Macrophage-derived exosomes promote telomere fragility and senescence in tubular epithelial cells by delivering miR-155.

BACKGROUND: Chronic kidney disease (CKD) is highly prevalent worldwide, and its global burden is substantial and growing. CKD displays a number of features of accelerated senescence. Tubular cell senescence is a common biological process that contributes to CKD progression. Tubulointerstitial inflammation is a driver of tubular cell senescence and a common characteristic of CKD. However, the mechanism by which the interstitial inflammation drives tubular cell senescence remains unclear. This paper aims to explore the role of exosomal miRNAs derived from macrophages in the development of tubular cell senescence. METHODS: Among the identified inflammation-related miRNAs, miR-155 is considered to be one of the most important miRNAs involved in the inflammatory response. Macrophages, the primary immune cells that mediate inflammatory processes, contain a high abundance of miR-155 in their released exosomes. We assessed the potential role of miR-155 in tubular cell senescence and renal fibrosis. We subjected miR-155-/- mice and wild-type controls, as well as tubular epithelial cells (TECs), to angiotensin II (AngII)-induced kidney injury. We assessed kidney function and injury using standard techniques. TECs were evaluated for cell senescence and telomere dysfunction in vivo and in vitro. Telomeres were measured by the fluorescence in situ hybridization. RESULTS: Compared with normal controls, miR-155 was up-regulated in proximal renal tubule cells in CKD patients and mouse models of CKD. Moreover, the expression of miR-155 was positively correlated with the extent of renal fibrosis, eGFR decline and p16INK4A expression. The overexpression of miR-155 exacerbated tubular senescence, evidenced by increased detection of p16INK4A/p21expression and senescence-associated ß-galactosidase activity. Notably, miR-155 knockout attenuates renal fibrosis and tubule cell senescence in vivo. Interestingly, once released, macrophages-derived exosomal miR-155 was internalized by TECs, leading to telomere shortening and dysfunction through targeting TRF1. A dual-luciferase reporter assay confirmed that TRF1 was the direct target of miR-155. Thus, our study clearly demonstrates that exosomal miR-155 may mediate communication between macrophages and TECs, subsequently inducing telomere dysfunction and senescence in TECs. CONCLUSIONS: Our work suggests a new mechanism by which macrophage exosomes are involved in the development of tubule senescence and renal fibrosis, in part by delivering miR-155 to target TRF1 to promote telomere dysfunction. Our study may provide novel strategies for the treatment of AngII-induced kidney injury.

Erratum: Exosomal miR-125b-5p deriving from mesenchymal stem cells promotes tubular repair by suppression of p53 in ischemic acute kidney injury: Erratum.

[This corrects the article DOI: 10.7150/thno.54550.].

Cell Migration Assays and Their Application to Wound Healing Assays-A Critical Review.

In recent years, cell migration assays (CMAs) have emerged as a tool to study the migration of cells along with their physiological responses under various stimuli, including both mechanical and bio-chemical properties. CMAs are a generic system in that they support various biological applications, such as wound healing assays. In this paper, we review the development of the CMA in the context of its application to wound healing assays. As such, the wound healing assay will be used to derive the requirements on CMAs. This paper will provide a comprehensive and critical review of the development of CMAs along with their application to wound healing assays. One salient feature of our methodology in this paper is the application of the so-called design thinking; namely we define the requirements of CMAs first and then take them as a benchmark for various developments of CMAs in the literature. The state-of-the-art CMAs are compared with this benchmark to derive the knowledge and technological gap with CMAs in the literature. We will also discuss future research directions for the CMA together with its application to wound healing assays.

Dendritic-cell-targeting virus-like particles as potent mRNA vaccine carriers.

