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The 1,3-diynes hold a prominent position among the many coupling partners employed in metal-catalysed C–H activation because of their ability to form complex bis-heterocycles in one shot.

The limited number of targetable tumor-specific antigens and the immunosuppressive nature of the microenvironment within solid malignancies represent major barriers to the success of chimeric antigen receptor (CAR)-T cell therapies. Here, using epithelial cell adhesion molecule (EpCAM) as a model antigen, we used alanine scanning of the complementarity-determining region to fine-tune CAR affinity. This allowed us to identify CARs that could spare primary epithelial cells while still effectively targeting EpCAMhigh tumors. Although affinity-tuned CARs showed suboptimal antitumor activity in vivo, we found that inducible secretion of interleukin-12 (IL-12), under the control of the NFAT promoter, can restore CAR activity to levels close to that of the parental CAR. This strategy was further validated with another affinity-tuned CAR specific for intercellular adhesion molecule-1 (ICAM-1). Only in affinity-tuned CAR-T cells was NFAT activity stringently controlled and restricted to tumors expressing the antigen of interest at high levels. Our study demonstrates the feasibility of specifically gearing CAR-T cells towards recognition of solid tumors by combining inducible IL-12 expression and affinity-tuned CAR.

Multi-tenant computing platforms are typically comprised of several software and hardware components including platform firmware, host operating system kernel, virtualization monitor, and the actual tenant payloads that run on them (typically in a virtual machine, container, or application). This model is well established in large scale commercial deployment, but the downside is that all platform components and operators are in the Trusted Computing Base (TCB) of the tenant. This aspect is ill-suited for privacy-oriented workloads that aim to minimize the TCB footprint. Confidential computing presents a good stepping-stone towards providing a quantifiable TCB for computing. Confidential computing [1] requires the use of a HW-attested Trusted Execution Environments for data-in-use protection. The RISC-V architecture presents a strong foundation for meeting the requirements for Confidential Computing and other security paradigms in a clean slate manner. This paper describes a reference architecture and discusses ISA, non-ISA and system-on-chip (SoC) requirements for confidential computing on RISC-V Platforms. It discusses proposed ISA and non-ISA Extension for Confidential Virtual Machine for RISC-V platforms, referred to as CoVE.

Supplementary figure S1-S6

Adoptive transfer of chimeric antigen receptor (CAR) T cells has demonstrated unparalleled responses in hematologic cancers, yet antigen escape and tumor relapse occur frequently. CAR T-cell therapy for patients with solid tumors faces even greater challenges due to the immunosuppressive tumor environment and antigen heterogeneity. Here, we developed a bispecific CAR to simultaneously target epithelial cell adhesion molecule (EpCAM) and intercellular adhesion molecule 1 (ICAM-1) to overcome antigen escape and to improve the durability of tumor responses. ICAM-1 is an adhesion molecule inducible by inflammatory cytokines and elevated in many types of tumors. Our study demonstrates superior efficacy of bispecific CAR T cells compared with CAR T cells targeting a single primary antigen. Bispecific CAR T achieved more durable antitumor responses in tumor models with either homogenous or heterogenous expression of EpCAM. We also showed that the activation of CAR T cells against EpCAM in tumors led to upregulation of ICAM-1, which rendered tumors more susceptible to ICAM-1 targeting by bispecific CAR T cells. Our strategy of additional targeting of ICAM-1 may have broad applications in augmenting the activity of CAR T cells against primary tumor antigens that are prone to antigen loss or downregulation.

A model for ICAM1-CAR T and anti-PD1 antibody activities in advanced thyroid cancers.

