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Hepatocellular carcinoma (HCC) is a major cause of cancer-related deaths worldwide. Chemotherapy using cisplatin, a drug that damages deoxyribonucleic acid (DNA), is not very effective in treating HCC due to its side effects and drug resistance. Manganese (Mn 2+ ), a trace element, has been shown to enhance immune responses, but its ability to improve cisplatin-induced antitumor immunity in HCC remains unclear. The present study found that treatment with Mn 2+ in combination with cisplatin promoted cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling activation and C-X-C motif chemokine ligand 10 (CXCL10) production in tumor and dendritic cells. CXCL10 is associated with CD8A levels, and its high expression is linked to better prognosis in patients with HCC. In addition, Mn 2+ and cisplatin co-treatment enhanced the recruitment of CD8 + T cells through the CXCL10/CXCR3 axis. Similarly, in an orthotopic transplantation tumor model, STING activation, CD8 + T cell infiltration, and tumor cell killing levels were higher in the combined treatment group. The above findings suggest that utilizing Mn 2+ in combination with cisplatin could be a potential treatment option for HCC., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Diffuse large B-cell lymphoma (DLBCL) is a highly aggressive neoplasm of lymphatic system that represent 38-58 % of non-Hodgkin lymphoma. Chemoresistance and immune escape constitute the major obstacles to the treatment of patients. Sphingosine kinase 1 (SphK1) is involved in multiple processes of cancer. Up to now, little research focuses on its function in DLBCL. In the current research, GEPIA and human Protein Atlas databases confirmed high expression of SphK1 in DLBCL tissues. Analogously, increased expression of SphK1 were determined in DLBCL tissues and cells. Intriguingly, knockdown of SphK1 suppressed DLBCL cell viability and increased chemosensitivity to doxorubicin by decreasing cell viability and increasing caspase-3 activity. Reversely, SphK1 elevation facilitated cancer cell resistance to doxorubicin. Furthermore, loss of SphK1 increased the productions of inflammatory cytokine IFN-γ and TNF-α, but reduced IL-10 levels in co-culture model of CD8 + T cells and DLBCL cells. Importantly, SphK1 knockdown enhanced T cell cytotoxicity to DLBCL cells, while its elevation restrained the ability of T cells to kill cancer cells. Concomitantly, targeting SphK1 enhanced the percentage of CD8 + T cells and attenuated co-culture-evoked CD8 + T cell apoptosis, indicating the important roles in T cell escape. Mechanically, SphK1 overexpression enhanced and its knockdown suppressed activation of the PI3K/AKT/PD-L1 pathway. After blockage of this pathway by its antagonist, the beneficial effects of SpHK1 on chemoresistance and immune escape were abrogated. In vivo, targeting SphK1 inhibited tumor growth and enhanced the anti-tumor efficacy of doxorubicin in DLBCL xenograft tumor, concomitant with the inhibition of the PI3K/AKT/PD-L1 signaling. Collectively, SphK1 knockdown counteracted chemoresistance and immune escape from T cell killing by inhibiting the PI3K/AKT/PD-L1 pathway. Therefore, targeting SphK1 may represent a promising therapeutic strategy for overcoming chemoresistance and immune escape in DLBCL., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Delayed-type hypersensitivity (DTH) reactions are a kind of chronic inflammatory diseases initiated by antigens and antigen-specific T cells. Currently, the therapy of DTH reactions is limited by the poor curative effects and serious adverse reactions of existing agents. In this study, we investigated the regulatory effects of tanshinone Ⅰ, a natural compound isolated from Salvia miltiorrhiza, on the functions of multiple immune cells and its therapeutic effects on DNFB-induced DTH reaction, and then explored its immunosuppressive mechanisms. The results showed that tanshinone Ⅰ at 5-20 μM moderately inhibited the activation of macrophages and dendritic cells, but did not weaken the activation of neutrophils. Tanshinone Ⅰ at 1-4 μM intensively suppressed the activation, proliferation, and differentiation of CD4 + and CD8 + T cells, and slightly affected the functions of B cells. Tanshinone Ⅰ administration markedly alleviated the edema, inflammatory response, and the infiltrations of CD4 + T cells, CD8 + T cells, and CD11b + cells in ear tissues of mice which were induced DTH reactions by DNFB. Transcriptome analysis revealed that tanshinone Ⅰ strongly inhibited CD4 + T cells to express genes involving in cell proliferation, metabolism, activation, and differentiation. Furthermore, immunoblotting analysis showed that tanshinone Ⅰ selectively inhibited the phosphorylation of STAT3 and STAT5 in CD4 + T cells stimulated by anti-CD3e and anti-CD28 antibodies or IL-2. Collectively, tanshinone Ⅰ can strongly inhibit the functions of T lymphocytes, exert therapeutic effects on DTH reaction by blocking STATs signaling pathways, and has potential to be developed into therapeutic drug for DTH reactions., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: PD-L1 blockade has been found to be effective in treating multiple malignancies. Combined therapy is proposed to provide better therapeutic effects. Cordycepin, a prominent bioactive compound found in cordyceps, can inhibit the development of various cancers., Purpose: This study aimed to determine the efficacy of combined anti-PD-L1 antibody and cordycepin in tumor treatment., Methods: A single-cell RNA sequencing was used to analyze the mechanism of combined treatment., Results: Combination therapy of anti-PD-L1 and cordycepin significantly inhibited tumor growth by regulating the T cell ratio and improving the function of CD8 + T cells. Furthermore, cordycepin promoted the reprogramming of type-II macrophages into type-I macrophages, a process confirmed through flow cytometry analysis of the underlying mechanism., Conclusion: Our findings demonstrate that the combination of anti-PD-L1 and cordycepin effectively suppressed tumor growth by regulating the proportion of T cells and reprograming type-II macrophages., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Therapeutic DNA cancer vaccines can stimulate specific immune responses against cancer antigens but often induce suboptimal therapeutic responses. Here, we demonstrate that a manganese-doped silica nanoparticle STING agonist (MSNA) enhances the immune response of plasmid DNA vaccines, promoting the activation and migration of distinct subsets of dendritic cell (DC) and improving antitumor immunity in three animal models. MSNA coadministered with an α-fetoprotein (AFP) encoded plasmid DNA (AFP-DNA) elicited significantly higher AFP-specific CD8 T cell responses than free AFP-DNA. Animals immunized with MSNA-AFP-DNA remained tumor-free in an AFP expressing hepatocellular carcinoma challenge model. MSNA combined with a DNA plasmid encoding the human papillomavirus type 16 oncoproteins E6 and E7 induced potent E7-specific CD8 T cell responses, preventing the growth of E7-expressing solid TC-1 tumors and promoting the shrinkage of E7-expressing skin grafts. These findings together demonstrate that coadministration of MSNA can improve the efficacy of therapeutic DNA vaccines targeting cancer-specific antigens.

Anti-tumor immunity is crucial for high-grade serous ovarian cancer (HGSC) prognosis, yet its adaptation upon standard chemotherapy remains poorly understood. Here, we conduct spatial and molecular characterization of 117 HGSC samples collected before and after chemotherapy. Our single-cell and spatial analyses reveal increasingly versatile immune cell states forming spatiotemporally dynamic microcommunities. We describe Myelonets, networks of interconnected myeloid cells that contribute to CD8 + T cell exhaustion post-chemotherapy and show that M1/M2 polarization at the tumor-stroma interface is associated with CD8 + T cell exhaustion and exclusion, correlating with poor chemoresponse. Single-cell and spatial transcriptomics reveal prominent myeloid-T cell interactions via NECTIN2-TIGIT induced by chemotherapy. Targeting these interactions using a functional patient-derived immuno-oncology platform demonstrates that high NECTIN2-TIGIT signaling in matched tumors predicts responses to immune checkpoint blockade. Our discovery of clinically relevant myeloid-driven spatial T cell exhaustion unlocks immunotherapeutic strategies to unleash CD8 + T cell-mediated anti-tumor immunity in HGSC., Competing Interests: Declaration of interests P.K.S. is a co-founder and member of the BOD of Glencoe Software, is a member of the SAB for RareCyte, Nanostring, Reverb Therapeutics and Montai Health, and consults for Merck; he holds equity in Glencoe and RareCyte., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Necroptosis can promote antigen-specific immune responses, suggesting induced necroptosis as a therapeutic approach for cancer. Here we sought to determine the mechanism of immune activation but found the necroptosis mediators RIPK3 and MLKL dispensable for tumor growth in genetic and implantable models of breast or lung cancer. Surprisingly, inducing necroptosis within established breast tumors generates a myeloid suppressive microenvironment that inhibits T cell function, promotes tumor growth, and reduces survival. This was dependent upon the release of the nuclear alarmin interleukin-1α (IL-1α) by dying cells. Critically, IL-1α release occurs during chemotherapy and targeting this molecule reduces the immunosuppressive capacity of tumor myeloid cells and promotes CD8 + T cell recruitment and effector function. Neutralizing IL-1α enhances the efficacy of single agent paclitaxel or combination therapy with PD-1 blockade in preclinical models. Low IL1A levels correlates with positive patient outcome in several solid malignancies, particularly in patients treated with chemotherapy., Competing Interests: Declaration of interests B.R. has a courtesy faculty appointment at the University of South Florida, Tampa, FL 33620. B.R. is on the scientific advisory board of Omios Biologics LLC, has received payments from Merck & Co., Inc. and Roche Farma S.A. for consulting, and has had sponsored research agreements with TESARO: A GSK Company unrelated to this work., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Triclocarban (TCC) is a widely applied environmental endocrine-disrupting chemical (EDC). Similar to most of EDCs, TCC potentially damages the immunity of various species. However, whether and how TCC impacts the adaptive immunity in mammals has yet to be determined. Herein, we discovered that TCC disrupts the activation and differentiation of CD8 + T cells in primary human peripheral blood samples, purified CD8 + T cells, and in mice in vivo. Mechanistically, TCC might block the activation of the vitamin D receptor (VDR) and reduce the synthesis of cholesterol, a precursor of vitamin D, resulting in inhibition of VDR signaling due to the suppression of both its ligand and the receptor itself by TCC. Our findings elucidate the hazard and potential mechanisms of TCC in mammalian adaptive immunity and highlighted VDR as a potential therapeutic target for the immunodeficiency caused by TCC., Competing Interests: Declaration of Competing Interest The authors declare they have no conflicts of interest., (Copyright © 2024. Published by Elsevier B.V.)