Messenger RNA vaccines lack specificity for dendritic cells (DCs)-the most effective cells at antigen presentation. Here we report the design and performance of a DC-targeting virus-like particle pseudotyped with an engineered Sindbis-virus glycoprotein that recognizes a surface protein on DCs, and packaging mRNA encoding for the Spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or for the glycoproteins B and D of herpes simplex virus 1. Injection of the DC-targeting SARS-CoV-2 mRNA vaccine in the footpad of mice led to substantially higher and durable antigen-specific immunoglobulin-G titres and cellular immune responses than untargeted virus-like particles and lipid-nanoparticle formulations. The vaccines also protected the mice from infection with SARS-CoV-2 or with herpes simplex virus 1. Virus-like particles with preferential uptake by DCs may facilitate the development of potent prophylactic and therapeutic vaccines.

Distribution of pathogens and risk factors for post-replantation wound infection in patients with traumatic major limb mutilation.

PURPOSE: Even though replantation of limb mutilation is increasing, postoperative wound infection can result in increasing the financial and psychological burden of patients. Here, we sought to explore the distribution of pathogens and identify risk factors for postoperative wound infection to help early identification and managements of high-risk patients. METHODS: Adult inpatients with severed traumatic major limb mutilation who underwent replantation from Suzhou Ruixing Medical Group between November 09, 2014, and September 6, 2022 were included in this retrospective study. Demographic, and clinical characteristics, treatments, and outcomes were collected. Data were used to analyze risk factors for postoperative wound infection. RESULTS: Among the 249 patients, 185 (74.3%) were males, the median age was 47.0 years old. Postoperative wound infection in 74 (29.7%) patients, of whom 51 (20.5%) had infection with multi-drug resistant bacteria. Ischemia time (OR 1.31, 95% CI 1.13-1.53, P = 0.001), wound contamination (OR 6.01, 95% CI 2.38-15.19, P <0.001), and stress hyperglycemia (OR 23.37, 95% CI 2.30-236.93, P = 0.008) were independent risk factors, while the albumin level after surgery (OR 0.94, 95% CI 0.89-0.99, P = 0.031) was significant associated with the decrease of postoperative wound infection. Ischemia time (OR 1.21, 95% CI 1.05-1.40, P = 0.010), wound contamination (OR 8.63, 95% CI 2.91-25.57, P <0.001), and MESS (OR 1.32, 95% CI 1.02-1.71, P = 0.037 were independent risk factors for multi-drug resistant bacteria infection. CONCLUSIONS: Post-replantation wound infection was common in patients with severe traumatic major limb mutilation, and most were multi-drug resistant bacteria. Ischemia time and wound contamination were associated with the increase of postoperative wound infection, including caused by multi-drug resistant. Positive correction of hypoproteinemia and control of stress hyperglycemia may be beneficial.

Carrageenan maintains the contractile phenotype of vascular smooth muscle cells by increasing macromolecular crowding in vitro.

BACKGROUND: The contractile phenotype of vascular smooth muscle cells (VSMCs) results in good diastolic and contractile capacities, and its altered function is the main pathophysiological basis for diseases such as hypertension. VSMCs exist as a synthetic phenotype in vitro, making it challenging to maintain a contractile phenotype for research. It is widely recognized that the common medium in vitro is significantly less crowded than in the in vivo environment. Additionally, VSMCs have a heightened sense for detecting changes in medium crowding. However, it is unclear whether macromolecular crowding (MMC) helps maintain the VSMCs contractile phenotype. PURPOSE: This study aimed to explore the phenotypic, behavioral and gene expression changes of VSMCs after increasing the crowding degree by adding carrageenan (CR). METHODS: The degree of medium crowding was examined by a dynamic light scattering assay; VSMCs survival and activity were examined by calcein/PI cell activity and toxicity and CCK-8 assays; VSMCs phenotypes and migration were examined by WB and wound healing assays; and gene expression was examined by transcriptomic analysis and RT-qPCR. RESULTS: Notably, 225 µg/mL CR significantly increased the crowding degree of the medium and did not affect cell survival. Simultaneously, CR significantly promoted the contraction phenotypic marker expression in VSMCs, shortened cell length, decreased cell proliferation, and inhibited cell migration. CR significantly altered gene expression in VSMCs. Specifically, 856 genes were upregulated and 1207 genes were downregulated. These alterations primarily affect the cellular ion channel transport, microtubule movement, respiratory metabolism, amino acid transport, and extracellular matrix synthesis. The upregulated genes were primarily involved in the cytoskeleton and contraction processes of VSMCs, whereas the downregulated genes were mainly involved in extracellular matrix synthesis. CONCLUSIONS: The in vitro study showed that VSMCs can maintain the contractile phenotype by sensing changes in the crowding of the culture environment, which can be maintained by adding CR.