Purpose:Advanced thyroid cancers, including poorly differentiated and anaplastic thyroid cancer (ATC), are lethal malignancies with limited treatment options. The majority of patients with ATC have responded poorly to programmed death 1 (PD1) blockade in early clinical trials. There is a need to explore new treatment options.Experimental Design:We examined the expression of PD-L1 (a ligand of PD1) and intercellular adhesion molecule 1 (ICAM1) in thyroid tumors and ATC cell lines, and investigated the PD1 expression level in peripheral T cells of patients with thyroid cancer. Next, we studied the tumor-targeting efficacy and T-cell dynamics of monotherapy and combination treatments of ICAM1-targeting chimeric antigen receptor (CAR) T cells and anti-PD1 antibody in a xenograft model of ATC.Results:Advanced thyroid cancers were associated with increased expression of both ICAM1 and PD-L1 in tumors, and elevated PD1 expression in CD8+ T cells of circulating blood. The expression of ICAM1 and PD-L1 in ATC lines was regulated by the IFNγ–JAK2 signaling pathway. ICAM1-targeted CAR T cells, produced from either healthy donor or patient T cells, in combination with PD1 blockade demonstrated an improved ability to eradicate ICAM1-expressing target tumor cells compared with CAR T treatment alone. PD1 blockade facilitated clearance of PD-L1 high tumor colonies and curtailed excessive CAR T expansion, resulting in rapid tumor clearance and prolonged survival in a mouse model.Conclusions:Targeting two IFNγ-inducible, tumor-associated antigens—ICAM1 and PD-L1—in a complementary manner might be an effective treatment strategy to control advanced thyroid cancers in vivo.

Figure S1. PTCs with BRAFV600E mutations are associated with ICAM-1 Overexpression; Figure S2. Tumor tissue morphology in ATC patients.; Figure S3. ICAM-1-overexpressing ATC cell lines are more proliferative.; Figure S4. ICAM-1 CAR T cell phenotype characterization; Figure S5. Validation of ICAM-1 CAR T cells used in vivo experiments.; Figure S6. Organ weight changes in ATC xenografted mice after ICAM-1 CAR T treatment.; Figure S7. CAR T cells in ICAM-1 CAR T treated and ATC xenografts.; Figure S8. Establishment of ATC patient-derived xenografts.; Figure S9. CAR T activity is detectable throughout the body.; Figure S10. Correlation between ICAM-1 overexpression in TCGA cancer patient tumor tissues and overall survival.

Expression of ICAM1 and PD-L1 in anaplastic thyroid tumor cell lines.

PD1 inhibition enhances survival benefit of CAR T treatment in KHM-5M xenografts.

Purpose: Poorly differentiated thyroid cancer and anaplastic thyroid cancer (ATC) are rare yet lethal malignancies with limited treatment options. Many malignant tumors, including papillary thyroid cancer (PTC) and ATC, are associated with increased expression of ICAM-1, providing a rationale for utilizing ICAM-1–targeting agents for the treatment of aggressive cancer. We developed a third-generation chimeric antigen receptor (CAR) targeting ICAM-1 to leverage adoptive T-cell therapy as a new treatment modality.Experimental Design: ICAM-1 CAR T cells were applied to multiple malignant and nonmalignant target cells to investigate specific target cell death and “off-tumor” toxicity in vitro. In vivo therapeutic efficacy of ICAM-1 CAR T cells was examined in ATC mouse models established from a cell line and patient-derived tumors that rapidly develop systemic metastases.Results: ICAM-1 CAR T cells demonstrated robust and specific killing of PTC and ATC cell lines in vitro. Interestingly, although certain ATC cell lines showed heterogeneous levels of ICAM-1 expression, addition of cytotoxic CAR T cells induced increased ICAM-1 expression such that all cell lines became targetable. In mice with systemic ATC, a single administration of ICAM-1 CAR T cells mediated profound tumor killing that resulted in long-term remission and significantly improved survival. Patient-derived ATC cells overexpressed ICAM-1 and were largely eliminated by autologous ICAM-1 CAR T cells in vitro and in animal models.Conclusions: Our findings are the first demonstration of CAR T therapy against both a metastatic, thyroid cancer cell line and advanced ATC patient-derived tumors that exhibit dramatic therapeutic efficacy and survival benefit in animal studies. Clin Cancer Res; 23(24); 7569–83. ©2017 AACR.

We report herein a cobalt-catalyzed 8-aminoquinoline-directed highly regio- and stereoselective C-H/N-H activation annulation of indole-2-carboxamides with 1,2-dihydronaphthalene for the synthesis of β-carboline-1-one derivatives at room temperature. A cheaper and commercially available cobalt catalyst has been used for this transformation. The protocol tolerates a wide range of functionalities, affording β-carboline-1-one derivatives in good yields. An initial mechanistic study revealed a reversible cyclometalation to be operative.

