Turning anecdotal irradiation-induced anticancer immune responses into reproducible in situ cancer vaccines via disulfiram/copper-mediated enhanced immunogenic cell death of breast cancer cells

Irradiation (IR) induces immunogenic cell death (ICD) in tumors, but it rarely leads to the abscopal effect (AE); even combining IR with immune checkpoint inhibitors has shown only anecdotal success in inducing AEs. In this study, we aimed to enhance the IR-induced immune response and generate reproducible AEs using the anti-alcoholism drug, disulfiram (DSF), complexed with copper (DSF/Cu) to induce tumor ICD. We measured ICD in vitro and in vivo. In mouse tumor models, DSF/Cu was injected intratumorally followed by localized tumor IR, creating an in situ cancer vaccine. We determined the anticancer response by primary tumor rejection and assessed systemic immune responses by tumor rechallenge and the occurrence of AEs relative to spontaneous lung metastasis. In addition, we analyzed immune cell subsets and quantified proinflammatory and immunosuppressive chemokines/cytokines in the tumor microenvironment (TME) and blood of the vaccinated mice. Immune cell depletion was investigated for its effects on the vaccine-induced anticancer response. The results showed that DSF/Cu and IR induced more potent ICD under hypoxia than normoxia in vitro. Low-dose intratumoral (i.t.) injection of DSF/Cu and IR(12Gy) demonstrated strong anti-primary and -rechallenged tumor effects and robust AEs in mouse models. These vaccinations also increased CD8+ and CD4+ cell numbers while decreasing Tregs and myeloid-derived suppressor cells in the 4T1 model, and increased CD8+, dendritic cells (DC), and decreased Treg cell numbers in the MCa-M3C model. Depleting both CD8+ and CD4+ cells abolished the vaccine's anticancer response. Moreover, vaccinated tumor-bearing mice exhibited increased TNFα levels and reduced levels of immunosuppressive chemokines/cytokines. In conclusion, our novel approach generated an anticancer immune response that results in a lack of or low tumor incidence post-rechallenge and robust AEs, i.e., absence of or decreased spontaneous lung metastasis in tumor-bearing mice. This approach is readily translatable to clinical settings and may increase IR-induced AEs in cancer patients.

[A case of crizotinib-associated renal cysts]

Crizotinib-associated renal cysts (CARC) are the development of new renal cysts or pre-existing renal cysts after the treatment with crizotinib. Most CARC disappear after crizotinib is stopped. A few CARC showed aggressive behavior that could go beyond the invasion of the renal cortex into nearby structures, including perirenal space, psoas major muscle, intestine, and abdominal wall. A case of EML4-ALK fusion mutation in invasive lung adenocarcinoma has been reported. Multiple cystic changes occurred repeatedly in both kidneys, right rectus muscle, and psoas major muscle after treatment with crizotinib, and spontaneous absorption and resolution after discontinuation of the drug.

Reprogramming the Intrahepatic Cholangiocarcinoma Immune Microenvironment by Chemotherapy and CTLA-4 Blockade Enhances Anti-PD-1 Therapy

Intrahepatic cholangiocarcinoma (ICC) has limited therapeutic options and a dismal prognosis. Adding blockade of the anti-programmed cell death protein (PD)-1 pathway to gemcitabine/cisplatin chemotherapy has recently shown efficacy in biliary tract cancers but with low response rates. Here, we studied the effects of anti-cytotoxic T lymphocyte antigen (CTLA)-4 when combined with anti-PD-1 and gemcitabine/cisplatin in orthotopic murine models of ICC. This combination therapy led to substantial survival benefits and reduction of morbidity in two aggressive ICC models that were resistant to immunotherapy alone. Gemcitabine/cisplatin treatment increased tumor-infiltrating lymphocytes and normalized the ICC vessels and, when combined with dual CTLA-4/PD-1 blockade, increased the number of activated CD8+Cxcr3+IFNγ+ T cells. CD8+ T cells were necessary for the therapeutic benefit because the efficacy was compromised when CD8+ T cells were depleted. Expression of Cxcr3 on CD8+ T cells is necessary and sufficient because CD8+ T cells from Cxcr3+/+ but not Cxcr3-/- mice rescued efficacy in T cell‒deficient mice. Finally, rational scheduling of anti-CTLA-4 "priming" with chemotherapy followed by anti-PD-1 therapy achieved equivalent efficacy with reduced overall drug exposure. These data suggest that this combination approach should be clinically tested to overcome resistance to current therapies in ICC patients.

Wnt inhibition alleviates resistance to immune checkpoint blockade in glioblastoma

Wnt signaling plays a critical role in the progression and treatment outcome of glioblastoma (GBM). Here, we identified WNT7b as a heretofore unknown mechanism of resistance to immune checkpoint inhibition (αPD1) in GBM patients and murine models. Acquired resistance to αPD1 was found to be associated with the upregulation of Wnt7b and β-catenin protein levels in GBM in patients and in a clinically relevant, stem-rich GBM model. Combining the porcupine inhibitor WNT974 with αPD1 prolonged the survival of GBM-bearing mice. However, this combination had a dichotomous response, with a subset of tumors showing refractoriness. WNT974 and αPD1 expanded a subset of DC3-like dendritic cells (DCs) and decreased the granulocytic myeloid-derived suppressor cells (gMDSCs) in the tumor microenvironment (TME). By contrast, monocytic MDSCs (mMDSCs) increased, while T-cell infiltration remained unchanged, suggesting potential TME-mediated resistance. Our preclinical findings warrant the testing of Wnt7b/β-catenin combined with αPD1 in GBM patients with elevated Wnt7b/β-catenin signaling.

Indole-3-Propionic Acid, a Gut Microbiota Metabolite, Protects Against the Development of Postoperative Delirium

OBJECTIVE

The aim was to determine preoperative gut microbiota metabolites that may be associated with postoperative delirium (POD) development in patients and further study in rodents.

SUMMARY BACKGROUND DATA

POD occurs in 9% to 50% of older patients undergoing anesthesia/surgery but lacks effective treatments or prevention. High-throughput metabolomics using liquid chromatography with tandem mass spectrometry has accelerated disease-related biomarkers discovery. We performed metabolomic studies in humans to identify potential metabolite biomarkers linked to POD and examined potential mechanisms in rodents.

METHODS

We performed a prospective observational cohort study to examine the metabolomic changes that were associated with the development of POD. Then the gut microbiota-related metabolomic changes were recapitulated by gut microbiota perturbation in rodents. POD was assessed in mice using a battery of behavioral tests including novel objective test, Y-maze test, open-field test, and buried food test. The mechanisms through which gut microbiota-related metabolomic changes influenced POD were examined using chemogenetics.

RESULTS

Indole-3-propionic acid (IPA) is a gut microbiota metabolite that belongs to the indole family. Baseline plasma levels of IPA were significantly inversely correlated with the onset of POD in 103 (17 cases) human individuals. This relationship was validated in preclinical mouse models for POD: reducing IPA levels through gut microbiota perturbation promoted POD-like behavior. More importantly, IPA administration deterred POD-like behavior. Colonization of germ-free mice with mutant Clostridium sporogenes that did not produce IPA-promoted POD-like behavior. Chemogenetic studies revealed that the protective effect of IPA in mice was mediated, in part, by peroxisome proliferator-activated receptor gamma coactivator 1-alpha in hippocampal interneurons.

