An in-situ peptide-antibody self-assembly to block CD47 and CD24 signaling enhances macrophage-mediated phagocytosis and anti-tumor immune responses.

Targeted immunomodulation for reactivating innate cells, especially macrophages, holds great promise to complement current adaptive immunotherapy. Nevertheless, there is still a lack of high-performance therapeutics for blocking macrophage phagocytosis checkpoint inhibitors in solid tumors. Herein, a peptide-antibody combo-supramolecular in situ assembled CD47 and CD24 bi-target inhibitor (PAC-SABI) is described, which undergoes biomimetic surface propagation on cancer cell membranes through ligand-receptor binding and enzyme-triggered reactions. By simultaneously blocking CD47 and CD24 signaling, PAC-SABI enhances the phagocytic ability of macrophages in vitro and in vivo, promoting anti-tumor responses in breast and pancreatic cancer mouse models. Moreover, building on the foundation of PAC-SABI-induced macrophage repolarization and increased CD8+ T cell tumor infiltration, sequential anti-PD-1 therapy further suppresses 4T1 tumor progression, prolonging survival rate. The in vivo construction of PAC-SABI-based nano-architectonics provides an efficient platform for bridging innate and adaptive immunity to maximize therapeutic potency.

Immunomic longitudinal profiling of the NeoPembrOv trial identifies drivers of immunoresistance in high-grade ovarian carcinoma.

PD-1/PD-L1 blockade has so far shown limited survival benefit for high-grade ovarian carcinomas. By using paired samples from the NeoPembrOv randomized phase II trial (NCT03275506), for which primary outcomes are published, and by combining RNA-seq and multiplexed immunofluorescence staining, we explore the impact of NeoAdjuvant ChemoTherapy (NACT) ± Pembrolizumab (P) on the tumor environment, and identify parameters that correlated with response to immunotherapy as a pre-planned exploratory analysis. Indeed, i) combination therapy results in a significant increase in intraepithelial CD8+PD-1+ T cells, ii) combining endothelial and monocyte gene signatures with the CD8B/FOXP3 expression ratio is predictive of response to NACT + P with an area under the curve of 0.93 (95% CI 0.85-1.00) and iii) high CD8B/FOXP3 and high CD8B/ENTPD1 ratios are significantly associated with positive response to NACT + P, while KDR and VEGFR2 expression are associated with resistance. These results indicate that targeting regulatory T cells and endothelial cells, especially VEGFR2+ endothelial cells, could overcome immune resistance of ovarian cancers.

Metformin synergizes with PD-1 blockade to promote normalization of tumor vessels via CD8T cells and IFNγ.

Tumor blood vessels are highly leaky in structure and have poor blood perfusion, which hampers infiltration and function of CD8T cells within tumor. Normalizing tumor vessels is thus thought to be important in promoting the flux of immune T cells and enhancing ant-tumor immunity. However, how tumor vasculature is normalized is poorly understood. Metformin (Met) combined with ant-PD-1 therapy is known to stimulate proliferation of and to produce large amounts of IFNγ from tumor-infiltrating CD8T lymphocytes (CD8TILs). We found that the combination therapy promotes the pericyte coverage of tumor vascular endothelial cells (ECs) to improve blood perfusion and that it suppresses the hyperpermeability through the increase of VE-cadherin. Peripheral node addressin(PNAd) and vascular cell adhesion molecule (VCAM)-1, both implicated to promote tumor infiltration of CD8T cells, were also increased. Importantly, tumor vessel normalization, characterized as the reduced 70-kDa dextran leakage and the enhancement of VE-cadherin and VCAM-1, were canceled by anti-CD8 Ab or anti-IFNγ Ab injection to mice. The increased CD8TILs were also abrogated by anti-IFNγ Ab injection. In vascular ECs, flow cytometry analysis revealed that pSTAT1 expression was found to be associated with VE-cadherin expression. Moreover, in vitro treatment with Met and IFNγ enhanced VE-cadherin and VCAM-1 on human umbilical vein endothelial cells (HUVECs). The Kaplan-Meier method revealed a correlation of VE-cadherin or VCAM-1 levels with overall survival in patients treated with immune checkpoint inhibitors. These data indicate that IFNγ-mediated cross talk of CD8TILs with tumor vessels is important for creating a better tumor microenvironment and maintaining sustained antitumor immunity.

