APLNR inhibited nasopharyngeal carcinoma growth and immune escape by downregulating PD-L1.

BACKGROUND: APLNR is a G protein-coupled receptor and our previous study had revealed that APLNR could inhibit nasopharyngeal carcinoma (NPC) growth and metastasis. However, the role of APLNR in regulating PD-L1 expression and immune escape in NPC is unknown. METHODS: We analyzed the expression and correlation of APLNR and PD-L1 in NPC tissues and cells. We investigated the effect of APLNR on PD-L1 expression and the underlying mechanism in vitro and in vivo. We also evaluated the therapeutic potential of targeting APLNR in combination with PD-L1 antibody in a nude mouse xenograft model. RESULTS: We found that APLNR was negatively correlated with PD-L1 in NPC tissues and cells. APLNR could inhibit PD-L1 expression by binding to the FERM domain of JAK1 and blocking the interaction between JAK1 and IFNGR1, thus suppressing IFN-γ-mediated activation of the JAK1/STAT1 pathway. APLNR could also inhibit NPC immune escape by enhancing IFN-γ secretion and CD8+ T-cell infiltration and reducing CD8+ T-cell apoptosis and dysfunction. Moreover, the best effect was achieved in inhibiting NPC growth in nude mice when APLNR combined with PD-L1 antibody. CONCLUSIONS: Our study revealed a novel mechanism of APLNR regulating PD-L1 expression and immune escape in NPC and suggested that APLNR maybe a potential therapeutic target for NPC immunotherapy.

Visible-light-induced C(sp3)-H bromination of 4-methylthiophene derivatives with HBr/H2O2.

A convenient method to synthesize ethyl 4-(bromomethyl)thiophene-3-carboxylate derivatives has been developed via a visible-light-induced radical process in good yields and with wide functional group tolerance under air conditions and at ambient temperature. The present protocol has the advantages of a high atom economy, easy purification, and environmental friendliness as it employs HBr as the bromine source and the cheap and low-toxic H2O2 as the oxidant. The synthetic utility of this method is demonstrated by a gram scale reaction and its application in the innovative synthesis of the clinical drug relugolix.

Layer-specific mechanisms of perfluoroalkyl acid (PFAA) transport and partition in estuarine environments: Unveiling the depth-dependent differences.

Understanding of characteristics and transport of perfluoroalkyl acids (PFAAs) in heterogeneous estuarine environments is limited. Furthermore, the role of suspended particles (SPS) in different layers remains unclear. This study explores the multiphase distribution process and mechanism of PFAAs controlled by SPS across surface and bottom layers in five small estuaries. Peaks in PFAA concentrations are consistently observed at strongly stratified sites. Concentrations of the PFAAs in both surface and bottom SPS decreased as the degree of mixing increased from strongly stratified levels to well-mixed levels. The water-SPS partitioning of some short-chain PFAAs (PFBS, PFHxA, and PFHpA) is influenced by environmental factors (pH, depth, temperature, and salinity) due to electrostatic interactions, while the sorption of some long-chain PFAAs (PFOA, PFOS, and PFNA) is controlled by SPS and dissolved organic carbon (OC), driven by hydrophobic interactions. Additionally, SPS dominates OC transport in estuarine systems, except in sandy sediment environments. SPS plays a dominant role in PFAA partitioning in both surface and bottom water-SPS systems (p < 0.05), and salinity only significantly affects PFBS in bottom layer (p < 0.01). These findings are critical for understanding the drivers of PFAA partitioning and the roles of SPS in different layers, underscoring the necessity of considering particle-associated PFAA fractions in future coastal environmental management.

Unnatural Amino Acids for Biological Spectroscopy and Microscopy.

Due to advances in methods for site-specific incorporation of unnatural amino acids (UAAs) into proteins, a large number of UAAs with tailored chemical and/or physical properties have been developed and used in a wide array of biological applications. In particular, UAAs with specific spectroscopic characteristics can be used as external reporters to produce additional signals, hence increasing the information content obtainable in protein spectroscopic and/or imaging measurements. In this Review, we summarize the progress in the past two decades in the development of such UAAs and their applications in biological spectroscopy and microscopy, with a focus on UAAs that can be used as site-specific vibrational, fluorescence, electron paramagnetic resonance (EPR), or nuclear magnetic resonance (NMR) probes. Wherever applicable, we also discuss future directions.

Triple-Bond Vibrations: Emerging Applications in Energy and Biological Sciences.

