Evaluation of serum Epstein-Barr virus envelope glycoproteins antibodies and their association with systemic autoimmune diseases

Systemic autoimmune diseases (SADs) are a growing spectrum of autoimmune disorders that commonly affect multiple organs. The role of Epstein-Barr virus (EBV) infection or reactivation as a trigger for the initiation and progression of SADs has been established, while the relationship between EBV envelope glycoproteins and SADs remains unclear. Here, we assessed the levels of IgG, IgA, and IgM against EBV glycoproteins (including gp350, gp42, gHgL, and gB) in serum samples obtained from patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), and found that RA and SLE patients exhibited a statistically significant increase in the levels of 8 and 11 glycoprotein antibodies, respectively, compared to healthy controls (p < 0.05). The LASSO model identified four factors as significant diagnostic markers for RA: gp350 IgG, gp350 IgA, gHgL IgM, and gp42 IgA; whereas for SLE it included gp350 IgG, gp350 IgA, gHgL IgA, and gp42 IgM. Combining these selected biomarkers yielded an area under the curve (AUC) of 0.749 for RA and 0.843 for SLE. We subsequently quantified the levels of autoantibodies associated with SADs in mouse sera following immunization with gp350. Remarkably, none of the tested autoantibody levels exhibited statistically significant alterations. Elevation of glycoprotein antibody concentration suggests that Epstein-Barr virus reactivation and replication occurred in SADs patients, potentially serving as a promising biomarker for diagnosing SADs. Moreover, the absence of cross-reactivity between gp350 antibodies and SADs-associated autoantigens indicates the safety profile of a vaccine based on gp350 antigen.

EBV abortive lytic cycle promotes nasopharyngeal carcinoma progression through recruiting monocytes and regulating their directed differentiation

Epstein-Barr virus (EBV) is associated with several types of human cancer including nasopharyngeal carcinoma (NPC). The activation of EBV to the lytic cycle has been observed in advanced NPC and is believed to contribute to late-stage NPC development. However, how EBV lytic cycle promotes NPC progression remains elusive. Analysis of clinical NPC samples indicated that EBV reactivation and immunosuppression were found in advanced NPC samples, as well as abnormal angiogenesis and invasiveness. To investigate the role of the EBV lytic cycle in tumor development, we established a system that consists of two NPC cell lines, respectively, in EBV abortive lytic cycle and latency. In a comparative analysis using this system, we found that the NPC cell line in EBV abortive lytic cycle exhibited the superior chemotactic capacity to recruit monocytes and polarized their differentiation toward tumor-associated macrophage (TAM)-like phenotype and away from DCs, compared to EBV-negative or EBV-latency NPC cells. EBV-encoded transcription activator ZTA is responsible for regulating monocyte chemotaxis and TAM phenotype by up-regulating the expression of GM-CSF, IL-8, and GRO-α. As a result, TAM induced by EBV abortive lytic cycle promotes NPC angiogenesis, invasion, and migration. Overall, this study elucidated the role of the EBV lytic life cycle in the late development of NPC and revealed a mechanism underlying the ZTA-mediated establishment of the tumor microenvironment (TME) that promotes NPC late-stage progression.

Neutralizing antibodies against EBV gp42 show potent in vivo protection and define novel epitopes

Epstein-Barr virus (EBV) is the first reported human oncogenic virus and infects more than 95% of the human population worldwide. EBV latent infection in B lymphocytes is essential for viral persistence. Glycoprotein gp42 is an indispensable member of the triggering complex for EBV entry into B cells. The C-type lectin domain (CTLD) of gp42 plays a key role in receptor binding and is the major target of neutralizing antibodies. Here, we isolated two rabbit antibodies, 1A7 and 6G7, targeting gp42 CTLD with potent neutralizing activity against B cell infection. Antibody 6G7 efficiently protects humanized mice from lethal EBV challenge and EBV-induced lymphoma. Neutralizing epitopes targeted by antibodies 1A7 and 6G7 are distinct and novel. Antibody 6G7 blocks gp42 binding to B cell surface and both 1A7 and 6G7 inhibit membrane fusion with B cells. Furthermore, 1A7- and 6G7-like antibodies in immunized sera are major contributors to B cell neutralization. This study demonstrates that anti-gp42 neutralizing antibodies are effective in inhibiting EBV infection and sheds light on the design of gp42-based vaccines and therapeutics.

Super-enhancer driven SOX2 promotes tumor formation by chromatin re-organization in nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a malignant head and neck cancer with a high incidence in Southern China and Southeast Asia. Patients with remote metastasis and recurrent NPC have poor prognosis. Thus, a better understanding of NPC pathogenesis may identify novel therapies to address the unmet clinical needs.

METHODS

H3K27ac ChIP-seq and HiChIP was applied to understand the enhancer landscapes and the chromosome interactions. Whole genome sequencing was conducted to analyze the relationship between genomic variations and epigenetic dysregulation. CRISPRi and JQ1 treatment were used to evaluate the transcriptional regulation of SOX2 SEs. Colony formation assay, survival analysis and in vivo subcutaneous patient-derived xenograft assays were applied to explore the function and clinical relevance of SOX2 in NPC.

FINDINGS

We globally mapped the enhancer landscapes and generated NPC enhancer connectomes, linking NPC specific enhancers and SEs. We found five overlapped genes, including SOX2, among super-enhancer regulated genes, survival related genes and NPC essential genes. The mRNA expression of SOX2 was repressed when applying CRISPRi targeting different SOX2 SEs or JQ1 treatment. Next, we identified a genetic variation (Chr3:181422197, G > A) in SOX2 SE which is correlated with higher expression of SOX2 and poor survival. In addition, SOX2 was highly expressed in NPC and is correlated with short survival in patients with NPC. Knock-down of SOX2 suppressed tumor growth in vitro and in vivo.

INTERPRETATION

Our study demonstrated the super-enhancer landscape with chromosome interactions and identified super-enhancer driven SOX2 promotes tumorigenesis, suggesting that SOX2 is a potential therapeutic target for patients with NPC.

FUNDING

A full list of funding bodies that contributed to this study can be found in the Acknowledgements section.

Non-overlapping epitopes on the gHgL-gp42 complex for the rational design of a triple-antibody cocktail against EBV infection

Epstein-Barr virus (EBV) is closely associated with cancer, multiple sclerosis, and post-acute coronavirus disease 2019 (COVID-19) sequelae. There are currently no approved therapeutics or vaccines against EBV. It is noteworthy that combining multiple EBV glycoproteins can elicit potent neutralizing antibodies (nAbs) against viral infection, suggesting possible synergistic effects. Here, we characterize three nAbs (anti-gp42 5E3, anti-gHgL 6H2, and anti-gHgL 10E4) targeting different glycoproteins of the gHgL-gp42 complex. Two antibody cocktails synergistically neutralize infection in B cells (5E3+6H2+10E4) and epithelial cells (6H2+10E4) in vitro. Moreover, 5E3 alone and the 5E3+6H2+10E4 cocktail confer potent in vivo protection against lethal EBV challenge in humanized mice. The cryo-EM structure of a heptatomic gHgL-gp42 immune complex reveals non-overlapping epitopes of 5E3, 6H2, and 10E4 on the gHgL-gp42 complex. Structural and functional analyses highlight different neutralization mechanisms for each of the three nAbs. In summary, our results provide insight for the rational design of therapeutics or vaccines against EBV infection.