Background: Gastric cancer (GC), especially the case with microsatellite stability (MSS) phenotype, has limited efficacy for immune checkpoint blockade (ICB) therapy. Metabolism reprogramming is newly recognized to affect tumor immune microenvironment (TIME). However, the relationship between metabolism reprogramming and immunotherapy for MSS GC has not been reported., Methods: A metabolic stratification for GC was developed based on the glycolysis/cholesterol synthesis axis using the R package "ConsensusClusterPlus". The T cell inflamed score was used to define "immune-hot" and "immune-cold" phenotypes in MSS GC. The anti-tumor and immunological effects of simvastatin were explored using in vitro and in vivo experiments., Results: Three metabolic subtypes were identified in GC patients, including cholesterol, glycolysis and quiescent subtypes. The cholesterol subtype was associated with poorer clinical features and higher tumor purity. Correspondingly, we demonstrated that simvastatin, a specific inhibitor of cholesterol synthesis, significantly inhibited the proliferation, migration, and induced ferroptosis in GC cells. Interestingly, simvastatin markedly inhibited tumor growth in immunocompetent mice, while no significant effect in immunodeficient mice. Upregulation of chemokines and increased recruitment of CD8+ T cells were observed after simvastatin treatment. Consistently, the cholesterol subtype exhibited a less inflamed TIME and coincided significantly with the "immune-cold" phenotype of MSS GC. Finally, we confirmed simvastatin enhanced PD-1 blockade efficacy via modulating the TIME and activating anti-tumor immunity in tumor-bearing mice., Conclusion: Our data revealed the significance of cholesterol synthesis in GC and demonstrated simvastatin served as a promising sensitizer for ICB therapy by inducing ferroptosis and anti-tumor immunity in MSS GC patients., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Unprecedented progress in immune checkpoint blockade (ICB) therapy has been made in cancer treatment. However, the response to ICB therapy is limited to a small subset of patients. The development of ICB sensitizers to improve cancer immunotherapy outcomes is urgently needed. Berberine (BBR), a well-known phytochemical compound isolated from many kinds of medicinal plants such as Berberis aristata, Coptis chinensis, and Phellondendron chinense Schneid, has shown the ability to inhibit the proliferation, invasion and metastasis of cancer cells. In this study, we investigated whether BBR can enhance the therapeutic benefit of ICB for melanoma, and explored the underlying mechanisms involved. The results showed that BBR could sensitize ICB to inhibit tumor growth and increased the survival rate of mice. Moreover, BBR stimulated intracellular ROS production partially by inhibiting NQO1 activity, which induced immunogenic cell death (ICD) in melanoma, elevated the levels of damage-associated molecular patterns (DAMPs), and subsequently activated DC cells and CD8 + T cells in vitro and in vivo. In conclusion, BBR is a novel ICD inducer. BBR could enhance the therapeutic benefit of ICB for melanoma. These effects were partially mediated through the inhibition of NQO1 and ROS activation., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Studies in SIV-infected macaques show that the virus reservoir is particularly refractory to conventional suppressive antiretroviral therapy (ART). We posit that optimized ART regimens designed to have robust penetration in tissue reservoirs and long-lasting antiviral activity may be advantageous for HIV or SIV remission. Here we treat macaques infected with RT-SHIV with oral emtricitabine/tenofovir alafenamide and long-acting cabotegravir/rilpivirine without (n = 4) or with (n = 4) the immune activator vesatolimod after the initial onset of viremia. We document full suppression in all animals during treatment (4-12 months) and no virus rebound after treatment discontinuation (1.5-2 years of follow up) despite CD8 + T cell depletion. We show efficient multidrug penetration in virus reservoirs and persisting rilpivirine in plasma for 2 years after the last dose. Our results document a type of virus remission that is achieved through early treatment initiation and provision of ultra long-lasting antiviral activity that persists after treatment cessation., Competing Interests: Competing interests: J.G.G.-L., M.B.D., W.H., P.W., and W.S. are named in a US Patent Application (No. 18/002,494) entitled “Methods for achieving viral remission using long-acting antiretroviral agents”. The remaining authors declare no competing interests., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

The induction of immunogenic cell death (ICD) can activate antitumor immune response to potentiate cancer immunotherapy. In this study, we observed the antitumor activity following combinatorial therapy with anti-CTLA4 antibody and epigallocatechin-3-gallate (EGCG) in CT26 tumors.Indeed, EGCG triggered colon cancer cells ICD with the secretion of high-mobility group protein B1 (HMGB1) and the surface expression of calreticulin (CRT) and heat shock protein 70 (HSP70). Mice treated with EGCG promoted the maturation of dendritic cells and enhanced the effector function of CD8 + T cells within tumors to remodel the tumor immune microenvironment. Overall, these results indicate that EGCG, a novel ICD inducer, triggers ICD in CRC, and provides a new concept for cancer immunotherapy., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Poly ADP-ribose polymerase inhibitors (PARPi) are first-line maintenance therapy for ovarian cancer and an alternative therapy for several other cancer types. However, PARPi-resistance is rising, and there is currently an unmet need to combat PARPi-resistant tumors. Here, we created an immunocompetent, PARPi-resistant mouse model to test the efficacy of combinatory PARPi and euchromatic histone methyltransferase 1/2 inhibitor (EHMTi) in the treatment of PARPi-resistant ovarian cancer. We discovered that inhibition of EHMT1/2 resensitizes cells to PARPi. Markedly, we show that single EHMTi and combinatory EHMTi/PARPi significantly reduced PARPi-resistant tumor burden and that this reduction is partially dependent on CD8 T cells. Altogether, our results show a low-toxicity drug that effectively treats PARPi-resistant ovarian cancer in an immune-dependent manner, supporting its entry into clinical development and potential incorporation of immunotherapy. Implications: Targeting the epigenome of therapy-resistant ovarian cancer induces an antitumor response mediated in part through an antitumor immune response., (©2024 American Association for Cancer Research.)

Aging compromises antitumor immunity, but the underlying mechanisms remain elusive. Here, we report that aging impairs the generation of CD8 + tissue resident memory T (T RM ) cells in nonlymphoid tissues in mice, thus compromising the antitumor activity of aged CD8 + T cells, which we also observed in human lung adenocarcinoma. We further identified that the apoptosis regulator BFAR was highly enriched in aged CD8 + T cells, in which BFAR suppressed cytokine-induced JAK2 signaling by activating JAK2 deubiquitination, thereby limiting downstream STAT1-mediated T RM reprogramming. Targeting BFAR either through Bfar knockout or treatment with our developed BFAR inhibitor, iBFAR2, rescued the antitumor activity of aged CD8 + T cells by restoring T RM generation in the tumor microenvironment, thus efficiently inhibiting tumor growth in aged CD8 + T cell transfer and anti-programmed cell death protein 1 (PD-1)-resistant mouse tumor models. Together, our findings establish BFAR-induced T RM restriction as a key mechanism causing aged CD8 + T cell dysfunction and highlight the translational potential of iBFAR2 in restoring antitumor activity in aged individuals or patients resistant to anti-PD-1 therapy., Competing Interests: Competing interests: Y.X., M.Z., S.P., X.D., R.Y., S.Z. and H. Hou have filed a patent application regarding the application of the BFAR inhibitor for the treatment of tumors. The other authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Background: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe adverse drug reactions with extensive keratinocyte death. Carbamazepine (CBZ), the most commonly implicated drug in SJS/TEN, is metabolized by the cytochrome P450 enzyme 3A4 (CYP3A4) into carbamazepine-10,11-epoxide (CBZE) in the liver. While CD8 + cytotoxic T cells play an important role in SJS/TEN, the underlying mechanism of exuberant immune response by CD8 + T cells in these conditions remains incompletely understood., Objectives: To examine the expression of NLRP3 inflammasome and their skin migration in CBZE-induced SJS/TEN., Methods: The expression of the NLRP3 inflammasome complex in skin lesions, sera, and blister fluids of SJS/TEN patients were analyzed by immunohistochemistry and enzyme-linked immunosorbent assay. NLRP3 formation and CD8 + T cell activation status and their functions were examined by immunoblotting, immunofluorescence, and chemotaxis assays., Results: The expression of the NLRP3 inflammasome complex was greatly increased in skin lesions of SJS/TEN patients. Moreover, IL-1β and IL-18 levels in sera and blister fluids of SJS/TEN patients were approximately 3-fold higher than those in healthy individuals, with a linear correlation between IL-1β levels and disease activity. CBZE induced NLRP3 inflammasome formation, upregulated CXCL9/CXCL10 levels, and activated CD8 + cytotoxic T cell functions via IL-1β/IL-1R or IL-18/IL-18R signaling in SJS/TEN keratinocytes, which promoted CD8 + cytotoxic T cell migration in SJS/TEN patients., Conclusion: This study showed that CBZE promoted NLRP3 inflammasome formation and strengthened the activation and function of CD8 + cytotoxic T cells in the skin, which contributed to the initiation and progression of SJS/TEN., (Copyright © 2024 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.)