CONCLUSIONS

Gut microbiota-derived IPA is an important molecule implicated in the pathogenesis of POD, which could potentially be harnessed for POD prevention.

Lymphatic muscle cells are unique cells that undergo aging induced changes

Lymphatic muscle cells (LMCs) within the wall of collecting lymphatic vessels exhibit tonic and autonomous phasic contractions, which drive active lymph transport to maintain tissue-fluid homeostasis and support immune surveillance. Damage to LMCs disrupts lymphatic function and is related to various diseases. Despite their importance, knowledge of the transcriptional signatures in LMCs and how they relate to lymphatic function in normal and disease contexts is largely missing. We have generated a comprehensive transcriptional single-cell atlas-including LMCs-of collecting lymphatic vessels in mouse dermis at various ages. We identified genes that distinguish LMCs from other types of muscle cells, characterized the phenotypical and transcriptomic changes in LMCs in aged vessels, and uncovered a pro-inflammatory microenvironment that suppresses the contractile apparatus in advanced-aged LMCs. Our findings provide a valuable resource to accelerate future research for the identification of potential drug targets on LMCs to preserve lymphatic vessel function as well as supporting studies to identify genetic causes of primary lymphedema currently with unknown molecular explanation.

Preventing NK cell activation in the damaged liver induced by cabozantinib/PD-1 blockade increases survival in hepatocellular carcinoma models

The addition of anti-VEGF antibody treatment to immune checkpoint blockade (ICB) has increased the efficacy of immunotherapy in advanced hepatocellular carcinoma (HCC). Despite an initial promise, adding multitargeted kinase inhibitors of VEGFR with ICB has failed to increase survival in HCC. To reveal the mechanisms underlying treatment failure, we studied the effects of cabozantinib/ICB using orthotopic murine HCC models with or without liver damage. We monitored tumor growth and liver function, recorded survival outcomes, and performed immune profiling studies for intra-tumoral and surrounding liver. Cabozantinib/ICB treatment led to tumor regression and significantly improved survival in mice with normal livers. However, consistent with the clinical findings, combination therapy failed to show survival benefits despite similar tumor control when tested in the same models but in mice with liver fibrosis. Moreover, preclinical and clinical data converged, showing that activating immune responses by cabozantinib/ICB treatment induced hepatoxicity. Immune profiling revealed that combination therapy effectively reprogrammed the tumor immune microenvironment and increased NK cell infiltration and activation in the damaged liver tissue. Surprisingly, systemic depletion of NK reduced hepatotoxicity elicited by the combination therapy without compromising its anti-cancer effect, and significantly enhanced the survival benefit even in mice with HCC and underlying liver fibrosis. These findings demonstrate that preventing NK activation allowed for maintaining a favorable therapeutic ratio when combining ICB with cabozantinib in advanced HCC models.

Predictive role of admission serum glucose, baseline NIHSS score, and fibrinogen on hemorrhagic transformation after intravenous thrombolysis with alteplase in acute ischemic stroke

OBJECTIVE

This study aimed to investigate the predictive role of admission serum glucose, baseline NIHSS score, and fibrinogen on hemorrhagic transformation after intravenous thrombolysis with alteplase in acute ischemic stroke.

PATIENTS AND METHODS

A total of 254 patients admitted with acute ischemic stroke who received intravenous thrombolysis with alteplase from January 2016 to December 2017 were selected to collect clinical data. Patients were divided into a hemorrhagic transformation group (n=70) and a no-hemorrhagic transformation group (n=184) based on repeat CT/magnetic resonance imaging (MRI) findings during the acute period. The demographic data, past medical history and laboratory examination indexes of the two groups were compared. Multivariate Logistic regression analysis was used to explore the influencing factors of hemorrhage transformation after intravenous thrombolysis in patients with acute ischemic stroke. ROC curve was used to plot the ability of blood glucose at admission, baseline NIHSS score and fibrinogen alone to predict bleeding transformation after intravenous thrombolysis of alteplase, and then the combined model of the three was constructed and the predictive ability of this model to bleeding transformation was evaluated.

RESULTS

Among 254 patients, 70% (27.55%) had hemorrhage transformation. Except for DNT, red blood cell count, platelet count, fibrinogen, smoking, atrial fibrillation, baseline NIHSS score and admission serum glucose, there were statistically significant differences between the hemorrhagic transformation group and the non-hemorrhagic transformation group (p<0.05), and there were no statistically significant differences in other indicators between the two groups (p>0.05). The combined model was better than the three models alone in predicting the risk of bleeding conversion (p<0.05). Compared with the group without hemorrhagic transformation, the 90d prognosis was worse in the hemorrhage transformation group (p<0.05).

CONCLUSIONS

Admission blood glucose, NIHSS score, and fibrinogen are independent risk factors for hemorrhage transformation after intravenous thrombolysis of alteplase in patients with acute ischemic stroke, and the combined model established by them has high predictive efficacy for hemorrhage transformation risk after intravenous thrombolysis of alteplase.

Stressed target cancer cells drive nongenetic reprogramming of CAR T cells and solid tumor microenvironment

The poor efficacy of chimeric antigen receptor T-cell therapy (CAR T) for solid tumors is due to insufficient CAR T cell tumor infiltration, in vivo expansion, persistence, and effector function, as well as exhaustion, intrinsic target antigen heterogeneity or antigen loss of target cancer cells, and immunosuppressive tumor microenvironment (TME). Here we describe a broadly applicable nongenetic approach that simultaneously addresses the multiple challenges of CAR T as a therapy for solid tumors. The approach reprograms CAR T cells by exposing them to stressed target cancer cells which have been exposed to the cell stress inducer disulfiram (DSF) and copper (Cu)(DSF/Cu) plus ionizing irradiation (IR). The reprogrammed CAR T cells acquire early memory-like characteristics, potent cytotoxicity, enhanced in vivo expansion, persistence, and decreased exhaustion. Tumors stressed by DSF/Cu and IR also reprogram and reverse the immunosuppressive TME in humanized mice. The reprogrammed CAR T cells, derived from peripheral blood mononuclear cells of healthy donors or metastatic female breast cancer patients, induce robust, sustained memory and curative anti-solid tumor responses in multiple xenograft mouse models, establishing proof of concept for empowering CAR T by stressing tumor as a promising therapy for solid tumors.

Cancer cell plasticity and MHC-II-mediated immune tolerance promote breast cancer metastasis to lymph nodes

Tumor-draining lymph nodes (TDLNs) are important for tumor antigen-specific T cell generation and effective anticancer immune responses. However, TDLNs are often the primary site of metastasis, causing immune suppression and worse outcomes. Through cross-species single-cell RNA-Seq analysis, we identified features defining cancer cell heterogeneity, plasticity, and immune evasion during breast cancer progression and lymph node metastasis (LNM). A subset of cancer cells in the lymph nodes exhibited elevated MHC class II (MHC-II) gene expression in both mice and humans. MHC-II+ cancer cells lacked costimulatory molecule expression, leading to regulatory T cell (Treg) expansion and fewer CD4+ effector T cells in TDLNs. Genetic knockout of MHC-II reduced LNM and Treg expansion, while overexpression of the MHC-II transactivator, Ciita, worsened LNM and caused excessive Treg expansion. These findings demonstrate that cancer cell MHC-II expression promotes metastasis and immune evasion in TDLNs.