Nitazoxanide protects against experimental ulcerative colitis through improving intestinal barrier and inhibiting inflammation.

Ulcerative colitis is a chronic disease with colonic mucosa injury. Nitazoxanide is an antiprotozoal drug in clinic. Nitazoxanide and its metabolite tizoxanide have been demonstrated to activate AMPK and inhibit inflammation, therefore, the aim of the present study is to investigate the effect of nitazoxanide on dextran sulfate sodium (DSS)-induced colitis and the underlying mechanism. Oral administration of nitazoxanide ameliorated the symptoms of mice with DSS-induced colitis, as evidenced by improving the increased disease activity index (DAI), the decreased body weight, and the shortened colon length. Oral administration of nitazoxanide ameliorated DSS-induced intestinal barrier dysfunction and reduced IL-6 and IL-17 expression in colon tissues. Mechanistically, nitazoxanide and its metabolite tizoxanide treatment activated AMPK and inhibited JAK2/STAT3 signals. Nitazoxanide and tizoxanide treatment increased caudal type homeobox 2 (CDX2) expression, increased alkaline phosphatase (ALP) activity and promoted tight junctions in Caco-2 cells. Nitazoxanide and tizoxanide treatment restored the decreased zonula occludens-1(ZO-1) and occludin protein levels induced by LPS or IL-6 in Caco-2 cells. On the other hand, nitazoxanide and tizoxanide regulated macrophage bias toward M2 polarization, as evidenced by the increased arginase-1expression in bone marrow-derived macrophages (BMDM). Nitazoxanide and tizoxanide reduced the increased IL-6, iNOS and CCL2 pro-inflammatory gene expressions and inhibited JAK2/STAT3 activation in BMDM induced by LPS. In conclusion, nitazoxanide protects against DSS-induced ulcerative colitis in mice through improving intestinal barrier and inhibiting inflammation and the underlying mechanism involves AMPK activation and JAK2/STAT3 inhibition.

Macromolecular Crowding Enhances Matrix Protein Deposition in Tissue-Engineered Vascular Grafts.

Successful in vitro culture of small-diameter tissue-engineered vascular grafts (TEVGs) requires rapid deposition of biomacromolecules secreted by vascular smooth muscle cells in a polyglycolic acid mesh scaffold's three-dimensional (3D) porous environment. However, common media have lower crowding conditions than in vivo tissue fluids. In addition, during the early stages of construction, most of the biomolecules secreted by the cells into the medium are lost, which negatively affects the TEVG culture process. In this study, we propose the use of macromolecular crowding (MMC) to enhance medium crowding to improve the deposition and self-assembly efficiency of major biomolecules in the early stages of TEVG culture. The addition of carrageenan significantly increased the degree of MMC in the culture medium without affecting cell viability, proliferation, and metabolic activity. Protein analysis demonstrated that the deposition of collagen types I and III and fibronectin increased significantly in the cell layers of two-dimensional and 3D smooth muscle cell cultures after the addition of a MMC agent. Collagen type I in the culture medium decreased significantly compared with that in the medium without a MMC agent. Scanning electron microscopy demonstrated that MMC agents considerably enhanced the formation of matrix protein structures during the early stages of 3D culture. Hence, MMC modifies the crowding degree of the culture medium, resulting in the rapid formation of numerous matrix proteins and fiber structures. Impact Statement Small-diameter tissue-engineered vascular grafts (TEVGs) are one of the most promising means of treating cardiovascular diseases; however, the in vitro construction of TEVGs has some limitations, such as slow deposition of extracellular matrix (ECM), long culture period, and poor mechanical properties. We hypothesized that macromolecular crowding can increase the crowding of the culture medium to construct a more bionic microenvironment, which enhances ECM deposition in the medium to the cell layer and reduces collagen loss, accelerating and enhancing TEVG culture and construction in vitro.