Neurological complications among hospitalized COVID-19 patients may be associated with elevated neurodegenerative biomarkers.Among hospitalized COVID-19 patients without a history of dementia (N = 251), we compared serum total tau (t-tau), phosphorylated tau-181 (p-tau181), glial fibrillary acidic protein (GFAP), neurofilament light chain (NfL), ubiquitin carboxy-terminal hydrolase L1 (UCHL1), and amyloid beta (Aβ40,42) between patients with or without encephalopathy, in-hospital death versus survival, and discharge home versus other dispositions. COVID-19 patient biomarker levels were also compared to non-COVID cognitively normal, mild cognitive impairment (MCI), and Alzheimer's disease (AD) dementia controls (N = 161).Admission t-tau, p-tau181, GFAP, and NfL were significantly elevated in patients with encephalopathy and in those who died in-hospital, while t-tau, GFAP, and NfL were significantly lower in those discharged home. These markers correlated with severity of COVID illness. NfL, GFAP, and UCHL1 were higher in COVID patients than in non-COVID controls with MCI or AD.Neurodegenerative biomarkers were elevated to levels observed in AD dementia and associated with encephalopathy and worse outcomes among hospitalized COVID-19 patients.

Alkynes occupy a prominent role as a coupling partner in the transition metal-catalysed directed C-H activation reactions. Due to low steric requirements and linear geometry, alkynes can effectively coordinate with metal d-orbitals. This makes alkynes one of the most successful coupling partners in terms of the number of useful transformations. Remarkably, by changing the reaction conditions and transition-metals from 5d to 3d, the pattern of reactivity of alkynes also changes. Due to the varied reactivity of alkynes, such as alkenylation, annulation, alkylation, and alkynylation, they have been extensively used for the synthesis of valuable organic molecules. Despite enormous explorations with alkynes, there are still a lot more possible ways by which they can be made to react with M-C bonds generated through C-H activation. Practically there is no limit for the creative use of this approach. In particular with the development of new high and low valent first-row metal catalysts, there is plenty of scope for this chemistry to evolve as one of the most explored areas of research in the coming years. Therefore, a highlight article about alkynes is both timely and useful for synthetic chemists working in this area. Herein, we have highlighted the diverse reactivity of alkynes with various transition metals (Ir, Rh, Ru, Pd, Mn, Fe, Co, Ni, Cu) and their applications, along with some of our thoughts on future prospects.

The stereoselective synthesis of 1,3-enynes from 1,3-diynes is demonstrated by palladium-catalyzed selective C-C bond cleavage of cyclopropanol. Exclusive formation of mono-alkenylated adducts was achieved by eliminating the possibility of di-functionalization with high stereoselectivity. Indeed, this protocol worked very well with electronically and sterically diverse substrates. Several studies, including deuterium labeling experiments and intermolecular competitive experiments, were carried out to understand the mechanistic details. The atomic-level mechanism followed in the catalytic process was also validated using DFT calculations, and the rate-controlling states in the catalytic cycle were identified. Furthermore, preliminary mechanistic investigations with radical scavengers revealed the non-involvement of the radical pathway in this transformation.

Background and objectives

High-resolution susceptibility weighted imaging (SWI) provides unique contrast to small venous vasculature. The conspicuity of these mesoscopic veins, such as deep medullary veins in white matter, is subject to change from SWI venography when venous oxygenation in these veins is altered due to oxygenated blood susceptibility changes. The changes of visualization in small veins shows potential to depict regional changes of oxygen utilization and/or vascular density changes in the aging brain. The goal of this study was to use WM venous density to quantify small vein visibility in WM and investigate its relationship with neurodegenerative features, white matter hyperintensities (WMHs), and cognitive/functional status in elderly subjects (N = 137). WM venous density was significantly associated with neurodegeneration characterized by brain atrophy (β = 0.046± 0.01, p < 0.001), but no significant association was found between WM venous density and WMHs lesion load (p = 0.3963). Further analysis of clinical features revealed a negative trend of WM venous density with the sum-of-boxes of Clinical Dementia Rating and a significant association with category fluency (1-min animal naming). These results suggest that WM venous density on SWI can be used as a sensitive marker to characterize cerebral oxygen metabolism and different stages of cognitive and functional status in neurodegenerative diseases.