Turning anecdotal irradiation-induced anti-cancer immune responses into reproducible in situ cancer vaccines via disulfiram/copper-mediated enhanced immunogenic cell death of breast cancer cells

Irradiation (IR) induces immunogenic cell death (ICD) in tumors, but it rarely leads to the abscopal effect (AE). However, combining IR with immune checkpoint inhibitors has shown anecdotal success in inducing AEs. In this study, we aimed to enhance the IR-induced immune response and generate reproducible AEs using the anti-alcoholism drug disulfiram (DSF) and copper complex (DSF/Cu) via induction of tumor ICD. We measured ICD in vitro and in vivo. In mouse tumor models, DSF/Cu was injected intratumorally followed by localized tumor IR, creating an in situ cancer vaccine. We determined the anti-cancer response by primary tumor rejection and assessed systemic immune responses by tumor rechallenge and the occurrence of AEs, i.e., spontaneous lung metastasis. Additionally, we analyzed immune cell subsets and quantified proinflammatory and immunosuppressive chemokines/cytokines in the tumor microenvironment (TME) and blood of the vaccinated mice. Immune cell depletion was investigated for its effects on the vaccine-induced anti-cancer response. The results showed that DSF/Cu and IR induced more potent ICD under hypoxia than normoxia in vitro. Low-dose intratumoral injection of DSF/Cu and IR demonstrated strong anti-primary and -rechallenged tumor effects and robust AEs in mouse models. These vaccinations also increased CD8 + and CD4 + cell numbers while decreasing Tregs and myeloid-derived suppressor cells in the 4T1 model, and increased CD8+, DC, and decreased Treg cell numbers in the MCa-M3C model. Depleting both CD8 + and CD4 + cells abolished the vaccine's anticancer response. Moreover, vaccinated tumor-bearing mice exhibited increased TNFα levels and reduced levels of immunosuppressive chemokines/cytokines. In conclusion, our novel approach generated an anti-cancer immune response, resulting in a lack of or low tumor incidence post-rechallenge and robust AEs, i.e., the absence of or decreased spontaneous lung metastasis in tumor-bearing mice. This approach is readily translatable to clinical settings and may increase IR-induced AEs in cancer patients.

Effects of different targeted therapies associated with adjuvant chemotherapy on clinical remission, survival and safety in patients with triple-negative breast cancer: a systematic review and meta-analysis

OBJECTIVE

The aim of this study was to systematically assess the effects of different targeted therapies associated with adjuvant chemotherapy on clinical remission, survival and safety of patients with triple-negative breast cancer (TNBC).

MATERIALS AND METHODS

This study searched for case-control trials of TNBC patients from January 2010 to May 2022. Two researchers independently extracted data. RevMan 5.3 statistical software was used for analysis.

RESULTS

This study included a total of 7 clinical controlled studies, containing 620 samples. The results showed that compared with the control group, the study group showed significant differences in objective response rate [OR = 2.44, 95% CI (1.69, 3.5), p < 0.00001], 1-year survival rate [OR = 3.59, 95% CI (2.01, 6.39), p < 0.0001], progression-free survival (PFS) [MD = 2.04, 95% CI (1.68, 2.41), p < 0.00001], with statistical significance (p < 0.05), while there are no significant differences in overall survival [MD = 6.33, 95% CI (-1.65, 14.30), p = 0.12] and incidence of adverse events [OR = 0.73, 95% CI (0.52, 1.02), p = 0.006] (p > 0.05).

CONCLUSIONS

Targeted therapy associated with adjuvant chemotherapy can remarkably enhance the outcome of patients with advanced TNBC, prolonging their progression-free survival (PFS) and overall survival (OS) without increasing adverse effects. The validity of this research, however, will require higher quality studies and longer follow-ups.

"Isolation and characterization of a novel hormone receptor positive mammary adenocarcinoma MCa-P1362 with stromal drivers of tumor growth, metastasis, and drug resistance"

Preclinical models that display spontaneous metastasis are necessary to improve therapeutic options for hormone receptor positive breast cancers. In this study, we conducted a detailed cellular and molecular characterization of MCa-P1362, a novel syngeneic Balb/c mouse model of metastatic breast cancer. MCa-P1362 cancer cells expressed estrogen receptors (ER), progesterone receptors (PR), and HER-2 receptors. MCa-P1362 cells proliferate in vitro and in vivo in response to estrogen, yet do not depend on steroid hormones for tumor progression. Further characterization of MCa-P1362 tumor explants shows that they contain a mixture of epithelial cancer cells and stromal cells. Based on transcriptomic and functional analyses of cancer and stromal cells, stem cells are present in both populations. Functional studies demonstrate that crosstalk between cancer and stromal cells promotes tumor growth, metastasis, and drug resistance. MCa-P1362 may serve as a useful preclinical model to investigate the cellular and molecular basis of hormone receptor positive tumor progression and therapeutic resistance.

Absence of Tissue-Sparing Effects in Partial Proton FLASH Irradiation in Murine Intestine

Ultra-high dose rate irradiation has been reported to protect normal tissues more than conventional dose rate irradiation. This tissue sparing has been termed the FLASH effect. We investigated the FLASH effect of proton irradiation on the intestine as well as the hypothesis that lymphocyte depletion is a cause of the FLASH effect. A 16 × 12 mm² elliptical field with a dose rate of ~120 Gy/s was provided by a 228 MeV proton pencil beam. Partial abdominal irradiation was delivered to C57BL/6j and immunodeficient Rag1^-/-/C57 mice. Proliferating crypt cells were counted at 2 days post exposure, and the thickness of the muscularis externa was measured at 280 days following irradiation. FLASH irradiation did not reduce the morbidity or mortality of conventional irradiation in either strain of mice; in fact, a tendency for worse survival in FLASH-irradiated mice was observed. There were no significant differences in lymphocyte numbers between FLASH and conventional-dose-rate mice. A similar number of proliferating crypt cells and a similar thickness of the muscularis externa following FLASH and conventional dose rate irradiation were observed. Partial abdominal FLASH proton irradiation at 120 Gy/s did not spare normal intestinal tissue, and no difference in lymphocyte depletion was observed. This study suggests that the effect of FLASH irradiation may depend on multiple factors, and in some cases dose rates of over 100 Gy/s do not induce a FLASH effect and can even result in worse outcomes.