Triple bonds, such as that formed between two carbon atoms (i.e., C≡C) or that formed between one carbon atom and one nitrogen atom (i.e., C≡N), afford unique chemical bonding and hence vibrational characteristics. As such, they are not only frequently used to construct molecules with tailored chemical and/or physical properties but also employed as vibrational probes to provide site-specific chemical and/or physical information at the molecular level. Herein, we offer our perspective on the emerging applications of various triple-bond vibrations in energy and biological sciences with a focus on C≡C and C≡N triple bonds.

C≡N Stretching Frequency as a Convenient Reporter of Charge Separation in Molecular Systems.

Previously, several studies have shown that, for a set of structurally related nitrile compounds, there could be a linear relationship between the total charge on the nitrile group (qCN) and its stretching frequency (νCN). However, it is unclear whether the corresponding frequency and charge properties of structurally different nitrile compounds can be described by a single linear νCN-qCN relationship. Herein, we compute the qCN magnitudes of a large number of nitrile-containing molecules whose νCN values cover a spectral range of ca. 200 cm-1 and are measured under different experimental conditions. Our results reveal that νCN indeed exhibits a linear dependence on qCN, with a slope of 637 ± 30 cm-1/charge. Because the nitrile moiety is a commonly used building block in electronic donor-acceptor (D-A) molecular systems, we believe that this linear relationship will find utility in a wide range of applications where such D-A constructs are used, such as in organic photovoltaic assemblies. In addition, we apply this linear relationship to characterize the degree of charge transfer upon photoexcitation of two indole derivatives, 5-cyanoindole and 6-cyanoindole, and are able to show that in both cases, the fluorescence emission arises from a charge-transfer or La state.

Photophysics of Two Indole-Based Cyan Fluorophores.

For the purpose of searching for new biological fluorophore, we assess the photophysical properties of two indole derivatives, 4-cyano-7-azaindole (4CN7AI) and 1-methyl-4-cyano-7-azaindole (1M4CN7AI), in a series of solvents. We find that (1) the absorption spectra of both derivatives are insensitive to solvents and are red-shifted from that of indole, having a maximum absorption wavelength of ca. 318 nm and a broad profile that extends beyond 370 nm; (2) both derivatives emit in the blue to green spectral range with a large Stokes shift, for example, in H2O, the maximum emission wavelength of 4CN7AI (1M4CN7AI) is at ca. 455 nm (470 nm); (3) 4CN7AI has a higher fluorescence quantum yield (QY) and a longer fluorescence lifetime (τF) in aprotic solvents than in protic solvents, for example, QY (τF) = 0.72 ± 0.04 (7.6 ± 0.8 ns) in tetrahydrofuran and QY (τF) = 0.29 ± 0.03 (6.2 ± 0.6 ns) in H2O; (4) in all of the solvents used except H2O, the fluorescence QY (τF) of 1M4CN7AI is equal to or higher (longer) than 0.69 ± 0.03 (11.2 ± 0.7 ns). Taken together, these results suggest that the corresponding non-natural amino acids, 4-cyano-7-azatryptophan and 1-methyl-4-cyano-7-azatryptophan, could be useful as biological fluorophores.

Adjuvant-Free COVID-19 Vaccine with Glycoprotein Antigen Oxidized by Periodate Rapidly Elicits Potent Immune Responses.

Modification of antigens to improve their immunogenicity represents a promising direction for the development of protein vaccine. Here, we designed facilely prepared adjuvant-free vaccines in which the N-glycan of SARS-CoV-2 receptor-binding domain (RBD) glycoprotein was oxidized by sodium periodate. This strategy only minimally modifies the glycans and does not interfere with the epitope peptides. The RBD glycoprotein oxidized by high concentrations of periodate (RBDHO) significantly enhanced antigen uptake mediated by scavenger receptors and promoted the activation of antigen-presenting cells. Without any external adjuvant, two doses of RBDHO elicited 324- and 27-fold increases in IgG antibody titers and neutralizing antibody titers, respectively, compared to the unmodified RBD antigen. Meanwhile, the RBDHO vaccine could cross-neutralize all of the SARS-CoV-2 variants of concern. In addition, RBDHO effectively enhanced cellular immune responses. This study provides a new insight for the development of adjuvant-free protein vaccines.

Metabolic dialogs between B cells and the tumor microenvironment: Implications for anticancer immunity.

