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Bacterial flagella and type IV pili (TFP) are surface appendages that enable motility and mechanosensing through distinct mechanisms. These structures were previously thought to have no components in common. Here, we report that TFP and some flagella share proteins PilO, PilN, and PilM, which we identified as part of the Helicobacter pylori flagellar motor. H. pylori mutants lacking PilO or PilN migrated better than wild type in semisolid agar because they continued swimming rather than aggregated into microcolonies, mimicking the TFP-regulated surface response. Like their TFP homologs, flagellar PilO/PilN heterodimers formed a peripheral cage that encircled the flagellar motor. These results indicate that PilO and PilN act similarly in flagella and TFP by differentially regulating motility and microcolony formation when bacteria encounter surfaces.

Glycoprotein 2 (GP2) is a widely distributed protein in the digestive tract, contributing to mucosal barrier maintenance, immune homeostasis, and antigen-specific immune response, while also being linked to inflammatory bowel disease (IBD) pathogenesis. This review sheds light on the extensive distribution of GP2 within the gastrointestinal tract and its intricate interplay with the immune system. Furthermore, the significance of GP2 autoantibodies in diagnosing and categorizing IBD is underscored, alongside the promising therapeutic avenues for modulating GP2 to regulate immunity and maintain mucosal balance.

By incompletely understood mechanisms, type 2 (T2) inflammation present in the airways of severe asthmatics drives the formation of pathologic mucus which leads to airway mucus plugging. Here we investigate the molecular role and clinical significance of intelectin-1 (ITLN-1) in the development of pathologic airway mucus in asthma. Through analyses of human airway epithelial cells we find that ITLN1 gene expression is highly induced by interleukin-13 (IL-13) in a subset of metaplastic MUC5AC+ mucus secretory cells, and that ITLN-1 protein is a secreted component of IL-13-induced mucus. Additionally, we find ITLN-1 protein binds the C-terminus of the MUC5AC mucin and that its deletion in airway epithelial cells partially reverses IL-13-induced mucostasis. Through analysis of nasal airway epithelial brushings, we find that ITLN1 is highly expressed in T2-high asthmatics, when compared to T2-low children. Furthermore, we demonstrate that both ITLN-1 gene expression and protein levels are significantly reduced by a common genetic variant that is associated with protection from the formation of mucus plugs in T2-high asthma. This work identifies an important biomarker and targetable pathways for the treatment of mucus obstruction in asthma.

HIV-infected individuals have increased risk for cardiovascular disease (CVD) despite suppressive antiretroviral therapy (ART). This is likely a result of persistent immune activation and systemic inflammation. Extracellular vesicles (EVs) have emerged as critical mediators of intercellular communication and may drive inflammation contributing to CVD. EVs were characterized in plasma from 74 HIV-infected individuals on combination antiretroviral therapy (cART) and 64 HIV-uninfected controls with paired carotid intima-media thickness (cIMT) assessment. EVs were profiled with markers reflecting lymphoid, myeloid, and endothelial origin. Seventeen plasma inflammatory biomarkers were also assessed. Human umbilical vein endothelial cell (HUVEC) apoptosis was quantified after EV exposure. A significant correlation was observed in HIV-infected participants between cIMT and EVs expressing CD16, and the monocyte-related markers CD4, CD14, and CX3CR1 showed a similar but nonsignificant association with cIMT. No significant correlation between cIMT measurements from HIV-uninfected individuals and EVs was observed. Levels of serum amyloid A, C-reactive protein, and myeloperoxidase significantly correlated with CD14+, CD16+, and CX3CR1+ EVs. No correlation was noted between cIMT and soluble inflammatory markers. HUVECs showed increased necrosis after exposure to the EV-containing fraction of plasma derived from HIV-infected individuals compared to uninfected controls. Our study reveals that EVs expressing monocyte markers correlated with cIMT in HIV-infected individuals on cART. Moreover, EV fractions derived from HIV-infected individuals lead to greater endothelial cell death via necrotic pathways. Collectively, EVs have potential as biomarkers of and therapeutic targets in the pathogenesis of CVD in the setting of treated HIV disease. IMPORTANCE HIV-infected individuals have a 2-fold-increased risk of cardiovascular disease compared with the general population, yet the mechanisms underlying this comorbidity are unclear. Extracellular vesicles have emerged as important mediators in cell-cell communication and, given what we know of their biology, may drive inflammation contributing to cardiovascular disease in this vulnerable population.

Natural killer (NK) cells can detect antibody-coated cells through recognition by the CD16 Fc receptor. The importance of CD16 in human NK cell biology has long been appreciated, but how CD16 functions in mouse NK cells remains poorly understood. Here, we report drastic differences between human and mouse CD16 functions in NK cells. We demonstrate that one of the adaptor molecules that CD16 associates with and signals through, CD3ζ, plays a critical role in these functional differences. Using a systematic approach, we demonstrate that residues in the transmembrane domain of the mouse CD3ζ molecule prevent efficient complex formation with mouse CD16, thereby dampening receptor function. Mutating these residues in mouse CD3ζ to those encoded by human CD3ζ resulted in rescue of CD16 receptor function. We reveal that the mouse CD3ζ transmembrane domain adopts a tightly packed confirmation, preventing association with CD16, whereas human CD3ζ adopts a versatile configuration that accommodates receptor assembly.

Intelectins are carbohydrate-binding proteins implicated in innate immunity and highly conserved across chordate evolution, including both ascidians and humans. Human intelectin-1 (ITLN1) is highly abundant within the intestinal mucosa and binds microbial but not host glycans. Genome-wide association studies identified SNPs in ITLN1 that are linked to susceptibility for Crohn's disease. Moreover, ITLN1 has been implicated in the pathophysiology of obesity and associated metabolic disease. To gain insight on biological activities of human ITLN1 in vivo, we developed a C57BL/6 mouse model genetically targeting the gene encoding the functional mouse ortholog. In wild-type C57BL/6 mice, both mRNA and protein analysis showed high expression of Itln1 in the small intestine, but manifold lower levels in colon and other extraintestinal tissues. Whereas intestinal expression of human ITLN1 localizes to goblet cells, our data confirm that mouse Itln1 is expressed in Paneth cells. Compared to wild-type littermate controls, mice homozygous for the Itln1 hypomorphic trapping allele had reduced expression levels of Itln1 expression (~10,000-fold). The knockout mice exhibited increased susceptibility in an acute model of experimentally induced colitis with 2% w/v dextran sulfate sodium (DSS). In a model of chronic colitis using a lower dose of DSS (1.5% w/v), which enabled a detailed view of disease activity across a protracted period, no differences were observed in body weight, fecal texture, hemoccult scores, food/water intake, or colon length at necropsy, but there was a statistically significant genotype over time effect for the combined fecal scores of disease activity. In model of diet-induced obesity, using two western-style diets, which varied in amounts of sugar (as sucrose) and saturated fat (as lard), mice with Itln1 expression ablated showed no increased susceptibility, in terms of weight gain, food intake, plasma markers of obesity compared to wildtype littermates. While the mouse genetic knockout model for Itln1 holds promise for elucidating physiological function(s) for mammalian intelectins, results reported here suggest that Itln1, a Paneth cell product in C57BL/6 mice, likely plays a minor role in the pathophysiology of chemically induced colitis or diet-induced obesity.

OBJECTIVES: Alterations in the intestinal microbiota are linked with a wide range of autoimmune and inflammatory conditions, including inflammatory bowel diseases (IBD), where pathobionts penetrate the intestinal barrier and promote inflammatory reactions. In patients with IBD, the ability of intestinal macrophages to efficiently clear invading pathogens is compromised resulting in increased bacterial translocation and excessive immune reactions. Here, we investigated how an IBD-associated loss-of-function variant in the protein tyrosine phosphatase non-receptor type 2 (PTPN2) gene, or loss of PTPN2 expression affected the ability of macrophages to respond to invading bacteria. DESIGN: IBD patient-derived macrophages with wild-type (WT) PTPN2 or carrying the IBD-associated PTPN2 SNP, peritoneal macrophages from WT and constitutive PTPN2-knockout mice, as well as mice specifically lacking PTPN2 in macrophages were infected with non-invasive K12 Escherichia coli, the human adherent-invasive E. coli (AIEC) LF82, or a novel mouse AIEC (mAIEC) strain. RESULTS: Loss of PTPN2 severely compromises the ability of macrophages to clear invading bacteria. Specifically, loss of functional PTPN2 promoted pathobiont invasion/uptake into macrophages and intracellular survival/proliferation by three distinct mechanisms: Increased bacterial uptake was mediated by enhanced expression of carcinoembryonic antigen cellular adhesion molecule (CEACAM)1 and CEACAM6 in PTPN2-deficient cells, while reduced bacterial clearance resulted from defects in autophagy coupled with compromised lysosomal acidification. In vivo, mice lacking PTPN2 in macrophages were more susceptible to mAIEC infection and mAIEC-induced disease. CONCLUSIONS: Our findings reveal a tripartite regulatory mechanism by which PTPN2 preserves macrophage antibacterial function, thus crucially contributing to host defence against invading bacteria.

