 T-cells in people living with HIV under suppressive antiretroviral therapy.

BACKGROUND: Despite the success of antiretroviral therapy (ART), people living with HIV (PLWH) suffer from a high burden of pulmonary diseases, even after accounting for their smoking status. Cytotoxic CD8 T-cells are likely implicated in this phenomenon and may act as a double-edged sword. While being essential in viral infection control, their hyperactivation can also contribute to lung mucosal tissue damage. The effects of HIV and smoking on pulmonary mucosal CD8 T-cell dynamics has been a neglected area of research, which we address herein. METHODS: Bronchoalveolar lavage (BAL) fluid were obtained from ART-treated PLWH (median duration of supressed viral load: 9 years; smokers: n = 14; non-smokers: n = 21) and HIV-uninfected controls (smokers: n = 11; non-smokers: n = 20) without any respiratory symptoms or active infection. Lymphocytes were isolated and CD8 T-cell subsets and homing markers were characterized by multiparametric flow cytometry. RESULTS: Both smoking and HIV infection were independently associated with a significant increase in frequencies of total pulmonary mucosal CD8 T-cell. BAL CD8 T-cells were primarily CD69 + expressing CD103 and/or CD49a, at least one of the two granzymes (GzmA/GzmB), and little Perforin. Higher expression levels of CD103, CD69, and GzmB were observed in smokers versus non-smokers. The ex vivo phenotype of GzmA + and GzmB + cells revealed increased expression of CD103 and CXCR6 in smokers, while PLWH displayed elevated levels of CX3CR1 compared to controls. CONCLUSION: Smoking and HIV could promote cytotoxic CD8 T-cell retention in small airways through different mechanisms. Smoking likely increases recruitment and retention of GzmB + CD8 Trm via CXCR6 and CD103. Heightened CX3CR1 expression could be associated with CD8 non-Trm recruitment from the periphery in PLWH.

Turning Waste into Wealth: A Potent Sono-Immune Strategy Based on Microcystis.

Currently, sonodynamic therapy (SDT) has limited therapeutic outcomes and immune responses, highlighting the urgent need for enhanced strategies that can stimulate robust and long-lasting antitumor effects. Microcystis, a notorious microalga, reveals the possibility of mediating SDT owing to the presence of gas vesicles (GVs) and phycocyanin (PC). Herein, a nontoxic strain of Microcystis elabens (labeled Me) is developed as a novel agent for SDT because it generates O2 under red light (RL) illumination, while GVs and PC act as cavitation nuclei and sonosensitizers, respectively. Moreover, algal debris is released after ultrasound (US) irradiation, which primes the Toll-like receptor pathway to initiate a cascade of immune responses. This sono-immune strategy inhibits CT26 colon tumor growth largely by promoting dendritic cell (DC) maturation and cytotoxic T-cell activation. After combination with the immune checkpoint blockade (ICB), the therapeutic outcome is further amplified, accompanied by satisfactory abscopal and immune memory effects; the similar potency is proven in the "cold" 4T1 triple-negative breast tumor. In addition, Me exhibits good biosafety without significant acute or chronic toxicity. Briefly, this study turns waste into wealth by introducing sono-immunotherapy based on Microcystis that achieved encouraging therapeutic effects on cancer, which is expected to be translated into the clinic.

Activating Iterative Revolutions of the Cancer-Immunity Cycle in Hypoxic Tumors with a Smart Nano-Regulator.

The activation of sequential events in the cancer-immunity cycle (CIC) is crucial for achieving effective antitumor immunity. However, formidable challenges, such as innate and adaptive immune resistance, along with the off-target adverse effects of nonselective immunomodulators, persist. In this study, a tumor-selective nano-regulator named PNBJQ has been presented, focusing on targeting two nonredundant immune nodes: inducing immunogenic cancer cell death and abrogating immune resistance to fully activate endogenous tumor immunity. PNBJQ is obtained by encapsulating the immunomodulating agent JQ1 within a self-assembling system formed by linking a Type-I photosensitizer to polyethylene glycol through a hypoxia-sensitive azo bond. Benefiting from the Type-I photosensitive mechanism, PNBJQ triggers the immunogenic cell death of hypoxic tumors under near-infrared (NIR) light irradiation. This process resolves innate immune resistance by stimulating sufficient cytotoxic T-lymphocytes. Simultaneously, PNBJQ smartly responds to the hypoxic tumor microenvironment for precise drug delivery, adeptly addressing adaptive immune resistance by using JQ1 to downregulate programmed death ligand 1 (PD-L1) and sustaining the response of cytotoxic T lymphocytes. The activatable synergic photoimmunotherapy promotes an immune-promoting tumor microenvironment by activating an iterative revolution of the CIC, which remarkably eradicates established hypoxic tumors and suppresses distal lesions under low light dose irradiation.

Polydopamine nanoparticles cross-linked hyaluronic acid photothermal hydrogel with cascading immunoinducible effects for in situ antitumor vaccination.