[Analysis of MRI features of hepatocyte nuclear factor 1α-inactivated hepatocellular adenoma]

Objective: To investigate the MRI imaging features of hepatocyte nuclear factor 1α- inactivated hepatocellular adenoma (H-HCA). Methods: Clinical data and MRI images of 19 H-HCA cases who were pathologically confirmed at Zhongshan Hospital Affiliated to Fudan University between August 2014 and July 2020 were retrospectively analyzed. Among them, there were 15 females and 4 males, aged 16-47 (32± 7) years old. Tumor number, location, shape, size, boundary, MRI plain scan signal intensity, dynamic enhancement features of each phase, presence or absence of intratumoral fat content, pseudocapsule, and others were analyzed. The differences in apparent diffusion coefficient (ADC) values between the lesion and the surrounding normal liver parenchyma were compared for statistical significance. t-test was used for statistical analysis. Results: There were a total of 24 lesions in 19 cases. 14 cases had solitary lesions, and five cases had multiple lesions. 15 and nine lesions were located in the right and left lobes of the liver, respectively. 20 lesions were round or quasi-round, and four were irregular or lobulated. The tumor's maximal diameter was 0.6-8.6 (3.5 ± 2.4) cm. T(1)-weighted image (WI) showed hyperintense to iso-intense signals in 20 lesions and hypointense signals in four. T(2)WI showed iso-to-slightly high signal intensity in 16 lesions, with two hyperintense and six hypointense signals. Diffusion-weighted image (DWI) revealed hyperintense to iso-intense signals. Lesions mean ADC value was (1.289 ± 0.222)×10(-3) mm(2)/s, while the adjacent normal liver parenchyma's mean ADC value was (1.307 ± 0.236)×10(-3) mm(2)/s, with no statistically significant difference between the two (P > 0.05). During the arterial phase, 15 of the 18 lesions that underwent dynamic contrast-enhanced scanning with gadoxetate disodium (Gd-DTPA) were mildly to moderately enhanced and three were strongly enhanced. The portal and hepatic venous phases had no continuous enhancement, while the delayed phase showed a hypointense signal. During the arterial phase, two of the six lesions scanned by gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid ((Gd-EOB-DTPA) dynamic enhancement were mildly to moderately enhanced, while four were strongly enhanced. The portal and hepatic venous phases had no continuous enhancement, while the transition and hepatobiliary-specific phases showed hypointense signals. Intracellular steatosis occurred in 21 lesions, of which 19 were diffuse steatosis and 16 formed pseudocapsules in the delayed phase. Conclusion: H-HCA often occurs in young females as solitary lesions and has certain MRI features. T1WI anti-phase diffuse signal reduction and post-enhanced hypovascular withdrawal enhancement patterns can aid in accurately diagnosing the disease condition.

A gB nanoparticle vaccine elicits a protective neutralizing antibody response against EBV

Epstein-Barr virus (EBV) is a global public health concern, as it is known to cause multiple diseases while also being etiologically associated with a wide range of epithelial and lymphoid malignancies. Currently, there is no available prophylactic vaccine against EBV. gB is the EBV fusion protein that mediates viral membrane fusion and participates in host recognition, making it critical for EBV infection in both B cells and epithelial cells. Here, we present a gB nanoparticle, gB-I53-50 NP, that displays multiple copies of gB. Compared with the gB trimer, gB-I53-50 NP shows improved structural integrity and stability, as well as enhanced immunogenicity in mice and non-human primate (NHP) preclinical models. Immunization and passive transfer demonstrate a robust and durable protective antibody response that protects humanized mice against lethal EBV challenge. This vaccine candidate demonstrates significant potential in preventing EBV infection, providing a possible platform for developing prophylactic vaccines for EBV.

Camrelizumab combined with apatinib in patients with first-line platinum-resistant or PD-1 inhibitor resistant recurrent/metastatic nasopharyngeal carcinoma: a single-arm, phase 2 trial

Immunotherapy combined with antiangiogenic targeted therapy has improved the treatment of certain solid tumors, but effective regimens remain elusive for refractory recurrent/metastatic nasopharyngeal carcinoma (RM-NPC). We conducted a phase 2 trial to evaluate the safety and activity of camrelizumab plus apatinib in platinum-resistant (cohort 1, NCT04547088) and PD-1 inhibitor resistant NPC (cohort 2, NCT04548271). Here we report on the primary outcome of objective response rate (ORR) and secondary endpoints of safety, duration of response, disease control rate, progression-free survival, and overall survival. The primary endpoint of ORR was met for cohort 1 (65%, 95% CI, 49.6-80.4, n = 40) and cohort 2 (34.3%; 95% CI, 17.0-51.8, n = 32). Grade ≥ 3 treatment-related adverse events (TRAE) were reported in 47 (65.3%) of 72 patients. Results of our predefined exploratory investigation of predictive biomarkers show: B cell markers are the most differentially expressed genes in the tumors of responders versus non-responders in cohort 1 and that tertiary lymphoid structure is associated with higher ORR; Angiogenesis gene expression signatures are strongly associated with ORR in cohort 2. Camrelizumab plus apatinib combination effectiveness is associated with high expression of PD-L1, VEGF Receptor 2 and B-cell-related genes signatures. Camrelizumab plus apatinib shows promising efficacy with a measurable safety profile in RM-NPC patients.

Multiple TMA-aided CRISPR/Cas13a platform for highly sensitive detection of IL-15 to predict immunotherapeutic response in nasopharyngeal carcinoma

BACKGROUND

Immune checkpoint inhibitors (ICIs)-based treatments have been recommended as the first line for refractory recurrent and/or metastatic nasopharyngeal carcinoma (NPC) patients, yet responses vary, and predictive biomarkers are urgently needed. We selected serum interleukin-15 (sIL-15) out of four interleukins as a candidate biomarker, while most patients' sIL-15 levels were too low to be detected by conventional methods, so it was necessary to construct a highly sensitive method to detect sIL-15 in order to select NPC patients who would benefit most or least from ICIs.

METHODS

Combining a primer exchange reaction (PER), transcription-mediated amplification (TMA), and a immuno-PER-TMA-CRISPR/Cas13a system, we developed a novel multiple signal amplification platform with a detection limit of 32 fg/mL, making it 153-fold more sensitive than ELISA.

RESULTS

This platform demonstrated high specificity, repeatability, and versatility. When applied to two independent cohorts of 130 NPC sera, the predictive value of sIL-15 was accurate in both cohorts (area under the curve: training, 0.882; validation, 0.898). Additionally, lower sIL-15 levels were correlated with poorer progression-free survival (training, HR: 0.080, p<0.0001; validation, HR: 0.053, p<0.0001).

CONCLUSION

This work proposes a simple and sensitive approach for sIL-15 detection to provide insights for personalized immunotherapy of NPC patients.