Therapies that boost the antitumor immune response have shown a great deal of success. Although most of these therapies have focused on enhancing T cell functions, there is a growing interest in developing therapies that can target other immune cell subsets. Like T cells, natural killer (NK) cells are cytotoxic effector cells that play a key role in the antitumor response. To advance the development of NK-based therapies, we developed a functional screen to rapidly identify antibodies that can activate NK cells. We displayed antibodies on a mammalian target cell line and probed their ability to stimulate NK cell-mediated cytotoxicity. From this screen, we identified five antibodies that bound with high affinity to NK cells and stimulated NK cell-mediated cytotoxicity and interferon-γ (IFN-γ) secretion. We demonstrate that these antibodies can be further developed into bispecific antibodies to redirect NK cell-mediated cytotoxicity toward CD20+ B cell lymphoma cells and HER2+ breast cancer cells. While antibodies to two of the receptors, CD16 and NCR1, have previously been targeted as bispecific antibodies to redirect NK cell-mediated cytotoxicity, we demonstrate that bispecific antibodies targeting NCR3 can also potently activate NK cells. These results show that this screen can be used to directly identify antibodies that can enhance antitumor immune responses.

BackgroundIt is difficult to distinguish between a tumor and its liver segment with traditional use of indocyanine green (ICG) alone. In the present study, a method was used to limit ICG to the liver segment adjacent to a tumor. A spectrally-distinct fluorescently-labeled tumor-specific antibody against human carcinoembryonic antigen-related cell-adhesion molecules was used to label the metastatic tumor in a patient-derived orthotopic xenograft mouse model to enable color-coded visualization and distinction of a colon-cancer liver metastases and its adjacent liver segment.Materials and methodsNude mice received surgical orthotopic implantation in the liver of colon-cancer liver metastases derived from two patients. An anti- carcinoembryonic antigen-related cell-adhesion molecules monoclonal antibody (mAb 6G5j) was conjugated to a near-infrared dye IR700DX (6G5j-IR700DX). After three weeks, mice received 6G5j-IR700DX via tail-vein injection 48 hours before surgery. ICG was intravenously injected after ligation of the left or left lateral Glissonean pedicle resulting in labeling of the segment with preserved blood-flow in the liver. Imaging was performed with the Pearl Trilogy and FLARE Imaging Systems.ResultsThe metastatic liver tumor had a clear fluorescence signal due to selective tumor targeting by 6G5j-IR700DX, which was imaged on the 700 nm channel. The adjacent liver segment, with preserved blood-flow in the liver, had a clear fluorescence ICG 800 nm signal, while the left or left lateral segment had no fluorescence signal. Overlay of the images showed clear color-coded differentiation between the tumor fluorescing at 700 nm and the adjacent liver segment fluorescing at 800 nm.ConclusionsColor-coding of a liver tumor and uninvolved liver segment has the potential for improved liver resection.

A deficient interferon (IFN) response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been implicated as a determinant of severe coronavirus disease 2019 (COVID-19). To identify the molecular effectors that govern IFN control of SARS-CoV-2 infection, we conducted a large-scale gain-of-function analysis that evaluated the impact of human IFN-stimulated genes (ISGs) on viral replication. A limited subset of ISGs were found to control viral infection, including endosomal factors inhibiting viral entry, RNA binding proteins suppressing viral RNA synthesis, and a highly enriched cluster of endoplasmic reticulum (ER)/Golgi-resident ISGs inhibiting viral assembly/egress. These included broad-acting antiviral ISGs and eight ISGs that specifically inhibited SARS-CoV-2 and SARS-CoV-1 replication. Among the broad-acting ISGs was BST2/tetherin, which impeded viral release and is antagonized by SARS-CoV-2 Orf7a protein. Overall, these data illuminate a set of ISGs that underlie innate immune control of SARS-CoV-2/SARS-CoV-1 infection, which will facilitate the understanding of host determinants that impact disease severity and offer potential therapeutic strategies for COVID-19.

A major barrier to the diagnosis and effective treatment of solid-tumor cancers is the difficulty in detection and visualization of tumor margins in primary and metastatic disease. The use of fluorescence can augment the surgeon's ability to detect cancer and aid in its resection. Several cancer types express carcinoembryonic antigen (CEA) including colorectal, pancreatic and gastric cancer. Antibodies to CEA have been developed and tagged with near-infrared fluorescent dyes. This review article surveyed the use of CEA antibodies conjugated to fluorescent probes for in vivo studies since 1990. PubMed and Google Scholar databases were queried, and 900 titles and abstracts were screened. Fifty-nine entries were identified as possibly meeting inclusion/exclusion criteria and were reviewed in full. Forty articles were included in the review and their citations were screened for additional entries. A total of 44 articles were included in the final review. The use of fluorescent anti-CEA antibodies has been shown to improve detection and resection of tumors in both murine models and clinically. The cumulative results indicate that fluorescent-conjugated anti-CEA antibodies have important potential to improve cancer diagnosis and surgery. In an emerging technology, anti-CEA fluorescent antibodies have also been successfully used for photoimmunotherapy treatment for cancer.

Intelectins are a family of multimeric secreted proteins that bind microbe-specific glycans. Both genetic and functional studies have suggested that intelectins have an important role in innate immunity and are involved in the etiology of various human diseases, including inflammatory bowel disease. Experiments investigating the role of intelectins in human disease using mouse models are limited by the fact that there is not a clear one-to-one relationship between intelectin genes in humans and mice, and that the number of intelectin genes varies between different mouse strains. In this study we show by gene sequence and gene expression analysis that human intelectin-1 (ITLN1) has multiple orthologues in mice, including a functional homologue Itln1; however, human intelectin-2 has no such orthologue or homologue. We confirm that all sub-strains of the C57 mouse strain have a large deletion resulting in retention of only one intelectin gene, Itln1. The majority of laboratory strains have a full complement of six intelectin genes, except CAST, SPRET, SKIVE, MOLF and PANCEVO strains, which are derived from different mouse species/subspecies and encode different complements of intelectin genes. In wild mice, intelectin deletions are polymorphic in Mus musculus castaneus and Mus musculus domesticus. Further sequence analysis shows that Itln3 and Itln5 are polymorphic pseudogenes due to premature truncating mutations, and that mouse Itln1 has undergone recent adaptive evolution. Taken together, our study shows extensive diversity in intelectin genes in both laboratory and wild-mice, suggesting a pattern of birth-and-death evolution. In addition, our data provide a foundation for further experimental investigation of the role of intelectins in disease.

Intelectins are ancient carbohydrate binding proteins, spanning chordate evolution and implicated in multiple human diseases. Previous GWAS have linked SNPs in ITLN1 (also known as omentin) with susceptibility to Crohn's disease (CD); however, analysis of possible functional significance of SNPs at this locus is lacking. Using the Ensembl database, pairwise linkage disequilibrium (LD) analyses indicated that several disease-associated SNPs at the ITLN1 locus, including SNPs in CD244 and Ly9, were in LD. The alleles comprising the risk haplotype are the major alleles in European (67%), but minor alleles in African superpopulations. Neither ITLN1 mRNA nor protein abundance in intestinal tissue, which we confirm as goblet-cell derived, was altered in the CD samples overall nor when samples were analyzed according to genotype. Moreover, the missense variant V109D does not influence ITLN1 glycan binding to the glycan β-D-galactofuranose or protein-protein oligomerization. Taken together, our data are an important step in defining the role(s) of the CD-risk haplotype by determining that risk is unlikely to be due to changes in ITLN1 carbohydrate recognition, protein oligomerization, or expression levels in intestinal mucosa. Our findings suggest that the relationship between the genomic data and disease arises from changes in CD244 or Ly9 biology, differences in ITLN1 expression in other tissues, or an alteration in ITLN1 interaction with other proteins.

Oxime antidotes regenerate organophosphate-inhibited acetylcholinesterase (AChE). Although they share a common mechanism of AChE reactivation, the rate and amount of oxime that enters the brain are critical to the efficacy, a process linked to the oxime structure and charge. Using a platform based on the organophosphate [18 F]-VXS as a positron emission tomography tracer for active AChE, the in vivo distribution of [18 F]-VXS was evaluated after an LD50 dose (250 μg/kg) of the organophosphate paraoxon (POX) and following oximes as antidotes. Rats given [18 F]-VXS tracer alone had significantly higher radioactivity (two- to threefold) in the heart and lung than rats given LD50 POX at 20 or 60 min prior to [18 F]-VXS. When rats were given LD50 POX followed by 2-PAM (cationic), RS194b (ionizable), or monoisonitrosoacetone (MINA) (neutral), central nervous system (CNS) radioactivity returned to levels at or above untreated naive rats (no POX), whereas CNS radioactivity did not increase in rats given the dication oximes HI-6 or MMB-4. MINA showed a significant, pairwise increase in CNS brain radioactivity compared with POX-treated rats. This new in vivo dynamic platform using [18 F]-VXS tracer measures and quantifies peripheral and CNS relative changes in AChE availability after POX exposure and is suitable for comparing oxime delivery and AChE reactivation in rats.