Immunometabolism, a branch of biology describing the link between immunity and metabolism, is an emerging topic in cancer immunology. It is currently well accepted that B cells and tertiary lymph structures formed by them are associated with favorable outcomes when patients undergo cancer immunotherapy. Understanding the determinants of B-cell fate and function in cancer patients is necessary for improving cancer immunotherapy. Accumulating evidence points to the tumor microenvironment being a critical metabolic hurdle to an efficient antitumor B-cell response. At the same time, several B-cell-derived metabolites have recently been reported to inhibit anticancer immunity. In this literature review, key B-cell immunometabolism studies and the metabolic life of B cells were summarized. Then, we discussed the intrinsic metabolic pathways of B cells themselves and how the tumor microenvironment and B cells in tumors metabolically influence each other. Finally, we pointed out key questions to provide some inspiration for further study of the role of B-cell immunometabolism in the antitumor immune response.

4-Cyanotryptophan as a Sensitive Fluorescence Probe of Local Electric Field of Proteins.

Electrostatic interactions are key determinants of protein structure, dynamics, and function. Since protein electrostatics are nonuniform, assessment of the internal electric fields (EFs) of proteins requires spatial resolution at the amino acid residue level. In this regard, vibrational Stark spectroscopy, in conjunction with various unnatural amino acid-based vibrational probes, has become a common method for site-specific interrogation of protein EFs. However, application of this method is often limited to proteins with relatively high solubility, due to the intrinsically low oscillator strength of vibrational transitions. Therefore, it would be useful to develop an alternative method that can overcome this limitation. To this end, we show that, using solvatochromic study and molecular dynamics simulations, the frequency of maximum emission intensity of the fluorophore of 4-cyanotryptophan (4CN-Trp), 3-methyl-1H-indole-4-carbonitrile, exhibits a linear dependence on the local EF. Since the absorption and emission spectra of 4CN-Trp are easily distinguishable from those of naturally occurring aromatic amino acids, we believe that this linear relationship provides an easier and more sensitive means to determine the local EF of proteins.

Photoenhancement of the C≡N Stretching Vibration Intensity of Aromatic Nitriles.

The C≡N stretching vibration is a versatile infrared (IR) reporter that is useful for a wide range of applications. Aiming to further expand its spectroscopic utility, herein, we show that, using 4-cyanoindole and 4-cyano-7-azaindole as examples, photoexcitation can significantly shift the frequency (νCN) and enhance the molar extinction coefficient (εCN) of this vibrational mode of aromatic nitriles and that, for these indole derivatives, the enhancement factor can reach 13. Moreover, we find that while solvent relaxation at the excited electronic state(s) always leads to an increase in εCN, its effect on νCN depends on the solute and the solvent. Taken together, these results demonstrate that solvent relaxation can differently affect the local environment of the nitrile group and its conjugation with the indole ring and, more importantly, that the C≡N stretching vibration can serve as a sensitive IR probe of charge and electron transfer processes in which an aromatic nitrile is involved.

NUCB2: roles in physiology and pathology

Nucleobindin2 (NUCB2) is a member of nucleobindin family which was first found in the nucleus of the hypothalamus, and had a relationship in diet and energy homeostasis. Its location in normal tissues such as stomach and islet further confirms that it plays a vital role in the regulation of physiological functions of the body. Besides, NUCB2 participates in tumorigenesis through activating various signal-pathways, more and more studies indicate that NUCB2 might impact tumor progression by promoting or inhibiting proliferation, apoptosis, autophagy, metastasis, and invasion of tumor cells. In this review, we comprehensively stated NUCB2’s expression and functions, and introduced the role of NUCB2 in physiology and pathology and its mechanism. What is more, pointed out the potential direction of future research. (AU)

NUCB2: roles in physiology and pathology.

Nucleobindin2 (NUCB2) is a member of nucleobindin family which was first found in the nucleus of the hypothalamus, and had a relationship in diet and energy homeostasis. Its location in normal tissues such as stomach and islet further confirms that it plays a vital role in the regulation of physiological functions of the body. Besides, NUCB2 participates in tumorigenesis through activating various signal-pathways, more and more studies indicate that NUCB2 might impact tumor progression by promoting or inhibiting proliferation, apoptosis, autophagy, metastasis, and invasion of tumor cells. In this review, we comprehensively stated NUCB2's expression and functions, and introduced the role of NUCB2 in physiology and pathology and its mechanism. What is more, pointed out the potential direction of future research.

Adjuvant-Protein Conjugate Vaccine with Built-In TLR7 Agonist on S1 Induces Potent Immunity against SARS-CoV-2 and Variants of Concern.