Inhibition of DUSP18 impairs cholesterol biosynthesis and promotes anti-tumor immunity in colorectal cancer.

Tumor cells reprogram their metabolism to produce specialized metabolites that both fuel their own growth and license tumor immune evasion. However, the relationships between these functions remain poorly understood. Here, we report CRISPR screens in a mouse model of colo-rectal cancer (CRC) that implicates the dual specificity phosphatase 18 (DUSP18) in the establishment of tumor-directed immune evasion. Dusp18 inhibition reduces CRC growth rates, which correlate with high levels of CD8+ T cell activation. Mechanistically, DUSP18 dephosphorylates and stabilizes the USF1 bHLH-ZIP transcription factor. In turn, USF1 induces the SREBF2 gene, which allows cells to accumulate the cholesterol biosynthesis intermediate lanosterol and release it into the tumor microenvironment (TME). There, lanosterol uptake by CD8+ T cells suppresses the mevalonate pathway and reduces KRAS protein prenylation and function, which in turn inhibits their activation and establishes a molecular basis for tumor cell immune escape. Finally, the combination of an anti-PD-1 antibody and Lumacaftor, an FDA-approved small molecule inhibitor of DUSP18, inhibits CRC growth in mice and synergistically enhances anti-tumor immunity. Collectively, our findings support the idea that a combination of immune checkpoint and metabolic blockade represents a rationally-designed, mechanistically-based and potential therapy for CRC.

Tofacitinib Treatment Suppresses CD4+ T-Cell Activation and Th1 Response, Contributing to Protection against Staphylococcal Toxic Shock.

Staphylococcal toxic shock syndrome (STSS) is a rare, yet potentially fatal disease caused by Staphylococcus aureus (S. aureus) enterotoxins, known as superantigens, which trigger an intense immune response. Our previous study demonstrated the protective effect of tofacitinib against murine toxin-induced shock and a beneficial effect against S. aureus sepsis. In the current study, we examined the effects of tofacitinib on T-cell response in peripheral blood using a mouse model of enterotoxin-induced shock. Our data revealed that tofacitinib suppresses the activation of both CD4+ and CD8+ T cells in peripheral blood. Furthermore, both gene and protein levels of Th1 cytokines were downregulated by tofacitinib treatment in mice with enterotoxin-induced shock. Importantly, we demonstrated that CD4+ cells, but not CD8+ cells, are pathogenic in mice with enterotoxin-induced shock. In conclusion, our findings suggest that tofacitinib treatment suppresses CD4+ T-cell activation and Th1 response, thereby aiding in protection against staphylococcal toxic shock in mice. This insight may guide the future development of novel therapies for STSS.

Antibody-Decorated Nanoplatform to Reprogram Macrophage and Block Immune Checkpoint LSECtin for Effective Cancer Immunotherapy.

Repolarizing tumor-associated macrophages (TAMs) into tumor-inhibiting M1 macrophages has been considered a promising strategy for enhanced cancer immunotherapy. However, several immunosuppressive ligands (e.g., LSECtin) can still be highly expressed on M1 macrophages, inducing unsatisfactory therapeutic outcomes. We herein developed an antibody-decorated nanoplatform composed of PEGylated iron oxide nanoparticles (IONPs) and LSECtin antibody conjugated onto the surface of IONPs via the hydrazone bond for enhanced cancer immunotherapy. After intravenous administration, the tumor microenvironment (TME) pH could trigger the hydrazone bond breakage and induce the disassociation of the nanoplatform into free LSECtin antibodies and IONPs. Consequently, the IONPs could repolarize TAMs into M1 macrophages to remodel immunosuppressive TME and provide an additional anticancer effect via secreting tumoricidal factors (e.g., interlukin-12). Meanwhile, the LSECtin antibody could further block the activity of LSECtin expressed on M1 macrophages and relieve its immunosuppressive effect on CD8+ T cells, ultimately leading to significant inhibition of tumor growth.