Abstract 1298: Single cell analysis of breast cancer progression and metastasis to lymph nodes reveals cancer cell plasticity and MHC class II-mediated immune regulation

Tumor-draining lymph nodes are critical sites for generating tumor antigen-specific T cells and are associated with durable immune responses. However, lymph nodes are often the first site of metastasis and lymph node metastases portend worse outcomes. Through cross species single cell gene expression analysis of breast cancer progression and metastasis to lymph nodes, we uncovered features that define the heterogeneity, plasticity, and immune evasion of cancer cells. Notably, a subpopulation of metastatic cancer cells in the lymph node were marked by high levels of MHC class II (MHC-II) gene expression both in mice and humans. Mechanistically, the IFN-γ and JAK/STAT signaling pathways mediate MHC-II expression in cancer cells. Ablation of IFNGR1/2 or CIITA, the transactivator of MHC-II, in cancer cells prevented tumor progression. Interestingly, MHC-II+ cancer cells lacked co-stimulatory molecule expression, engendered the expansion of regulatory T cells and blunted CD4+ effector T cells in the tumor draining lymph nodes and favor tumor progression. Overall, our data suggests that cancer cell plasticity during breast cancer progression and metastasis to lymph nodes endows metastatic cells with the ability to avoid immune surveillance. These data provide the basis for new opportunities to therapeutically stimulate anti-cancer immune responses against local and systemic metastases.

Citation Format: Pin-Ji Lei, Ethel Pereira, Patrik Andersson, Zohreh Amoozgar, Jan Willem Van Wijnbergen, Meghan J. O'Melia, Hengbo Zhou, Sampurna Chatterjee, William Wee Ho, Jessica M. Posada, Ashwin Srinivasan Kumar, Satoru Morita, Charlie Chuang, Ilgin Ergin, Dennis Jones, Peigen Huang, Semir Beyaz, Timothy P. Padera. Single cell analysis of breast cancer progression and metastasis to lymph nodes reveals cancer cell plasticity and MHC class II-mediated immune regulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1298.

Proton FLASH effects on mouse skin at different oxygen tensions

Objective. Irradiation at FLASH dose rates (>40 Gy s-1) has received great attention due to its reported normal tissue sparing effect. The FLASH effect was originally observed in electron irradiations but has since been shown to also occur with both photon and proton beams. Several mechanisms have been proposed to explain the tissue sparing at high dose rates, including effects involving oxygen, such as depletion of oxygen within the irradiated cells. In this study, we investigated the protective role of FLASH proton irradiation on the skin when varying the oxygen concentration.Approach. Our double scattering proton system provided a 1.2 × 1.6 cm2elliptical field at a dose rate of ∼130 Gy s-1. The conventional dose rate was ∼0.4 Gy s-1. The legs of the FVB/N mice were marked with two tattooed dots and fixed in a holder for exposure. To alter the skin oxygen concentration, the mice were breathing pure oxygen or had their legs tied to restrict blood flow. The distance between the two dots was measured to analyze skin contraction over time.Main results. FLASH irradiation mitigated skin contraction by 15% compared to conventional dose rate irradiation. The epidermis thickness and collagen deposition at 75 d following 25 to 30 Gy exposure suggested a long-term protective function in the skin from FLASH irradiation. Providing the mice with oxygen or reducing the skin oxygen concentration removed the dose-rate-dependent difference in response.Significance. FLASH proton irradiation decreased skin contraction, epidermis thickness and collagen deposition compared to standard dose rate irradiations. The observed oxygen-dependence of the FLASH effect is consistent with, but not conclusive of, fast oxygen depletion during the exposure.

Stressed target cancer cells drive nongenetic reprogramming of CAR T cells and tumor microenvironment, overcoming multiple obstacles of CAR T therapy for solid tumors

The poor efficacy of chimeric antigen receptor T-cell therapy (CAR T) for solid tumor is due to insufficient CAR T cell tumor infiltration, in vivo expansion, persistence, and effector function, as well as exhaustion, intrinsic target antigen heterogeneity or antigen loss of target cancer cells, and immunosuppressive tumor microenvironment (TME). Here we describe a broadly applicable nongenetic approach that simultaneously addresses the multiple challenges of CAR T as a therapy for solid tumors. The approach massively reprograms CAR T cells by exposing them to stressed target cancer cells which have been exposed to the cell stress inducer disulfiram (DSF) and copper (Cu)(DSF/Cu) plus ionizing irradiation (IR). The reprogrammed CAR T cells acquired early memory-like characteristics, potent cytotoxicity, enhanced in vivo expansion, persistence, and decreased exhaustion. Tumors stressed by DSF/Cu and IR also reprogrammed and reversed immunosuppressive TME in humanized mice. The reprogrammed CAR T cells, derived from peripheral blood mononuclear cells (PBMC) of healthy or metastatic breast cancer patients, induced robust, sustained memory and curative anti-solid tumor responses in multiple xenograft mouse models, establishing proof of concept for empowering CAR T by stressing tumor as a novel therapy for solid tumor.

Inhibition of CXCR4 Enhances the Efficacy of Radiotherapy in Metastatic Prostate Cancer Models

Radiotherapy (RT) is a standard treatment for patients with advanced prostate cancer (PCa). Previous preclinical studies showed that SDF1α/CXCR4 axis could mediate PCa metastasis (most often to the bones) and cancer resistance to RT. We found high levels of expression for both SDF1α and its receptor CXCR4 in primary and metastatic PCa tissue samples. In vitro analyses using PCa cells revealed an important role of CXCR4 in cell invasion but not radiotolerance. Pharmacologic inhibition of CXCR4 using AMD3100 showed no efficacy in orthotopic primary and bone metastatic PCa models. However, when combined with RT, AMD3100 potentiated the effect of local single-dose RT (12 Gy) in both models. Moreover, CXCR4 inhibition also reduced lymph node metastasis from primary PCa. Notably, CXCR4 inhibition promoted the normalization of bone metastatic PCa vasculature and reduced tissue hypoxia. In conclusion, the SDF1α/CXCR4 axis is a potential therapeutic target in metastatic PCa patients treated with RT.

Reprogramming Intrahepatic Cholangiocarcinoma Immune Microenvironment by Chemotherapy and CTLA-4 Blockade Enhances Anti-PD1 Therapy

Intrahepatic cholangiocarcinoma (ICC) has limited therapeutic options and a dismal prognosis. Anti-PD-L1 immunotherapy combined with gemcitabine/cisplatin chemotherapy has recently shown efficacy in biliary tract cancers, but responses are seen only in a minority of patients. Here, we studied the roles of anti-PD1 and anti-CTLA-4 immune checkpoint blockade (ICB) therapies when combined with gemcitabine/cisplatin and the mechanisms of treatment benefit in orthotopic murine ICC models. We evaluated the effects of the combined treatments on ICC vasculature and immune microenvironment using flow cytometry analysis, immunofluorescence, imaging mass cytometry, RNA-sequencing, qPCR, and in vivo T-cell depletion and CD8+ T-cell transfer using orthotopic ICC models and transgenic mice. Combining gemcitabine/cisplatin with anti-PD1 and anti-CTLA-4 antibodies led to substantial survival benefits and reduction of morbidity in two aggressive ICC models, which were ICB-resistant. Gemcitabine/cisplatin treatment increased the frequency of tumor-infiltrating lymphocytes and normalized the ICC vessels, and when combined with dual CTLA-4/PD1 blockade, increased the number of activated CD8+Cxcr3+IFN-γ+ T-cells. Depletion of CD8+ but not CD4+ T-cells compromised efficacy. Conversely, CD8+ T-cell transfer from Cxcr3-/- versus Cxcr3+/+ mice into Rag1-/- immunodeficient mice restored the anti-tumor effect of gemcitabine/cisplatin/ICB combination therapy. Finally, rational scheduling of the ICBs (anti-CTLA-4 "priming") with chemotherapy and anti-PD1 therapy achieved equivalent efficacy with continuous dosing while reducing overall drug exposure. In summary, gemcitabine/cisplatin chemotherapy normalizes vessel structure, increases activated T-cell infiltration, and enhances anti-PD1/CTLA-4 immunotherapy efficacy in aggressive murine ICC. This combination approach should be clinically tested to overcome resistance to current therapies in ICC patients.