With the global pandemic of the new coronavirus disease (COVID-19), a safe, effective, and affordable mass-produced vaccine remains the current focus of research. Herein, we designed an adjuvant-protein conjugate vaccine candidate, in which the TLR7 agonist (TLR7a) was conjugated to S1 subunit of SARS-CoV-2 spike protein, and systematically compared the effect of different numbers of built-in TLR7a on the immune activity for the first time. As the number of built-in TLR7a increased, a bell-shaped reaction was observed in three TLR7a-S1 conjugates, with TLR7a(10)-S1 (with around 10 built-in adjuvant molecules on one S1 protein) eliciting a more potent immune response than TLR7a(2)-S1 and TLR7a(18)-S1. This adjuvant-protein conjugate strategy allows the built-in adjuvant to provide cluster effects and prevents systemic toxicity and facilitates the co-delivery of adjuvant and antigen. Vaccination of mice with TLR7a(10)-S1 triggered a potent humoral and cellular immunity and a balanced Th1/Th2 immune response. Meanwhile, the vaccine induces effective neutralizing antibodies against SARS-CoV-2 and all variants of concern (B.1.1.7/alpha, B.1.351/beta, P.1/gamma, B.1.617.2/delta, and B.1.1.529/omicron). It is expected that the adjuvant-protein conjugate strategy has great potential to construct a potent recombinant protein vaccine candidate against various types of diseases.

Export and risk from antibiotic remobilization from surrounding water to lake in the extreme 2020 Yangtze River basin flooding.

Global climate change increased the frequency of extreme rainfall events, leading to higher flood risk. In addition to the personal and property losses, another important consequence of a flood disaster was release and exposure risks from emerging contaminants, which was usually overlooked. The remobilization and fate of the antibiotics induced by floods remain unclear. We captured antibiotic concentrations around the Chaohu Lake after an unprecedented flood with a range of 5.0-317 ng/L. Higher concentrations in polder waters than their receiving rivers were attributed to the antibiotic release from soil particles and the sharp increase of water: soil ratio by flood storage. Source apportionment analysis of antibiotics implied that diffuse pollution by manure application and aquaculture activity was the predominant sources. Commonalities of spatial variations of antibiotics in polders were related to the condition of waterlogging and pollution source. The total antibiotic storage for all submerged polders was estimated at 27.9 kg. The concentrations and risks from pumping floodwater detained by polders into the lake were much higher than that from discharging flood directly into the lake. The retention-reaction-remobilization process would pose unexpectedly high risks for the lake. This study provided a new sight for constructing ecological wetland flood storage areas.

A protein vaccine with Alum/c-GAMP/poly(I:C) rapidly boosts robust immunity against SARS-CoV-2 and variants of concern.

Adjuvants are important components in vaccines to increase the immunogenicity of proteins and induce optimal immunity. In this study, we designed a novel ternary adjuvant system Alum + c-GAMP + poly(I:C) with STING agonist 3,3'-c-GAMP (c-GAMP) and TLR3 agonist poly(I:C) co-adsorbed on the conventional adjuvant aluminum gel (Alum), and further constructed an S1 protein vaccine. Two doses of vaccination with the ternary adjuvant vaccine were sufficient to induce a balanced Th1/Th2 immune response and robust humoral and cellular immunity. Additionally, the ternary adjuvant group had effective neutralizing activity against live virus SARS-CoV-2 and pseudovirus of all variants of concern (alpha, beta, gamma, delta and omicron). These results indicate that the ternary adjuvants have a significant synergistic effect and can rapidly trigger potent immune responses; the combination of the ternary adjuvant system with S1 protein is a promising COVID-19 vaccine candidate.

Follicular Helper T Cells in Pulmonary Tuberculosis: A Retrospective Study.