The ruthenium(II)-catalyzed regioselective annulation of N-(7-azaindole)amides with 1,3-diynes has been demonstrated. Bioactive N-amino-7-azaindole has been used as a new bidentate directing group to furnish an array of 3-alkynylated isoquinolones. Furthermore, the developed protocol works efficiently for both aryl- and heteroaryl-substituted amides producing a range of pharmacologically useful 7-azaindole-based isoquinolones with a wide range of functionality.

A ruthenium(II)-catalyzed cross dehydrogenative annulation of N-(7-azaindole)benzamides with maleimides has been demonstrated. Herein, we have explored the use of N-amino-7-azaindole as a new bidentate directing group for dehydrogenative [4 + 2] annulation. This method works efficiently, affording a variety of pharmacologically useful 7-azaindole-based isoquinolones and showing a wide functional group tolerance.

The ability to image adoptively transferred T cells in the body and to eliminate them to avoid toxicity will be vital for chimeric antigen receptor (CAR) T cell therapy, particularly against solid tumors with higher risk of off-tumor toxicity. Previously, we have demonstrated the utility of somatostatin receptor 2 (SSTR2) for CAR T cell imaging, illustrating the expansion and contraction of CAR T cells in tumor as well as off-tumor expansion. Using intercellular adhesion molecule 1 (ICAM-1)-specific CAR T cells that secrete interleukin (IL)-12 as a model, herein we examined the potential of SSTR2 as a safety switch when combined with the SSTR2-specific maytansine-octreotate conjugate PEN-221. Constitutive secretion of IL-12 led to continuous expansion of CAR T cells after rapid elimination of tumors, causing systemic toxicity in mice with intact MHC expression. Treatment with PEN-221 rapidly reduced the abundance of CAR T cells, decreasing the severity of xenogeneic graft-versus-host disease (GvHD), and prolonged survival. Our study supports the development of SSTR2 as a single genetic marker for CAR T cells that is readily applicable to humans both for anatomical detection of T cell distribution and an image-guided safety switch for rapid elimination of CAR T cells.

We report here a Rh(III) catalyzed regio- and stereoselective synthesis of alkynylated and bis-isocoumarin from 1,3-dialkyne. Exclusive one-pot formation of 3,3-bis-isocoumarin isomers has been achieved by eliminating several other possibilities. This is the first example of transition metal catalyzed synthesis of alkynylated and bis-isocoumarin scaffolds. The protocol is compatible with a wide range of functional groups affording good to excellent yields. Several mechanistic investigations, including deuterium labeling experiments and kinetic isotope effect studies, have been carried out.

We report here a Rh(III) catalysed regio- and stereo-selective synthesis of alkynylated and bis-iso- coumarin from 1,3-dialkyne. Exclusive one-pot formation of 3,3-bis-isocoumarin isomer has been achieved by elim- inating several other possibilities. This is the first example of transition metal catalyzed synthesis of alkynylated and bis-isocoumarin scaffold. The protocol is compatible with a wide range of functional groups affording good to excel- lent yields. Several mechanistic investigations including deuterium labeling experiment and kinetic isotope effect study have been carried out.

In recent years, transition metal catalysed strong C-C bond activation has significantly attracted the attention of synthetic chemists. This enables simultaneous and direct functionalization of two different M-C bonds. Among different types of C-C bond activation strategies, strain-driven C-C bond activation has resulted in a variety of transformations, which is otherwise impossible. In this context, palladium catalyst has been extensively used and studied due to its robust nature in terms of its reactivity and selectivity. Herein, we have provided a brief discussion about palladium catalysed C-C bond activation of three and four-membered cycloalkane derivatives.