Effect of Multicomponent Intervention on Functional Decline in Chinese Older Adults: A Multicenter Randomized Clinical Trial

OBJECTIVES

To confirm whether multicomponent exercise following vivifrail recommendations was an effective method for improving physical ability, cognitive function, gait, balance, and muscle strength in Chinese older adults.

METHODS

This was a multicenter and randomized clinical trial conducted in Jiangsu, China, from April 2021 to April 2022. Intervention lasted for 12 weeks and 104 older adults with functional declines were enrolled. All participants were randomly assigned to a control (usual care plus health education) or exercise group (usual care plus health education plus exercise). Primary outcomes were the change score of Short Physical Performance Battery (SPPB) and activities of daily living (ADL). The secondary outcomes included instrumental activities of daily living, Tinetti scores, Frailty score, short-form Mini Nutritional Assessment, Mini-Mental State Examination, Geriatric Depression Scale-15, the 12-item Short Form Survey, 4-meter gait speed test, 6-min walking distance, grip strength, and body composition analysis.

RESULTS

Among the participants, the average age was 85 (82, 88) years. After 12 weeks of follow-up, the exercise group showed a significant improvement in SPPB, with a change of 2 points (95% confidence interval [0, 3.5], P<0.001) compared to control. In contrast, SPPB remained stable in the control group. Compared to the control group, ADL improved in the exercise group, as did instrumental activities of daily living, Tinetti, Frailty, Short Form Survey, 4-meter gait speed test, and 6-min walking distance. Although there was no significant difference between groups in body composition analysis after post-intervention, the exercise group still improved in soft lean mass (P=0.002), fat-free mass (P=0.002), skeletal muscle mass index (P<0.001), fat-free mass index (P=0.004), appendicular skeletal muscle mass (P<0.001), and leg muscle mass (P<0.001), while the control group had no significant increase. No difference was observed in adverse events during trial period.

CONCLUSIONS

The multicomponent exercise intervention following vivifrail recommendations is an effective method for older adults with functional decline and can reverse the functional decline and improve gait, balance, and muscle strength. Additionally, the 12-week multicomponent exercise method provides guidance for Chinese medical professionals working in the field of geriatrics and is a promising method to improve physical function in the general population.

The relationship between serum iron levels and AChR-Ab and IL-6 in patients with myasthenia gravis

OBJECTIVE

  To investigate the correlation between serum iron (SI) levels and acetylcholine receptor antibodies (AChR-Ab) and interleukin 6 (IL-6) in patients with myasthenia gravis (MG).

PATIENTS AND METHODS

A total of 76 patients with myasthenia gravis (MG group) between July 2015 to March 2018, and another 50 healthy subjects during the same period were selected for this study. SI levels in the peripheral blood serum of all participants were measured using the colorimetric method (a SI level of < 8.95 umol/L was considered the standard for SI deficiency). Enzyme-linked immunosorbent assays (ELISA) and radioimmunoassays (RIA) were used to detect the expression and levels of IL-6 and AChR-Ab in the peripheral blood of all participants. The presence and levels of IL-6 and AChR-Ab in the serum of MG patients and normal healthy subjects were compared. The levels of IL-6 and AChR-Ab in MG patients with normal SI levels and those with SI deficiency were analyzed.

RESULTS

The SI deficiency rate, AChR-Ab positivity rate, AChR-Ab levels, and IL-6 levels in the MG group were significantly higher than those in the control group (73.68% vs. 26.00%, 81.58% vs. 0.00%, 1.05 ± 0.40 nmol/L vs. 0.21 ± 0.09 nmol/L, and 183.54 ± 35.26 ng/mL vs. 121.43 ± 28.45 ng/mL, respectively; all p-values were < 0.01). In MG patients, the levels of AChR-AB and IL-6 in the SI deficiency group were significantly higher than those in the normal SI group (1.15 ± 0.34 nmol/L vs. 0.81 ± 0.45 nmol/L and 193.12 ± 31.70 ng/mL vs. 156.74 ± 31.19 ng/mL, respectively; all p-values were < 0.01). The correlation analysis showed that SI levels were negatively correlated with AChR-AB and IL-6 levels in MG patients (r = -0.776, r = -0.663, both p-values were < 0.01).

CONCLUSIONS

Iron deficiency in MG patients and SI levels are negatively correlated with AChR-Ab and IL-6 levels in MG patients.

Increased CD8+ T-cell Infiltration and Efficacy for Multikinase Inhibitors After PD-1 Blockade in Hepatocellular Carcinoma

Immune checkpoint blockade combined with antiangiogenic therapy induces vascular normalization and antitumor immunity and is efficacious in hepatocellular carcinoma (HCC); but whether and how initial immunotherapy affects the efficacy of subsequent antiangiogenic therapy are unknown. We evaluated a cohort of HCC patients (n = 25) who received the pan-vascular endothelial growth factor receptor multikinase inhibitor sorafenib after initial therapy with an antiprogrammed cell death protein (PD)-1 antibody and found superior outcomes in these patients (12% overall response rate to sorafenib and a median overall survival of 12.1 months). To prove this potential benefit, we examined the impact of an anti-PD-1 antibody on response to subsequent sorafenib treatment in orthotopic models of murine HCC. Prior anti-PD-1 antibody treatment amplified HCC response to sorafenib therapy and increased survival (n = 8-9 mice per group, hazard ratio = 0.28, 95% confidence interval = 0.09 to 0.91; 2-sided P = .04). Anti-PD-1 therapy showed angioprotective effects on HCC vessels to subsequent sorafenib treatment, which enhanced the benefit of this therapy sequence in a CD8+ T-cell-dependent manner. This priming approach using immunotherapy provides an immediately translatable strategy for effective HCC treatment while reducing drug exposure.

[Bioinformatic analysis of differentially expressed proteins in the dorsal raphe nucleus of rats after continuous treatment with olanzapine]

OBJECTIVE

To analyze the differentially expressed proteins in the dorsal raphe nucleus of rats treated with olanzapine and explore the possible mechanism of metabolic disorders in the early stage of olanzapine treatment.

METHODS

Twenty male and 20 female SD rats were both randomized equally into olanzapine group and control group for daily treatment with olanzapine and saline for 4 weeks, respectively. One hour after the last treatment, the dorsal raphe nucleus of the rats was dissected for proteomic analysis using iTRAQ combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS). GO, KEGG pathway, COG, pathways and protein interaction network analyses of the differentially expressed proteins were performed. Several target genes were selected from the proteomic list, and their expression levels in the dorsal raphe nucleus of another 24 mice with identical grouping and treatment using real time real-time quantitative PCR and Western blotting.