B cells infiltrate pancreatic ductal adenocarcinoma (PDAC) and in preclinical cancer models, can suppress T cell immunosurveillance in cancer. Here, we conducted a pilot study to assess the safety and feasibility of administering lentiviral-transduced chimeric antigen receptor (CAR)-modified autologous T cells redirected against mesothelin to target tumor cells along with CART cells redirected against CD19 to deplete B cells. Both CARs contained 4-1BB and CD3ζ signaling domains. Three patients with chemotherapy-refractory PDAC received 1.5 g/m2 cyclophosphamide prior to separate infusions of lentiviral-transduced T cells engineered to express chimeric anti-mesothelin immunoreceptor SS1 (CART-Meso, 3 × 107/m2) and chimeric anti-CD19 immunoreceptor (CART-19, 3 × 107/m2). Treatment was well tolerated without dose-limiting toxicities. Best response was stable disease (1 of 3 patients). CART-19 (compared to CART-Meso) cells showed the greatest expansion in the blood, although persistence was transient. B cells were successfully depleted in all subjects, became undetectable by 7-10 days post-infusion, and remained undetectable for at least 28 days. Together, concomitant delivery of CART-Meso and CART-19 cells in patients with PDAC is safe. CART-19 cells deplete normal B cells but at the dose tested in these 3 subjects did not improve CART-Meso cell persistence.

Identification of tumor-specific cell surface antigens has proven challenging, as the vast majority of tumor-associated antigens are also expressed in normal tissues. In mesothelioma, we identified a highly specific tumor cell surface antigen that can be targeted for therapy development. Mesothelioma is caused by malignant transformation of the mesothelium, is incurable, and can be categorized into three histologic subtypes: epithelioid, biphasic, and sarcomatoid. To identity novel mesothelioma cell surface antigens with broad subtype coverage and high tissue specificity, we have previously selected phage antibody display libraries on live mesothelioma cells and tissues following counterselection on normal cells and identified a panel of human antibodies that bind all subtypes of mesothelioma, but not normal mesothelium. One of the antibodies, M25, showed high specificity against an antigen we identify here as ALPPL2. IHC on normal human tissues found that ALPPL2 is expressed only on placental trophoblasts, but not on any other normal tissues. This significant tissue specificity and broad tumor type coverage suggest that ALPPL2 could be an excellent cell surface target for therapeutic development against mesothelioma. To evaluate therapeutic potential of ALPPL2 targeting, an ALPPL2-targeted antibody-drug conjugate was developed and demonstrated potent and specific tumor killing in vitro and in vivo against both epithelioid and sarcomatoid mesothelioma. Thus, ALPPL2 belongs to a rare class of cell surface antigens classified as truly tumor specific and is well suited for therapy development against ALPPL2-expressing tumors. SIGNIFICANCE: These findings identify ALPP2 as a true tumor-specific cell surface antigen whose tissue specificity enables the development of novel therapies.

To identify candidate biomarkers associated with neuromyelitis optica spectrum disorder (NMOSD) using high-throughput technologies that broadly assay the concentrations of serum analytes and frequencies of immune cell subsets. Sera, peripheral blood mononuclear cells (PBMCs), and matched clinical data from participants with NMOSD and healthy controls (HCs) were obtained from the Collaborative International Research in Clinical and Longitudinal Experience Study NMOSD biorepository. Flow cytometry panels were used to measure the frequencies of 39 T-cell, B-cell, regulatory T-cell, monocyte, natural killer (NK) cell, and dendritic cell subsets in unstimulated PBMCs. In parallel, multiplex proteomics assays were used to measure 46 serum cytokines and chemokines in 2 independent NMOSD and HC cohorts. Multivariable regression models were used to assess molecular and cellular profiles in NMOSD compared with HC. NMOSD samples had a lower frequency of CD16+CD56+ NK cells. Both serum cohorts and multivariable logistic regression revealed increased levels of B-cell activating factor associated with NMOSD. Interleukin 6, CCL22, and CCL3 were also elevated in 1 NMOSD cohort of the 2 analyzed. Multivariable linear regression of serum analyte levels revealed a correlation between CX3CL1 (fractalkine) levels and the number of days since most recent disease relapse. Integrative analyses of cytokines, chemokines, and immune cells in participants with NMOSD and HCs provide congruence with previously identified biomarkers of NMOSD and highlight CD16+CD56+ NK cells and CX3CL1 as potential novel biomarker candidates.

ObjectiveThe recessive disease arterial calcification due to deficiency of CD73 (ACDC) presents with extensive nonatherosclerotic medial layer calcification in lower extremity arteries. Lack of CD73 induces a concomitant increase in TNAP (tissue nonspecific alkaline phosphatase; ALPL), a key enzyme in ectopic mineralization. Our aim was to investigate how loss of CD73 activity leads to increased ALPL expression and calcification in CD73-deficient patients and assess whether this mechanism may apply to peripheral artery disease calcification. Approach and Results: We previously developed a patient-specific disease model using ACDC primary dermal fibroblasts that recapitulates the calcification phenotype in vitro. We found that lack of CD73-mediated adenosine signaling reduced cAMP production and resulted in increased activation of AKT. The AKT/mTOR (mammalian target of rapamycin) axis blocks autophagy and inducing autophagy prevented calcification; however, we did not observe autophagy defects in ACDC cells. In silico analysis identified a putative FOXO1 (forkhead box O1 protein) binding site in the human ALPL promoter. Exogenous AMP induced FOXO1 nuclear localization in ACDC but not in control cells, and this was prevented with a cAMP analogue or activation of A2a/2b adenosine receptors. Inhibiting FOXO1 reduced ALPL expression and TNAP activity and prevented calcification. Mutating the FOXO1 binding site reduced ALPL promoter activation. Importantly, we provide evidence that non-ACDC calcified femoropopliteal arteries exhibit decreased CD73 and increased FOXO1 levels compared with control arteries.ConclusionsThese data show that lack of CD73-mediated cAMP signaling promotes expression of the human ALPL gene via a FOXO1-dependent mechanism. Decreased CD73 and increased FOXO1 was also observed in more common peripheral artery disease calcification.

Downregulation of BST-2/tetherin and CD4 by HIV-1 viral protein U (Vpu) promotes viral egress and allows infected cells to evade host immunity. Little is known however about the natural variability in these Vpu functions among the genetically diverse viral subtypes that contribute to the HIV-1 pandemic. We collected Vpu isolates from 332 treatment-naive individuals living with chronic HIV-1 infection in Uganda, Rwanda, South Africa, and Canada. Together, these Vpu isolates represent four major HIV-1 group M subtypes (A [n = 63], B [n = 84], C [n = 94], and D [n = 59]) plus intersubtype recombinants and uncommon strains (n = 32). The ability of each Vpu clone to downregulate endogenous CD4 and tetherin was quantified using flow cytometry following transfection into an immortalized T-cell line and compared to that of a reference Vpu clone derived from HIV-1 subtype B NL4.3. Overall, the median CD4 downregulation function of natural Vpu isolates was similar to that of NL4.3 (1.01 [interquartile range {IQR}, 0.86 to 1.18]), while the median tetherin downregulation function was moderately lower than that of NL4.3 (0.90 [0.79 to 0.97]). Both Vpu functions varied significantly among HIV-1 subtypes (Kruskal-Wallis P

Organophosphate (OP) threat agents can trigger seizures that progress to status epilepticus, resulting in persistent neuropathology and cognitive deficits in humans and preclinical models. However, it remains unclear whether patients who do not show overt seizure behavior develop neurological consequences. Therefore, this study compared two subpopulations of rats with a low versus high seizure response to diisopropylfluorophosphate (DFP) to evaluate whether acute OP intoxication causes persistent neuropathology in non-seizing individuals. Adult male Sprague Dawley rats administered DFP (4 mg/kg, sc), atropine sulfate (2 mg/kg, im), and pralidoxime (25 mg/kg, im) were monitored for seizure activity for 4 h post-exposure. Animals were separated into groups with low versus high seizure response based on behavioral criteria and electroencephalogram (EEG) recordings. Cholinesterase activity was evaluated by Ellman assay, and neuropathology was evaluated at 1, 2, 4, and 60 days post-exposure by Fluoro-Jade C (FJC) staining and micro-CT imaging. DFP significantly inhibited cholinesterase activity in the cortex, hippocampus, and amygdala to the same extent in low and high responders. FJC staining revealed significant neurodegeneration in DFP low responders albeit this response was delayed, less persistent, and decreased in magnitude compared to DFP high responders. Micro-CT scans at 60 days revealed extensive mineralization that was not significantly different between low versus high DFP responders. These findings highlight the importance of considering non-seizing patients for medical care in the event of acute OP intoxication. They also suggest that OP intoxication may induce neurological damage via seizure-independent mechanisms, which if identified, might provide insight into novel therapeutic targets.