Background: Pancreatic cancer (PC) is characterized by abnormally fibrotic mesenchyme, which notably influences on the effectiveness of immunotherapy. Low-dose arsenic trioxide (ATO, 1.0 μM) can inhibit the activation of pancreatic stellate cells (PSCs) and affect fibrosis, which is a potential strategy for enhancing the sensitivity to immunotherapy., Methods: Extracellular matrix (ECM) models were employed to assess the regulatory effects of ATO on ECM and peripheral blood mononuclear cells. Orthotopic C57BL/6J models were utilized to evaluate the influence of ATO on CD8 + T cell infiltration and immunotherapy in PC. Additionally, nanomaterials loaded with ATO designed to specifically target PSCs (scAbFAP-α-HMSNs-PAA-ATO) were produced to enhance targeting effects of ATO., Results: Low-dose ATO (1.0 μM) suppressed PSCs activation, exhibiting potential for synergistic immunotherapy. Under low-dose ATO intervention, ECM underwent remodeling, leading to increases in CD8 + T cell infiltration, thereby enhancing anti-PD-L1 therapy effect. We further demonstrated that low-dose ATO remodeled ECM by regulating the expression of LOXL3 in PSCs. scAbFAP-α-HMSNs-PAA-ATO exhibited improved targeting capabilities, and enhanced capacity to inhibit fibrosis and sensitize immunotherapy., Conclusions: Our research reveals that low-dose ATO, by regulating LOXL3, remodels the ECM and enhances CD8 + T cell infiltration, thus sensitizing the efficacy of immunotherapy, which provides a novel strategy for comprehensive treatment to PC., Competing Interests: Competing interests: The authors declare no competing interests. Ethics approval and consent to participate: The use of human samples was approved by Sun Yat-sen Memorial Hospital Ethics Committee and the informed consent from all participants were obtained (SYSKY-2023-116-01). All methods involved in this study were carried out in accordance with relevant guidelines and regulations. All animals care and experimental procedures were conducted according to the National Research Council’s Guidelines for the Care and Use of Laboratory Animals, and were approved by the Institutional Animal Care and Use Committee of Sun Yat-sen University Cancer Center (L102012022040E)., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Background: The exact role of different immune cells and cytokines in control or promotion of intracellular growth of leishmania has still remained a controversial topic. The aim of the present study was to study effects of cellular changes and relevant cytokines in cell mediated immunity by diphencyprone (DCP) in pathogenicity of acute L.major infection in BALB/c mice., Methods: 45 healthy female BALB/c mice were injected with L. major promastigotes under the base of tail. The mice were randomly divided to three groups of 15 mice: (1) control group without any treatment. (2) acetone group: Acetone was applied topically on the cutaneous lesions weekly and (3) DCP group: DCP was applied topically on the cutaneous lesions with increasing concentrations to induce local allergy. The mice were followed by the end of eighth week, and then macroscopic changes, histopathology, immunology studies, and organ parasite burden were determined., Results: In DCP group, in comparison to other groups the ulcer size and parasite burden in ulcer site and spleen increased, significantly. There was a deep lymphohistiocytic infiltration in the ulcer site. Total IgG, IgG1, and IgG2a levels as well as IgG2a/IgG1 ratio and intracellular IFN-gamma in CD8 + lymphocytes were significantly higher. IL4 and T CD8 + lymphocytes were significantly lower in DCP group. The IgG2a/IgG1 ratio was more than 1 in all groups., Conclusion: Our findings demonstrated that DCP reduced the CD8 + lymphocytes and IL-4 production. In spite of increased IgG2a/IgG1 ratio, the parasite burden and inflammation severity increased in infected mice. The results can show the pivotal role of CD8 + lymphocytes in conjunction with Th1 lymphocytes in the control of acute leishmania infection in mice., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Significance: Immunophenotypic analysis identified a BM CD57+CXCR3+ subset of CD8+ T cells associated with response to AZA in patients with MDS and AML. Single-cell RNA sequencing analysis revealed that IFN signaling is linked to the response to treatment, whereas TGF-β signaling is associated with treatment failure, providing insights into new therapeutic approaches., (©2024 The Authors; Published by the American Association for Cancer Research.)

Agaricus blazei murill (ABM) mainly exerts its antitumor effect via modulation of the immune system. However, the immunomodulatory role of the ABM polysaccharide (ABMP) in mice with subcutaneously and intraperitoneally implanted MC38 tumor remains to be explored. This study aimed to define the progression effect of inhibiting tumor of ABMP in subcutaneous and intraperitoneal models and its effect on tumor microenvironment (TME) metabolism. In vitro experiments showed that ABMP could significantly promote the activity of CD8+ T immune cells in the co-culture system and promoted their colorectal cancer killing function (p < 0.05). In vivo animal exploration further showed that ABMP could inhibit the growth of intraperitoneal but not subcutaneous tumors. MCR-ALS analysis revealed a significant reduction in the signal of lipid-related spectral components in the TME of peritoneal tumors after ABMP intervention. In addition, preventive intervention with ABMP increased ω-3 polyunsaturated fatty acids content in intraperitoneal TME, revealing that ABMP shifted the metabolic landscape of the TME to promote T cell function and achieved immune regulation. These results suggest that the inhibitory effect of ABMP on colon cancer may be tumor stage-dependent, and that remodeling of fatty acid composition may be an important determinant of its action at any given stage., Competing Interests: Declaration of competing interest No potential conflict of interest was reported by the authors., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Hydroxychloroquine (HCQ) is widely used in the treatment of a variety of autoimmune diseases. However, the mechanisms responsible for the immunomodulatory properties of HCQ in T cells remain unclear. Here we used single-cell RNA-sequencing to examine the effect of HCQ on T cells following in vitro stimulation. HCQ treatment led to a reduction in effector CD4 + T cells and upregulation of inhibitory genes including CTLA4 and TNFAIP3 in effector and naive CD4 + T cells, respectively. HCQ induced a significant expansion of effector CD8 + T cells, and significantly upregulated key cytotoxicity genes including GZMA, GZMB, GZMH, KLRD1, NKG7, and PRF1, as well as IFNG expression. Furthermore, HCQ treatment led to a reduction in the CD38 + CD8 + T cell subset, which is characterized by defective cytotoxicity and thought to both play a pathogenic role and increase susceptibility to infections in autoimmunity. We analyzed single-cell RNA-sequencing data in effector CD8 + T cells from lupus patients with or without HCQ treatment and confirmed upregulation of key cytotoxicity genes in patients receiving HCQ. In conclusion, this work provides additional insights into the immunomodulatory effects of HCQ and indicates that HCQ improves T cell cytotoxicity, which could explain a previously suggested protective effect of HCQ against infections in patients with autoimmune diseases., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Immune checkpoint blockade, such as monoclonal antibodies targeting programmed cell death protein 1 (PD-1), has been a major breakthrough in the treatment of several cancers, but has limited effect in colorectal cancer (CRC), which is a highly prevalent cancer worldwide. Current chemotherapy-based strategies to boost PD-1 response have many limitations. And the role of peripheral immunity in boosting PD-1 response continues to attract attention. Therefore, candidate combinations of PD-1 blockade need to be drugs with multi-targets and multi-modulatory functions. However, it is still unknown whether traditional Chinese medicines with such property can enhance the applicability and efficacy of PD-1 blockade in colorectal cancer., Methods: Euphorbia Pekinensis extract (EP) was prepared and the constituents were analyzed by HPLC. CRC cells were used for in vitro experiments, including cell viability assay, colony formation assay, flow cytometry for 7-AAD staining, western blotting for caspase 3 and caspase 7, HMGB1 and ATP detection. An orthotopic CT26 mouse model was subsequently used to investigate the combination of EP and PD-1 blockade therapy. Tumor volume and tumor weight were assessed, tumor tissues were subjected to histopathological HE staining and TUNEL staining, and tumor-infiltrating immune cells were evaluated by immunofluorescence staining. RNA-sequencing, target prediction and pathway analysis were further employed to explore the mechanism. Molecular docking and cellular thermal shift assay (CETSA) were utilized to verify the direct target of the core component of EP. And, loss-of-function analysis was carried to confirm the upstream-downstream relationship. Flow cytometry was employed to analyze CD8 + T cells in the peripheral blood and spleen., Results: The main constituents of EP are diterpenoids and flavonoids. EP dramatically suppresses CRC cell growth and exerts its cytotoxic effect by triggering immunogenic cell death in vitro. Moreover, EP synergizes with PD-1 blockade to inhibit tumorigenesis in tumor-bearing mice. Disruption of ISX nuclear localization by helioscopinolide E is a central mechanism of EP-induced apoptosis in CRC cell. Meanwhile, EP activates immune response by upregulating Phox2b to reshape the immune microenvironment. In addition, EP regulates peripheral immunity by regulating the T cell activation and proliferation, and the ratio of CD8 + T cells in peripheral blood is drastically increased, thereby enhancing the therapeutic efficacy of anti-PD1 immunotherapy., Conclusion: EP triggers intra-tumor immunogenic cell death and modulates the immunoregulatory signaling to elicit the tumor immunogenicity. Moreover, EP participates in transcriptional activation of immune response-related pathways. Consequently, multiple stimulating functions of EP on macro- and micro-immune potentiates the anti-tumor effect of PD-1 blockade in CRC., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