RESULTS

A total of 214 differentially expressed proteins were identified in the dorsal raphe nucleus of olanzapine-treated mice, including 72 unregulated and 142 downregulated proteins. GO analyses showed that the differentially expressed proteins were enriched in cellular process, biological regulation, metabolic process, response to stimulus, multicellular organismal process, bindings, catalytic activity, molecular function regulator and transcription regulator activity. KEGG analysis suggested that these proteins were enriched in fluid shear stress and atherosclerosis, serotonergic synapse, butanoate metabolism, thyroid hormone synthesis and IL-17 signaling pathway. The differentially expressed proteins Cav1, Hsp90b1, Canx, Gnai1, MAPK9, and LOC685513 were located at the nodes of the protein-protein interaction network in close relation with metabolic disorders. In olanzapine-treated mice, the expression of Hmgcs2, a negative regulator of apoptosis, was significantly down-regulated in the dorsal raphe nucleus, where the expressions of Pla2g4e, Slc6a4 and Gnai1 involved in serotonergic synapse were significantly upregulated.

CONCLUSION

In the early stage of treatment, olanzapine may contribute to the occurrence of metabolic disorders in rats by regulating the expressions of Cav1, Hsp90b1, Canx, Gnai1, MAPK9, LOC685513 (Gng14) and 5-HTR2 synapse-related proteins in the dorsal raphe nucleus.

[Clinical features and prognostic factors of severe hemophagocytic syndrome in children]

Objective: To explore the clinical characteristics, prognostic risk factors and effective treatment of severe hemophagocytic syndrome (HPS) in children, so as to provide reference for the clinical diagnosis and treatment of the disease. Methods: The clinical data of 83 children with severe HPS admitted in Affiliated Hospital of Zunyi Medical University from January 2014 to April 2021 were collected, and their clinical characteristics, prognosis and prognostic risk factors were analyzed. The children were divided into central nervous system (CNS) dysfunction group and non-CNS dysfunction group according to whether they were accompanied with CNS dysfunction, and were divided into blood purification group and non-blood purification group according to whether they received blood purification, then the survival differences were compared. Results: Among the 83 children, there were 43 males and 40 females, aged[M(Q₁,Q₃)] 36(15,27)months. A total of 51 children were induced by infection, among which 41 children (80.4%) were infected with EB virus. All the children were accompanied by multiple organ dysfunction (MODS), and dysfunction of the blood system (72.3%), liver (71.1%), respiratory system (53.0%) and CNS (37.3%) were common. By the end of follow-up, 40 cases (48.2%) survived, 38 cases (45.8%) died, and 5 cases (6.0%) were lost to follow-up. CNS dysfunction was a risk factor (HR=3.358, 95%CI: 1.445-7.803, P=0.005) and blood purification was a protective factor (HR=0.362, 95%CI: 0.179-0.730, P=0.005) affecting the prognosis of children. The mortality of CNS dysfunction group was statistically higher than that of non-CNS dysfunction group (74.2% vs 28.8%) (P<0.001); The mortality of blood purification group was statistically lower than that of non-blood purification group (31.0% vs 61.0%) (P=0.010). Conclusions: Severe HPS in children was dangerous and had a poor overall prognosis. CNS dysfunction was a risk factor for death. Blood purification could significantly improve the prognosis and improve the survival rate of children.

[Effects of sodium iodide symporter co-expression on proliferation and cytotoxic activity of chimeric antigen receptor T cells in vitro]

OBJECTIVE

To investigate the effects of co-expression of sodium iodide symporter (NIS) reporter gene on the proliferation and cytotoxic activity of chimeric antigen receptor (CAR)-T cells in vitro.

METHODS

T cells expressing CD19 CAR (CAR-T cells), NIS reporter gene (NIS-T cells), and both (NIS-CAR-T cells) were prepared by lentiviral infection. The transfection rates of NIS and CAR were determined by flow cytometry, and the cell proliferation rate was assessed using CCK-8 assay at 24, 48 and 72 h of routine cell culture. The T cells were co-cultured with Nalm6 tumor cells at the effector-target ratios of 1∶2, 1∶1, 2∶1 and 4∶1 for 24, 48 and 72 h, and the cytotoxicity of CAR-T cells to the tumor cells was evaluated using lactate dehydrogenase (LDH) assay. ELISA was used to detect the release of IFN-γ and TNF-β in the co-culture supernatant, and the function of NIS was detected with iodine uptake test.

RESULTS

The CAR transfection rate was 91.91% in CAR-T cells and 99.41% in NIS-CAR-T cells; the NIS transfection rate was 47.83% in NIS-T cells and 50.24% in NIS- CAR-T cells. No significant difference in the proliferation rate was observed between CAR-T and NIS-CAR-T cells cultured for 24, 48 or 72 h (P> 0.05). In the co-cultures with different effector-target ratios, the tumor cell killing rate was significantly higher in CAR-T group than in NIS-CAR-T group at 24 h (P < 0.05), but no significant difference was observed between the two groups at 48 h or 72 h (P>0.05). Higher IFN-γ and TNF-β release levels were detected in both CAR-T and NIS-CAR-T groups than in the control group (P < 0.05). NIS-T cells and NIS-CAR-T cells showed similar capacity of specific iodine uptake (P>0.05), which was significantly higher than that in the control T cells (P < 0.05).

CONCLUSION

The co-expression of the NIS reporter gene does not affect CAR expression, proliferation or tumor cell-killing ability of CAR-T cells.

Association of prenatal renal ultrasound abnormalities with pathogenic copy number variants in a large Chinese cohort

OBJECTIVES

To assess the clinical utility of prenatal chromosomal microarray analysis (CMA) in fetuses with abnormal renal sonographic findings, and to evaluate the association of pathogenic or likely pathogenic copy number variants (P/LP CNVs) with different types of renal abnormality.

METHODS

This was a retrospective study of fetuses at 14-36 weeks screened routinely for renal and other structural abnormalities at the Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region. We retrieved and analyzed data from fetuses with abnormal renal sonographic findings, examined between January 2013 and November 2019, which underwent CMA analysis using tissue obtained from chorionic villus sampling (CVS), amniocentesis or cordocentesis. We evaluated the CMA findings according to type of renal ultrasound anomaly and according to whether renal anomalies were isolated or non-isolated.