Pulse irradiation synthesis of metal chalcogenides on flexible substrates for enhanced photothermoelectric performance.

High synthesis temperatures and specific growth substrates are typically required to obtain crystalline or oriented inorganic functional thin films, posing a significant challenge for their utilization in large-scale, low-cost (opto-)electronic applications on conventional flexible substrates. Here, we explore a pulse irradiation synthesis (PIS) to prepare thermoelectric metal chalcogenide (e.g., Bi2Se3, SnSe2, and Bi2Te3) films on multiple polymeric substrates. The self-propagating combustion process enables PIS to achieve a synthesis temperature as low as 150 °C, with an ultrafast reaction completed within one second. Beyond the photothermoelectric (PTE) property, the thermal coupling between polymeric substrates and bismuth selenide films is also examined to enhance the PTE performance, resulting in a responsivity of 71.9 V/W and a response time of less than 50 ms at 1550 nm, surpassing most of its counterparts. This PIS platform offers a promising route for realizing flexible PTE or thermoelectric devices in an energy-, time-, and cost-efficient manner.

Multiscale Confinement Engineering for Boosting Overall Water Splitting by One-Step Stringing of a Single Atom and a Janus Nanoparticle within a Carbon Nanotube.

Enzyme-mimicking confined catalysis has attracted great interest in heterogeneous catalytic systems that can regulate the geometric or electronic structure of the active site and improve its performance. Herein, a liquid-assisted chemical vapor deposition (LCVD) strategy is proposed to simultaneously confine the single-atom Ru sites onto sidewalls and Janus Ni/NiO nanoparticles (NPs) at the apical nanocavities to thoroughly energize the N-doped carbon nanotube arrays (denoted as Ni/NiO@Ru-NC). The bifunctional Ni/NiO@Ru-NC electrocatalyst exhibits overpotentials of 88 and 261 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at 100 mA cm-2 in alkaline solution, respectively, all ranking the top tier among the carbon-supported metal-based electrocatalysts. Moreover, once integrated into an anion-exchange membrane water electrolysis (AEMWE) system, Ni/NiO@Ru-NC can act as an efficient and robust bifunctional electrocatalyst to operate stably for 50 h under 500 mA cm-2. Theoretical calculations and experimental exploration demonstrate that the confinement of Ru single atoms and Janus Ni/NiO NPs can regulate the electron distribution with strong orbital couplings to activate the NC nanotube from sidewall to top, thus boosting overall water splitting.

PRP significantly promotes the adhesion and migration of vascular smooth muscle cells on stent material.

BACKGROUND: The adhesion and survival state of cells on scaffold material is a major problem in tissue-engineered blood vessel (TEBV) culture. Platelet-rich plasma (PRP) contains a large amount of biologically active factors and fibrin, which is expected to play an important role in TEBV culture. PURPOSE: To combine PRP with cells and scaffold material to promote cell adhesion and biological activity on the scaffold material. METHODS: The adhesion status and migration of SMCs under the optimal concentration suitable for SMC growth and the optimal concentration of PRP were examined by scanning electron microscopy, HE staining, CCK-8 assays, qPCR, WB, and other experimental methods and compared with those under the conventional culture (20% FBS); finally, the effect of PRP on the deposition of ECM in vascular tissue engineering culture was verified by three-dimensional culture. RESULTS: PRP at 20% is a suitable concentration for SMCs. Compared with the control group, the 20% PRP group had better migration, and the number of SMC adhesions was significantly higher than that of the control group. In addition, collagen deposition in the experimental group was significantly higher than that in the control group. CONCLUSION: PRP (20%) can promote SMC adhesion, migration, and collagen deposition on the scaffold material.

The admission pH is a risk factor of preoperative deep vein thrombosis in geriatric hip fracture: a retrospective cohort study.