Acetylcholinesterase (AChE) is a pivotal enzyme in neurotransmission. Its inhibition leads to cholinergic crises and could ultimately result in death. A related enzyme, butyrylcholinesterase (BChE), may act in the CNS as a co-regulator in terminating nerve impulses and is a natural plasma scavenger upon exposure to organophosphate (OP) nerve agents that irreversibly inhibit both enzymes. With the aim of improving reactivation of cholinesterases phosphylated by nerve agents sarin, VX, cyclosarin, and tabun, ten phenyltetrahydroisoquinoline (PIQ) aldoximes were synthesized by Huisgen 1,3 dipolar cycloaddition between alkyne- and azide-building blocks. The PIQ moiety may serve as a peripheral site anchor positioning the aldoxime moiety at the AChE active site. In terms of evaluated dissociation inhibition constants, the aldoximes could be characterized as high-affinity ligands. Nevertheless, high binding affinity of these oximes to AChE or its phosphylated conjugates did not assure rapid and selective AChE reactivation. Rather, potential reactivators of phosphylated BChE, with its enlarged acyl pocket, were identified, especially in case of cyclosarin, where the reactivation rates of the lead reactivator was 100- and 6-times that of 2-PAM and HI-6, respectively. Nevertheless, the return of the enzyme activity was affected by the nerve agent conjugated to catalytic serine, which highlights the lack of the universality of reactivators with respect to both the target enzyme and OP structure.

Previous studies have shown that CD73 is pivotal in the conversion of pro-inflammatory adenosine triphosphate into anti-inflammatory adenosine and that immune cells of the same type that express different levels of CD73 are functionally distinct. In this study we show that adenosine enhances the Th17 promoting effect of dendritic cells (DCs), and DCs expressing CD73 critically augment Th17 responses. Bone marrow dendritic cells (BMDCs) do not constantly express CD73; however, a significant portion of the BMDCs expressed CD73 after exposure to Toll-like receptor ligand, leading to stronger Th17 responses by converting adenosine monophosphate to adenosine. We show that the CD73+ BMDCs play a critical role in cascading Th17 responses, and CD73+ BMDCs are functionally augmented after treatment with Toll-like receptor ligand. Splenic antigen presenting cells (DCs) of CD73-/- mouse have a poor Th17-stimulating effect, even after exposure to lipopolysaccharide (LPS) or γδ T cells, indicating that induction of CD73+ DCs is critically involved in augmented Th17 responses. We conclude that CD73+ DCs critically trigger cascading Th17 responses, and the activated Th17 cells that express CD73 further augment Th17 responses, leading to cascading exacerbation. Hence, disabling the CD73 function of DCs should block this cascading response and mitigate Th17 responses.

Antibody-based dual-modality (PET/fluorescence) imaging enables both presurgery antigen-specific immuno-PET for noninvasive whole-body evaluation and intraoperative fluorescence for visualization of superficial tissue layers for image-guided surgery. Methods: We developed a universal dual-modality linker (DML) that facilitates site-specific conjugation to a cysteine residue-bearing antibody fragment, introduction of a commercially available fluorescent dye (via an amine-reactive prosthetic group), and rapid and efficient radiolabeling via click chemistry with 18F-labeled trans-cyclooctene (18F-TCO). To generate a dual-modality antibody fragment-based imaging agent, the DML was labeled with the far-red dye sulfonate cyanine 5 (sCy5), site-specifically conjugated to the C-terminal cysteine of the anti-prostate stem cell antigen (PSCA) cys-diabody A2, and subsequently radiolabeled by click chemistry with 18F-TCO. The new imaging probe was evaluated in a human PSCA-positive prostate cancer xenograft model by sequential immuno-PET and optical imaging. Uptake in target tissues was confirmed by ex vivo biodistribution. Results: We successfully synthesized a DML for conjugation of a fluorescent dye and 18F. The anti-PSCA cys-diabody A2 was site-specifically conjugated with either DML or sCy5 and radiolabeled via click chemistry with 18F-TCO. Immuno-PET imaging confirmed in vivo antigen-specific targeting of prostate cancer xenografts as early as 1 h after injection. Rapid renal clearance of the 50-kDa antibody fragment enables same-day imaging. Optical imaging showed antigen-specific fluorescent signal in PSCA-positive xenografts and high contrast to surrounding tissue and PSCA-negative xenografts. Conclusion: The DML enables site-specific conjugation away from the antigen-binding site of antibody fragments, with a controlled linker-to-protein ratio, and combines signaling moieties for 2 imaging systems into 1 molecule. Dual-modality imaging could provide both noninvasive whole-body imaging with organ-level biodistribution and fluorescence image-guided identification of tumor margins during surgery.

The plasma membrane is a site of conflict between host defenses and many viruses. One aspect of this conflict is the host's attempt to eliminate infected cells using innate and adaptive cell-mediated immune mechanisms that recognize features of the plasma membrane characteristic of viral infection. Another is the expression of plasma membrane-associated proteins, so-called restriction factors, which inhibit enveloped virions directly. HIV-1 encodes two countermeasures to these host defenses: The membrane-associated accessory proteins Vpu and Nef. In addition to inhibiting cell-mediated immune-surveillance, Vpu and Nef counteract membrane-associated restriction factors. These include BST-2, which traps newly formed virions at the plasma membrane unless counteracted by Vpu, and SERINC5, which decreases the infectivity of virions unless counteracted by Nef. Here we review key features of these two antiviral proteins, and we review Vpu and Nef, which deplete them from the plasma membrane by co-opting specific cellular proteins and pathways of membrane trafficking and protein-degradation. We also discuss other plasma membrane proteins modulated by HIV-1, particularly CD4, which, if not opposed in infected cells by Vpu and Nef, inhibits viral infectivity and increases the sensitivity of the viral envelope glycoprotein to host immunity.

Acute intoxication with organophosphate cholinesterase inhibitors (OPs) is a significant human health threat, and current medical countermeasures for OP poisoning are of limited therapeutic efficacy. The rat model of acute intoxication with diisopropylfluorophosphate (DFP) is increasingly being used to test candidate compounds for efficacy in protecting against the immediate and long-term consequences of acute OP toxicity. In this model, rats are typically pretreated with pyridostigmine bromide (PB), a reversible cholinesterase inhibitor, to enhance survival. However, PB pretreatment is not likely in most scenarios of civilian exposure to acutely neurotoxic levels of OPs. Therefore, the goal of this study was to determine whether PB pretreatment significantly increases survival in DFP-intoxicated rats. Adult male Sprague Dawley rats were injected with DFP (4 mg/kg, s.c.) or vehicle (VEH) followed 1 min later by combined i.m. injection of atropine sulfate (2 mg/kg) and 2-pralidoxime (25 mg/kg). Animals were pretreated 30 min prior to these injections with PB (0.1 mg/kg, i.m.) or an equal volume of saline. DFP triggered rapid and sustained seizure behavior irrespective of PB pretreatment, and there was no significant difference in average seizure behavior score during the first 4 h following injection between DFP animals pretreated with PB or not. PB pretreatment also had no significant effect on survival or brain AChE activity at 24 h post-DFP exposure. In summary, PB pretreatment is not necessary to ensure survival of rats acutely intoxicated with DFP, and eliminating PB pretreatment in the rat model of acute DFP intoxication would increase its relevance to acute OP intoxication in civilians.

The cellular protein bone marrow stromal antigen-2 (BST-2)/tetherin acts against a variety of enveloped viruses by restricting their release from the plasma membrane. The HIV-1 accessory protein Vpu counteracts BST-2 by downregulating it from the cell surface and displacing it from virion assembly sites. Previous comparisons of Vpus from transmitted/founder viruses and between viruses isolated during acute and chronic infection led to the identification of a tryptophan at position 76 in Vpu (W76) as a key determinant for the displacement of BST-2 from virion assembly sites. Although present in Vpus from clades B, D, and G, W76 is absent from Vpus from clades A, C, and H. Mutagenesis of the C-terminal region of Vpu from two clade C viruses led to the identification of a conserved LL sequence that is functionally analogous to W76 of clade B. Alanine substitution of these leucines partially impaired virion release. This impairment was even greater when the mutations were combined with mutations of the Vpu β-TrCP binding site, resulting in Vpu proteins that induced high surface levels of BST-2 and reduced the efficiency of virion release to less than that of virus lacking vpu Microscopy confirmed that these C-terminal leucines in clade C Vpu, like W76 in clade B, contribute to virion release by supporting the displacement of BST-2 from virion assembly sites. These results suggest that although encoded differently, the ability of Vpu to displace BST-2 from sites of virion assembly on the plasma membrane is evolutionarily conserved among clade B and C HIV-1 isolates.IMPORTANCE Although targeted by a variety of restriction mechanisms, HIV-1 establishes chronic infection in most cases, in part due to the counteraction of these host defenses by viral accessory proteins. Using conserved motifs, the accessory proteins exploit the cellular machinery to degrade or mistraffic host restriction factors, thereby counteracting them. The Vpu protein counteracts the virion-tethering factor BST-2 in part by displacing it from virion assembly sites along the plasma membrane, but a previously identified determinant of that activity is clade specific at the level of protein sequence and not found in the clade C viruses that dominate the pandemic. Here, we show that clade C Vpu provides this activity via a leucine-containing sequence rather than the tryptophan-containing sequence found in clade B Vpu. This difference seems likely to reflect the different evolutionary paths taken by clade B and clade C HIV-1 in human populations.