Background: Research on immunotherapy for gastric cancer is currently receiving significant attention, with particular emphasis on the role of CD8+ T cells in anti-tumor immune responses. In recent years, the importance of the chemokine CXCL10 in promoting anti-tumor immunity has been increasingly recognized because it plays a crucial role in recruiting CD8+ T cells to the tumor microenvironment. The Huang-Jin-Shuang-Shen (HJSS) Decoction, a Chinese medicine, has been used as an adjuvant drug for gastric cancer chemotherapy. Its mechanism of action may be related to the activation of anti-tumor immunity., Purpose: To assess the role of the HJSS Decoction in regulating the immune microenvironment of gastric cancer and elucidate its mechanism., Study Design/methods: Ultra-high performance liquid chromatography Q Exactive-mass spectrometry was used to analyze the main components of the HJSS Decoction and evaluate the therapeutic effect of the HJSS Decoction synergized with 5-fluorouracil (5-FU) on gastric cancer. The proportions of CD8+ T cells and killing markers were determined using flow cytometry. Mechanisms of action and targets were screened using network pharmacology. The level of CXCL10 was detected using enzyme-linked immunosorbent assay and western blot, and nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) related signaling pathway was detected in vitro. The target function was validated by siRNA transfection., Results: The combination of HJSS Decoction and 5-FU demonstrated a synergistic effect in impeding the progression of subcutaneous gastric cancer. This was achieved through the facilitation of apoptosis and suppression of proliferation. Furthermore, HJSS Decoction exhibited the ability to enhance the population of CD8+ T cells and augment their cytotoxic capabilities, both in laboratory settings and in living organisms. Notably, HJSS Decoction upregulated the expression of CXCL10, and mechanistically, it activated the NFκB-related signaling pathway to initiate subsequent transcription of chemokines., Conclusion: The present study aimed to investigate the pharmacological mechanism of the HJSS Decoction and its potential clinical application in inhibiting gastric cancer in mice. HJSS Decoction can cooperate with 5-FU to inhibit gastric cancer, and the optimal dose is medium. HJSS Decoction exerts anti-tumor immunity by activating the NFκB-related signaling pathway and promoting the expression of CXCL10, which in turn recruits CD8+ T cells into the tumor immune microenvironment. Overall, these findings provide valuable evidence for the potential clinical application of HJSS Decoction., Competing Interests: Declaration of competing interest All authors disclosed no relevant relationships, (Copyright © 2024 The Author(s). Published by Elsevier GmbH.. All rights reserved.)

Background: Pomalidomide, a third-generation oral immunomodulatory drug, exhibits efficacy in patients with relapsed multiple myeloma or those refractory to bortezomib and lenalidomide (RRMM)., Methods: In this clinical context, we employed flow cytometry and CDR3 spectratyping to monitor the dynamics of the T-cell repertoire during Pomalidomide treatment, aiming to investigate its potential to reverse the immunological abnormalities characteristic of RRMM., Results: By flow cytometry at baseline we found a significant decrease in CD4 + frequency in MM patients, while CD8 + frequency were significantly higher in patients when compared to controls. Most T cell populations remained stable across all time points, except for CD4 + frequency, which notably decreased from t1 to subsequent assessments. Our investigation revealed as most relevant finding the notable increase in CD4 + expansions and the growing prevalence of patients manifesting these expansions. This pattern is even more evident in patients receiving their treatment until t3 and therefore still responding to treatment with Pomalidomide. We also conducted a comparison of spectratyping data before and after treatment, substantially demonstrating a relatively stable pattern throughout the course of Pomalidomide treatment., Conclusions: These observations imply that Pomalidomide treatment influences the T-cell repertoire, particularly in the CD4 + subpopulation during the later stages of treatment, raising speculation about the potential involvement of these lymphocyte expansions in mechanisms related to antitumor immunity., Competing Interests: Declarations. Conflict of interest: The authors declare that they have no conflict of interest., (© 2024. The Author(s).)

Tumour immune evasion presents a significant challenge to the effectiveness of cancer immunotherapies. Recent advances in high-throughput screening techniques have uncovered that loss of antigen presentation and cytokine signalling pathways are central mechanisms by which tumours evade T cell immunity. To uncover additional vulnerabilities in tumour cells beyond the well-recognized antigen presentation pathway, we conducted a genome-wide CRISPR/Cas9 screen to identify genes that mediate resistance to chimeric-antigen receptor (CAR)-T cells, which function independently of classical antigen presentation. Our study revealed that loss of core-binding factor subunit beta (CBFβ) enhances tumour cell resistance to T cell killing, mediated through T cell-derived TNF. Mechanistically, RNA-sequencing and elemental analyses revealed that deletion of CBFβ disrupts numerous pathways including those involved in zinc homoeostasis. Moreover, we demonstrated that modulation of cellular zinc, achieved by supplementation or chelation, significantly altered tumour cell susceptibility to TNF by regulating the levels of inhibitor of apoptosis proteins. Consistent with this, treatment of tumour cells with a membrane-permeable zinc chelator had no impact on tumour cell viability alone, but significantly increased tumour cell lysis by CD8+ T cells in a TNF-dependent but perforin-independent manner. These results underscore the crucial role of intracellular zinc in regulating tumour cell susceptibility to T cell-mediated killing, revealing a novel vulnerability in tumour cells that might be exploited for the development of future cancer immunotherapeutics., Competing Interests: Competing interests: The authors declare no competing interests. Ethics approval and consent to participate: All animal studies were performed in accordance with the NHMRC Australian Code for the Care and Use of Animals for Scientific Purposes 8th edition (2013) and with approval from the Peter MacCallum Cancer Centre Animal Experimentation Ethics Committee (Ethics approvals E548, E638, 2023-17)., (© 2024. The Author(s).)

Cancer vaccines aim at generating cytotoxic CD8 + T cells that kill cancer cells and confer durable tumor regression. Hereto, CD8 + peptide epitopes should be presented by antigen presenting cells to CD8 + T cells in lymphoid tissue. Unfortunately, in unformulated soluble form, peptide antigens are poorly taken up by antigen presenting cells and do not efficiently reach lymph nodes. Hence, the lack of efficient delivery remains a major limitation for successful clinical translation of cancer vaccination using peptide antigens. Here we propose a generic peptide nanoformulation strategy by extending the amino acid sequence of the peptide antigen epitope with 10 glutamic acid residues. The resulting overall anionic charge of the peptide allows encapsulation into lipid nanoparticles (peptide-LNP) by electrostatic interaction with an ionizable cationic lipid. We demonstrate that intravenous injection of peptide-LNP efficiently delivers the peptide to immune cells in the spleen. Peptide-LNP that co-encapsulate an imidazoquinoline TLR7/8 agonist (IMDQ) induce robust innate immune activation in a broad range of immune cell subsets in the spleen. Peptide-LNP containing the minimal CD8 + T cell epitope of the HPV type 16 E7 oncoprotein and IMDQ induces high levels of antigen-specific CD8 + T cells in the blood, and can confer protective immunity against E7-expressing tumors in both prophylactic and therapeutic settings., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Bruno De Geest and Yong Chen have patent #WO2022136641A1 licensed to etherna. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Owing to the desmoplastic stroma constituted by cancer-associated fibroblasts (CAFs), few immune cells infiltrate the pancreatic ductal adenocarcinoma (PDAC). Gabapentin can impede the production of ketoacids by CAFs to support cancer cells. However, in our study, we discovered a dose-dependent increase in transforming growth factor β1 (TGF-β1) levels in cancer cells in response to gabapentin. This reverse increase of TGF-β1 contributes to 'Gabapentin-resistance', leading to the antitumor effects on PDAC cell lines are negatively negotiated in the presence of pancreatic stellate cells. Pirfenidone synergistically inhibited the growth and apoptosis resistance of PDAC when combined with Gabapentin. In a mouse orthotopic PDAC model, Fe 3+ -mediated coordination nanodrugs, which contain gabapentin, pirfenidone and the natural polyphenol (EGCG), efficiently promoted the infiltration of naïve CD8 + T cells (CD44 low CD62L high ) and the accumulation of inflammatory CAFs (α-SMA low IL-6 high ). This led to a nearly two-fold increase in survival compared to the control. Furthermore, we identified a new subpopulation as Hmox1 high iCAFs following treatment with our nanodrugs. Hmox1 high iCAFs overexpressed the Cxcl10 receptor (Sdc4) and facilitated functional CD8 + T-cell infiltration through the Tnfsf9-Tnfrsf9 axis. Overall, our nanodrugs reshape the phenotype of CAFs and enhance functional CD8 + T-cell infiltration into tumors, holding the potential to be a safe and promising therapy for PDAC., Competing Interests: Declaration of competing interest The authors declare no competing financial interests., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

PD-1 immune checkpoint blockade (ICB) is a key cancer treatment. While blocking PD-1 binding to ligand is known, the role of internalization in enhancing ICB efficacy is less explored. Our study reveals that PD-1 internalization helps unlock ICB's full potential in cancer immunotherapy. Anti-PD-1 induces 50%-60% surface PD-1 internalization from human and mouse cells, leaving low to intermediate levels of resistant receptors. Complexes then appear in early and late endosomes. Both CD4 and CD8 T cells, especially CD8 + effectors, are affected. Nivolumab outperforms pembrolizumab in human T cells, while PD-1 internalization requires crosslinking by bivalent antibody. While mono- and bivalent anti-PD-1 inhibit tumor growth with CD8 tumor-infiltrating cells expressing increased granzyme B, bivalent antibody is more effective where the combination of steric blockade and endocytosis induces greater CD8 + T cell tumor infiltration and the expression of the cytolytic pore protein, perforin. Our findings highlight an ICB mechanism that combines steric blockade and PD-1 endocytosis for optimal checkpoint immunotherapy., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