This study evaluated the association between body pH value and preoperative deep vein thrombosis (DVT) in geriatric hip fractures. Older adult patients with hip fractures were screened between January 2015 and September 2019. The demographic and clinical characteristics of the patients were collected. Multivariate binary logistic regression and generalized additive models were used to identify the linear and nonlinear associations between pH value and preoperative DVT. Analyses were performed using EmpowerStats and R software. A total of 1465 patients were included in the study. DVT occurred in 476 (32.6%) of these admitted older adults. We observed a nonlinear association between the serum pH value and preoperative DVT in geriatric patients with hip fractures. A pH value of 7.39 was the inflection point in the curve, with pH highly correlated with DVT at pH < 7.39 (odds ratio [OR] 19.47; 95% confidence interval [CI] 1.45-260.91; P = 0.0249). Patients with lower pH had a lower chance of preoperative DVT formation, and the risk of DVT increased 18.47-fold for every 0.1 unit change in pH. Although at pH > 7.39, pH was not correlated with DVT (OR 1.26; 95% CI 0.85-1.86; P = 0.2561), the odds of DVT did not vary with pH, and the highest risk of thrombosis was reached. The body pH value is nonlinearly associated with preoperative DVT in geriatric patients with hip fractures, and it could be considered a predictor of the risk of DVT.Registered information This study is registered in the website of Chinese Clinical Trial Registry (ChiCTR: ChiCTR2200057323).

Effect of seasonal coronavirus immune imprinting on the immunogenicity of inactivated COVID-19 vaccination.

Background: Pre-existing cross-reactive immunity among different coronaviruses, also termed immune imprinting, may have a comprehensive impact on subsequent SARS-CoV-2 infection and COVID-19 vaccination effectiveness. Here, we aim to explore the interplay between pre-existing seasonal coronaviruses (sCoVs) antibodies and the humoral immunity induced by COVID-19 vaccination. Methods: We first collected serum samples from healthy donors prior to COVID-19 pandemic and individuals who had received COVID-19 vaccination post-pandemic in China, and the levels of IgG antibodies against sCoVs and SARS-CoV-2 were detected by ELISA. Wilcoxon rank sum test and chi-square test were used to compare the difference in magnitude and seropositivity rate between two groups. Then, we recruited a longitudinal cohort to collect serum samples before and after COVID-19 vaccination. The levels of IgG antibodies against SARS-CoV-2 S, S1, S2 and N antigen were monitored. Association between pre-existing sCoVs antibody and COVID-19 vaccination-induced antibodies were analyzed by Spearman rank correlation. Results: 96.0% samples (339/353) showed the presence of IgG antibodies against at least one subtype of sCoVs. 229E and OC43 exhibited the highest seroprevalence rates at 78.5% and 72.0%, respectively, followed by NL63 (60.9%) and HKU1 (52.4%). The levels of IgG antibodies against two ß coronaviruses (OC43 and HKU1) were significantly higher in these donors who had inoculated with COVID-19 vaccines compared to pre-pandemic healthy donors. However, we found that COVID-19 vaccine-induced antibody levels were not significant different between two groups with high levelor low level of pre-existing sCoVs antibody among the longitudinal cohort. Conclusion: We found a high prevalence of antibodies against sCoVs in Chinese population. The immune imprinting by sCoVs could be reactivated by COVID-19 vaccination, but it did not appear to be a major factor affecting the immunogenicity of COVID-19 vaccine. These findings will provide insights into understanding the impact of immune imprinting on subsequent multiple shots of COVID-19 vaccines.

Using the metabolite alterations monitoring the AEG-1 expression level and cell biological behaviour of U251 cell in vitro.