MEK-inhibitor treatment reduces the induction of regulatory T cells in mice after influenza A virus infection.

Regulatory T cells (Tregs) play a crucial and complex role in balancing the immune response to viral infection. Primarily, they serve to regulate the immune response by limiting the expression of proinflammatory cytokines, reducing inflammation in infected tissue, and limiting virus-specific T cell responses. But excessive activity of Tregs can also be detrimental and hinder the ability to effectively clear viral infection, leading to prolonged disease and potential worsening of disease severity. Not much is known about the impact of Tregs during severe influenza. In the present study, we show that CD4+/CD25+FoxP3+ Tregs are strongly involved in disease progression during influenza A virus (IAV) infection in mice. By comparing sublethal with lethal dose infection in vivo, we found that not the viral load but an increased number of CD4+/CD25+FoxP3+ Tregs may impair the immune response by suppressing virus specific CD8+ T cells and favors disease progression. Moreover, the transfer of induced Tregs into mice with mild disease symptoms had a negative and prolonged effect on disease outcome, emphasizing their importance for pathogenesis. Furthermore, treatment with MEK-inhibitors resulted in a significant reduction of induced Tregs in vitro and in vivo and positively influenced the progression of the disease. Our results demonstrate that CD4+/CD25+FoxP3+ Tregs are involved in the pathogenesis of severe influenza and indicate the potential of the MEK-inhibitor zapnometinib to modulate CD4+/CD25+FoxP3+ Tregs. Thus, making MEK-inhibitors even more promising for the treatment of severe influenza virus infections.

Pexidartinib and Immune Checkpoint Inhibitors Combine to Activate Tumor Immunity in a Murine Colorectal Cancer Model by Depleting M2 Macrophages Differentiated by Cancer-Associated Fibroblasts.

Tumor-associated macrophages (TAMs) and cancer-associated fibroblasts (CAFs) are known to play supportive roles in tumor development and progression, but their interactions in colorectal cancer (CRC) remain unclear. Here, we investigated the effects of colon-cancer-derived CAFs on TAM differentiation, migration, and tumor immunity, both in vitro and in vivo. When co-cultured with monocytes, CAFs attracted monocytes and induced their differentiation into M2 macrophages. Immunohistology of surgically resected human CRC specimens and orthotopically transplanted mouse tumors revealed a correlation between numbers of CAFs and numbers of M2 macrophages. In a mouse model of CRC orthotopic transplantation, treatment with an inhibitor of the colony-stimulating factor-1 receptor (PLX3397) depleted M2 macrophages and increased CD8-positive T cells infiltrating the tumor nest. While this treatment had a minor effect on tumor growth, combining PLX3397 with anti-PD-1 antibody significantly reduced tumor growth. RNA-seq following combination therapy showed activation of tumor immunity. In summary, CAFs are involved in the induction and mobilization of M2 macrophage differentiation in the CRC tumor immune microenvironment, and the combination of cancer immunotherapy and PLX3397 may represent a novel therapeutic option for CRC.

Parabacteroides distasonis-Derived Outer Membrane Vesicles Enhance Antitumor Immunity Against Colon Tumors by Modulating CXCL10 and CD8+ T Cells.