The goal of therapeutic cancer vaccines and immune checkpoint therapy (ICT) is to promote T cells with anti-tumor capabilities. Here, we compared mutant neoantigen (neoAg) peptide-based vaccines with ICT in preclinical models. NeoAg vaccines induce the most robust expansion of proliferating and stem-like PD-1 + TCF-1 + neoAg-specific CD8 T cells in tumors. Anti-CTLA-4 and/or anti-PD-1 ICT promotes intratumoral TCF-1 - neoAg-specific CD8 T cells, although their phenotype depends in part on the specific ICT used. Anti-CTLA-4 also prompts substantial changes to CD4 T cells, including induction of ICOS + Bhlhe40 + T helper 1 (Th1)-like cells. Although neoAg vaccines or ICTs expand iNOS + macrophages, neoAg vaccines maintain CX3CR1 + CD206 + macrophages expressing the TREM2 receptor, unlike ICT, which suppresses them. TREM2 blockade enhances neoAg vaccine efficacy and is associated with fewer CX3CR1 + CD206 + macrophages and induction of neoAg-specific CD8 T cells. Our findings highlight different mechanisms underlying neoAg vaccines and different forms of ICT and identify combinatorial therapies to enhance neoAg vaccine efficacy., Competing Interests: Declaration of interests A.M.H. is currently employed by Lifecycle Biotechnologies, and her employment does not pose any direct conflict of interest with the research presented in this article. M.M.G. reports a personal honorarium of US $1,000.00 per year from Springer Nature Ltd (as an associate editor for Nature Precision Oncology) and served as a paid consultant for Merck. M. Colonna reports that they are a member of the scientific advisory board of Vigil Neuro and Cell Signaling Technology, received research grants from Vigil Neuro during the conduct of the study, and has a patent related to TREM2 modulation pending (PCT/US2021/019914). K.E.P. reports an advising relationship with Guardant Health that will result in advising fees., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

The RVd therapy, combining lenalidomide, bortezomib, and dexamethasone, is a mainstay treatment for multiple myeloma. A multiple myeloma patient developed pure red cell aplasia (PRCA) following RVd treatment, despite the absence of common PRCA triggers. In vitro analyses reveal lenalidomide as a pivotal disruptor of erythropoiesis. Single-cell transcriptome analysis unveils hyperactive CD8 +  T cells and impaired erythropoiesis in the patient's bone marrow. Unexpectedly, the patient's erythroid cells display abnormally high expression of genes in the antigen presentation pathway, particularly those for major histocompatibility class I (MHC-I) molecules. Functional assays demonstrate that lenalidomide treatment further augmented MHC-I expression in the patient's erythroid cells. Blocking MHC-I or depleting T cells alleviates the defective erythropoiesis of PRCA, suggesting that the interaction between erythroid cells with elevated MHC-I and T cells in the bone marrow might contribute to PRCA. Taken together, our study implicates a mechanism underlying lenalidomide-induced PRCA in treating cancer patients., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Context: Low magnesium levels, which are common in people with type 2 diabetes, are associated with increased levels of proinflammatory molecules. It is unknown whether magnesium supplementation decreases this low-grade inflammation in people with type 2 diabetes., Objective: We performed multidimensional immunophenotyping to better understand the effect of magnesium supplementation on the immune system of people with type 2 diabetes and low magnesium levels., Methods: Using a randomized, double-blind, placebo-controlled, 2-period, crossover study, we compared the effect of magnesium supplementation (15 mmol/day) with placebo on the immunophenotype, including whole blood immune cell counts, T-cell and CD14+ monocyte function after ex vivo stimulation, and the circulating inflammatory proteome., Results: We included 12 adults with insulin-treated type 2 diabetes (7 males, mean ± SD age 67 ± 7 years, body mass index 31 ± 5 kg/m2, HbA1c 7.5 ± 0.9%) and low magnesium levels (0.73 ± 0.05 mmol/L). Magnesium treatment significantly increased serum magnesium and urinary magnesium excretion compared with placebo. Interferon-γ production from phorbol myristate acetate/ionomycin stimulated CD8+ T-cells and T-helper 1 cells, as well as interleukin (IL) 4/IL5/IL13 production from T-helper 2 cells was lower after treatment with magnesium compared with placebo. Magnesium supplementation did not affect immune cell numbers, ex vivo monocyte function, and circulating inflammatory proteins, although we found a tendency for lower high sensitivity C-reactive protein levels after magnesium supplementation compared with placebo., Conclusion: In conclusion, magnesium supplementation modulates the function of CD4+ and CD8+ T-cells in people with type 2 diabetes and low serum magnesium levels., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.)

Histone deacetylase 6 (HDAC6) inhibition is associated with an increased pro-inflammatory tumor microenvironment and antitumoral immune responses. Here, we show that the HDAC6 inhibitor AVS100 (SS208) had an antitumoral effect in SM1 melanoma and CT26 colon cancer models and increased the efficacy of anti-programmed cell death protein 1 treatment, leading to complete remission in melanoma and increased response in colon cancer. AVS100 treatment increased pro-inflammatory tumor-infiltrating macrophages and CD8 effector T cells with an inflammatory and T cell effector gene signature. Acquired T cell immunity and long-term protection were evidenced as increased immunodominant T cell clones after AVS100 treatment. Last, AVS100 showed no mutagenicity, toxicity, or adverse effects in preclinical good laboratory practice studies, part of the package that has led to US Food and Drug Administration clearance of an investigational new drug application for initiating clinical trials. This would be a first-in-human combination therapy of pembrolizumab with HDAC6 inhibition for locally advanced or metastatic solid tumors.

Most non-muscle invasive bladder cancers have been treated by transurethral resection and following intravesical injection of immunotherapeutic agents. However, the delivery efficiency of therapeutic agents into bladder wall is low due to frequent urination, which leads to the failure of treatment with side effects. Here, we report a urease-powered nanomotor containing the agonist of stimulator of interferon genes (STING) for the efficient activation of immune cells in the bladder wall. After characterization, we perform in vitro motion analysis and assess in vivo swarming behaviors of nanomotors. The intravesical instillation results in the effective penetration and retention of nanomotors in the bladder. In addition, we confirm the anti-tumor effect of nanomotor containing the STING agonist (94.2% of inhibition), with recruitment of CD8 + T cells (11.2-fold compared with PBS) and enhanced anti-tumor immune responses in bladder cancer model in female mice. Furthermore, we demonstrate the better anti-tumor effect of nanomotor containing the STING agonist than those of the gold standard Bacille Calmette-Guerin therapy and the anti-PD-1 inhibitor pembrolizumab in bladder cancer model. Taken together, the urease-powered nanomotor would provide a paradigm as a next-generation platform for bladder cancer immunotherapy., Competing Interests: Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Purpose: The IMMUNOSARC trial combined an antiangiogenic agent (sunitinib) with a PD1 inhibitor (nivolumab) in advanced sarcomas. Here, we present the first correlative studies of the soft-tissue sarcoma cohort enrolled in this trial., Experimental Design: Formalin-fixed paraffin-embedded and peripheral blood samples were collected at baseline and week 13. Formalin-fixed paraffin-embedded samples were used for transcriptomics and multiplex immunofluorescence, whereas peripheral blood samples were used for multiplexed immunoassays. Flow cytometry and Luminex assays were performed to validate translational findings in tumor-isolated cells and peripheral blood mononuclear cells derived from patients., Results: The density of intratumoral CD8+ T cells, measured by multiplexed immunophenotyping, was significantly increased after treatment. This augment was accompanied by the dynamic significant increase in the gene expressions of CD86, CHI3L1, CXCL10, CXCL9, LAG3, and VCAM1 and the decrease in the expression levels of NR4A1. In peripheral blood, 12 proteins were significantly modulated by treatment at week 13. A score integrating the dynamic expression of the 7 genes and the 12 soluble factors separated 2 groups with distinct progression-free survival (PFS): 4.1 months [95% confidence interval, 3.5-not reached (NR)] versus 17 months (95% confidence interval, 12.0-NR), P = 0.014. This molecular score was predictive of PFS when applied to the normalized data determined in the baseline samples., Conclusions: Treatment with sunitinib and nivolumab inflamed the sarcoma microenvironment, increasing CD8+ T-cell density and the expression of several genes/proteins with relevance in the response to PD1 inhibitors. A molecular signature identified two groups of patients with distinct PFS for the combination of antiangiogenics plus PD1 inhibitor therapy., (©2024 American Association for Cancer Research.)

Our study aims to explore the effects of neoadjuvant chemotherapy (NACT) on tumour cells and immune cells in the immune microenvironment of patients with high-grade serous ovarian cancer (HGSOC). Single-cell RNA sequencing data of paired ovarian cancer tissues were analysed before and after NACT in 11 patients with HGSOC. The effect of NACT on two major cell components of the tumour microenvironment, epithelial cells and CD8+T cells, was investigated. The mechanisms of epithelial cell evasion by NACT and immune killing were explored from the perspectives of gene expression, functional characteristics, transcriptional regulation, and cell communication. Key targets for reversing NACT resistance were identified and possible therapeutic strategies proposed. While NACT improved the de novo differentiation of anti-tumour CD8+T cells, enhancing their anti-tumour function, it increased the proportion of cancer cells with high HSP90B1 expression. Thus, the potential reasons for NACT resistance were identified as: 1) high levels of endoplasmic reticulum stress (ERS) characteristics, 2) high expression of the MDK-NCL ligand-receptor pair between them and exhausted CD8+T cells before NACT, and 3) high expression of the NECTIN2-TIGIT immune ligand-receptor pair between them and exhausted CD8+T cells after NACT. Thus, our study reveals the mechanisms underlying NACT resistance in patients with HGSOC from the perspective of the independent and interactive roles of cancer cells and CD8+T cells. We propose therapeutic strategies targeting the ERS marker HSP90B1 and the immune escape marker MDK before or during NACT, while targeting NECTIN2 blockade after NACT. This approach may offer new insights into combination treatments for patients with HGSOC displaying NACT resistance., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