Astrocyte elevated gene-1 (AEG-1) is an important oncogene that overexpresses in gliomas and plays a vital role in their occurrence and progression. However, few reports have shown which biomarkers could reflect the level of AEG-1 expression in vivo so far. In recent years, intracellular metabolites monitored by proton magnetic resonance spectroscopy (1H MRS) as non-invasive imaging biomarkers have been applied to the precise diagnosis and therapy feedback of gliomas. Therefore, understanding the correlation between 1H MRS metabolites and AEG-1 gene expression in U251 cells may help to identify relevant biomarkers. This study constructed three monoclonal AEG-1-knockout U251 cell lines using the clustered regularly interspaced short palindromic repeat (CRISPR) /Cas9 technique and evaluated the biological behaviors and metabolite ratios of these cell lines. With the decline in AEG-1 expression, the apoptosis rate of the AEG-1-knockout cell lines increased. At the same time, the metastatic capacities decreased, and the relative contents of total choline (tCho) and lactate (Lac) were also reduced. In conclusion, deviations in AEG-1 expression influence the apoptosis rate and metastasis capacity of U251 cells, which the 1H MRS metabolite ratio could monitor. The tCho/creatinine(Cr) and Lac/Cr ratios positively correlated with the AEG-1 expression and malignant cell behavior. This study may provide potential biomarkers for accurate preoperative diagnosis and future AEG-1-targeting treatment evaluation of gliomas in vivo.

In vivo CRISPR gene editing in patients with herpetic stromal keratitis.

In vivo CRISPR gene therapy holds large clinical potential, but the safety and efficacy remain largely unknown. Here, we injected a single dose of herpes simplex virus 1 (HSV-1)-targeting CRISPR formulation in the cornea of three patients with severe refractory herpetic stromal keratitis (HSK) during corneal transplantation. Our study is an investigator-initiated, open-label, single-arm, non-randomized interventional trial at a single center (NCT04560790). We found neither detectable CRISPR-induced off-target cleavages by GUIDE-seq nor systemic adverse events for 18 months on average in all three patients. The HSV-1 remained undetectable during the study. Our preliminary clinical results suggest that in vivo gene editing targeting the HSV-1 genome holds acceptable safety as a potential therapy for HSK.

Controlling Surface Chemical Inhomogeneity of Ni2 P/MoNiP2 /MoP Heterostructure Electrocatalysts for Efficient Hydrogen Evolution Reaction.

Crystalline/amorphous phase engineering is demonstrated as a powerful strategy for electrochemical performance optimization. However, it is still a considerable challenge to prepare transition metal-based crystalline/amorphous heterostructures because of the low redox potential of transition metal ions. Herein, a facile H2 -assisted method is developed to prepare ternary Ni2 P/MoNiP2 /MoP crystalline/amorphous heterostructure nanowires on the conductive substrate. The characterization results show that the content of the MoNiP2 phase and the crystallinity of the MoP phase can be tuned by simply controlling the H2 concentration. The obtained electrocatalyst exhibits a superior alkaline hydrogen evolution reaction performance, delivering overpotentials of 20 and 76 mV to reach current densities of 10 and 100 mA cm-2 with a Tafel slope of 30.6 mV dec-1 , respectively. The catalysts also reveal excellent stability under a constant 100 h operation, higher than most previously reported electrocatalysts. These striking performances are ascribed to the optimized hydrogen binding energy and favorable hydrogen adsorption/desorption kinetics. This work not only exhibits the potential application of ternary Ni2 P/MoNiP2 /MoP crystalline/amorphous heterostructure nanowires catalysts for practical electrochemical water splitting, but also paves the way to prepare non-noble transition metal-based electrocatalysts with optimized crystalline/amorphous heterostructures.

Synthesis of Imidazo[1,2-a]pyridine-Fused 1,3-Benzodiazepine Derivatives with Anticancer Activity via a One-Pot Cascade GBB-3CR/Pd(II)-Catalyzed Azide-Isocyanide Coupling/Cyclization Process.