RESULTS

Ten types of renal anomaly were reported on prenatal ultrasound screening, at a mean ± SD gestational age of 24.9 ± 4.8 weeks. The anomalies were diagnosed relatively late in this series, as 64% of cases with an isolated renal anomaly underwent cordocentesis rather than CVS. Fetal pyelectasis was the most common renal ultrasound finding, affecting around one-third (34.32%, 301/877) of fetuses with a renal anomaly, but only 3.65% (n = 11) of these harbored a P/LP CNV (comprising: isolated cases, 2.37% (4/169); non-isolated cases, 5.30% (7/132)). Hyperechogenic kidney was found in 5.47% (n = 48) of fetuses with a renal anomaly, of which 39.58% (n = 19) had a P/LP CNV finding (comprising: isolated cases, 44.44% (16/36); non-isolated cases, 25.00% (3/12)), the highest diagnostic yield among the different types of renal anomaly. Renal agenesis, which accounted for 9.92% (n = 87) of all abnormal renal cases, had a CMA diagnostic yield of 12.64% (n = 11) (comprising: isolated cases, 11.54% (9/78); non-isolated cases, 22.22% (2/9); unilateral cases, 11.39% (9/79); bilateral cases, 25.00% (2/8)), while multicystic dysplastic kidney (n = 110), renal cyst (n = 34), renal dysplasia (n = 27), crossed fused renal ectopia (n = 31), hydronephrosis (n = 98), renal duplication (n = 42) and ectopic kidney (n = 99) had overall diagnostic rates of 11.82%, 11.76%, 7.41%, 6.45%, 6.12%, 4.76% and 3.03%, respectively. Compared with the combined group of CMA-negative fetuses with any other type of renal anomaly, the rate of infant being alive and well at birth was significantly higher in CMA-negative fetuses with isolated fetal pyelectasis or ectopic kidney, whereas the rate was significantly lower in fetuses with isolated renal agenesis, multicystic dysplastic kidney or severe hydronephrosis. The most common pathogenic CNV was 17q12 deletion, which accounted for 30.14% (22/73) of all positive CMA findings, with a rate of 2.51% (22/877) among fetuses with an abnormal renal finding. Fetuses with 17q12 deletion exhibited a wide range of renal phenotypes. Other P/LP CNVs in the recurrent region that were associated with prenatal renal ultrasound abnormalities included 22q11.2, Xp21.1, Xp22.3, 2q13, 16p11.2 and 1q21, which, collectively, accounted for 2.17% (19/877) of the fetuses with prenatal renal anomalies.

CONCLUSIONS

In this retrospective review of CMA findings in a large cohort of fetuses with different types of renal ultrasound abnormality, the P/LP CNV detection rate varied significantly (3.03-39.58%) among the different types of kidney anomaly. Our data may help in the decision regarding whether to perform prenatal genetic testing in fetuses with renal ultrasound findings. Specifically, prenatal CMA testing should be performed in cases of hyperechogenic kidney, regardless of whether or not the anomaly is isolated, while it should be performed postnatally rather than prenatally in cases of fetal pyelectasis. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Abstract P057: Targeting Treg cells with GITR activation alleviates resistance to immunotherapy in murine glioblastomas

Glioblastoma (GBM) shows high level of resistance to currently available treatments including the standard of care and immunotherapy, representing the most fatal cancer type. Our study revealed that immune suppression by regulatory T cells (Treg) secondary to therapy with immune checkpoint blocker (anti-PD1) confers this resistance. In the GBM tumor microenvironment, Treg cells with increased suppressive phenotype were found of which frequency and anergic phenotype increase after ICB therapy, potentially contributing to the resistance. Targeting Treg has a dual-barreled effect on enhancing anti-tumor immunity: GBM is highly infiltrated with Treg while CD8 T cells are excluded. In view of Treg's intrinsic reactivity to self-antigens, mobilizing converted Treg as effector T cells can be an effective strategy to a tumor type that expresses a low level of neoantigens including GBM. Our study revealed that GITR (glucocorticoid induced TNFR family related protein) is a desirable therapeutic target based on its increased expression on GBM Tregs as compared to peripheral Tregs. Engagement of GITR with agonistic antibody led to conversion of Treg to Th1-like effector T cells, which is accompanied with downregulation of Helios and IL-10 expression that are associated with Treg suppressive function. Through combining anti-GITR with anti-PD1 therapy, tumor recognition by converted Treg and CD8 T cells could be enhanced via IFNg induced promotion of MHC class I and II expression by GBM cells, which also resulted in T cell memory formation in the long-term survivors. To obtain clinically relevant information, we established a standard of care regimen consisting of surgery, radiation, and chemotherapy for orthotopic mouse GBM. We found that the anti-GITR +anti-PD1 therapy tailored to the GBM specific TME synergizes with the standard of care, suggesting a translational potential in patients.

Citation Format: Zohreh Amoozgar, Jonas Kloepper, Jun Ren, Rong En Tay, Samuel W. Kazer, Evgeny Kiner, Shanmugarajan Krishnan, Jessica M. Posada, Mitrajit Ghosh, Emilie Mamessier, Christina Wong, Gino B. Ferraro, Ana Batista, Nancy Wang, Mark Badeaux, Sylvie Roberge, Lei Xu, Peigen Huang, Alex K. Shalek, Dai Fukumura, Hye-Jung Kim, Rakesh K. Jain. Targeting Treg cells with GITR activation alleviates resistance to immunotherapy in murine glioblastomas [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P057.

The Relationship between Dietary Copper intake and Telomere Length in Hypertension

BACKGROUND

More indications proved that diet might be involved in the telomere length, a marker of biological aging and chronic diseases. Copper is widely viewed as one of the essential elements in the diet. Therefore, this study aimed to evaluate the relationship between telomere length and dietary copper intake in hypertension and provide a basis for guiding dietary copper intake in patients with hypertension.

METHODS

The data was collected from the National Health and Nutrition Examination Survey (NHANES) in 1999-2000 and 2001-2002. The relevance between telomere length and dietary copper intake in hypertension is assessed using a multivariable linear regression model.

RESULTS

We gathered 1,867 participants with hypertension with assessed telomere length and dietary copper intake. We found that one unit increasing log-transformed dietary copper intake in hypertension was significantly associated with longer telomere length base pair (bp) (β = 112.20, 95% confidence interval [CI]: 5.48, 218.92), after controlling for covariates, including age, sex, ethnicity, body mass index (BMI), physical activity, and taking medication for hypertension. For the age group, we found that one unit increasing log-transformed dietary copper in hypertension was associated with longer telomere length (β = 237.95, 95% CI: 114.39, 361.51) in the age group >45 years. The grouping was based on whether the participants take medication for hypertension. We found that one unit increasing log-transformed dietary copper in hypertension was associated with longer telomere length (β = 116.47, 95% CI: 0.72, 232.21) in the group that takes medication for hypertension.

CONCLUSIONS

This study demonstrates that dietary copper intake was associated with longer telomere length in patients with hypertension, which provides evidence for guiding dietary copper intake in patients with hypertension. However, further studies are needed to evaluate the effect of copper supplementation on telomere length in patients with hypertension in well-designed random control studies and prospective studies.