Peptidome-wide association analysis of Epstein-Barr virus identifies epitope repertoires associated with nasopharyngeal carcinoma

Human leukocyte antigen (HLA) molecules are essential for presenting Epstein-Barr virus (EBV) antigens and are closely related to nasopharyngeal carcinoma (NPC). This study aims to systematically investigate the association between HLA-bound EBV peptides and NPC risk through in silico HLA-peptide binding prediction. A total of 455 NPC patients and 463 healthy individuals in NPC endemic areas were recruited, and HLA-target sequencing was performed. HLA-peptide binding prediction for EBV, followed by peptidome-wide logistic regression and motif analysis, was applied. Binding affinity changes for EBV peptides carrying high-risk mutations were analyzed. We found that NPC-associated EBV peptides were significantly enriched in immunogenic proteins and core linkage disequilibrium (LD) proteins related to evolution, especially those binding HLA-A alleles (p = 3.10 × 10^-4 for immunogenic proteins and p = 8.10 × 10^-5 for core LD proteins related to evolution). These peptides were clustered and showed binding motifs of HLA supertypes, among which supertype A02 presented an NPC-risk effect (p_adj  = 3.77 × 10^-4 ) and supertype A03 presented an NPC-protective effect (p_adj  = 4.89 × 10^-4 ). Moreover, a decreased binding affinity toward risk HLA supertype A02 was observed for the peptide carrying the NPC-risk mutation BNRF1 V1222I (p = 0.0078), and an increased binding affinity toward protective HLA supertype A03 was observed for the peptide carrying the NPC-risk mutation BALF2 I613V (p = 0.022). This study revealed the distinct preference of EBV peptides for binding HLA supertypes, which may contribute to shaping EBV population structure and be involved in NPC development.

Neuropilin 1 is an entry receptor for KSHV infection of mesenchymal stem cell through TGFBR1/2-mediated macropinocytosis

Kaposi's sarcoma-associated herpesvirus (KSHV) has been implicated in the pathogenesis of Kaposi's sarcoma (KS) and other malignancies. The cellular origin of KS has been suggested to be either mesenchymal stem cells (MSCs) or endothelial cells. However, receptor(s) for KSHV to infect MSCs remains unknown. By combining bioinformatics analysis and shRNA screening, we identify neuropilin 1 (NRP1) as an entry receptor for KSHV infection of MSCs. Functionally, NRP1 knockout and overexpression in MSCs significantly reduce and promote, respectively, KSHV infection. Mechanistically, NRP1 facilitated the binding and internalization of KSHV by interacting with KSHV glycoprotein B (gB), which was blocked by soluble NRP1 protein. Furthermore, NRP1 interacts with TGF-β receptor type 2 (TGFBR2) through their respective cytoplasmic domains and thus activates the TGFBR1/2 complex, which facilitates the macropinocytosis-mediated KSHV internalization via the small GTPases Cdc42 and Rac1. Together, these findings implicate that KSHV has evolved a strategy to invade MSCs by harnessing NRP1 and TGF-beta receptors to stimulate macropinocytosis.

EphA2 is a functional entry receptor for HCMV infection of glioblastoma cells

Human cytomegalovirus (HCMV) infection is associated with human glioblastoma, the most common and aggressive primary brain tumor, but the underlying infection mechanism has not been fully demonstrated. Here, we show that EphA2 was upregulated in glioblastoma and correlated with the poor prognosis of the patients. EphA2 silencing inhibits, whereas overexpression promotes HCMV infection, establishing EphA2 as a crucial cell factor for HCMV infection of glioblastoma cells. Mechanistically, EphA2 binds to HCMV gH/gL complex to mediate membrane fusion. Importantly, the HCMV infection was inhibited by the treatment of inhibitor or antibody targeting EphA2 in glioblastoma cells. Furthermore, HCMV infection was also impaired in optimal glioblastoma organoids by EphA2 inhibitor. Taken together, we propose EphA2 as a crucial cell factor for HCMV infection in glioblastoma cells and a potential target for intervention.

Anti-EBV antibodies: Roles in diagnosis, pathogenesis, and antiviral therapy

Epstein-Barr virus (EBV) infection is prevalent in global population and associated with multiple malignancies and autoimmune diseases. During the infection, EBV-harbored or infected cell-expressing antigen could elicit a variety of antibodies with significant role in viral host response and pathogenesis. These antibodies have been extensively evaluated and found to be valuable in predicting disease diagnosis and prognosis, exploring disease mechanisms, and developing antiviral agents. In this review, we discuss the versatile roles of EBV antibodies as important biomarkers for EBV-related diseases, potential driving factors of autoimmunity, and promising therapeutic agents for viral infection and pathogenesis.

Retraction notice to "Endogenous production of C-C motif chemokine ligand 2 by nasopharyngeal carcinoma cells drives radioresistance-associated metastasis" [Canc. Lett. 468 (2020) 27-40]

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). .

A DNA tumor virus globally reprograms host 3D genome architecture to achieve immortal growth

Epstein-Barr virus (EBV) immortalization of resting B lymphocytes (RBLs) to lymphoblastoid cell lines (LCLs) models human DNA tumor virus oncogenesis. RBL and LCL chromatin interaction maps are compared to identify the spatial and temporal genome architectural changes during EBV B cell transformation. EBV induces global genome reorganization where contact domains frequently merge or subdivide during transformation. Repressed B compartments in RBLs frequently switch to active A compartments in LCLs. LCLs gain 40% new contact domain boundaries. Newly gained LCL boundaries have strong CTCF binding at their borders while in RBLs, the same sites have much less CTCF binding. Some LCL CTCF sites also have EBV nuclear antigen (EBNA) leader protein EBNALP binding. LCLs have more local interactions than RBLs at LCL dependency factors and super-enhancer targets. RNA Pol II HiChIP and FISH of RBL and LCL further validate the Hi-C results. EBNA3A inactivation globally alters LCL genome interactions. EBNA3A inactivation reduces CTCF and RAD21 DNA binding. EBNA3C inactivation rewires the looping at the CDKN2A/B and AICDA loci. Disruption of a CTCF site at AICDA locus increases AICDA expression. These data suggest that EBV controls lymphocyte growth by globally reorganizing host genome architecture to facilitate the expression of key oncogenes.

Urgency and necessity of Epstein-Barr virus prophylactic vaccines

Epstein-Barr virus (EBV), a γ-herpesvirus, is the first identified oncogenic virus, which establishes permanent infection in humans. EBV causes infectious mononucleosis and is also tightly linked to many malignant diseases. Various vaccine formulations underwent testing in different animals or in humans. However, none of them was able to prevent EBV infection and no vaccine has been approved to date. Current efforts focus on antigen selection, combination, and design to improve the efficacy of vaccines. EBV glycoproteins such as gH/gL, gp42, and gB show excellent immunogenicity in preclinical studies compared to the previously favored gp350 antigen. Combinations of multiple EBV proteins in various vaccine designs become more attractive approaches considering the complex life cycle and complicated infection mechanisms of EBV. Besides, rationally designed vaccines such as virus-like particles (VLPs) and protein scaffold-based vaccines elicited more potent immune responses than soluble antigens. In addition, humanized mice, rabbits, as well as nonhuman primates that can be infected by EBV significantly aid vaccine development. Innovative vaccine design approaches, including polymer-based nanoparticles, the development of effective adjuvants, and antibody-guided vaccine design, will further enhance the immunogenicity of vaccine candidates. In this review, we will summarize (i) the disease burden caused by EBV and the necessity of developing an EBV vaccine; (ii) previous EBV vaccine studies and available animal models; (iii) future trends of EBV vaccines, including activation of cellular immune responses, novel immunogen design, heterologous prime-boost approach, induction of mucosal immunity, application of nanoparticle delivery system, and modern adjuvant development.