ObjectivesIn a genome-wide association study, we discovered chromosome 12q15 (defined as rs73329476) as a silica-related pneumoconiosis susceptibility region. However, the causal variants in this region have not yet been reported.MethodsWe systematically screened eight potentially functional single-neucleotide polymorphism (SNPs) in the genes near rs73329476 (carboxypeptidase M (CPM) and cleavage and polyadenylation specific factor 6 (CPSF6)) in a case-control study including 177 cases with silicosis and 204 healthy controls, matched to cases with years of silica dust exposure. We evaluated the associations between these eight SNPs and the development of silicosis. Luciferase reporter gene assays were performed to test the effects of selected SNP on the activity of CPM in the promoter. In addition, a two-stage case-control study was performed to investigate the expression differences of the two genes in peripheral blood leucocytes from a total of 64 cases with silicosis and 64 healthy controls with similar years of silica dust exposure as the cases.ResultsWe found a strong association between the mutant rs12812500 G allele and the susceptibility of silicosis (OR=1.45, 95% CI 1.03 to 2.04, p=0.034), while luciferase reporter gene assays indicated that the mutant G allele of rs12812500 is strongly associated with increased luciferase levels compared with the wild-type C allele (p

Cell migration is essential for proper development and the defense against pathogens. Our previous work detailed a pathway of REversion-inducing-Cysteine-rich protein with Kazal motifs (RECK) isoform-mediated invasion in which a shorter RECK protein competes with MMP9 for interaction with the canonical RECK protein on the cell surface. Here we demonstrate that the mechanism through which RECK isoforms affect cell migration is mediated through changes in the levels of post-translational modifications (PTM) of α-tubulin. We show that both the canonical and short RECK isoforms modulate levels of tubulin acetylation and detyrosination. We demonstrate that these changes are sufficient to modulate the rate of fibroblast migration. If these tubulin PTMs are not altered, the effects of the canonical RECK isoform on cell migration are reversed. In defining the molecular pathway linking RECK and tubulin PTMs, we found that MMP9 and integrin activity both act as upstream regulators of tubulin acetylation and detyrosination. Overall, we propose a mechanism in which RECK isoforms on the cell surface have opposing effects on cell migration through MMP9-modulated changes to integrin-extracellular matrix (ECM) interactions that, in turn, affect microtubule PTMs.

Recently, we reported that the herpesvirus entry mediator (HVEM; also called TNFRSF14 or CD270) is upregulated by the latency-associated transcript (LAT) of herpes simplex virus 1 (HSV-1) and that the absence of HVEM affects latency reactivation but not primary infection in ocularly infected mice. gD has been shown to bind to HVEM. LIGHT (TNFSF14), CD160, and BTLA (B- and T-lymphocyte attenuator) also interact with HVEM and can interfere with HSV gD binding. It was not known if LIGHT, CD160, or BTLA affected the level of latency reactivation in the trigeminal ganglia (TG) of latently infected mice. To address this issue, we ocularly infected LIGHT-/-, CD160-/-, and BTLA-/- mice with LAT(+) and LAT(-) viruses, using similarly infected wild-type (WT) and HVEM-/- mice as controls. The amount of latency, as determined by the levels of gB DNA in the TG of the LIGHT-/-, CD160-/-, and BTLA-/- mice infected with either LAT(+) or LAT(-) viruses, was lower than that in WT mice infected with LAT(+) virus and was similar in WT mice infected with LAT(-) virus. The levels of LAT RNA in HVEM-/-, LIGHT-/-, CD160-/-, and BTLA-/- mice infected with LAT(+) virus were similar and were lower than the levels of LAT RNA in WT mice. However, LIGHT-/-, CD160-/-, and BTLA-/- mice, independent of the presence of LAT, had levels of reactivation similar to those of WT mice infected with LAT(+) virus. Faster reactivation correlated with the upregulation of HVEM transcript. The LIGHT-/-, CD160-/-, and BTLA-/- mice had higher levels of HVEM expression, and this, along with the absence of BTLA, LIGHT, or CD160, may contribute to faster reactivation, while the absence of each molecule, independent of LAT, may have contributed to lower latency. This study suggests that, in the absence of competition with gD for binding to HVEM, LAT RNA is important for WT levels of latency but not for WT levels of reactivation.IMPORTANCE The effects of BTLA, LIGHT, and CD160 on latency reactivation are not known. We show here that in BTLA, LIGHT, or CD160 null mice, latency is reduced; however, HVEM expression is upregulated compared to that of WT mice, and this upregulation is associated with higher reactivation that is independent of LAT but dependent on gD expression. Thus, one of the mechanisms by which BTLA, LIGHT, and CD160 null mice enhance reactivation appears to be the increased expression of HVEM in the presence of gD. Thus, our results suggest that blockade of HVEM-LIGHT-BTLA-CD160 contributes to reduced HSV-1 latency and reactivation.

UNLABELLED: Interferon (IFN) inhibits HIV replication by inducing antiviral effectors. To comprehensively identify IFN-induced HIV restriction factors, we assembled a CRISPR sgRNA library of Interferon Stimulated Genes (ISGs) into a modified lentiviral vector that allows for packaging of sgRNA-encoding genomes in trans into budding HIV-1 particles. We observed that knockout of Zinc Antiviral Protein (ZAP) improved the performance of the screen due to ZAP-mediated inhibition of the vector. A small panel of IFN-induced HIV restriction factors, including MxB, IFITM1, Tetherin/BST2 and TRIM5alpha together explain the inhibitory effects of IFN on the CXCR4-tropic HIV-1 strain, HIV-1LAI, in THP-1 cells. A second screen with a CCR5-tropic primary strain, HIV-1Q23.BG505, described an overlapping, but non-identical, panel of restriction factors. Further, this screen also identifies HIV dependency factors. The ability of IFN-induced restriction factors to inhibit HIV strains to replicate in human cells suggests that these human restriction factors are incompletely antagonized. EDITORIAL NOTE: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editors assessment is that all the issues have been addressed (see decision letter).

mRNA translation in axons enables neurons to introduce new proteins at sites distant from their cell body. mRNA-protein interactions drive this post-transcriptional regulation, yet knowledge of RNA binding proteins (RBP) in axons is limited. Here we used proteomics to identify RBPs interacting with the axonal localizing motifs of Nrn1, Hmgb1, Actb, and Gap43 mRNAs, revealing many novel RBPs in axons. Interestingly, no RBP is shared between all four RNA motifs, suggesting graded and overlapping specificities of RBP-mRNA pairings. A systematic assessment of axonal mRNAs interacting with hnRNP H1, hnRNP F, and hnRNP K, proteins that bound with high specificity to Nrn1 and Hmgb1, revealed that axonal mRNAs segregate into axon growth-associated RNA regulons based on hnRNP interactions. Axotomy increases axonal transport of hnRNPs H1, F, and K, depletion of these hnRNPs decreases axon growth and reduces axonal mRNA levels and axonal protein synthesis. Thus, subcellular hnRNP-interacting RNA regulons support neuronal growth and regeneration.

PURPOSE OF REVIEW:Luminal chemosensing is a term used to describe how small molecules in the gut lumen interact with the host through surface receptors or via transport into the submucosa. In this review, we have summarized recent advances of understanding luminal chemosensing in the gastroduodenal mucosa, with a particular emphasis on how chemosensing affects mucosal protective responses and the metabolic syndrome. RECENT FINDINGS:In the past decade, data have supported the hypothesis that gut luminal chemosensing not only is important for the local or remote regulation of gut function but also contributes to the systemic regulation of metabolism, energy balance and food intake. We have provided examples of how luminal nutrients such as long-chain fatty acids (LCFAs), endogenous compounds such as bile acids, bacterial metabolites such as short-chain fatty acids (SCFAs) and bacterial components such as lipopolysaccharide (LPS) activate cognate receptors expressed on key effector cells such as enteroendocrine cells and inflammatory cells in order to profoundly affect organ function through the initiation or suppression of inflammatory pathways, altering gut barrier function and nutrient uptake, altering gut motility and visceral pain pathways, and preventing mucosal injury. SUMMARY:These recent discoveries in this area have provided new possibilities for identifying novel molecular targets for the treatment of mucosal injury, metabolic disorders and abnormal visceral sensation. Understanding luminal chemosensory mechanisms may help to identify novel molecular targets for the treatment and prevention of mucosal injury, metabolic disorders and abnormal visceral sensation.