Background: We have described the clinical stages of the brain aging and Alzheimer’s disease (AD) continuum. In terms of the pre-dementia stages of AD, we introduced the terminology “mild cognitive impairment” (MCI) for the first pre-dementia stage and “subjective cognitive decline” (SCD) for the pre-MCI stage. We now report the characteristics of a pre-SCD condition eventuating in likely AD. Objective: The aim of this study was to characterize a pre-SCD condition eventuating in AD. Method: Sixty healthy persons with “no cognitive decline” (NCD) were recruited and 47 were followed (mean baseline age, 64.1 ± 8.9 years; mean follow-up time, 6.7 ± 3.1 years). Outcome was determined at the final assessment prior to 2002 as “decliner,” if SCD or worse, or “nondecliner” if NCD. Results: After controlling for age, gender, years of education, and follow-up time, there was a between-group difference in the decline rate (p < 0.001). Also, after controlling for demographic variables and follow-up time, the combinatorial psychometric score was lower at baseline in the future decliners (p = 0.035). Of the 9 psychometric variables, after controlling for demographic variables and follow-up time, 3 were significantly lower at baseline in future decliners. Since AD is known to be age related and all subjects in this study were otherwise healthy, we also did an analysis without controlling for age. The combinatorial psychometric score was highly significantly better at baseline in the future nondecliners than in the future decliners (p = 0.008). Conclusion: This is ostensibly the first study to link psychometric cognitive decline to the subsequent SCD stage of eventual AD.

Strain-driven palladium/N-heterocyclic carbene-catalyzed C–C bond activation of diphenylcyclopropenone (DPC) has been explored for one-step access to trisubstituted α,β-unsaturated esters and amide...

This review focuses on providing comprehensive highlights of the recent advances in the field of cobalt-catalysed C–H functionalization and related synthetic concepts, relying on these through oxygen atom coordination. In recent years, 3d transition metal (Fe, Co, Cu & Ni) catalysed C–H functionalization reactions have received immense attention on account of its higher abundance and low cost, as compared to noble metals such as Ir, Rh, Ru and Pd. Among the first-row transition metals, cobalt is one of the extensively used metals for sustainable synthesis due to its unique reactivity towards the functionalization of inert C–H bonds. The functionalization of the inert C–H bond necessitates a proximal directing group. In this context, strongly coordinating nitrogen atom directed C–H functionalizations have been well explored. Nevertheless, strongly coordinating nitrogen-containing scaffolds, such as pyridine, pyrimidine, and 8-aminoquinoline, have to be installed and removed in a separate process. In contrast, C–H functionalizations through weakly coordinating atoms, such as oxygen, are largely underdeveloped. Since the oxygen atom is a part of many readily available functional groups, such as aldehydes, ketones, carboxylic acids, and esters, it could be used as directing groups for selective C–H functionalization reactions without any modification. Thus, the use of 3d transition metals, such as cobalt, along with weakly coordinating (oxygen) directing groups for C–H functionalization reactions are more sustainable, especially for the large-scale production of pharmaceuticals in industries. During the last decade, notable progress has been made using this concept. Nonetheless, almost all the reports are restricted to the formation of C–C and C–N bond. Therefore, there is a wide scope for developing this area for the formation of other bonds, such as C–X (halogens), C–B, C–S, and C–Se.

A redox neutral Co(III)-catalyzed annulation of α,β-unsaturated oxime ether with alkyne has been reported. Multisubstituted pyridines were synthesized in good yields without the use of any heavy metal oxidants. The developed methodology tolerates a variety of functional groups. Notably, this transformation has been applied to the late-stage modification of the bioactive molecule dehydropregnenolone.

A Rh-catalyzed pot and step economic synthesis of aza-polycyclic aromatic hydrocarbons (N-PAHs) from readily available aryl ketones and alkynes has been disclosed. Additionally, a novel synthetic application of the well-known aminating reagent hydroxylamine

Introduction: Despite extensive research in various preventive technologies over the years, white spot lesion (WSL) development in association with orthodontic treatment with fixed appliances remains an unwanted clinical problem. Materials and Methods: This study was conducted to compare the efficacy of various cariostatic products available commercially that would help in prevention of white spot lesions. Total 120 healthy extracted premolars were taken and divided into a sample of four groups. GC Tooth Mousse, Clin pro and Anticay were compared for their protective efficiency. Three test groups had three different topical agents applied and the fourth group acted as a control. After the test materials were applied they were subjected to pH cycling using artificial saliva with a pH of 4.5 that acted as a demineralization agent and fluorescence was assessed using spectroscopy. Results: One way Anova and Student‘t’ test revealed the efficacy of all the three materials as cariostatic agents, GC Tooth Mousse and Anticay were revealed to have the best protective efficiency. Conclusion: GC Tooth Mousse and Anticay can be used by the orthodontic patients as an in home application product for the prevention of development of white spot lesions. Keywords: White spot lesions, Spectroscopy, Artificial Saliva, CPP-ACP, CaSP.