A high-throughput neutralizing assay for antibodies and sera evaluation against Epstein-Barr virus

BACKGROUND

Epstein-Barr virus (EBV) is a wide-spread human herpesvirus that is highly associated with infectious mononucleosis and several malignancies. Evaluation of EBV neutralizing antibody titers is important for serological studies, vaccine development and monoclonal antibody screening. The traditional method based on antibody inhibition of EBV transformation of B cells is very time-consuming. A more practical flow cytometry-based (FCM) approach to evaluate neutralizing titers is not amenable to achieving high-throughput evaluation of large-scale samples. A high-throughput approach is urgently needed.

RESULTS

Here, we present a rapid and high-throughput method based on high content imaging system (HCIS) analysis. EBV titers determined by the HCIS-based assay were similar to those obtained by the FCM-based assay. Neutralizing titers of sera and monoclonal antibodies measured by the HCIS-based assay strongly correlated with titers measured by the FCM-based assay. HCIS assays showed a strong correlation between B cell infection neutralizing titers and the anti-gp350 IgG titers in healthy EBV carriers and monkey sera. Finally, anti-gHgL IgG titers from sera of healthy EBV carriers significantly correlated with epithelial cell infection neutralizing titers.

CONCLUSIONS

This HCIS-based assay is a high-throughput assay to determine viral titers and evaluate neutralizing potentials of sera and monoclonal antibodies. This HCIS-based assay will aid the development of vaccines and therapeutic monoclonal antibody against EBV.

[MRI features of lymphoepithelioma-like intrahepatic cholangiocarcinoma]

Objective: To investigate the MRI manifestations of lymphoepithelioma-like intrahep cholangiocarcinoma (LEL-ICC). Methods: MR images of 26 cases with LEL-ICC confirmed pathologically at Zhongshan Hospital Affiliated with Fudan University between March 2011 and March 2021 were retrospectively analyzed. The number, location, size, morphology, edges of lesions, non-scan signal intensity, cystic necrosis, enhancement mode, peak, and capsule, vascular invasion, lymph node metastasis, and other MR images were included for analysis. The apparent diffusion coefficient (ADC) value of the lesion and the surrounding normal liver parenchyma were measured. A paired-sample t-test was used to statistically analyze the measurement data. Results: All 26 cases of LEL-ICC had solitary lesions. Mass-type LEL-ICC was the most common [n=23, lesion size (4.02±2.32) cm] with distribution along the bile duct [n=3, lesion size (7.23±1.40 cm)]. Among the 23 lesions of mass type LEL-ICC, most of the lesions were close to the liver capsule (n=20), round (n=22), clearly bordered (n=13), and cystic necrosis (n=22). In the three lesions of LEL-ICC distributed along the bile duct, most of them were close to the liver capsule (n=2), irregular (n=3), blurred edges (n=3), and cystic necrosis (n=3). All 26 lesions showed a low/slightly low signal on T₁WI, a high/slightly high signal on T₂WI, and a slightly high or high signal on DWI. Three lesions showed fast-in and fast-out enhancement modes, and 23 lesions showed continuous enhancement. Twenty-five lesions showed peak enhancement in the arterial phase, and one lesion appeared in the delayed phase. The ADC value of 26 lesions and adjacent normal liver parenchyma was (1.112±0.274)×10^-3 mm²/s and (1.482±0.346)×10^-3 mm²/s, respectively, and the both had a statistically significant difference (P<0.05). Conclusion: Certain manifestations of LEL-ICC in magnetic resonance imaging are advantageous for diagnosis and differential diagnosis.

Molecular characteristics, immune evasion, and impact of SARS-CoV-2 variants

The persistent COVID-19 pandemic since 2020 has brought an enormous public health burden to the global society and is accompanied by various evolution of the virus genome. The consistently emerging SARS-CoV-2 variants harboring critical mutations impact the molecular characteristics of viral proteins and display heterogeneous behaviors in immune evasion, transmissibility, and the clinical manifestation during infection, which differ each strain and endow them with distinguished features during populational spread. Several SARS-CoV-2 variants, identified as Variants of Concern (VOC) by the World Health Organization, challenged global efforts on COVID-19 control due to the rapid worldwide spread and enhanced immune evasion from current antibodies and vaccines. Moreover, the recent Omicron variant even exacerbated the global anxiety in the continuous pandemic. Its significant evasion from current medical treatment and disease control even highlights the necessity of combinatory investigation of the mutational pattern and influence of the mutations on viral dynamics against populational immunity, which would greatly facilitate drug and vaccine development and benefit the global public health policymaking. Hence in this review, we summarized the molecular characteristics, immune evasion, and impacts of the SARS-CoV-2 variants and focused on the parallel comparison of different variants in mutational profile, transmissibility and tropism alteration, treatment effectiveness, and clinical manifestations, in order to provide a comprehensive landscape for SARS-CoV-2 variant research.

A potent and protective human neutralizing antibody targeting a novel vulnerable site of Epstein-Barr virus

Epstein-Barr virus (EBV) is associated with a range of epithelial and B cell malignancies as well as autoimmune disorders, for which there are still no specific treatments or effective vaccines. Here, we isolate EBV gH/gL-specific antibodies from an EBV-infected individual. One antibody, 1D8, efficiently neutralizes EBV infection of two major target cell types, B cells and epithelial cells. In humanized mice, 1D8 provides protection against a high-dose EBV challenge by substantially reducing viral loads and associated tumor burden. Crystal structure analysis reveals that 1D8 binds to a key vulnerable interface between the D-I/D-II domains of the viral gH/gL protein, especially the D-II of the gH, thereby interfering with the gH/gL-mediated membrane fusion and binding to target cells. Overall, we identify a potent and protective neutralizing antibody capable of reducing the EBV load. The novel vulnerable site represents an attractive target that is potentially important for antibody and vaccine intervention against EBV infection.

Advances in pathogenesis and precision medicine for nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a squamous carcinoma with apparent geographical and racial distribution, mostly prevalent in East and Southeast Asia, particularly concentrated in southern China. The epidemiological trend over the past decades has suggested a substantial reduction in the incidence rate and mortality rate due to NPC. These results may reflect changes in lifestyle and environment, and more importantly, a deeper comprehension of the pathogenic mechanism of NPC, leading to much progress in the preventing, screening, and treating for this cancer. Herein, we present the recent advances on the key signal pathways involved in pathogenesis of NPC, the mechanism of Epstein‐Barr virus (EBV) entry into the cell, and the progress of EBV vaccine and screening biomarkers. We will also discuss in depth the development of various therapeutic approaches including radiotherapy, chemotherapy, surgery, targeted therapy, and immunotherapy. These research advancements have led to a new era of precision medicine in NPC.