A new one-pot synthesis of imidazo[1,2-a]pyridine-fused 1,3-benzodiazepine derivatives via a sequential GBB-3CR/Pd(II)-catalyzed azide-isocyanide coupling/cyclization process was developed. The Groebke-Blackburn-Bienaymé three-component reactions (GBB-3CR) of 2-aminopyridine, 2-azidobenzaldehydes, and isocyanides in the presence of a catalytic amount of p-toluenesulfonic acid gave azide intermediates without separation. The reaction was followed by using another molecule of isocyanides to produce imidazo[1,2-a]pyridine-fused 1,3-benzodiazepine derivatives in good yields by the Pd(II)-catalyzed azide-isocyanide coupling/cyclization reaction. The synthetic approach produces novel nitrogen-fused polycyclic heterocycles under mild reaction conditions. The preliminary biological evaluation demonstrated that compound 6a inhibited glioma cells efficiently, suggesting potentially broad applications of the approach for synthesis and medicinal chemistry.

Characterizing the dynamics of BCR repertoire from repeated influenza vaccination.

Yearly epidemics of seasonal influenza cause an enormous disease burden around the globe. An understanding of the rules behind the immune response with repeated vaccination still presents a significant challenge, which would be helpful for optimizing the vaccination strategy. In this study, 34 healthy volunteers with 16 vaccinated were recruited, and the dynamics of the BCR repertoire for consecutive vaccinations in two seasons were tracked. In terms of diversity, length, network, V and J gene segments usage, somatic hypermutation (SHM) rate and isotype, it was found that the overall changes were stronger in the acute phase of the first vaccination than the second vaccination. However, the V gene segments of IGHV4-39, IGHV3-9, IGHV3-7 and IGHV1-69 were amplified in the acute phase of the first vaccination, with IGHV3-7 dominant. On the other hand, for the second vaccination, the changes were dominated by IGHV1-69, with potential for coding broad neutralizing antibody. Additional analysis indicates that the application of V gene segment for IGHV3-7 in the acute phase of the first vaccination was due to the elevated usage of isotypes IgM and IgG3. While for IGHV1-69 in the second vaccination, it was contributed by isotypes IgG1 and IgG2. Finally, 41 public BCR clusters were identified in the vaccine group, with both IGHV3-7 and IGHV1-69 were involved and representative complementarity determining region 3 (CDR3) motifs were characterized. This study provides insights into the immune response dynamics following repeated influenza vaccination in humans and can inform universal vaccine design and vaccine strategies in the future.

Characteristics of genotype, drug resistance, and molecular transmission network among newly diagnosed HIV-1 infections in Shenzhen, China.

The HIV-1 pandemic has persisted for four decades, and poses a major challenge to global public health. Shenzhen, a city with large number of migrant populations in China, is suffering HIV-1 epidemic. It is necessary to continuously conduct the molecular surveillance among newly diagnosed HIV-1 patients in these migrant population. In this study, plasma samples of newly diagnosed and ART-naive HIV-1 infections were collected from Shenzhen city in China. The partial genes of HIV-1 gag and pol were amplified and sequenced for the analysis of genotype, drug resistance, and molecular transmission network. Ninety-one sequences of pol gene were obtained from newly diagnosed HIV-1 infections in Shenzhen, and seven HIV-1 subtypes were revealed in this investigation. Among them, the circulating recombinant form (CRF) 07_BC was the mostly frequent subtype (53.8%, 49/91), followed by CRF01_AE (20.9%, 19/91), CRF55_01B (9.9%, 9/91), unique recombinant forms (URFs) (8.8%, 8/91), B (3.3%, 3/91), CRF59_01B (2.2%, 2/91), and CRF08_BC (1.1%, 1/91). The overall prevalence of pretreatment drug resistance (PDR) was 23.1% (21/91), and 52.38% (11/21) of the PDR was specific for the nonnucleotide reverse transcriptase inhibitors (NNRTIs). Furthermore, a total of 3091 pol gene sequences were used to generate 19 molecular transmission clusters, and then one growing cluster, a new cluster, and a cluster with growth reactivation were identified. The result revealed that more sexual partner, CRF_07BC subtype, and seven amino acid deletions in gag p6 region might be the influencing factors associated with the high risk of transmission behavior. Compared with CRF01_AE subtype, CRF07_BC subtype strains were more likely to form clusters in molecular transmission network. This suggests that long-term surveillance of the HIV-1 molecular transmission should be a critical measure to achieve a precise intervention for controlling the spread of HIV-1 in China.