Intestinal production of endocannabinoid and oleoylethanolamide (OEA) is impaired in high-fat diet/obese rodents, leading to reduced satiety. Such diets also alter the intestinal microbiome in association with enhanced intestinal permeability and inflammation; however, little is known of these effects in humans. This study aimed to 1) evaluate effects of lipid on plasma anandamide (AEA), 2-arachidonyl- sn-glycerol (2-AG), and OEA in humans; and 2) examine relationships to intestinal permeability, inflammation markers, and incretin hormone secretion. Twenty lean, 18 overweight, and 19 obese participants underwent intraduodenal Intralipid infusion (2 kcal/min) with collection of endoscopic duodenal biopsies and blood. Plasma AEA, 2-AG, and OEA (HPLC/tandem mass spectrometry), tumor necrosis factor-α (TNFα), glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic peptide (GIP) (multiplex), and duodenal expression of occludin, zona-occludin-1 (ZO-1), intestinal-alkaline-phosphatase (IAP), and Toll-like receptor 4 (TLR4) (by RT-PCR) were assessed. Fasting plasma AEA was increased in obese compared with lean and overweight patients ( P < 0.05), with no effect of BMI group or ID lipid infusion on plasma 2-AG or OEA. Duodenal expression of IAP and ZO-1 was reduced in obese compared with lean ( P < 0.05), and these levels related negatively to plasma AEA ( P < 0.05). The iAUC for AEA was positively related to iAUC GIP ( r = 0.384, P = 0.005). Obese individuals have increased plasma AEA and decreased duodenal expression of ZO-1 and IAP compared with lean and overweight subjects. The relationships between plasma AEA with duodenal ZO-1, IAP, and GIP suggest that altered endocannabinoid signaling may contribute to changes in intestinal permeability, inflammation, and incretin release in human obesity.

Invariant natural killer T (iNKT) cells are activated at sites of local tissue injury, or globally during vaso-occlusive episodes of sickle cell disease (SCD). Tissue damage stimulates production of CD1d-restricted lipid antigens that activate iNKT cells to produce Th1- and Th2-type cytokines. Here, we show that circulating iNKT cells in SCD patients express elevated levels of the ectonucleoside triphosphate diphosphosphohydrolase, CD39, as well the adenosine A2A receptor (A2AR). We also investigated the effects of stimulating cultured human iNKT cells on the expression of genes involved in the regulation of purinergic signaling. iNKT cell stimulation caused induction of ADORA2A, P2RX7, CD38, CD39, ENPP1, CD73, PANX1, and ENT1. Transcription of ADA, which degrades adenosine, was reduced. Induction of CD39 mRNA was associated with increased ecto-ATPase activity on iNKT cells that was blocked by POM1. Exposure of iNKT cells to A2AR agonists during stimulation reduced production of IFN-γ and enhanced production of IL-13 and CD39. Based on these findings, we define purinergic Th2-type cytokine bias as an antiinflammatory purinergic response to iNKT cell stimulation resulting from changes in the transcription of several genes involved in purine release, extracellular metabolism, and signaling.

Cell migration is a highly conserved process involving cytoskeletal reorganization and restructuring of the surrounding extracellular matrix. Although there are many studies describing mechanisms underlying cell motility, little has been reported about the contribution of alternative isoform use toward cell migration. Here, we investigated whether alternative isoform use can affect cell migration focusing on reversion-inducing-cysteine-rich protein with Kazal motifs (RECK), an established inhibitor of cell migration. We found that a shorter isoform of RECK is more highly expressed in proliferating fibroblasts, in TGF-β-treated fibroblasts, and in tumors compared with differentiated tissue. Knockdown of this short RECK isoform reduces fibroblast migration through Matrigel. Thus, this short isoform of RECK generated by a combination of alternative splicing and alternative polyadenylation plays an opposing role to the canonical RECK isoform, as knockdown of canonical RECK results in faster cell migration through Matrigel. We show that the short RECK protein competes with matrix metalloprotease 9 (MMP9) for binding to the Kazal motifs of canonical RECK, thus liberating MMP9 from an inactivating interaction with canonical RECK. Our studies provide a new paradigm and a detailed mechanism for how alternative isoform use can regulate cell migration by producing two proteins with opposing effects from the same genetic locus.

Prostate cancer is a heterogeneous disease composed of divergent molecular and histologic subtypes, including prostate adenocarcinoma (PrAd) and neuroendocrine prostate cancer (NEPC). While PrAd is the major histology in prostate cancer, NEPC can evolve from PrAd as a mechanism of treatment resistance that involves a transition from an epithelial to a neurosecretory cancer phenotype. Cell surface markers are often associated with specific cell lineages and differentiation states in normal development and cancer. Here, we show that PrAd and NEPC can be broadly discriminated by cell-surface profiles based on the analysis of prostate cancer gene expression datasets. To overcome a dependence on predictions of human cell-surface genes and an assumed correlation between mRNA levels and protein expression, we integrated transcriptomic and cell-surface proteomic data generated from a panel of prostate cancer cell lines to nominate cell-surface markers associated with these cancer subtypes. FXYD3 and CEACAM5 were validated as cell-surface antigens enriched in PrAd and NEPC, respectively. Given the lack of effective treatments for NEPC, CEACAM5 appeared to be a promising target for cell-based immunotherapy. As a proof of concept, engineered chimeric antigen receptor T cells targeting CEACAM5 induced antigen-specific cytotoxicity in NEPC cell lines. Our findings demonstrate that the surfaceomes of PrAd and NEPC reflect unique cancer differentiation states and broadly represent vulnerabilities amenable to therapeutic targeting.

Background: Lymphocyte antigen 6 complex, locus E (Ly6E) has been initially demonstrated to involve in T cell activity and impair viral infectivity. Recently, high expression levels of Ly6E have been reported in tumor microenvironment (TME) of various types of cancers. However, the immunoregulatory mechanism of Ly6E manipulating TME remains unknown., Methods: TCGA database and Kaplan-Meier plotter database were used to evaluate the correlation between Ly6E expression levels and cancer patient survival. After analyzing Ly6E expression levels in human breast cancer tissues and tumor cell lines, we generated Ly6E knockout (KO) and overexpression (OE) mouse cell lines. Cell proliferation ability in vitro and the ability of growth and metastasis in mouse tumor models were compared between KO/OE and wild-type tumor cells. On day 7 after tumor implantation, tumor tissues were separated for flow cytometric assay, bulk RNA sequencing and single-cell RNA sequencing (ScRNA-seq). The role of Ly6E-expressing tumor cell on macrophage was analyzed in vitro., Results: Our result surprisingly found that high Ly6E expression levels were associated with CD8 + T cell exclusion in tumor tissues and resistance to immunotherapy. Our data showed that knockout of Ly6E in tumor cells prompts tumor regression and inhibits tumor metastases, and Ly6E-OE tumor cells vice versa. The enhanced anti-tumor effect of Ly6E knockout in tumor cells was dependent on T cell response and formed long-lasting memory. The increase in the CD8 + T-cell infiltration into the tumor islet of Ly6E-KO tumors confirmed the role of Ly6E on T cell exclusion. ScRNA-seq analysis showed that M2 macrophages are particularly abundant in the Ly6E-expressing tumor tissues, especially M2-4 macrophage cluster identified by high levels of Arg-1, indicates that Ly6E-expressing tumor cells might restrict T cell infiltration via M2 macrophages. Moreover, in vitro assay showed that cell culture media derived from Ly6E-positive tumor cells promoted macrophage migration and M2 polarization., Conclusion: Our study illuminated that Ly6E-expressing tumor cells facilitated the accumulation of M2 macrophages in TME, which contributes to CD8 + T cell exclusion and provides new insights for improving efficacy of cancer immunotherapy., (© 2024. The Author(s).)