[Nodular regenerative hyperplasia of liver caused by chemotherapy: magnetic resonance imaging features]

Objective: To investigate the MRI features of hepatic nodular regenerative hyperplasia (NRH) induced by chemotherapy. Methods: The clinical data and MRI of 20 cases with hepatic NRH induced by chemotherapy and confirmed by pathology in Zhongshan Hospital Fudan University from August 2014 to May 2019 were retrospectively analyzed. There were 13 males and 7 females, with an average age of 49.8 ± 9.7 years. Contrast-enhanced MR scan with Gd-DTPA was performed eighteen patients, and two patients underwent contrast-enhanced MR scan with hepatobiliary specific contrast (Gd-EOB-DTPA). The image analysis includes the number, location, size, shape, signal intensity in plain scan and enhancement pattern of lesions. The apparent diffusion coefficient (ADC) values of the lesions and adjacent hepatic parenchyma were measured on the ADC map, and the difference was compared with paired sample t test. Results: A total of 36 lesions in 20 patients were rounded or oval, including 23 (63.9%) lesions in the right lobe, 12 (33.3%) in the left lobe and 1 (2.8%) in the caudate lobe. The average diameter of all lesions was 15.4 ± 6.4 (7.0-37.0) mm. The boundary was clear in 9 (25.0%) lesions and blurred in 27 (75%) lesions. In T1WI, 35 (97.2%) lesions showed slightly hypointensity, and in 1 (2.8%) lesion was iosintensity. All 36 lesions showed slightly hyperintensity in T2WI. 33 (91.7%) lesions showed slightly hyperintensity in DWI, and 3 (8.3%) lesions showed iosintensity. 31 lesions with Gd-DTPA enhanced MR scan were significantly enhanced in the arterial phase and showed slightly high signal intensity in early portal vein phase, late portal vein phase and equilibrium phase. 5 lesions with Gd-EOB-DTPA enhanced MR scan were also significantly enhanced in the arterial phase and showed slightly high signal intensity in early portal vein phase, late portal vein phase and equilibrium phase, then all lesions showed circular high signal intensity in hepatobiliary specific phase. The average ADC value of 29 lesions was (1.471 ± 0.253) × 10(-3) mm(2)/s, and that of adjacent liver parenchyma was (1.460 ± 0.235) ×10(-3) mm(2)/s. There was no significant difference between the two groups (P > 0.05). Conclusion: MR findings of NRH induced by chemotherapy have certain characteristics, and the morphological manifestations, diffusion-weighted imaging, enhanced imaging and hepatobiliary specific phase features of the lesions can help to diagnose the disease.

The genomic architecture of EBV and infected gastric tissue from precursor lesions to carcinoma

BACKGROUND

Epstein-Barr virus (EBV)-associated gastric carcinomas (EBVaGCs) present unique molecular signatures, but the tumorigenesis of EBVaGCs and the role EBV plays during this process remain poorly understood.

METHODS

We applied whole-exome sequencing, EBV genome sequencing, and whole-genome bisulfite sequencing to multiple samples (n = 123) derived from the same patients (n = 25), which covered saliva samples and different histological stages from morphologically normal epithelial tissues to dysplasia and EBVaGCs. We compared the genomic landscape between EBVaGCs and their precursor lesions and traced the clonal evolution for each patient. We also analyzed genome sequences of EBV from samples of different histological types. Finally, the key molecular events promoting the tumor evolution were demonstrated by MTT, IC50, and colony formation assay in vitro experiments and in vivo xenograft experiments.

RESULTS

Our analysis revealed increasing mutational burden and EBV load from normal tissues and low-grade dysplasia (LD) to high-grade dysplasia (HD) and EBVaGCs, and oncogenic amplifications occurred late in EBVaGCs. Interestingly, within each patient, EBVaGCs and HDs were monoclonal and harbored single-strain-originated EBV, but saliva or normal tissues/LDs had different EBV strains from that in EBVaGCs. Compared with precursor lesions, tumor cells showed incremental methylation in promotor regions, whereas EBV presented consistent hypermethylation. Dominant alterations targeting the PI3K-Akt and Wnt pathways were found in EBV-infected cells. The combinational inhibition of these two pathways in EBV-positive tumor cells confirmed their synergistic function.

CONCLUSIONS

We portrayed the (epi) genomic evolution process of EBVaGCs, revealed the extensive genomic diversity of EBV between tumors and normal tissue sites, and demonstrated the synergistic activation of the PI3K and Wnt pathways in EBVaGCs, offering a new potential treatment strategy for this disease.

EBV latent membrane proteins promote hybrid epithelial-mesenchymal and extreme mesenchymal states of nasopharyngeal carcinoma cells for tumorigenicity

EBV-encoded LMPs are consistently detected in nasopharyngeal carcinoma (NPC). Recent evidence suggests potential roles of LMP1 and LMP2A in Epithelial-to-mesenchymal transition (EMT) process in NPC. EMT engages in the generation and maintenance of cancer stem cells (CSCs) and confers on cancer cells increased tumor-initiating and metastatic potential, and higher resistance to anticancer therapies. However, how LMP1 and LMP2A regulate the EMT process to generate cells with different EMT states and its implications for tumor progression remain unclear. Here we report that LMP1 and LMP2A promote EMT that drives NPC cells from the epithelial-like state (E) (CD104⁺, CD44^low) to epithelial-mesenchymal hybrid (E/M) state (CD104⁺, CD44^high). Furthermore, LMP2A possesses an additional function in stabilizing LMP1 and increasing the level of LMP1 in NPC cells. The elevated LMP1 further forces the EMT to generate extreme-mesenchymal (xM) state cells (CD104^-, CD44^high). To define the tumorigenic features of cancer stem cells at different states in the EMT spectrum, E, E/M and xM subpopulations were isolated and tested for tumorigenic capability in a tumor xenograft animal model. We found that the cells with E/M phenotypes possess the highest tumor initiating capacity. However, the xM subpopulation exhibits increased vasculogenic mimicry, a hallmark of metastatic cancers. Taken together, coordinated action of LMP1 and LMP2A generates an array of intermediate subpopulations in the EMT spectrum that are responsible for distinct tumorigenic features of NPC such as tumor-initiation, vasculogenesis, and metastasis.

Intratumoral heterogeneity, characterized by the existence of distinct cellular populations within tumor lesions, poses a significant challenge for the treatment of high-grade cancers. Using an EBV-associated nasopharyngeal carcinoma (NPC) model, we sought to elucidate how a virus or its oncoproteins promote the establishment of cancer stem cells that comprises heterogeneous subpopulations. We found that the coordinated action of EBV membrane proteins LMP1 and LMP2A generates heterogeneous subpopulations of cancer stem cells in nasopharyngeal carcinoma by activating the epithelial-to-mesenchymal transition (EMT). Furthermore, the contributions of the different subpopulations to NPC oncogenesis were investigated. Results showed that cells with an epithelial/mesenchymal hybrid state (E/M) possess the highest tumor initiating capacity; and a highly mesenchymal state (xM) subpopulation exhibits increased vasculogenic mimicry. These finding suggest that cancer stem cells residing at various EMT states are responsible for distinct tumorigenic features such as tumor-initiation, vasculogenesis, and metastasis.

PD-1+CXCR5-CD4+ Th-CXCL13 cell subset drives B cells into tertiary lymphoid structures of nasopharyngeal carcinoma

Background

A major current challenge is to exploit tertiary lymphoid structures (TLSs) to promote the lymphocyte infiltration, activation and differentiation by tumor antigens to increase antitumor immune responses. The mechanisms that underlie the role of TLS formation in the adaptive immune responses against nasopharyngeal carcinoma (NPC) remain largely unknown.

Methods

Cell populations and the corresponding markers were identified by single-cell RNA sequencing and fluorescence-activated cell sorting analysis. In vitro differentiation experiments were used to simulate the generation, regulation and function of the Th-CXCL13 cell subset in the tumor microenvironment of NPC. These were followed by histological evaluation of the colocalization of tumor-associated B cells (TABs) and Th-CXCL13 cells within TLSs, and statistical analysis of the relationship between the cells in TLSs and overall survival.