Purpose: Advanced thyroid cancers, including poorly differentiated and anaplastic thyroid cancer (ATC), are lethal malignancies with limited treatment options. The majority of patients with ATC have responded poorly to programmed death 1 (PD1) blockade in early clinical trials. There is a need to explore new treatment options. Experimental Design: We examined the expression of PD-L1 (a ligand of PD1) and intercellular adhesion molecule 1 (ICAM1) in thyroid tumors and ATC cell lines, and investigated the PD1 expression level in peripheral T cells of patients with thyroid cancer. Next, we studied the tumor-targeting efficacy and T-cell dynamics of monotherapy and combination treatments of ICAM1-targeting chimeric antigen receptor (CAR) T cells and anti-PD1 antibody in a xenograft model of ATC. Results: Advanced thyroid cancers were associated with increased expression of both ICAM1 and PD-L1 in tumors, and elevated PD1 expression in CD8+ T cells of circulating blood. The expression of ICAM1 and PD-L1 in ATC lines was regulated by the IFNγ–JAK2 signaling pathway. ICAM1-targeted CAR T cells, produced from either healthy donor or patient T cells, in combination with PD1 blockade demonstrated an improved ability to eradicate ICAM1-expressing target tumor cells compared with CAR T treatment alone. PD1 blockade facilitated clearance of PD-L1 high tumor colonies and curtailed excessive CAR T expansion, resulting in rapid tumor clearance and prolonged survival in a mouse model. Conclusions: Targeting two IFNγ-inducible, tumor-associated antigens—ICAM1 and PD-L1—in a complementary manner might be an effective treatment strategy to control advanced thyroid cancers in vivo.

Cancer therapy utilizing adoptive transfer of chimeric antigen receptor (CAR) T cells has demonstrated remarkable clinical outcomes in hematologic malignancies. However, CAR T cell application to solid tumors has had limited success, partly due to the lack of tumor-specific antigens and an immune-suppressive tumor microenvironment. From the tumor tissues of gastric cancer patients, we found that intercellular adhesion molecule 1 (ICAM-1) expression is significantly associated with advanced stage and shorter survival. In this study, we report a proof-of-concept study using ICAM-1-targeting CAR T cells against gastric cancer. The efficacy of ICAM-1 CAR T cells showed a significant correlation with the level of ICAM-1 expression in target cells in vitro. In animal models of human gastric cancer, ICAM-1-targeting CAR T cells potently eliminated tumors that developed in the lungs, while their efficacy was more limited against the tumors in the peritoneum. To augment CAR T cell activity against intraperitoneal tumors, combinations with paclitaxel or CAR activation-dependent interleukin (IL)-12 release were explored and found to significantly increase anti-tumor activity and survival benefit. Collectively, ICAM-1-targeting CAR T cells alone or in combination with chemotherapy represent a promising strategy to treat patients with ICAM-1+ advanced gastric cancer., Graphical Abstract, In this study, we demonstrated the therapeutic potential of CAR T cells targeting ICAM-1 in preclinical models of systemic and intraperitoneal metastases of gastric cancer. A combination with paclitaxel or armoring CAR T cells with inducible IL-12 was found to significantly enhance the treatment effect of CAR T cells.

Transition metal-catalyzed C-H activation and functionalization with various coupling partners is a well-explored area of research. Among the various coupling partners used, alkynes occupy a prominent position on account of their varied reactivity. Due to their low steric demand and a high degree of unsaturation they effectively overlap with metal d-orbitals and form multiple bond-forming events giving rise to complex skeletons that are otherwise challenging to synthesize. This makes alkyne one of the most successful coupling partners in terms of the number of useful transformations. Remarkably, by changing the reaction conditions and transition-metals from 5d to 3d, the behaviors of alkynes also change. Despite enormous explorations with alkynes, there are still a lot more possible ways by which alkynes can be made to react with M-C bonds generated through C-H activation. Especially with the development of new high and low valent first-row metal catalysts, there is plenty of scope for this chemistry to evolve as one of the most explored areas of research in coming years. Therefore, a review on this topic is both timely and useful for synthetic chemists who are working in this area. In this review, we have highlighted the diverse reactivity of alkynes with various transition metals and their applications along with some of our thoughts on future prospects.