Purpose: Given the potent immunostimulatory effects of bacterial outer membrane vesicles (OMVs) and the significant anti-colon tumor properties of Parabacteroides distasonis (Pd), this study aimed to elucidate the role and potential mechanisms of Pd-derived OMVs (Pd-OMVs) against colon cancer. Methods: This study isolated and purified Pd-OMVs from Pd cultures and assessed their characteristics. The effects of Pd-OMVs on CT26 cell uptake, proliferation, and invasion were investigated in vitro. In vivo, a CT26 colon tumor model was used to investigate the anti-colon tumor effects and underlying mechanisms of Pd-OMVs. Finally, we evaluated the biosafety of Pd-OMVs. Results: Purified Pd-OMVs had a uniform cup-shaped structure with an average size of 165.5 nm and a zeta potential of approximately -9.56 mV, and their proteins were associated with pathways related to immunity and apoptosis. In vitro experiments demonstrated that CT26 cells internalized the Pd-OMVs, resulting in a significant decrease in their proliferation and invasion abilities. Further in vivo studies confirmed the accumulation of Pd-OMVs in tumor tissues, which significantly inhibited the growth of colon tumors. Mechanistically, Pd-OMVs increased the expression of CXCL10, promoting infiltration of CD8+ T cells into tumor tissues and expression of pro-inflammatory factors TNF-α, IL-1ß, and IL-6. Notably, Pd-OMVs demonstrated a high level of biosafety. Conclusion: This paper elucidates that Pd-OMVs can exert significant anti-colon tumor effects by upregulating the expression of the chemokine CXCL10, thereby increasing the infiltration of CD8+ T cells into tumors and enhancing antitumor immune responses. This suggests that Pd-OMVs may be developed as a novel nanoscale potent immunostimulant with great potential for application in tumor immunotherapy. As well as developed as a novel nano-delivery carrier for combination with other antitumor drugs.

NIR-responsive CN-Pt-GEM hydrogel induces necroptosis and immunotherapeutic responses prevent postoperative recurrence and wound infection in lung carcinoma.

BACKGROUND: Cancer recurrence following surgical resection is a major cause of treatment failure. Finding effective methods to prevent postoperative recurrence and wound infection is an important component of successful surgery. With the development of new nanotechnology, more treatment options have been provided for postoperative adjuvant therapy. This study presents an innovative hydrogel system that stimulates tumoricidal immunity after surgical resection of non-small cell lung cancer (NSCLC) and prevents cancer relapse. RESULTS: The hydrogel system is based on the excellent photothermal conversion performance of single-atom platinum (CN-Pt) along with the delivery and release of the chemotherapy drug, gemcitabine (GEM). The system is coated onto the wound surface after tumor removal with subsequent near-infrared (NIR) photothermal therapy, which efficiently induces necroptosis of residual cancer cells, amplifies the levels of damage-associated molecular patterns (DAMPs), and increases the number of M1 macrophages. The significantly higher levels of phagocytic macrophages enhance tumor immunogenicity and sensitize cancer cells to CD8 + T-cell immunity to control postoperative recurrence, which has been verified using an animal model of postoperative lung cancer recurrence. The CN-Pt-GEM-hydrogel with NIR can also inhibit postoperative wound infection. CONCLUSIONS: These findings introduce an alternative strategy for supplementing antitumor immunity in patients undergoing resection of NSCLC tumors. The CN-Pt-GEM-hydrogel with the NIR system also exhibits good biosafety and may be adaptable for clinical application in relation to tumor resection surgery, wound tissue filling, infection prevention, and recurrence prevention.

PAK4 inhibition augments anti-tumour effect by immunomodulation in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumours, warranting novel treatments. Here, we examined the therapeutic efficacy of inhibiting p21 activated kinase 4 (PAK4) in OSCC and determined its immunomodulatory effect by focusing on the enhancement of anti-tumour effects. We examined PAK4 expression in OSCC cells and human clinical samples and analysed the proliferation and apoptosis of OSCC cells following PAK4 inhibition in vitro. We also investigated the effects of in vivo administration of a PAK4 inhibitor on immune cell distribution and T-cell immune responses in OSCC tumour-bearing mice. PAK4 was detected in all OSCC cells and OSCC tissue samples. PAK4 inhibitor reduced the proliferation of OSCC cells and induced apoptosis. PAK4 inhibitor significantly attenuated tumour growth in mouse and was associated with increased proportions of IFN-γ-producing CD8+ T-cells. Furthermore, PAK4 inhibitor increased the number of dendritic cells (DCs) and up-regulated the surface expression of various lymphocyte co-stimulatory molecules, including MHC-class I molecules, CD80, CD83, CD86, and CD40. These DCs augmented CD8+ T-cell activation upon co-culture. Our results suggest that PAK4 inhibition in OSCC can have direct anti-tumour and immunomodulatory effects, which might benefit the treatment of this malignancy.