Results

A PD-1⁺CXCR5⁻CD4⁺ Th-CXCL13 cell subset was identified in NPC. This subset was a major source of CXCL13, representing the majority of the CD4⁺ T cells at levels comparable with Th1 and Tfh cells present in the TLSs. Monocytes activated by toll-like receptor 4 agonists served as the antigen-presenting cells that most efficiently triggered the expansion of Th-CXCL13 cells. Transforming growth factor beta 1 (TGF-β1) stimulation and activation of Sox4 were critical for the induction and polarization of Th-CXCL13 cells in this process. The potential functional contributions of TABs recruited by Th-CXCL13 cells which induced plasma cell differentiation and immunoglobulin production via interleukin-21 and CD84 interactions in the TLSs demonstrated improved survival.

Conclusions

Induction of Th-CXCL13 cells links innate inflammation to immune privilege in tumor-associated TLSs and might predict better survival.

The Status and Prospects of Epstein-Barr Virus Prophylactic Vaccine Development

Epstein–Barr virus (EBV) is a human herpesvirus that is common among the global population, causing an enormous disease burden. EBV can directly cause infectious mononucleosis and is also associated with various malignancies and autoimmune diseases. In order to prevent primary infection and subsequent chronic disease, efforts have been made to develop a prophylactic vaccine against EBV in recent years, but there is still no vaccine in clinical use. The outbreak of the COVID-19 pandemic and the global cooperation in vaccine development against SARS-CoV-2 provide insights for next-generation antiviral vaccine design and opportunities for developing an effective prophylactic EBV vaccine. With improvements in antigen selection, vaccine platforms, formulation and evaluation systems, novel vaccines against EBV are expected to elicit dual protection against infection of both B lymphocytes and epithelial cells. This would provide sustainable immunity against EBV-associated malignancies, finally enabling the control of worldwide EBV infection and management of EBV-associated diseases.

Immunization with a Self-Assembled Nanoparticle Vaccine Elicits Potent Neutralizing Antibody Responses against EBV Infection

Epstein-Barr virus (EBV) infection is a global health concern infecting over 90% of the population. However, there is no currently available vaccine. EBV primarily infects B cells, where the major glycoprotein 350 (gp350) is the main target of neutralizing antibodies. Given the advancement of nanoparticle vaccines, we describe rationally designed vaccine modalities presenting 60 copies of gp350 on self-assembled nanoparticles in a repetitive array. In a mouse model, gp350s on lumazine synthase (LS) and I3-01 adjuvanted with MF59 or aluminum hydroxide (Alhydrogel) elicited over 65- to 133-fold higher neutralizing antibody titers than the corresponding gp350 monomer to EBV. Furthermore, immunization with gp350D₁₂₃-LS and gp350D₁₂₃-I3-01 vaccine induced a Th2-biased response. For the nonhuman primate model, gp350D₁₂₃-LS in MF59 elicited higher titers of total IgG and neutralizing antibodies than the monomeric gp350D₁₂₃. Overall, these results support gp350D₁₂₃-based nanoparticle vaccine design as a promising vaccine candidate for potent protection against EBV infection.

Identification of an N6-methyladenosine-mediated positive feedback loop that promotes Epstein-Barr virus infection

N6-methyladenosine (m⁶A) is among the most abundant mRNA modifications, particularly in eukaryotes, and is found in mammals, plants, and even some viruses. Although essential for the regulation of many biological processes, the exact role of m⁶A modification in virus–host interaction remains largely unknown. Here, using m⁶A -immunoprecipitation and sequencing, we find that Epstein–Barr virus (EBV) infection decreases the m⁶A modification of transcriptional factor KLF4 mRNA and subsequently increases its protein level. Mechanistically, EBV immediate-early protein BZLF1 interacts with the promoter of m⁶A methyltransferase METTL3, inhibiting its expression. Subsequently, the decrease of METTL3 reduces the level of KLF4 mRNA m⁶A modification, preventing its decay by the m⁶A reader protein YTHDF2. As a result, KLF4 protein level is upregulated and, in turn, promotes EBV infection of nasopharyngeal epithelial cells. Thus, our results suggest the existence of a positive feedback loop formed between EBV and host molecules via cellular mRNA m⁶A levels, and this feedback loop acts to facilitate viral infection. This mechanism contains multiple potential targets for controlling viral infectious diseases.

Rapid Development of SARS-CoV-2 Spike Protein Receptor-Binding Domain Self-Assembled Nanoparticle Vaccine Candidates

The coronavirus disease pandemic of 2019 (COVID-19) caused by the novel SARS-CoV-2 coronavirus resulted in economic losses and threatened human health worldwide. The pandemic highlights an urgent need for a stable, easily produced, and effective vaccine. SARS-CoV-2 uses the spike protein receptor-binding domain (RBD) to bind its cognate receptor, angiotensin-converting enzyme 2 (ACE2), and initiate membrane fusion. Thus, the RBD is an ideal target for vaccine development. In this study, we designed three different RBD-conjugated nanoparticle vaccine candidates, namely, RBD-Ferritin (24-mer), RBD-mi3 (60-mer), and RBD-I53-50 (120-mer), via covalent conjugation using the SpyTag-SpyCatcher system. When mice were immunized with the RBD-conjugated nanoparticles (NPs) in conjunction with the AddaVax or Sigma Adjuvant System, the resulting antisera exhibited 8- to 120-fold greater neutralizing activity against both a pseudovirus and the authentic virus than those of mice immunized with monomeric RBD. Most importantly, sera from mice immunized with RBD-conjugated NPs more efficiently blocked the binding of RBD to ACE2 in vitro, further corroborating the promising immunization effect. Additionally, the vaccine has distinct advantages in terms of a relatively simple scale-up and flexible assembly. These results illustrate that the SARS-CoV-2 RBD-conjugated nanoparticles developed in this study are a competitive vaccine candidate and that the carrier nanoparticles could be adopted as a universal platform for a future vaccine development.

N(6)-methyladenosine-binding protein YTHDF1 suppresses EBV replication and promotes EBV RNA decay

N⁶‐methyladenosine (m⁶A) modification of mRNA mediates diverse cellular and viral functions. Infection with Epstein–Barr virus (EBV) is causally associated with nasopharyngeal carcinoma (NPC), 10% of gastric carcinoma, and various B‐cell lymphomas, in which the viral latent and lytic phases both play vital roles. Here, we show that EBV transcripts exhibit differential m⁶A modification in human NPC biopsies, patient‐derived xenograft tissues, and cells at different EBV infection stages. m⁶A‐modified EBV transcripts are recognized and destabilized by the YTHDF1 protein, which leads to the m⁶A‐dependent suppression of EBV infection and replication. Mechanistically, YTHDF1 hastens viral RNA decapping and mediates RNA decay by recruiting RNA degradation complexes, including ZAP, DDX17, and DCP2, thereby post‐transcriptionally downregulating the expression of EBV genes. Taken together, our results reveal the critical roles of m⁶A modifications and their reader YTHDF1 in EBV replication. These findings contribute novel targets for the treatment of EBV‐associated cancers.