Background/aim: Atherosclerosis is a vascular inflammatory disease characterized by the activation and stress of various inflammatory cells, leading to the development of coronary artery disease and subsequently acute myocardial infarction (AMI). Among AMI cases, ST-segment elevation myocardial infarction (STEMI) is typically more severe than non-STEMI (NSTEMI). UL16-binding proteins (ULBPs), which are NKG2D ligands, can be expressed on the surface of stressed and activated cells, prompting these cells to generate microparticles (MPs). Consequently, MPs carrying ULBPs, particularly ULBP1 (ULBP1 + MPs), may be released into the bloodstream. This study aimed to investigate the association between ULBP1 + MPs and the presence of AMI and its severity., Materials and Methods: We recruited 58 AMI patients and 45 age-matched control subjects. Levels of ULBP1 + MPs and ULBP1 + MPs originating from T lymphocytes (ULBP1 + TMPs) were measured using flow cytometry., Results: Both ULBP1 + MP and ULBP1 + TMP levels were significantly elevated in AMI patients compared to controls. Elevated levels of these MPs were independent risk factors for AMI with odds ratios (OR) of 4.3 (95%CI=1.5-12.3) for ULBP1 + MPs and 5.8 (95%CI=2.0-17.0) for ULBP1 + TMPs. Additionally, ULBP1 + TMP levels were significantly higher in STEMI patients compared to NSTEMI patients, with an independent association observed between ULBP1 + TMPs and STEMI (OR=3.9; 95%CI=1.2-12.8)., Conclusion: Elevated levels of ULBP1 + MPs and ULBP1 + TMPs are associated with AMI and its severity. These biomarkers could serve as indicators of vulnerable plaques that lead to AMI., (Copyright © 2024, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Various osteogenic factors are involved in ectopic human aortic valve calcification; however, the key cell species involved in calcification remains unclear. In a previous study, we reported that mesenchymal stem (CD73, 90, 105) and endothelial (VEGFR2) cell markers are positive in almost all human aortic valve interstitial cells (HAVICs) obtained from a patient with calcified aortic valve stenosis (CAVS). Further, CD34-negative HAVICs are highly sensitive to calcification stimulations. Here, we aimed to pathophysiologically clarify the role of CD34 in HAVICs obtained from individual patients with severe CAVS. A DNA microarray between CD34-positive and CD34-negative HAVICs, separated by fluorescence-activated cell sorting, indicated that tenascin X (TNX) mRNA expression significantly decreased in CD34-negative cells. Furthermore, the inflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin (IL)-1β significantly downregulated CD34 expression in HAVICs. TGF-β, a key cytokine of endothelial-mesenchymal transition, did not affect HAVIC calcification. CD34 overexpression strongly inhibited TNF-α- and IL-1β-induced calcification and maintained TNX mRNA expression. These results suggest one possibility that CD34 is an inhibitory regulator of valve calcification. Furthermore, TNF-α- and IL-1β-induced CD34 downregulation in HAVICs contributes to HAVIC calcification by downregulating TNX protein expression., (Copyright © 2024 The Authors. Production and hosting by Elsevier B.V. All rights reserved.)

Objective: CD73 (ecto-5'-nucleotidase, NT5E), a cell-surface enzyme converting 5'-AMP to adenosine, is crucial for cancer progression. However, its role in the tumorigenesis process remains mostly obscure. We aimed to demonstrate CD73's role in breast cancer (BC) tumorigenesis through metabolic rewiring of fatty acid metabolism, a process recently indicated to be regulated by BC major prognostic markers, hormone receptors (HR) for estrogen (ER), and progesterone (PR)., Methods: A murine model of chemically induced mammary gland tumorigenesis was applied to analyze CD73 knock-out (KO)-induced changes at the transcriptome (RNA-seq), proteome (IHC, WB), and lipidome (GC-EI-MS) levels. CD73 KO-induced changes were correlated with scRNA-seq and bulk RNA-seq data for human breast tissues and BCs from public collections and confirmed at the proteome level with IHC or WB analysis of BC tissue microarrays and cell lines., Results: CD73 KO delayed the onset of HR/PR-negative mammary tumors in a murine model. This delay correlated with increased expression of genes related to biosynthesis and β-oxidation of fatty acids (FAs) in the CD73 KO group at the initiation stage. STRING analysis based on RNA-seq data indicated an interplay between CD73 KO, up-regulated expression of PR-coding gene, and DEGs involved in FA metabolism, with PPARγ, a main regulator of FA synthesis, as a main connective node. In epithelial cells of mammary glands, PPARγ expression correlated with CD73 at the RNA level. With cancer progression, CD73 KO increased the levels of PUFAn3/6 (polyunsaturated omega 3/6 FAs), known ligands of PPARγ and target for lipid peroxidation, which may lead to oxidative DNA damage. It correlated with the downregulation of genes involved in cellular stress response (Mlh1, Gsta3), PR-or CD73-dependent changes in the intracellular ROS levels and expression or activation of proteins involved in DNA repair or oxidative stress response in mammary tumor or human BC cell lines, increased tumor mutational burden (TMB) and genomic instability markers in CD73 low HR-negative human BCs, and the prolonged onset of tumors in the CD73 KO HR/PR-negative group., Conclusions: CD73 has a significant role in tumorigenesis driving the reprogramming of lipid metabolism through the regulatory loop with PR and PPARγ in epithelial cells of mammary glands. Low CD73 expression/CD73 KO might enhance mutational burden by disrupting this regulatory loop, delaying the onset of HR-negative tumors. Our results support combining therapy targeting the CD73-adenosine axis and tumor lipidome against HR-negative tumors, especially at their earliest developmental stage., Competing Interests: Declaration of competing interest None., (Copyright © 2024 The Authors. Published by Elsevier GmbH.. All rights reserved.)

Carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) are overexpressed in some tumor types. The antibody-drug conjugate tusamitamab ravtansine specifically recognizes the A3-B3 domains of human CEACAM5 (hCEACAM5). To understand this specificity, here we map the epitope-paratope interface between the A3-B3 domains of hCEACAM5 (hCEACAM5 A3-B3 ) and the antigen-binding fragment of tusamitamab (tusa Fab). We use hydrogen/deuterium exchange mass spectrometry to identify the tusa Fab paratope, which involves heavy chain (HC) residues 101-109 and light chain residues 48-54 and 88-104. Using surface plasmon resonance, we demonstrate that alanine variants of HC residues 96-108 abolish binding to hCEACAM5, suggesting that these residues are critical for tusa-Fab-antigen complex formation. The cryogenic electron microscopy structure of the hCEACAM5 A3-B3 - tusa Fab complex (3.11 Å overall resolution) reveals a discontinuous epitope involving residues in the A3-B3 domains and an N-linked mannose at residue Asn612. Conformational constraints on the epitope-paratope interface enable tusamitamab to target hCEACAM5 A3-B3 and distinguish CEACAM5 from other CEACAMs., (© 2024. The Author(s).)

Diabetes, a chronic metabolic disease, affects approximately 422 million people and leads to 1.5 million deaths every year, It is found that 45% of individuals with diabetes eventually develop cognitive impairment. Here we study effects of Vitamin K2 on diabetes-associated cognitive decline (DACD) and its underlying mechanism. Diabetes was induced in adult Swiss albino mice with high-fat diet and a low dose (35 mg/kg) of streptozotocin and measured by fasting glucose and HbA1c levels. After one week of development of diabetes, one group of animals received Vitamin K2 (100 µg/kg) via oral gavage for 21 days. Then different behavioural studies, including the elevated plus maze, Morris water maze, passive avoidance test and novel object recognition test were performed followed by biochemical tests including AchE, different oxidative stress parameters (SOD, GSH, MDA, catalase, SIRT1, NRF2), inflammatory markers (TNFα, IL1β, MCP1, NFκB), apoptosis marker (Caspase 3). Hippocampal neuronal density was measured using histopathology. Vitamin K2 treatment in diabetic animals led to reduced fasting glucose and HbA1c, It could partially reverse DACD as shown by behavioural studies. Vitamin K2 adminstration reduced corticohippocampal AchE level and neuroinflammation (TNFα, IL1β, MCP1, NFκB, SIRT1). It reduced oxidative stress by increasing antioxidant enzymes (SOD, GSH, catalase), transcription factor NRF2 while reducing caspase 3. This eventually increased CA1 and CA3 neuronal density in diabetic animals. Vitamin K2 partially reverses DACD by increasing ACh while reducing the oxidative stress via Nrf2/ARE pathway and neuroinflammation, thus protecting the hippocampal neurons from diabetes associated damage., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Pantetheinase is a key biomarker for the diagnosis of acute kidney injury and the monitoring of malaria progression. Currently, existing methods for sensing pantetheinase, also known as Vanin-1, show considerable potential but come with certain limitations, including their inability to directly sense analytes in turbid biofluid samples without tedious sample pretreatment. Here, we describe the first activity-based electrochemical probe, termed VaninLP, for convenient and specific direct targeting of pantetheinase activity in turbid liquid biopsy samples. The probe was designed such that cleavage of the pantetheinase amide linkage, triggered by a self-immolative reaction, simultaneously ejects an amino ferrocene reporter. Among the distinctive properties of the VaninLP probe for sensing pantetheinase are its high selectivity, sensitivity, and enzyme affinity, a wide linear concentration range (8-300 ng/mL), and low limit of detection (2.47 ng/mL). The designed probe precisely targeted pantetheinase and was free of interference by other electroactive biological species. We further successfully applied the VaninLP probe to monitor and quantify the activity of pantetheinase on the surfaces of HepG2 tumor cells, blood, and urine samples. Collectively, our findings indicate that VaninLP holds significant promise as a point-of-care tool for diagnosing early-stage kidney injury, as well as monitoring the progression of malaria.