G-quadruplex (G4) is a noncanonical DNA secondary structure known to induce DNA damage and regulate the expression of immune-related genes. We aim to exploit the G4 folding as a treatment strategy to trigger anti-tumor immune response. In this study, we observe that the abundant genomic G4 in epithelial cells coexists with increased infiltration of CD8 + T cells in colorectal cancer tissue. Furthermore, our data substantiate the inhibitory effect of the G4 ligand TMPyP4 on cancer progression while concurrently stimulating anti-tumor immunity. Mechanistically, TMPyP4 impedes cancer cell proliferation and induces G2/M cell cycle arrest. Additionally, in vivo experiments demonstrate that TMPyP4 enhances the anti-tumor immune response by triggering DNA damage and activating the cGAS-STING pathway, which fosters CD8 + T cell activation and dendritic cell maturation. Importantly, the combined treatment of TMPyP4 and anti-PD1 exhibits a synergistic therapeutic effect on colorectal cancer. In summary, our findings underscore the potential of the G4 ligand TMPyP4 as a dual strategy to target colorectal cancer: inhibiting cancer progression and augmenting anti-tumor immunity through the activation of cGAS-STING pathway., Competing Interests: Competing interests The authors declare no competing interests. Ethics Approval And Consent To Participate The animal experiments were authorized by the Research Ethical Committee of the Sixth Affiliated Hospital of Sun Yat-sen University (Registration number: IACUC-2023061601). This study was approved by the Institutional Review Board of The Sixth Affiliated Hospital, Sun Yat-sen University, and written informed consent was obtained from all patients., (© 2024. The Author(s).)

Cancer immunotherapy is often hindered by an immunosuppressive tumor microenvironment (TME). Various strategies are being evaluated to shift the TME from an immunologically 'cold' to 'hot' tumor and hereby improve current immune checkpoint blockades (ICB). One particular hot topic is the use of combination therapies. Here, we set out to screen a variety of metallic nanoparticles and explored their in vitro toxicity against a series of tumor and non-tumor cell lines. For silver nanoparticles, we also explored the effects of core size and surface chemistry on cytotoxicity. Ag-citrate-5 nm nanoparticles were found to induce high cytotoxicity in Renca cells through excessive generation of reactive oxygen species (ROS) and significantly increased cytokine production. The induced toxicity resulted in a shift of the immunogenic cell death (ICD) marker calreticulin to the cell surface in vitro and in vivo. Subcutaneous Renca tumors were treated with anti-PD1 or in combination with Ag-citrate-5 nm. The combination group resulted in significant reduction in tumor size, increased necrosis, and immune cell infiltration at the tumor site. Inhibition of cytotoxic CD8 + T cells confirmed the involvement of these cells in the observed therapeutic effects. Our results suggest that Ag-citrate-5 nm is able to promote immune cell influx and increase tumor responsiveness to ICB therapies., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Background: Blockade of the programmed cell death protein 1 (PD-1) immune checkpoint (ICB) is revolutionizing cancer therapy, but little is known about the mechanisms governing its expression on CD8 T cells. Because PD-1 is induced during activation of T cells, we set out to uncover regulators whose inhibition suppresses PD-1 abundance without adversely impacting on T cell activation., Methods: To identify PD-1 regulators in an unbiased fashion, we performed a whole-genome, fluorescence-activated cell sorting (FACS)-based CRISPR-Cas9 screen in primary murine CD8 T cells. A dual-readout design using the activation marker CD137 allowed us to uncouple genes involved in PD-1 regulation from those governing general T cell activation., Results: We found that the inactivation of one of several members of the TMED/EMP24/GP25L/p24 family of transport proteins, most prominently TMED10, reduced PD-1 cell surface abundance, thereby augmenting T cell activity. Another client protein was cytotoxic T lymphocyte-associated protein 4 (CTLA-4), which was also suppressed by TMED inactivation. Treatment with TMED inhibitor AGN192403 led to lysosomal degradation of the TMED-PD-1 complex and reduced PD-1 abundance in tumor-infiltrating CD8 T cells (TIL) in mice, thus reversing T cell dysfunction. Clinically corroborating these findings, single-cell RNA analyses revealed a positive correlation between TMED expression in CD8 TIL, and both a T cell dysfunction signature and lack of ICB response. Similarly, patients receiving a TIL product with high TMED expression had a shorter overall survival., Conclusion: Our results uncover a novel mechanism of PD-1 regulation, and identify a pharmacologically tractable target whose inhibition suppresses PD-1 abundance and T cell dysfunction., Competing Interests: Competing interests: DSP and MAL are co-founders, shareholders and advisors of Flindr Tx (previously Immagene), which is unrelated to this study. The other authors declare no competing interests., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY. Published by BMJ.)

Current antibody-based immunotherapy depends on tumor antigen shedding for proper T cell priming. Here we select a novel human CD40 agonistic drug candidate and generate a bispecific antibody, herein named BiA9*2&#95;HF, that allows for rapid antibody-peptide conjugate formation. The format is designed to facilitate peptide antigen delivery to CD40 expressing cells combined with simultaneous CD40 agonistic activity. In vivo, the selected bispecific antibody BiA9*2&#95;HF loaded with peptide cargos induces improved antigen-specific proliferation of CD8 + (10-15 fold) and CD4 + T cells (2-7 fold) over control in draining lymph nodes. In both virus-induced and neoantigen-based mouse tumor models, BiA9*2&#95;HF demonstrates therapeutic efficacy and elevated safety profile, with complete tumor clearance, as well as measured abscopal impact on tumor growth. The BiA9*2&#95;HF drug candidate can thus be utilized to tailor immunotherapeutics for cancer patients., (© 2024. The Author(s).)

Introduction: Regulatory CD8 T cells (CD8 Treg) are responsible for the selective killing of self-reactive and pathogenic CD4 T cells. In autoimmune disease, CD8 Treg may accumulate in the peripheral blood but fail to control the expansion of pathogenic CD4 T cells that subsequently cause tissue destruction. This CD8 Treg dysfunction is due in part to the expression of inhibitory killer immunoglobulin-like receptors (KIR; KIR2DL isoforms [KIR2DL1, KIR2DL2, and KIR2DL3]); these molecules serve as autoimmune checkpoints and limit CD8 Treg activation., Methods: Here we describe the pre-clinical characterization of MTX-101, a bispecific antibody targeting inhibitory KIR and CD8. Using human peripheral blood mononuculear cells (PBMC) derived from healthy donors and autoimmune patients, humanized mouse models, and human derived tissue organoids, we evaluated the molecular mechanisms and functional effects of MTX-101., Results: By binding to KIR, MTX-101 inhibited KIR signaling that can restore CD8 Treg ability to eliminate pathogenic CD4 T cells. MTX-101 bound and activated CD8 Treg in human peripheral blood mononuclear cells (PBMC), resulting in increased CD8 Treg cytolytic capacity, activation, and prevalence. Enhancing CD8 Treg function with MTX-101 reduced pathogenic CD4 T cell expansion and inflammation, without increasing pro-inflammatory cytokines or activating immune cells that express either target alone. MTX-101 reduced antigen induced epithelial cell death in disease affected tissues, including in tissue biopsies from individuals with autoimmune disease (i.e., celiac disease, Crohn's disease). The effects of MTX-101 were specific to autoreactive CD4 T cells and did not suppress responses to viral and bacterial antigens. In a human PBMC engrafted Graft versus Host Disease (GvHD) mouse model of acute inflammation, MTX-101 bound CD8 Treg and delayed onset of disease. MTX-101 induced dose dependent binding, increased prevalence and cytolytic capacity of CD8 Treg, as well as increased CD4 T cell death. MTX-101 selectively bound CD8 Treg without unwanted immune cell activation or increase of pro-inflammatory serum cytokines and exhibited an antibody-like half-life in pharmacokinetic and exploratory tolerability studies performed using IL-15 transgenic humanized mice with engrafted human lymphocytes, including CD8 Treg at physiologic ratios., Conclusion: Collectively, these data support the development of MTX-101 for the treatment of autoimmune diseases., Competing Interests: The authors were employed by Mozart Therapeutics and declare that the study was funded by Mozart Therapeutics. Mozart Therapeutics was involved in the study design, collection, analysis, interpretation of data, the writing of this article, and the decision to submit it for publication., (Copyright © 2024 Gardell, Maurer, Childs, Pham, Meengs, Julien, Tan, Boster, Quach, Therriault, Hermansky, Patton, Bowser, Chen, Morgan, Gilbertson, Bogatzki, Encarnacion, McMahan, Crane and Swiderek.)