Structure of Epstein-Barr virus tegument protein complex BBRF2-BSRF1 reveals its potential role in viral envelopment

Epstein-Barr virus (EBV) is a γ-herpesvirus associated with the occurrence of several human malignancies. BBRF2 and BSRF1 are two EBV tegument proteins that have been suggested to form a hetero-complex and mediate viral envelopment, but the molecular basis of their interaction and the functional mechanism of this complex remains unknown. Here, we present crystal structures of BBRF2 alone and in complex with BSRF1. BBRF2 has a compact globular architecture featuring a central β-sheet that is surrounded by 10 helices, it represents a novel fold distinct from other known protein structures. The central portion of BSRF1 folds into two tightly associated antiparallel α-helices, forming a composite four-helix bundle with two α-helices from BBRF2 via a massive hydrophobic network. In vitro, a BSRF1-derived peptide binds to BBRF2 and reduces the number of viral genome copies in EBV-positive cells. Exogenous BBRF2 and BSRF1 co-localize at the Golgi apparatus. Furthermore, BBRF2 binds capsid and capsid-associated proteins, whereas BSRF1 associates with glycoproteins. These findings indicate that the BBRF2-BSRF1 complex tethers EBV nucleocapsids to the glycoprotein-enriched Golgi membrane, facilitating secondary envelopment.

[The value of 3.0T magnetic resonance -diffusion kurtosis imaging in the differential diagnosis of rectal mucinous adenocarcinoma and common adenocarcinoma]

Objective: To investigate the value of 3.0T MRI diffusion kurtosis imaging (DKI) quantitative histogram parameters in the differential diagnosis of rectal mucinous adenocarcinoma (MC) and common adenocarcinoma (AC). Methods: One hundred and ten patients from Department of Radiology, the Second Affiliated Hospital of Soochow University between September 2015 and September 2019 with complete magnetic resonance imaging (MRI) and DKI results confirmed by surgery and pathology were retrospectively analyzed, including 16 patients in MC group and 94 patients in AC group. Two physicians outlined the region of interest (ROI) on the DKI image with b=1 000 s/mm(2), and obtained quantitative DKI parameters, including the diffusion coefficient (D value) and kurtosis coefficient (K value) corrected for non-Gaussian distribution. The apparent diffusion coefficient (ADC) values of quantitative parameters of diffusion-weighted imaging (DWI) were obtained through image registration, and histogram analysis was performed to obtain the mean value, 25th percentile, 50th percentile, 75th percentile, skewness and kurtosis of the above parameters, respectively. The difference between the quantitative histogram parameter analysis results of the rectal MC group and the AC group was evaluated, and the main indicators and multivariate comprehensive analysis indicators was screened, and the effectiveness of quantitative histogram parameters related to histopathological classification in the differential diagnosis of rectal MC and AC was evaluated. Results: There was no significant differences in gender, age, lesion location, T stage or N stage between MC group and AC group (all P>0.05). The multivariate binary logistic stepwise regression screening showed that D50th percentile and K25th percentile are statistically significant indicators (B values were 2 966.166 and -4.550, respectively; Wals values were 9.000 and 15.720, respectively; and P values were 0.003 and <0.001, respectively). The combined area under the curve of the two indictors was 0.85, but there was no statistically significant difference in pairwise comparison using DeLong method (P>0.05). The results of histogram analysis of quantitative parameters measured by the two physicians were consistent, and the inter-group correlation coefficient ranged from 0.880 to 0.981. Conclusions: The quantitative parameter histogram analysis of the DKI double-index model is helpful for the differentiation of rectal MC and AC, in which the D50th percentile and K25th percentile have differential diagnosis significance, and are superior to the ADC value of the single-index model.

Single-cell transcriptomic analysis defines the interplay between tumor cells, viral infection, and the microenvironment in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV)-associated malignancy with a complex tumor ecosystem. How the interplay between tumor cells, EBV, and the microenvironment contributes to NPC progression and immune evasion remains unclear. Here we performed single-cell RNA sequencing on ~104,000 cells from 19 EBV⁺ NPCs and 7 nonmalignant nasopharyngeal biopsies, simultaneously profiling the transcriptomes of malignant cells, EBV, stromal and immune cells. Overall, we identified global upregulation of interferon responses in the multicellular ecosystem of NPC. Notably, an epithelial-immune dual feature of malignant cells was discovered and associated with poor prognosis. Functional experiments revealed that tumor cells with this dual feature exhibited a higher capacity for tumorigenesis. Further characterization of the cellular components of the tumor microenvironment (TME) and their interactions with tumor cells revealed that the dual feature of tumor cells was positively correlated with the expression of co-inhibitory receptors on CD8⁺ tumor-infiltrating T cells. In addition, tumor cells with the dual feature were found to repress IFN-γ production by T cells, demonstrating their capacity for immune suppression. Our results provide new insights into the multicellular ecosystem of NPC and offer important clinical implications.

Autocrine INSL5 promotes tumor progression and glycolysis via activation of STAT5 signaling

Metabolic reprogramming plays important roles in development and progression of nasopharyngeal carcinoma (NPC), but the underlying mechanism has not been completely defined. In this work, we found INSL5 was elevated in NPC tumor tissue and the plasma of NPC patients. Plasma INSL5 could serve as a novel diagnostic marker for NPC, especially for serum VCA-IgA-negative patients. Moreover, higher plasma INSL5 level was associated with poor disease outcome. Functionally, INSL5 overexpression increased, whereas knockdown of its receptor GPCR142 or inhibition of INSL5 reduced cell proliferation, colony formation, and cell invasion in vitro and tumorigenicity in vivo. Mechanistically, INSL5 enhanced phosphorylation and nuclear translocation of STAT5 and promoted glycolytic gene expression, leading to induced glycolysis in cancer cells. Pharmaceutical inhibition of glycolysis by 2-DG or blockade of INSL5 by a neutralizing antibody reversed INSL5-induced proliferation and invasion, indicating that INSL5 can be a potential therapeutic target in NPC. In conclusion, INSL5 enhances NPC progression by regulating cancer cell metabolic reprogramming and is a potential diagnostic and prognostic marker as well as a therapeutic target for NPC.

The anti-inflammatory drug dimethyl itaconate protects against colitis-associated colorectal cancer

Colorectal cancer (CRC) is the third most common diagnosed cancer of which risk factors include unhealthy diet, smoking, and chronic inflammation. Weakening the inflammatory response emerges as an effective therapeutic strategy to prevent the progression of CRC. Inflammatory macrophages produce substantial amounts of immunoregulatory metabolite itaconate, which is synthesized by the immune response gene 1 (Irg1). In this study, we use a membrane-permeable itaconate derivative, dimethyl itaconate (DI), for the protection against CRC in mouse model. DI decreased the high inflammatory state of ulcerative colitis and reduced the colitis-associated cancer (CAC) risk. Mechanistically, DI inhibited the secretion of the cytokines IL-1β and CCL2 from intestinal epithelial cells, and therefore reduced the recruitment of macrophages into tumor microenvironment. Meanwhile, the decrease of macrophage infiltration was accompanied by a decrease of myeloid-derived suppressor cell (MDSC) infiltration and the differentiation of T cell subsets into cytotoxic T cells. We showed that itaconate derivative limits inflammatory response, indicating a negative feedback loop that involves an inflammatory agent and itaconate. Our findings demonstrate the potential application of DI for the prevention of colitis-associated CRC. KEY MESSAGES: Dimethyl itaconate (DI) suppresses ulcerative colitis and colitis-associated colorectal cancer DI decreases infiltration of macrophages and myeloid-derived suppressor cells into tumor DI weakens the inflammatory response via inhibiting the secretion of IL-1β and CCL2.