Ecto-5-nucleotidase (CD73) is overexpressed in a variety of cancers and associated with the immunosuppressive tumor microenvironment, making it an attractive target for cancer immunotherapy. Herein, we designed and synthesized a series of novel (pyridazine-3-yl)pyrimidine-2,4(1 H ,3 H )-dione derivatives as CD73 inhibitors. These compounds exhibited remarkable inhibitory activity against CD73 in both enzymatic biochemical and cellular assays. Among them, compound 35j proved to be one of the most potent inhibitors and an uncompetitive inhibitor with no obvious cytotoxicity. This compound showed high metabolic stability in rat liver microsomes and favorable pharmacokinetic profiles in rats ( T 1/2 = 3.37 h, F = 50.24%). Importantly, orally administered 35j significantly inhibited tumor growth in the triple-negative breast cancer 4T1 mouse model (TGI = 73.6%, 50 mg/kg). Immunoassays suggested that 35j remarkably increased the infiltration of positive immune cells, thereby reinvigorating antitumor immunity. These results demonstrate that 35j is a potent CD73 inhibitor worthy of further development.

Atopic dermatitis (AD) is a chronic inflammatory skin condition with complex etiology involving genetic, environmental, and immunological factors. This study employs Mendelian randomization to explore the causal relationships between immune cell phenotypes and AD, and the mediating effects of plasma metabolites. Using data from European cohorts, we identified 7 immune cell phenotypes significantly associated with AD. Mediation analysis revealed that the alpha-ketobutyrate to 4-methyl-2-oxopentanoate ratio negatively regulates CCR2 on monocytes, while the glycerol to carnitine ratio positively regulates HLA-DR on CD14- CD16- cells. These findings underscore the critical role of metabolic pathways in modulating immune responses and suggest potential dietary and therapeutic interventions for AD management. Further research should consider more diverse populations to validate these findings., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Schizophrenia is a neuropsychiatric illness characterized by altered neurotransmission, in which adenosine, a modulator of glutamate and dopamine, plays a critical role that is relatively unexplored in the human brain. In the present study, postmortem human brain tissue from the anterior cingulate cortex (ACC) of individuals with schizophrenia ( n = 20) and sex- and age-matched control subjects without psychiatric illness ( n = 20) was obtained from the Bronx-Mount Sinai NIH Brain and Tissue Repository. Enriched populations of ACC pyramidal neurons were isolated using laser microdissection (LMD). The mRNA expression levels of six key adenosine pathway components-adenosine kinase (ADK), equilibrative nucleoside transporters 1 and 2 (ENT1 and ENT2), ectonucleoside triphosphate diphosphohydrolases 1 and 3 (ENTPD1 and ENTPD3), and ecto-5'-nucleotidase (NT5E)-were quantified using real-time PCR (qPCR) in neurons from these individuals. No significant mRNA expression differences were observed between the schizophrenia and control groups ( p > 0.05). However, a significant sex difference was found in ADK mRNA expression, with higher levels in male compared with female subjects (Mann-Whitney U = 86; p < 0.05), a finding significantly driven by disease (t (17) = 3.289; p < 0.05). Correlation analyses also demonstrated significant associations ( n = 12) between the expression of several adenosine pathway components ( p < 0.05). In our dementia severity analysis, ENTPD1 mRNA expression was significantly higher in males in the "mild" clinical dementia rating (CDR) bin compared with males in the "none" CDR bin (F (2, 13) = 5.212; p < 0.05 ). Lastly, antipsychotic analysis revealed no significant impact on the expression of adenosine pathway components between medicated and non-medicated schizophrenia subjects ( p > 0.05). The observed sex-specific variations and inter-component correlations highlight the value of investigating sex differences in disease and contribute to the molecular basis of schizophrenia's pathology.

Background: The application of normo- and hyperbaric O 2 is a common therapy option in various disease patterns. Thereby, the applied O 2 affects the whole body, including the blood and its components. This study investigates influences of pressure and oxygen fraction on human blood plasma, nutrient media, and the functions of neutrophil granulocytes (PMNs). Methods: Neutrophil migration, reactive oxygen species (ROS) production, and NETosis were examined by live cell imaging. The treatment of various matrices (Roswell Park Memorial Institute 1640 medium, Dulbecco's Modified Eagle's Medium, H 2 O, human plasma, and isolated PMNs) with hyperbaric oxygen (HBO) was performed. In addition, the expression of different neutrophil surface epitopes (CD11b, CD62L, CD66b) and the oxidative burst were investigated by flow cytometry (FACS). The application of cold atmospheric plasma (CAP) to normoxic and normobaric culture media served as a positive control. Soluble reaction products such as H 2 O 2 , reactive nitrogen species (RNS: NO 2 - and NO 3 - ), and ROS-dependent dihydrorhodamine oxidation were quantified by fluoro- and colorimetric assay kits. Results: Under normobaric normoxia, PMNs migrate slower and shorter in comparison with normobaric hyper- or hypoxic conditions and hyperbaric hyperoxia. The pressure component has less effect on the migration behavior of PMNs than the O 2 concentration. Individual PMN cells produce prolonged ROS at normoxic conditions. PMNs showed increased expression of CD11b in normobaric normoxia, lower expression of CD62L in normobaric normoxia, and lower expression of CD66b after HBO and CAP treatment. Treatment with CAP increased the amount of ROS and RNS in common culture media. Conclusions: Hyperbaric and normobaric O 2 influences neutrophil functionality and surface epitopes in a measurable way, which may have an impact on disorders with neutrophil involvement. In the context of hyperbaric experiments, especially high amounts of H 2 O 2 in RPMI after hyperbaric oxygen should be taken into account. Therefore, our data support a critical indication for the use of normobaric and hyperbaric oxygen and conscientious and careful handling of oxygen in everyday clinical practice.

Abstract: The promising results obtained with immunotherapeutic approaches for multiple myeloma (MM) call for a better stratification of patients based on immune components. The most pressing being cytotoxic lymphocytes such as natural killer (NK) cells that are mandatory for MM surveillance and therapy. Here, we performed a single-cell RNA sequencing analysis of NK cells from 10 patients with MM and 10 age/sex-matched healthy donors that revealed important transcriptomic changes in the NK cell landscape affecting both the bone marrow (BM) and peripheral blood compartment. The frequency of mature cytotoxic CD56dim NK cell subsets was reduced in patients with MM at the advantage of late-stage NK cell subsets expressing NF-κB and interferon-I inflammatory signatures. These NK cell subsets accumulating in patients with MM were characterized by low CD16 and CD226 expression and poor cytotoxic functions. MM CD16/CD226Lo NK cells also had adhesion defects with reduced lymphocyte function-associated antigen 1 (LFA-1) integrin activation and actin polymerization that may account for their limited effector functions in vitro. Finally, analysis of BM-infiltrating NK cells in a retrospective cohort of 177 patients with MM from the Intergroupe Francophone du Myélome (IFM) 2009 trial demonstrated that a high frequency of NK cells and their low CD16 and CD226 expression were associated with a shorter overall survival. Thus, CD16/CD226Lo NK cells with reduced effector functions accumulate along MM development and negatively affect patients' clinical outcomes. Given the growing interest in harnessing NK cells to treat myeloma, this improved knowledge around MM-associated NK cell dysfunction will stimulate the development of more efficient immunotherapeutic drugs against MM., (© 2024 American Society of Hematology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Doxorubicin (DOX), a commonly used anticancer agent, causes cardiotoxicity that begins with the first dose and may progress to heart failure years after treatment. An inflammatory response associated with neutrophil recruitment has been recognized as a mechanism of DOX-induced cardiotoxicity. This study aimed to validate mRNA expression of the previously identified biomarkers of DOX-induced cardiotoxicity, PGLYRP1, CAMP, MMP9, and CEACAM8, and to assay their protein expression in the peripheral blood of breast cancer patients. Blood samples from 40 breast cancer patients treated with DOX-based chemotherapy were collected before and after the first chemotherapy cycle and > 2 years after treatment. The protein and gene expression of PGLYRP1/Tag7, CAMP/LL37, MMP9/gelatinase B, and CEACAM8/CD66b were determined using ELISA and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Receiver operating characteristic (ROC) curve analysis was used to determine the diagnostic value of each candidate biomarker. Patients with cardiotoxicity (n = 20) had significantly elevated levels of PGLYRP1, CAMP, MMP9, and CEACAM8 at baseline, after the first dose of DOX-based chemotherapy, and at > 2 years after treatment relative to patients without cardiotoxicity (n = 20). The first dose of DOX induced significantly higher levels of all examined biomarkers in both groups of patients. At > 2 years post treatment, the levels of all but MMP9 dropped below the baseline. There was a good correlation between the expression of mRNA and the target proteins. We demonstrate that circulating levels of PGLYRP1, CAMP, MMP9, and CEACAM8 can predict the cardiotoxicity of DOX. This novel finding may be of value in the early identification of patients at risk for cardiotoxicity.