Introduction: IL-15 agonists hold promise as immunotherapeutics due to their ability to induce the proliferation and expansion of cytotoxic immune cells including natural killer (NK) and CD8 + T cells. However, they generally have short half-lives that necessitate frequent administration to achieve efficacy. To address this limitation, we have developed a half-life extension technology using hydrogel microspheres (MS). Here, the therapeutic is tethered to MSs by a releasable linker with pre-programed cleavage rates. We previously showed the MS conjugate of single-chain IL-15, MS~IL-15, effectively increased the half-life of IL-15 to approximately 1 week and enhanced the pharmacodynamics. We sought to determine whether the same would be true with a MS conjugate of the IL-15 agonist, receptor-linker IL-15 (RLI)., Methods: We prepared a long acting MS conjugate of RLI, MS~RLI. The pharmacokinetics and pharmacodynamics of MS~RLI were measured in C57BL/6J mice and compared to MS~IL-15. The antitumor efficacy of MS~RLI was measured when delivered subcutaneously or intratumorally in the CT26 tumor model and intratumorally in the orthotopic EO771 tumor model., Results: MS~RLI exhibited a half-life of 30 h, longer than most IL-15 agonists but shorter than MS~IL-15. The shorter than expected half-life of MS~RLI was shown to be due to target-mediated-disposition caused by an IL-15 induced cytokine sink. MS~RLI resulted in very potent stimulation of NK and CD44 hi CD8 + T cells, but also caused significant injection-site toxicity that may preclude subcutaneous administration. We thus pivoted our efforts toward studying the MS~RLI for long-acting intra-tumoral therapy, where some degree of necrosis might be beneficial. When delivered intra- tumorally, both MS~IL-15 and MS~RLI had modest anti-tumor efficacy, but high anti- metastatic activity., Conclusion: Intra-tumoral MS~RLI and MS~RLI combined with systemic treatment with other agents could provide beneficial antitumor and anti-metastatic effects without the toxic effects of systemic IL-15 agonists. Our findings demonstrate that intra-tumorally administered long-acting IL-15 agonists counter two criticisms of loco-regional therapy: the necessity for frequent injections and the challenge of managing metastases., Competing Interests: JH, RF, GH, GA and DVS are employees and hold options or stock in ProLynx Inc. BF and GP are inventors on US Government-owned patents related to hetIL-15. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Hangasky, Fernández, Stellas, Hails, Karaliota, Ashley, Felber, Pavlakis and Santi.)

Despite the potent immunoadjuvant properties of mevalonate pathway inhibitors, their application is constrained by poor solubility and instability. In this study, we developed a cationic nanoparticle-stabilized Pickering emulsion loaded with lovastatin (Lov-PPE), using polyethylenimine (PEI)-modified PLGA nanoparticles and squalene as carriers. The system was prepared and tested by evaluating the physicochemical properties and adjuvant efficacy of the Lov-PPE. Lov-PPE/O demonstrated good particle size distribution and zeta potential, with an adsorption efficiency of up to 73.07%. The immunization results showed that Lov-PPE/O significantly promoted the production of OVA-specific IgG antibodies, activated CD4 + and CD8 + T cells, and induced a strong mixed Th1/2 immune response. Additionally, safety assessments indicated that Lov-PPE/O has good in vivo safety. This study demonstrates that the PEI-modified lovastatin PLGA nanoparticle Pickering emulsion (Lov-PPE) is an effective vaccine adjuvant capable of significantly enhancing humoral and cellular immune responses while possessing good safety, offering a new strategy for vaccine formulation development.

Background/aim: Tremelimumab plus durvalumab is an approved first-line therapy for advanced hepatocellular carcinoma (HCC). Previous studies identified WNT/β-catenin mutations or CD8+ tumor-infiltrating lymphocytes (TILs) as biomarkers that can predict responsiveness to immune checkpoint inhibitor therapy in HCC. However, biomarkers for effectiveness of tremelimumab plus durvalumab in HCC have not been reported. This study investigated whether evaluation of WNT/β-catenin signaling and CD8+ TILs by immunohistochemical staining of tumor biopsy tissues can predict the response to tremelimumab plus durvalumab in patients with HCC., Patients and Methods: Fifteen HCC patients who underwent tumor biopsies were classified into three groups based on WNT/β-catenin signal activation and CD8+ TIL infiltration. The clinical responses to treatment in the groups were evaluated., Results: Four patients had HCC with WNT/β-catenin signal inactivation and high-level CD8+ TIL infiltration, four patients had HCC with WNT/β-catenin signal activation and low-level CD8+ TIL infiltration, and seven patients had WNT/β-catenin signal activation and high-level CD8+ TIL infiltration or WNT/β-catenin signal inactivation and low-level CD8+ TIL infiltration. A better response rate was observed in the WNT/β-catenin signal inactivation and high-level CD8+ TIL infiltration group, and a worse response rate was observed in the WNT/β-catenin signal activation and low-level CD8+ TIL infiltration group., Conclusion: Although the present study involved a small number of patients, the findings suggest that the efficacy of tremelimumab plus durvalumab may be affected by WNT/β-catenin signaling and CD8+ TIL infiltration., (Copyright © 2024, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Gallbladder cancer (GBC) is the most common and leading cause of cancer-associated mortality among biliary tract carcinomas worldwide and there is no specific drug for treatment. Activation of CD8+ T cell immune activity is one of the strategies to improve GBC treatment. This study is aimed to investigate the role of Ginsenoside Rg3 on CD8+ T cell activation and pathogenesis of GBC. In GBC cells, Rg3 administration led to the significant reduction of circFOXP1 and PD-L1 as measured by Quantitative real-time polymerase chain reaction (RT-qPCR) and Western blotting. Mechanistically, circFOXP1 acted as the sponge of miR-4477a to regulate PD-L1 expression as demonstrated by RNA pull-down assay and dual luciferase reporter assay. Rg3 treatment enhanced the activity of CD8+ T cells by inhibiting the circFOXP1/miR-4477a/PD-L1 signaling axis. Besides, Rg3 administration induced lipid oxidation and ROS reduction as detected by Flow cytometry, resulting in ferroptosis via the inactivation of circFOXP1/miR-4477a/PD-L1 axis. Ferroptosis inhibitor Fer-1 administration could reverse the beneficial effects caused by Rg3 treatment while ferroptosis inducer Erastin treatment enhanced the effects. Moreover, Rg3 gavage alleviated tumor growth and elevated ferroptosis and apoptosis in tumor tissues, which were prevented by PD-L1 overexpression. Furthermore, Rg3 was demonstrated to activate the function of CD8+ T cells via regulating the circFOXP1-miR-4477a-PD-L1 signaling axis in vivo. Rg3 inactivated the circFOXP1-miR-4477a-PD-L1 signaling axis to activate the immune function of CD8+ T cells, thereby inducing ferroptosis and apoptosis in GBC cells. This research recognizes the mechanism of Rg3-mediated anti-cancer effect and offers evidence for the potentiality of Rg3 in clinical application for GBC therapy., Competing Interests: Declarations. Conflict of interest: The authors declared no conflict of interest., (© 2024. The Pharmaceutical Society of Korea.)

Interleukin-4 (IL-4) controls cell growth and immune system regulation in tumorigenesis and can inhibit the growth of colon cancer cell lines, but the possible mechanism is unclear. In this study, we investigated the possible mechanism of IL-4 in colorectal cancer (CRC) through in vitro experiments. CRC cells received treatment with IL-4 (50 ng/mL), investigating the suppressor of cytokine signaling 1 (SOCS1)-related mechanism underlying the role of IL-4 in the progression and immunosuppression of CRC. The malignant processes of CRC cells and CD8 + T cell-mediated immune response in CRC cells were determined by CCK-8, Transwell, wound healing, and flow cytometry assays. Programmed death ligand 1 (PD-L1), SOCS1 expressions, and c-Jun N-terminal kinase (JNK) activation in CRC cells were analyzed by quantitative reverse transcription polymerase chain reaction and/or Western blot. IL-4 repressed the malignant processes, yet promoted the apoptosis of CRC cells. Besides, IL-4 downregulated PD-L1 level, upregulated SOCS1 level, and restrained JNK activation in CRC cells, while enhancing CRC cell-killing effect of CD8 + T cells. IL-4-induced effects on the aforementioned malignant processes of CRC cells and the killing effect of CD8 + T cells toward CRC cells were all reversed when SOCS1 was knocked down in the CRC cells. IL-4 downregulates PD-L1 level via SOCS1 upregulation-induced JNK deactivation to enhance antitumor immunity in in vitro CRC. The study provides a theoretical basis for the clinical application of IL-4 in antitumor immunity in CRC.

Immune checkpoint inhibition (ICI) with chemotherapy is now the standard of care for stage II-III triple-negative breast cancer; however, it is largely unknown for which patients ICI without chemotherapy could be an option and what the benefit of combination ICI could be. The adaptive BELLINI trial explored whether short combination ICI induces immune activation (primary end point, twofold increase in CD8 + T cells or IFNG), providing a rationale for neoadjuvant ICI without chemotherapy. Here, in window-of-opportunity cohorts A (4 weeks of anti-PD-1) and B (4 weeks of anti-PD-1 + anti-CTLA4), we observed immune activation in 53% (8 of 15) and 60% (9 of 15) of patients, respectively. High levels of tumor-infiltrating lymphocytes correlated with response. Single-cell RNA sequencing revealed that higher pretreatment tumor-reactive CD8 + T cells, follicular helper T cells and shorter distances between tumor and CD8 + T cells correlated with response. Higher levels of regulatory T cells after treatment were associated with nonresponse. Based on these data, we opened cohort C for patients with high levels of tumor-infiltrating lymphocytes (≥50%) who received 6 weeks of neoadjuvant anti-PD-1 + anti-CTLA4 followed by surgery (primary end point, pathological complete response). Overall, 53% (8 of 15) of patients had a major pathological response (<10% viable tumor) at resection, with 33% (5 of 15) having a pathological complete response. All cohorts met Simon's two-stage threshold for expansion to stage II. We observed grade ≥3 adverse events for 17% of patients and a high rate (57%) of immune-mediated endocrinopathies. In conclusion, neoadjuvant immunotherapy without chemotherapy demonstrates potential efficacy and warrants further investigation in patients with early triple-negative breast cancer. ClinicalTrials.gov registration: NCT03815890 ., Competing Interests: Competing interests R.M.M. reports research grants from Siemens Healhtineers, Bayer Healthcare, Screenpoint Medical, Beckton & Dickinson, PA Imaging, Lunit and Koning, and is an advisory board member for Screenpoint, Bayer, Siemens and Guerbet, all outside the scope of this work. E. Kalashnikova is an employee of Natera. G.S.S. reports research funding to the institute from Merck, Agendia, AstraZeneca, Roche and Novartis and a consulting role for Novartis, Seattle Genetics and Biovica, outside the submitted work. S.C.L. reports research funding to the institute from Roche/Genentech, AstraZeneca, BMS, Tesaro, Merck, Immunomedics, Eurocept Pharmaceuticals, Agendia and Novartis and a consulting role and travel grant from Daiichi Sankyo, outside this work. C.U.B. has received research grants from Novartis, BMS and NanoString, is a paid advisory board member for BMS, MSD, Roche, Novartis, GlaxoSmithKline, AstraZeneca, Pfizer, Lilly, GenMab and Pierre Fabre and holds ownership interest in Uniti Card, Neon Therapeutics and Forty Seven, all outside this submitted work. K.E.d.V. reports research funding from Roche and is a consultant for Macomics, outside the scope of this work. R.S. reports nonfinancial support from Merck and BMS, research support from Merck, Puma Biotechnology and Roche and personal fees from Roche, BMS and Exact Sciences for advisory boards, all outside the scope of this paper. L.F.A.W. reports funding to the institute from Genmab BV. T.N.S. is an advisor for Allogene Therapeutics, Asher Bio, Merus, Neogene Therapeutics and Scenic Biotech; is a stockholder in Allogene Therapeutics, Asher Bio, Cell Control, Celsius, Merus and Scenic Biotech; and is venture partner at Third Rock Ventures, all outside of the current work. M.K. reports research funding to the institute from BMS, Roche and AstraZeneca/MedImmune and an advisory role/speakers’ fee (all compensated to the institute) for Alderaan, BMS, Domain Therapeutics, Medscape, Roche, MSD and Daiichi Sankyo, outside the submitted work. Natera provided nonfinancial support to this study. The other authors declare no competing interests., (© 2024. The Author(s).)