Tumor vaccine, which can effectively prevent tumor recurrence and metastasis, is a promising tool in tumor immunotherapy. However, heterogeneity of tumors and the inability to achieve a cascade effect limit the therapeutic effects of most developing tumor vaccine. We have developed a cascading immunoinducible in-situ mannose-functionalized polydopamine loaded with imiquimod phenylboronic hyaluronic acid nanocomposite gel vaccine (M/P-PDA@IQ PHA) through a boronic ester-based reaction. This reaction utilizes mannose-functionalized polydopamine loaded with imiquimod (M/P-PDA@IQ NAs) as a cross-linking agent to react with phenylboronic-grafted hyaluronic acid. Under near-infrared light irradiation, the M/P-PDA@IQ PHA caused local hyperthermia to trigger immunogenic cell death of tumor cells and tumor-associated antigens (TAAs) releasing. Subsequently, the M/P-PDA@IQ NAs which were gradually released by the pH/ROS/GSH-triggered degradation of M/P-PDA@IQ PHA, could capture and deliver these TAAs to lymph nodes. Finally, the M/P-PDA@IQ NAs facilitated maturation and cross-presentation of dendritic cells, as well as activation of cytotoxic T lymphocytes. Overall, the M/P-PDA@IQ PHA could serve as a novel in situ vaccine to stimulate several key nodes including TAAs release and capture, targeting lymph nodes and enhanced dendritic cells uptake and maturation as well as T cells activation. This cascading immune activation strategy can effectively elicit antitumor immune response.

Ocrelizumab Alters Cytotoxic Lymphocyte Function While Reducing EBV-Specific CD8+ T-Cell Proliferation in Patients With Multiple Sclerosis.

BACKGROUND AND OBJECTIVES: The role of B cells in the pathogenic events leading to relapsing multiple sclerosis (R-MS) has only been recently elucidated. A pivotal step in defining this role has been provided by therapeutic efficacy of anti-CD20 monoclonal antibodies. Indeed, treatment with anti-CD20 can also alter number and function of other immune cells not directly expressing CD20 on their cell surface, whose activities can contribute to unknown aspects influencing therapeutic efficacy. We examined the phenotype and function of cytotoxic lymphocytes and Epstein-Barr virus (EBV)-specific immune responses in people with R-MS before and after ocrelizumab treatment. METHODS: In this prospective study, we collected blood samples from people with R-MS (n = 41) before and 6 and 12 months after initiating ocrelizumab to assess the immune phenotype and the indirect impact on cytotoxic functions of CD8+ T and NK cells. In addition, we evaluated the specific anti-EBV proliferative responses of both CD8+ T and NK lymphocytes as surrogate markers of anti-EBV activity. RESULTS: We observed that while ocrelizumab depleted circulating B cells, it also reduced the expression of activation and migratory markers on both CD8+ T and NK cells as well as their in vitro cytotoxic activity. A comparable pattern in the modulation of immune molecules by ocrelizumab was observed in cytotoxic cells even when patients with R-MS were divided into groups based on their prior disease-modifying treatment. These effects were accompanied by a significant and selective reduction of CD8+ T-cell proliferation in response to EBV antigenic peptides. DISCUSSION: Taken together, our findings suggest that ocrelizumab-while depleting B cells-affects the cytotoxic function of CD8+ and NK cells, whose reduced cross-activity against myelin antigens might also contribute to its therapeutic efficacy during MS.

Self-adjuvanting polymeric nanovaccines enhance IFN production and cytotoxic T cell response.

Vaccines represent one of the most powerful and cost-effective innovations for controlling a wide range of infectious diseases caused by various viruses and bacteria. Unlike mRNA and DNA-based vaccines, subunit vaccines carry no risk of insertional mutagenesis and can be lyophilized for convenient transportation and long-term storage. However, existing adjuvants are often associated with toxic effect and reactogenicity, necessitating expanding the repertoire of adjuvants with better biocompatibility, for instance, designing self-adjuvating polymeric carriers. We herein report a novel subunit vaccine delivery platform constructed via in situ free radical polymerization of C7A (2-(Hexamethyleneimino) ethyl methacrylate) and acrylamide around the surface of individual protein antigens. Using ovalbumin (OVA) as a model antigen, we observed substantial increases in both diameter (∼70 nm) and surface potential (-1.18 mV) following encapsulation, referred to as n(OVA)C7A. C7A's ultra pH sensitivity with a transition pH around 6.9 allows for rapid protonation in acidic environments. This property facilitates crucial processes such as endosomal escape and major histocompatibility complex (MHC)-I-mediated antigen presentation, culminating in the substantial CD8+ T cell activation. Additionally, compared to OVA nanocapsules without the C7A components and native OVA without modifications, we observed heightened B cell activation within the germinal center, along with remarkable increases in serum antibody and cytokine production. It's important to note that mounting evidence suggests that adjuvant effects, particularly its targeted stimulation of type I interferons (IFNs), can contribute to advantageous adaptive immune responses. Beyond its exceptional potency, the nanovaccine also demonstrated robust formation of immune memory and exhibited a favorable biosafety profile. These findings collectively underscore the promising potential of our nanovaccine in the realm of immunotherapy and vaccine development.

PIEZO1 mechanically regulates the antitumour cytotoxicity of T lymphocytes.

The killing function of cytotoxic T cells can be enhanced biochemically. Here we show that blocking the mechanical sensor PIEZO1 in T cells strengthens their traction forces and augments their cytotoxicity against tumour cells. By leveraging cytotoxic T cells collected from tumour models in mice and from patients with cancers, we show that PIEZO1 upregulates the transcriptional factor GRHL3, which in turn induces the expression of the E3 ubiquitin ligase RNF114. RNF114 binds to filamentous actin, causing its downregulation and rearrangement, which depresses traction forces in the T cells. In mice with tumours, the injection of cytotoxic T cells collected from the animals and treated with a PIEZO1 antagonist promoted their infiltration into the tumour and attenuated tumour growth. As an immunomechanical regulator, PIEZO1 could be targeted to enhance the outcomes of cancer immunotherapies.