Modulation of blood T cell polyfunctionality and HVEM/BTLA expression are critical determinants of clinical outcome in anti-PD1-treated metastatic melanoma patients.

The need for reliable biomarkers to predict clinical benefit from anti-PD1 treatment in metastatic melanoma (MM) patients remains unmet. Several parameters have been considered in the tumor environment or the blood, but none has yet achieved sufficient accuracy for routine clinical practice. Whole blood samples from MM patients receiving second-line anti-PD1 treatment (NCT02626065), collected longitudinally, were analyzed by flow cytometry to assess the immune cell subsets absolute numbers, the expression of immune checkpoints or ligands on T cells and the functionality of innate immune cells and T cells. Clinical response was assessed according to Progression-Free Survival (PFS) status at one-year following initiation of anti-PD1 (responders: PFS > 1 year; non-responders: PFS ≤ 1 year). At baseline, several phenotypic and functional alterations in blood immune cells were observed in MM patients compared to healthy donors, but only the proportion of polyfunctional memory CD4+ T cells was associated with response to anti-PD1. Under treatment, a decreased frequency of HVEM on CD4+ and CD8+ T cells after 3 months of treatment identified responding patients, whereas its receptor BTLA was not modulated. Both reduced proportion of CD69-expressing CD4+ and CD8+ T cells and increased number of polyfunctional blood memory T cells after 3 months of treatment were associated with response to anti-PD1. Of upmost importance, the combination of changes of all these markers accurately discriminated between responding and non-responding patients. These results suggest that drugs targeting HVEM/BTLA pathway may be of interest to improve anti-PD1 efficacy.

Lactate drives the ESM1-SCD1 axis to inhibit the antitumor CD8+ T-cell response by activating the Wnt/ß-catenin pathway in ovarian cancer cells and inducing cisplatin resistance.

Ovarian cancer (OC) is a gynecological malignancy that results in a global threat to women's lives. Lactic acid, a key metabolite produced from the glycolytic metabolism of glucose molecules, is correlated with tumor immune infiltration and platinum resistance. In our previous study, we found that endothelial cell-specific molecule 1 (ESM1) plays a key role in OC progression. This study revealed that lactate could upregulate ESM1, which enhances SCD1 to attenuate the antitumor CD8+ T-cell response. ESM1 and SCD1 expression levels were significantly greater in OC patients with high lactic acid levels than in those with low lactic acid levels. Further mechanistic studies suggested that the Wnt/ß-catenin pathway was inactivated after ESM1 knockdown and rescued by SCD1 overexpression. IC50 analysis indicated that the ESM1-SCD1 axis induces the resistance of OC cells to platinum agents, including cisplatin, carboplatin, and oxaliplatin, by upregulating P-gp. In conclusion, our study indicated that the induction of SCD1 by lactic acid-induced ESM1 can impede the CD8+ T-cell response against tumors and promote resistance to cisplatin by activating the Wnt/ß-catenin pathway in ovarian cancer. Consequently, targeting ESM1 may have considerable therapeutic potential for modulating the tumor immune microenvironment and enhancing drug sensitivity in OC patients.

A novel oral TLR7 agonist orchestrates immune response and synergizes with PD-L1 blockade via type I IFN pathway in lung cancer.

Despite the groundbreaking impact of immune checkpoint blockade (ICB), response rates in non-small cell lung cancer remain modest, particularly in immune-excluded or immune-desert microenvironments. Toll-like receptor 7 (TLR7) emerges as a latent target bridging innate and adaptive immunity, offering a promising avenue for combination therapies to augment ICB efficacy. Here, we explored the anti-tumor activity of the novel oral TLR7 agonist TQ-A3334 and its potential to enhance anti-programmed death ligand 1 (PD-L1) therapy through a combination strategy in a syngeneic murine lung cancer model. Oral administration of TQ-A3334 significantly alleviated tumor burden in C57BL/6J mice, modulated by type I interferon (IFN), and exhibited low toxicity. This therapy elicited activation of both innate and adaptive immune cells in tumor tissue, particularly increasing the abundance of CD8+ TILs through type I IFN pathway and subsequent CXCL10 expression. In vitro examinations validated that IFN-α-stimulated tumor cells exhibited increased secretion of CXCL10, conducive to the promoted trafficking of CD8+ T cells. Furthermore, combining TQ-A3334 with anti-PD-L1 treatment exceeded tumor control, with a further increase in CD8+ TIL frequency compared to monotherapy. These findings suggest that TQ-A3334 can mobilize innate immunity and promote T cell recruitment into the tumor microenvironment; a combination of TQ-A3334 and anti-PD-L1 antibodies can intensify the sensitivity of tumors to anti-PD-L1 therapy, which demonstrates significant potential for treating poorly immune-infiltrated lung cancer.