Ammonia is thought to be a cytotoxin and its increase in the blood impairs cell function. However, whether and how this toxin triggers cell death under pathophysiological conditions remains unclear. Here we show that ammonia induces a distinct form of cell death in effector T cells. We found that rapidly proliferating T cells use glutaminolysis to release ammonia in the mitochondria, which is then translocated to and stored in the lysosomes. Excessive ammonia accumulation increases lysosomal pH and results in the termination of lysosomal ammonia storage and ammonia reflux into mitochondria, leading to mitochondrial damage and cell death, which is characterized by lysosomal alkalization, mitochondrial swelling and impaired autophagic flux. Inhibition of glutaminolysis or blocking lysosomal alkalization prevents ammonia-induced T cell death and improves T cell-based antitumour immunotherapy. These findings identify a distinct form of cell death that differs from previously known mechanisms., Competing Interests: Competing interests The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

The immunoregulatory cation channel TMEM176B plays a dual role in tumor immunity. On the one hand, TMEM176B promotes antigen cross-presentation to CD8 + T cells by regulating phagosomal pH in dendritic cells (DCs). On the other hand, it inhibits NLRP3 inflammasome activation through ionic mechanisms in DCs, monocytes and macrophages. We speculated that formulating BayK8644 in PEGylated chitosan nanoparticles (NP-PEG-BayK8644) should slowly release the compound and by that mean avoid cross-presentation inhibition (which happens with a fast 30 min kinetics) while still triggering inflammasome activation. Chitosan nanocarriers were successfully obtained, exhibiting a particle size within the range of 200 nm; they had a high positive surface charge and a 99 % encapsulation efficiency. In in vitro studies, NP-PEG-BayK8644 did not inhibit antigen cross-presentation by DCs, unlike the free compound. The NP-PEG-BayK8644 activated the inflammasome in a Tmem176b-dependent manner in DCs. We administered either empty (eNP-PEG) or NP-PEG-BayK8644 to mice with established tumors. NP-PEG-BayK8644 significantly controlled tumor growth and improved mice survival compared to both eNP-PEG and free BayK8644 in melanoma and lymphoma models. This effect was associated with enhanced inflammasome activation by DCs in the tumor-draining lymph node and infiltration of the tumor by CD8 + T cells. Thus, encapsulation of BayK8644 in chitosan NPs improves the anti-tumoral properties of the compound by avoiding inhibition of antigen cross-presentation., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: MH is founder and CSO of ARDAN Pharma. One patent application related to this work has been filed at the USA Patent and Trademark Office., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Immuno-oncology (IO) is a growing strategy in cancer treatment. Oncolytic viruses (OVs) can selectively infect cancer cells and lead to direct and/or immune-dependent tumor lysis. This approach represents an opportunity to potentiate the efficacy of immune checkpoint inhibitors (ICI), such as pembrolizumab. Currently, there is a lack of comprehensive quantitative models for the aforementioned scenarios. In this work, we developed a mechanistic framework describing viral kinetics, viral dynamics, and tumor response after intratumoral (i.t.) or intravenous (i.v.) administration of V937 alone or in combination with pembrolizumab. The model accounts for tumor shrinkage, in both injected and non-injected lesions, induced by: viral-infected tumor cell death and activated CD8 cells. OV-infected tumor cells enhanced the expansion of CD8 cells, whereas pembrolizumab inhibits their exhaustion by competing with PD-L1 in their binding to PD-1. Circulating viral levels and treatment effects on tumor volume were adequately characterized in all the different scenarios. This mechanistic-based model has been developed by combining top-down and bottom-up approaches and provides individual estimates of viral and ICI responses. The robustness of the model is reflected by the description of the tumor size time profiles in a variety of clinical scenarios. Additionally, this platform allows us to investigate not only the contribution of processes related to the viral kinetics and dynamics on tumor response, but also the influence of its interaction with an ICI. Additionally, the model can be used to explore different scenarios aiming to optimize treatment combinations and support clinical development., (© 2024 The Author(s). Clinical Pharmacology & Therapeutics published by Wiley Periodicals LLC on behalf of American Society for Clinical Pharmacology and Therapeutics.)

Lentinula edodes polysaccharides are natural immunomodulators. SeLe30, analyzed in this study, is a new mixture of selenium-enriched linear 1,4-α-glucans and 1,3-β- and 1,6-β-glucans isolated from L. edodes mycelium. In the present study, we evaluated its immunomodulatory properties in human T cells. Peripheral blood mononuclear cells (PBMCs) and T cells were isolated from healthy donors' buffy coats. The effects of SeLe30 on CD25, CD366, and CD279 expression, the subsets of CD8+ T cells, and IFN-γ, IL-6, and TNF-α production were analyzed. SeLe30 downregulated CD25, CD279, and CD366 expression on T cells stimulated by the anti-CD3 antibody (Ab) and upregulated in unstimulated and anti-CD3/CD28-Abs-stimulated T cells. It increased the percentage of central memory CD8+ T cells in unstimulated PBMCs and naïve and central memory T cells in anti-CD3-Ab-stimulated PBMCs. SeLe30 decreased the number of central memory and naïve CD8+ T cells in anti-CD3/CD28-stimulated T cells, whereas, in PBMCs, it reduced the percentage of effector memory CD8+ T cells. Moreover, SeLe30 upregulated cytokine production. SeLe30 exhibits context-dependent effects on T cells. It acts on unstimulated T cells, affecting their activation while increasing the expression of immune checkpoints, which sensitizes them to inhibitory signals that can silence this activation. In the case of a lack of costimulation, SeLe30 exhibits an inhibitory effect, reducing T-cell activation. In cells stimulated by dual signals, its effect is further enhanced, again increasing the "safety brake" of CD366 and CD279. However, the final SeLe30 effect is mediated by its indirect impacts by altering interactions with other immune cells.

Background: Oclacitinib (OCL), a Janus kinase inhibitor, is a novel immunomodulatory/immunosuppressive agent which is an approved as the first-line treatment for atopic dermatitis (AD) in dogs. The aim of the study was to investigate the effects of OCL on CD4 + and CD8 + T cells and their selected subsets under clinical conditions, i.e. in dogs suffering from AD, in terms of both safety and immune mechanisms underlying its therapeutic actions. Eight dogs were treated for 28 days with OCL at the recommended dose. Blood samples were taken at day 0, 7, 14 and 28., Results: The study showed that the mean percentage and absolute count of CD4 + and CD8 + T cells on the 14th and 28th day of the treatment with OCL did not differ from the corresponding baseline values, i.e. those before the treatment. On the 7th day of the treatment, the mean absolute count of CD4 + T cells and the mean percentage and absolute count of CD8 + T cells were significantly increased. The research found that on the 14th day of the treatment, the mean percentage and absolute count of CD25 + CD4 + and CD25 + CD8 + T cells were significantly decreased; the reduction in the percentage of CD25 + CD4 + T cells persisted on 28th day of the treatment. A two-week treatment with OCL resulted in an increase in the mean percentage of Foxp3 + CD4 + T cells, and this effect was sustained at the last time point. The treatment with OCL decreased the eosinophil level but does not affect the absolute counts of basophils, monocytes and neutrophils., Conclusions: The findings of the study strongly suggest that: (a) in terms of the impact of OCL on the number of PB CD4 + and CD8 + T cells, monthly treatment with the drug should be considered as a relatively safe; (b) the eosinophil-reducing effect and the down-regulation of the AD up-regulated CD25 expression on CD4 + Teff cells may constitute significant elements of the mechanism of action underlying the therapeutic effects of the drug in the treatment of canine AD; (c) the generation of inducible Foxp3-expressing CD4 + regulatory T cells - resulting in the shift of the CD4 + Treg cell (i.e. Foxp3 + CD4 + )/activated Teff (i.e. CD25 + CD4 + ) cell balance toward an increased proportion of Treg cells - may be considered as additional mechanism involved in producing the immunomodulatory/immunosuppressive properties of OCL., (© 2024. The Author(s).)