Abstract P061: Dendritic cell paucity in mismatch repair-proficient colorectal cancer liver metastases limits the efficacy of immune checkpoint blockade

Liver metastasis is a major cause of mortality for patients with colorectal cancer (CRC). Mismatch repair-proficient (pMMR) CRCs make up about 95% of metastatic CRCs, and are unresponsive to immune checkpoint blockade (ICB) therapy. Here we show that mouse models of orthotopic pMMR CRC liver metastasis accurately recapitulate the inefficacy of ICB therapy in patients, whereas the same pMMR CRC tumors are sensitive to ICB therapy when grown subcutaneously. To reveal local, nonmalignant components that determine CRC sensitivity to treatment, we compared the microenvironments of pMMR CRC cells grown as liver metastases and subcutaneous tumors. We found a paucity of both activated T cells and dendritic cells in ICB-treated orthotopic liver metastases, when compared to their subcutaneous tumor counterparts. Furthermore, treatment with FMS-like tyrosine kinase 3 ligand (Flt3L) plus ICB therapy increased dendritic cell infiltration into pMMR CRC liver metastases and improved mouse survival. Lastly, we show that human CRC liver metastases and microsatellite stable (MSS) primary CRC have a similar paucity of T cells and dendritic cells. These studies indicate that orthotopic tumor models, but not subcutaneous models, should be used to guide human clinical trials. Our findings also posit dendritic cells as antitumor components that can increase the efficacy of immunotherapies against pMMR CRC.

Citation Format: William W. Ho, Igor L. Gomes-Santos, Shuichi Aoki, Meenal Datta, Kosuke Kawaguchi, Nilesh P Talele, Sylvie Roberge, Jun Ren, Hao Liu, Ivy X Chen, Patrik Andersson, Sampurna Chatterjee, Ashwin S. Kumar, Zohreh Amoozgar, Qixian Zhang, Peigen Huang, Mei Rosa Ng, Vikash P Chauhan, Lei Xu, Dan G. Duda, Jeffrey W. Clark, Mikael J. Pittet, Dai Fukumura, Rakesh K Jain. Dendritic cell paucity in mismatch repair-proficient colorectal cancer liver metastases limits the efficacy of immune checkpoint blockade [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr P061.

Solid stress impairs lymphocyte infiltration into lymph-node metastases

Strong and durable anticancer immune responses are associated with the generation of activated cancer-specific T cells in the draining lymph nodes. However, cancer cells can colonize lymph nodes and drive tumour progression. Here, we show that lymphocytes fail to penetrate metastatic lesions in lymph nodes. In tissue from patients with breast, colon, and head and neck cancers, as well as in mice with spontaneously developing breast-cancer lymph-node metastases, we found that lymphocyte exclusion from nodal lesions is associated with the presence of solid stress caused by lesion growth, that solid stress induces reductions in the number of functional high endothelial venules in the nodes, and that relieving solid stress in the mice increased the presence of lymphocytes in lymph-node lesions by about 15-fold. Solid-stress-mediated impairment of lymphocyte infiltration into lymph-node metastases suggests a therapeutic route for overcoming T-cell exclusion during immunotherapy.

Dendritic cell paucity in mismatch repair-proficient colorectal cancer liver metastases limits immune checkpoint blockade efficacy

Liver metastasis is a major cause of mortality for patients with colorectal cancer (CRC). Mismatch repair-proficient (pMMR) CRCs make up about 95% of metastatic CRCs, and are unresponsive to immune checkpoint blockade (ICB) therapy. Here we show that mouse models of orthotopic pMMR CRC liver metastasis accurately recapitulate the inefficacy of ICB therapy in patients, whereas the same pMMR CRC tumors are sensitive to ICB therapy when grown subcutaneously. To reveal local, nonmalignant components that determine CRC sensitivity to treatment, we compared the microenvironments of pMMR CRC cells grown as liver metastases and subcutaneous tumors. We found a paucity of both activated T cells and dendritic cells in ICB-treated orthotopic liver metastases, when compared with their subcutaneous tumor counterparts. Furthermore, treatment with Feline McDonough sarcoma (FMS)-like tyrosine kinase 3 ligand (Flt3L) plus ICB therapy increased dendritic cell infiltration into pMMR CRC liver metastases and improved mouse survival. Lastly, we show that human CRC liver metastases and microsatellite stable (MSS) primary CRC have a similar paucity of T cells and dendritic cells. These studies indicate that orthotopic tumor models, but not subcutaneous models, should be used to guide human clinical trials. Our findings also posit dendritic cells as antitumor components that can increase the efficacy of immunotherapies against pMMR CRC.

[Genetic characteristics of hantavirus from rodents in port area of Ningde , Fujian province in the summer of 2020]

Objective: To explore the genetic characteristics and evolution of hantavirus carried by rodents in port area of Ningde in Fujian province in the summer of 2020. Methods: Rodents were captured in the port area of Ningde, the RNA was extracted from rodent lung tissues and detected by using specific kit. The positive samples were used for whole-genome sequencing of the virus. Bioinformatics software was used for the analysis on the similarity and genetic variation of the sequences. Results: A total of 112 rodents were captured, including 5 Rattus norvegicus and 2 Rattus flavipectus, the positive rate of hantavirus was 6.25% (7/112). By virus gene sequencing, two hantavirus complete genome sequences were obtained (named as FJ35 and FJ36, GenBank accession numbers: MW449188-MW449193). The genetic analysis results showed that the hantavirus detected in positive samples were SEOV and shared 99% nucleotide similarity with hantavirus strains LZSF21 and JX20140581 isolated from Shandong province. Phylogenetic analysis using the maximum likelihood method showed that the hantavirus detected in positive samples belonged to S3 subtype, sharing the same subtype with hantavirus strains Z37 from Zhejiang province, LZSF21 from Shandong province, and zy27 and Gongzhuling 415 from northeastern China. Compared with FJ372, the amino acid variation of N259S was observed at sites 251-264 of nucleoprotein, which might be related to antigenicity. Another variation of Q81R was observed in glycoprotein compared with SEOV 80-39 segment of coded amino acid of international reference strain, which might also cause the change in antigenicity. Conclusion: The high positive rate of hantavirus in rodents in the port area of Ningde- would increase the risk of natural human infection and epidemic in local area. The hantavirus positive rodents in this focus might be from an endemic area in Shandong. It is necessary to strengthen the imported rodent control in the port area of Ningde. The virus detected in 2 positive samples belonged to SEOV subtype Ⅲ and shared high homologies of nucleotides and amino acid sequences with the hantavirus strains in surrounding area. However, some slight variations occurred in glycoprotein and nucleoprotein amino acid sequences, which might cause changes in its antigeniity.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.

Constraints on Cosmic Strings Using Data from the Third Advanced LIGO-Virgo Observing Run

We search for gravitational-wave signals produced by cosmic strings in the Advanced LIGO and Virgo full O3 dataset. Search results are presented for gravitational waves produced by cosmic string loop features such as cusps, kinks, and, for the first time, kink-kink collisions. A template-based search for short-duration transient signals does not yield a detection. We also use the stochastic gravitational-wave background energy density upper limits derived from the O3 data to constrain the cosmic string tension Gμ as a function of the number of kinks, or the number of cusps, for two cosmic string loop distribution models. Additionally, we develop and test a third model that interpolates between these two models. Our results improve upon the previous LIGO-Virgo constraints on Gμ by 1 to 2 orders of magnitude depending on the model that is tested. In particular, for the one-loop distribution model, we set the most competitive constraints to date: Gμ≲4×10^{-15}. In the case of cosmic strings formed at the end of inflation in the context of grand unified theories, these results challenge simple inflationary models.