Glycoengineering-based anti-PD-1-iRGD peptide conjugate boosts antitumor efficacy through T cell engagement.

Despite the important breakthroughs of immune checkpoint inhibitors in recent years, the objective response rates remain limited. Here, we synthesize programmed cell death protein-1 (PD-1) antibody-iRGD cyclic peptide conjugate (αPD-1-(iRGD)2) through glycoengineering methods. In addition to enhancing tissue penetration, αPD-1-(iRGD)2 simultaneously engages tumor cells and PD-1+ T cells via dual targeting, thus mediating tumor-specific T cell activation and proliferation with mild effects on non-specific T cells. In multiple syngeneic mouse models, αPD-1-(iRGD)2 effectively reduces tumor growth with satisfactory biosafety. Moreover, results of flow cytometry and single-cell RNA-seq reveal that αPD-1-(iRGD)2 remodels the tumor microenvironment and expands a population of "better effector" CD8+ tumor infiltrating T cells expressing stem- and memory-associated genes, including Tcf7, Il7r, Lef1, and Bach2. Conclusively, αPD-1-(iRGD)2 is a promising antibody conjugate therapeutic beyond antibody-drug conjugate for cancer immunotherapy.

A novel doxorubicin/CTLA-4 blocker co-loaded drug delivery system improves efficacy and safety in antitumor therapy.

Doxorubicin's antitumor effectiveness may be constrained with ineffective tumor penetration, systemic adverse effects, as well as drug resistance. The co-loading of immune checkpoint inhibitors and doxorubicin into liposomes can produce synergistic benefits and address problems, including quick drug clearance, toxicity, and low drug penetration efficiency. In our previous study, we modified a nanobody targeting CTLA-4 onto liposomes (LPS-Nb36) to be an extremely potent CTLA-4 signal blocker which improve the CD8+ T-cell activity against tumors under physiological conditions. In this study, we designed a drug delivery system (LPS-RGD-Nb36-DOX) based on LPS-Nb36 that realized the doxorubicin and anti-CTLA-4 Nb co-loaded and RGD modification, and was applied to antitumor therapy. We tested whether LPS-RGD-Nb36-DOX could targets the tumor by in vivo animal photography, and more importantly, promote cytotoxic T cells proliferation, pro-inflammatory cytokine production, and cytotoxicity. Our findings demonstrated that the combination of activated CD8+ T cells with doxorubicin/anti-CTLA-4 Nb co-loaded liposomes can effectively eradicate tumor cells both in vivo and in vitro. This combination therapy is anticipated to have synergistic antitumor effects. More importantly, it has the potential to reduce the dose of chemotherapeutic drugs and improve safety.

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.

Delivery of mRNA Encoding Interleukin-12 and a Stimulator of Interferon Genes Agonist Potentiates Antitumor Efficacy through Reversing T Cell Exhaustion.