Purpose: Current understanding of resistance to CAR-T cell therapy in solid tumors implicates inadequate CAR-T cell potency in the immunosuppressive tumor microenvironment (TME). We have previously developed a platform using somatostatin receptor 2 (SSTR2) as a positron emission tomography (PET) reporter to detect CAR-T cell expansion and trafficking. The current study aimed to leverage SSTR2 for low-dose targeted radionuclide therapy (177Lu-DOTATATE, Lutathera), which under dosimetry guidance might enhance antitumor immunity by reprograming the TME and promoting T-cell reinvigoration. Methods: Using intercellular adhesion molecule 1 (ICAM-1) as a model antigen, we evaluated the immunomodulatory effects of low-dose radiation in a gastric cancer animal model. NSG mice were inoculated subcutaneously with firefly luciferase-expressing Hs 746T cells (0.1 × 106 per mouse) and treated 5 days later with 10 × 106 SSTR2-expressing ICAM-1 CAR-T cells. CAR-T cell expansion was monitored weekly by PET scan using 18F-NOTA-Octreotide, a radiotracer targeting SSTR2. Three weeks post-T cell infusion, a cohort of mice were injected with 7.4 MBq of 177Lu-DOTATATE via the tail vein. SPECT imaging was performed for dosimetry analysis. Tumor growth was monitored by bioluminescence imaging and tumor size measurement. Serum cytokines were analyzed. Results: Single dose 177Lu-DOTATATE treatment (delivering 1-6 Gy to tumor) improved response of established gastric cancer tumor (>1,000 mm3) that was not responsive to CAR-T cell treatment alone and significantly prolonged survival. All mice receiving CAR-T cells plus 177Lu-DOTATATE displayed rapid tumor shrinkage, with 83% of mice achieving complete remission within 3 weeks of 177Lu-DOTATATE treatment. SPECT imaging confirmed specific delivery of 177Lu-DOTATATE by tumor-infiltrating CAR-T cells, with tumor uptake of 0.43 ± 0.24 and 0.19 ± 0.08 MBq/g at 24 and 144 hours post 177Lu-DOTATATE injection, respectively. Most radioactivity reduction over time (73%) is explained by physical decay of 177Lu, indicating persistent tumor retention of 177Lu-DOTATATE. In contrast, rapid clearance of 177Lu-DOTATATE was observed in liver and kidneys. Importantly, longitudinal CAR-T cell imaging using 18F-NOTA-Octreotide revealed increased CAR-T cell expansion induced by low-dose radiation. Furthermore, we detected high levels of IFN-γ and perforin in serum after 177Lu-DOTATATE treatment, which were >10 folds higher than that in control mice receiving CAR-T cell only, indicating activation of T cells by low-dose radiation. Conclusions: We developed a translatable radioimmunotherapy platform that incorporates a FDA-approved theranostic endoradiotherapy (Lutathera) to improve tumor response to CAR-T cell therapy. The next steps would be to explore the immunomodulatory effects of low-dose radiation systematically and elucidate the mechanism of action. Citation Format: Yanping Yang, Yago Alcaina, Yogindra Vedvyas, Maria Cristina Riascos, Edward K. Fung, Brett Vaughn, Sarah M. Cheal, Irene M. Min, Claire Vanpouille-Box, Moonsoo M. Jin. Targeted delivery of low-dose radiation alleviates tumor resistance to CAR-T cell therapy. [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 5084.