BACKGROUND: Follicular helper T lymphocyte (Tfh) promotes antibody production by B lymphocytes in various diseases, including Pulmonary Tuberculosis (PTB). OBJECTIVE: To explore the potential role of Tfh cells and assess the expression level of PD-1, and IL-21 in PTB. METHODS: 54 newly diagnosed smear-positive PTB, 27 people with latent tuberculosis (LTB) and 27 healthy controls (HC) were enrolled. The PTB group was further divided based on the range of lung field involved (focus number>=3, PTB-X3; <3, PTB-X2). After 6-month therapy, sputum smear (positive, PTB-SP; negative, PTB-SN) or imaging examinations (lesion reduction significant, PTB-os; insignificant, PTB-s) were used to evaluate the conditions of PTB patients. Blood samples were collected from PTB group at month six. CD4+CXCR5+Tfh, and its subsets, CD4+CXCR5+PD-1+Tfh and CD4+CXCR5+ICOS+Tfh in peripheral blood mononuclear cells (PBMCs) were detected. Serum IL-21 concentrations were measured. RESULTS: The frequencies of CD4+CXCR5+Tfh, CD4+CXCR5+ICOS+Tfh and CD4+CXCR5+PD-1+Tfh were higher in PTB group than in HC. IL-21, IL-4 and IFNγ concentrations were significantly higher in PTB group than in HC. The proportion of CD4+CXCR5+Tfh in PTB-X2 was lower than in PTB-X3 group. CD4+CXCR5+PD-1+Tfh proportion in PTB-X2 was lower than that in the PTB-X3. After treatment, CD4+CXCR5+Tfh proportion was significantly lower in the PTB-SN group. CD4+CXCR5+Tfh was lower in the PTB-os group than in the PTB-s group. However, the CD4+CXCR5+PD-1+Tfh and cytokine concentrations of IL-21 were not different. CONCLUSIONS: CD4+CXCR5+Tfh level might predict the sputum results, and lesion decrease rate while CD4+CXCR5+PD-1+Tfh subset and IL-21 were not associated with sputum results or lesion decrease after treatment.

The role of B7-H3 in tumors and its potential in clinical application.

B7-H3 (CD276 molecule) is an immune checkpoint from the B7 family of molecules that acts more as a co-inhibitory molecule to promote tumor progression. It is abnormally expressed on tumor cells and can be induced to express on antigen-presenting cells (APCs) including dendritic cells (DCs) and macrophages. In the tumor microenvironment (TME), B7-H3 promotes tumor progression by impairing T cell response, promoting the polarization of tumor-associated macrophages (TAMs) to M2, inhibiting the function of DCs, and promoting the migration and invasion of cancer-associated fibroblasts (CAFs). In addition, through non-immunological functions, B7-H3 promotes tumor cell proliferation, invasion, metastasis, resistance, angiogenesis, and metabolism, or in the form of exosomes to promote tumor progression. In this process, microRNAs can regulate the expression of B7-H3. B7-H3 may serve as a potential biomarker for tumor diagnosis and a marker of poor prognosis. Immunotherapy targeting B7-H3 and the combination of B7-H3 and other immune checkpoints have shown certain efficacy. In this review, we summarized the basic characteristics of B7-H3 and its mechanism to promote tumor progression by inducing immunosuppression and non-immunological functions, as well as the potential clinical applications of B7-H3 and immunotherapy based on B7-H3.

Transport and fate of antibiotics in a typical aqua-agricultural catchment explained by rainfall events: Implications for catchment management.

Antibiotics receive many concerns since their negative environmental impacts are being revealed, especially in aqua-agricultural areas. Rainfall events are responsible for transferring excess contaminants to receiving waters. However, the understanding of antibiotics transport and fate responding to rainfall events was constrained by limited event-based data and lacking integrated consideration of dissolved and particulate forms. We developed an intensive monitoring strategy to capture responses of fourteen antibiotics to different types of rainfall events and inter-event low flow periods. Pollutant-rich suspended particles, as high as 1471 ng/g, were found in low flow periods while the very heavy rainfall events and consecutive rainfall events stimulated the release of antibiotics from eroded soil particles to river water. Therefore, these rainfall events drove radical increase of dissolved antibiotic concentration up to 592 ng/L and total flux up to 25.0 g/d. Sulfonamides were particularly sensitive to rainfall events because of their residues in manure-applied agricultural lands. Transport dynamics of most antibiotics were accretion whereas only clarithromycin exhibited a dilution pattern by concentration-discharge relationships. Aquaculture ponds were inferred to significantly contribute tetracycline, oxytetracycline, and clarithromycin. Conventional contaminants were compared to discriminate potential sources of antibiotics and imply effective catchment management. The results provided novel insights into event-based drivers and dynamics of antibiotics and could lead to appropriate management strategy.

C-H Imidation and Dual C-H Bond Aminobromination of Five-Membered Heterocycles.

Here, we report a practical C-H imidation of five-membered heterocycles under metal-free conditions. We also report the first dual C-H bond aminobromination of thiophenes, with benzotriazole, saccharin, 1,2,4-triazole, benzimidazole, pyrazole, 4-bromopyrazole, 5-methyltetrazole, and dibenzenesulfonimides as effective amine sources. Mechanistic studies support the radical pathway of the imidation and aminobromination reactions.