T cell exhaustion has emerged as a major hurdle that impedes the clinical translation of stimulator of interferon genes (STING) agonists. It is crucial to explore innovative strategies to rejuvenate exhausted T cells and potentiate the antitumor efficacy. Here, we propose an approach utilizing MSA-2 as a STING agonist, along with nanoparticle-mediated delivery of mRNA encoding interleukin-12 (IL-12) to restore the function of T cells. We developed a lipid nanoparticle (DMT7-IL12 LNP) that encapsulated IL12 mRNA. Our findings convincingly demonstrated that the combination of MSA-2 and DMT7-IL12 LNP can effectively reverse the exhausted T cell phenotype, as evidenced by the enhanced secretion of cytokines, such as tumor necrosis factor alpha, interferon gamma, and Granzyme B, coupled with reduced levels of inhibitory molecules such as T cell immunoglobulin and mucin domain-3 and programmed cell death protein-1 on CD8+ T cells. Furthermore, this approach led to improved survival and tumor regression without causing any systemic toxicity in melanoma and lung metastasis models. These findings suggest that mRNA encoding IL-12 in conjunction with STING agonists has the potential to confer superior clinical outcomes, representing a promising advancement in cancer immunotherapy.

Anti-PD-1 cis-delivery of low-affinity IL-12 activates intratumoral CD8+T cells for systemic antitumor responses.

Immune checkpoint blockade (ICB) therapies function by alleviating immunosuppression on tumor-infiltrating lymphocytes (TILs) but are often insufficient to fully reactivate these dysfunctional TILs. Although interleukin 12 (IL-12) has been used in combination with ICB to improve efficacy, this remains limited by severe toxicity associated with systemic administration of this cytokine. Here, we engineer a fusion protein composed of an anti-PD-1 antibody and a mouse low-affinity IL-12 mutant-2 (αPD1-mIL12mut2). Systemic administration of αPD1-mIL12mut2 displays robust antitumor activities with undetectable toxicity. Mechanistically, αPD1-mIL12mut2 preferentially activates tumor-infiltrating PD-1+CD8+T cells via high-affinity αPD-1 mediated cis-binding of low-affinity IL-12. Additionally, αPD1-mIL12mut2 treatment exerts an abscopal effect to suppress distal tumors, as well as metastasis. Collectively, αPD1-mIL12mut2 treatment induces robust systemic antitumor responses with reduced side effects.

Exploration of Immune-Modulatory Effects of Amivantamab in Combination with Pembrolizumab in Lung and Head and Neck Squamous Cell Carcinoma.

Immune checkpoint inhibitors are effective first-line therapy for solid cancers. However, low response rate and acquired resistance over time has led to the need for additional therapeutic options. Here, we evaluated synergistic antitumor efficacy of EGFR × MET targeting bispecific antibody, amivantamab with PD-L1 immunotherapy, pembrolizumab in head and neck squamous cell carcinoma (HNSCC) and lung squamous cell carcinoma tumor-bearing humanized patient-derived xenograft (PDX) models. We demonstrated that pembrolizumab or amivantamab alone was ineffective and that combination treatment induced a significant reduction of tumor growth in both models (P < 0.0001 and P < 0.01, respectively). It appeared that combination of amivantamab and pembrolizumab significantly enhanced infiltration of granzyme B-producing CD8 T cells was in the TME of HNSCC PDX (P < 0.01) and enhanced neoantigen-associated central memory CD8 T cells in circulating immune cells. Analysis of single-cell RNA transcriptomics suggested that the tumor cells dramatically upregulated EGFR and MET in response to PD-L1 immunotherapy, potentially creating a metabolic state fit for tumor persistence in the tumor microenvironment (TME) and rendered pembrolizumab ineffective. We demonstrated that EGFRHIGHMETHIGH subcluster displayed an increased expression of genes implicated in production of lactate [SLC16A3 and lactate dehydrogenase A (LDHA)] compared to the EGFRLOWMETLOW cluster. Accumulation of lactate in the TME has been associated with immunosuppression by hindering the infiltration of tumor killing CD8 T and NK cells. This study proved that amivantamab reduced glycolytic markers in the EGFRHIGHMETHIGH subcluster including SLC16A3 and LDHA and highlighted remodeling of the TME by combination treatment, providing rationale for additional therapy of amivantamab with PD-1 immunotherapy. SIGNIFICANCE: Amivantamab in synergy with pembrolizumab effectively eradicated EGFRHIGHMETHIGH tumor subcluster in the tumor microenvironment of head and neck squamous cell carcinoma and overcame resistance against anti-PD-1 immunotherapy.