Purpose: While there have been extensive studies about defining T cell states associated with response to checkpoint immunotherapy, relatively little is known about the crosstalk between tumor and tumor-infiltrating chimeric antigen receptor (CAR) T cells and how it leads to tumor resistance and CAR T cell dysfunction. Here we employ a two-pronged approach using CAR T cell imaging and single cell multi-omics techniques to elucidate the complex tumor-CAR T cell interactions in a gastric cancer xenograft model. Methods: Human CAR-T cells targeting epithelial cell adhesion molecule were engineered to co-express somatostatin receptor 2 (SSTR2) for positron emission tomography (PET) imaging using 18F-NOTA-Octreotide radiotracer. NSG mice were inoculated subcutaneously with firefly luciferase-expressing MKN-45 cells (1 × 106 per mouse) and treated 5 days later with 10 × 106 SSTR2-expressing CAR-T or non-transduced T cells. Tumor growth and CAR T cell expansion were monitored near synchronously by bioluminescence and PET-CT imaging, respectively. Resistant or relapsing tumors were harvested and MACS sorted into human CD45+ tumor-infiltrating T cells (TILs) and CD45-depleted tumor cells. CAR T cell products and MKN-45 tumor cell line prior to injection were included in single cell analysis for comparison. Results: TCR clonal analysis supports that CAR T cells in resistant tumors are proliferative and clonally expanded, which finding is corroborated by whole-body CAR T cell imaging. Highly expanded clones were observed within the CD4+ CAR T cell compartment, especially within the regulatory T (Treg) cell cluster. CD8+ CAR T cells underwent less clonal expansion with most clones found within the exhausted cells (LAG3, PDCD1, and TIGIT, LAYN and SOX4), whereas non-transduced control CD8+ T cells did not express high levels of exhaustion associated genes. Differential gene expression (DGE) analysis between TILs and pre-infusion CAR T cells showed increased expression of LAYN, CXCL13, LMNA, and DUSP4 in TILs. The most upregulated DUSP4 was previously found to be overexpressed in Treg and aged T cells, and the DUSP4 induction is linked to a defective adaptive immune response. In addition, we observed the loss of cell-surface CAR in TILs, likely from chronic exposure to antigens in resistant tumors. Furthermore, DGE analysis reveals that under CAR T cell treatment MKN-45 tumors upregulated interferon alpha inducible protein 27 (IFI27), TNFRSF14 and a group of pathways related to metabolic activity and antigen processing and presentation, implying the evolution of tumor cells to resist T cell killing. Conclusions: Our findings highlight the complex tumor-T cell interplay as tumor evades CAR T cell killing. Tumor resistance is associated with CAR T cell transition from cytotoxic to dysfunctional phenotypes, the suppression of expanded Treg cells, and the acquisition of resistant features by tumors. Citation Format: Yanping Yang, Raymond Louie, Janusz Puc, Yogindra Vedvyas, Yago Alcaina, Irene M. Min, Matt Britz, Fabio Luciani, Moonsoo M. Jin. Single cell analysis reveals tumor evolution and CAR T cell dysfunction associated with tumor resistance [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 912.

A catalytic system was discovered for the intramolecular C-H amidation of N-phenoxy acetamide derivatives. For the first time, a cobalt catalyst was employed for the Catellani reaction. Additionally, a monocyclic olefin, maleimide, was used as a transient mediator in place of bicyclic norbornenes. Maleimide promotes a Co(III) intermediate to undergo oxidative addition into the O–N bond to form a Co(V) nitrene species and subsequently directs nitrene addition to the ortho position. A plausible mechanism for the transformation is proposed, supported by experimental and density functional theory (DFT) computational studies. Further, the synthetic utility of this methodology was demonstrated via the ortho-amidation of estrone.

INTRODUCTIONOlder adults hospitalized with COVID-19 are susceptible to neurological complications, particularly encephalopathy, which may reflect age-related neurodegenerative processes.METHODSSerum total tau, ptau-181, GFAP, NFL, UCHL1, and amyloid-beta(Aβ-40,42) were measured in hospitalized COVID-19 patients without a history of dementia, and compared among patients with or without encephalopathy, in-hospital death versus survival, and discharge home versus other dispositions using multivariable Cox proportional hazards regression analyses.RESULTSAmong 251 patients, admission serum ptau-181 and UCHL1 were significantly elevated in patients with encephalopathy (both PDISCUSSIONAge-related neurodegenerative biomarkers were elevated to levels observed in AD and associated with encephalopathy and worse outcomes among hospitalized COVID-19 patients.