Plasma Epstein-Barr Virus-Deoxyribonucleic Acid Copy Number Predicts Disease Progression in Stage I-III Pulmonary Lymphoepithelioma-Like Carcinoma

Purpose: To investigate the predictive values of plasma Epstein-Barr Virus (EBV)- deoxyribonucleic acid (DNA) copy number on disease progression and survival in stage I-III pulmonary lymphoepithelioma-like carcinoma (LELC).

Patients and Methods: Patients with pathologically confirmed, initially diagnosed or locally recurrent stage I-III pulmonary LELC, who received locally radical treatment and had plasma EBV-DNA results, were retrospectively reviewed. Risk factors of progression-free survival (PFS) and overall survival (OS) were assessed, including the predictive value of pre- and post-treatment EBV-DNA levels. The EBV-DNA change during follow-up was analyzed to determine its association with tumor progression and survival.

Results: A total of 102 patients were included in analysis. Eighty-eight patients had initially-diagnosed and 14 had locally recurrent disease. There were 33 patients treated with radical surgery, 55 with definite radiotherapy and 14 with both. EBV-DNA was tested pre-treatment (N = 66), post-treatment (N = 93) and/or during follow-up (N = 58). Forty-one patients had complete EBV-DNA results of all three time points. The overall 2-year PFS and OS were 66.3 and 96.0%, respectively. Pre-treatment EBV-DNA copy number > 10,000 copies/mL was a risk factor of PFS (2-year PFS, > 10,000 vs. ≤ 10,000 copies/mL, 37.2 vs. 75.1%, p = 0.007). Positive post-treatment EBV-DNA also indicated a worse PFS in univariable (2-year PFS, > 0 vs. 0 copy/mL, 25.6 vs. 76.8%, p < 0.001) and multivariable analysis (HR = 3.44, 95% CI, 1.52–7.78; p = 0.003). In the follow-up set, an increasing EBV-DNA exceeding 1,000 copies/mL strongly predicted disease progression within 3 months, with a specificity of 97.5% (95% CI: 86.8–99.6%) and was associated with impaired OS (2-year OS, > 1,000 vs. ≤ 1,000 copies/mL, 72.9 vs. 100%, p < 0.001).

Conclusions: Regular testing of EBV-DNA is suggested for pulmonary LELC to predict disease progression. If EBV-DNA copy number was increasing and beyond 1,000 copies/mL during follow-up, intensive radiologic evaluations are recommended.

Upregulation of METTL3 Expression Predicts Poor Prognosis in Patients with Esophageal Squamous Cell Carcinoma

Background

The N⁶-methyladenosine (m⁶A) RNA modification of mRNA mediates various cellular functions and cancer progression. However, the roles of m⁶A RNA modification in the regulation of esophageal squamous cell carcinoma (ESCC), the dominant subtype of esophageal cancer in Asia, were unclear.

Materials and Methods

Here, we analyzed the mRNA expression level of methyltransferase like 3 (METTL3) in the public available datasets of ESCC tissues and matched adjacent normal tissues. We also performed immunohistochemistry (IHC) assays to detect the protein expression of METTL3 in human ESCC tissue specimen. In our study, we also analyzed the association between METTL3 expression and prognosis using Cox proportional hazard regression in 207 ESCC patients.

Results

The results of public available datasets and IHC assays showed that METTL3 was upregulated in tumor compared with adjacent nonmalignant esophageal mucosal tissues. The IHC results indicated that higher expression level of METTL3 was associated with worse survival. We also found that METTL3 expression level was an independent predictor for disease-free survival and overall survival of ESCC patients.

Conclusion

Our results revealed that the METTL3 expression level could be used as an independent prognostic biomarker for ESCC prognosis.

CryoEM structure of the tegumented capsid of Epstein-Barr virus

Epstein-Barr virus (EBV) is the primary cause of infectious mononucleosis and has been shown to be closely associated with various malignancies. Here, we present a complete atomic model of EBV, including the icosahedral capsid, the dodecameric portal and the capsid-associated tegument complex (CATC). Our in situ portal from the tegumented capsid adopts a closed conformation with its channel valve holding the terminal viral DNA and with its crown region firmly engaged by three layers of ring-like dsDNA, which, together with the penton flexibility, effectively alleviates the capsid inner pressure placed on the portal cap. In contrast, the CATCs, through binding to the flexible penton vertices in a stoichiometric manner, accurately increase the inner capsid pressure to facilitate the pressure-driven genome delivery. Together, our results provide important insights into the mechanism by which the EBV capsid, portal, packaged genome and the CATCs coordinately achieve a pressure balance to simultaneously benefit both viral genome retention and ejection.

FAM46B is a prokaryotic-like cytoplasmic poly(A) polymerase essential in human embryonic stem cells

Family with sequence similarity (FAM46) proteins are newly identified metazoan-specific poly(A) polymerases (PAPs). Although predicted as Gld-2-like eukaryotic non-canonical PAPs, the detailed architecture of FAM46 proteins is still unclear. Exact biological functions for most of FAM46 proteins also remain largely unknown. Here, we report the first crystal structure of a FAM46 protein, FAM46B. FAM46B is composed of a prominently larger N-terminal catalytic domain as compared to known eukaryotic PAPs, and a C-terminal helical domain. FAM46B resembles prokaryotic PAP/CCA-adding enzymes in overall folding as well as certain inter-domain connections, which distinguishes FAM46B from other eukaryotic non-canonical PAPs. Biochemical analysis reveals that FAM46B is an active PAP, and prefers adenosine-rich substrate RNAs. FAM46B is uniquely and highly expressed in human pre-implantation embryos and pluripotent stem cells, but sharply down-regulated following differentiation. FAM46B is localized to both cell nucleus and cytosol, and is indispensable for the viability of human embryonic stem cells. Knock-out of FAM46B is lethal. Knock-down of FAM46B induces apoptosis and restricts protein synthesis. The identification of the bacterial-like FAM46B, as a pluripotent stem cell-specific PAP involved in the maintenance of translational efficiency, provides important clues for further functional studies of this PAP in the early embryonic development of high eukaryotes.

A method to establish a c-Myc transgenic mouse model of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains one of the most lethal malignant cancers worldwide. HCC mouse models are widely used to explore the molecular pathogenesis of HCC and to test novel drug candidates.

The advantages of this mouse model are as follows:•

This method developed a H11^LNL-Myc knock-in HCC mouse model by crossing H11^LNL-Myc heterozygous mice with (albumin (Alb))-cre transgenic mice to generate c-Myc/Alb-cre double positive mice.

•

The c-Myc/Alb-cre double-positive mice exhibited a typical HCC phenotype, and showed accelerated tumor initiation and rapid HCC progression. Early stage HCC tumors (2–3 mm in diameter) were observed in male mice at the age of 47 days and in female mice at the age of 60 days.

•

Approximately 3 months later, the HCC tumors had progressed to a late stage (> 1 cm in diameter), and 100% of the male and female mice had HCC.

EphA2 phosphorylates NLRP3 and inhibits inflammasomes in airway epithelial cells

Inflammasomes are intracellular complexes that form in the cytosol of inflammatory cells. NLRP3 is one of the sensor proteins in the complex that can recognize a wide variety of stimuli ranging from microbial components to environmental particulates. Here, we report that in mouse airway epithelial cells (AECs), inflammasome activation is inhibited by EphA2, a member of the transmembrane tyrosine kinase receptor family, via tyrosine phosphorylation of NLRP3 in a model of reovirus infection. We find that EphA2 depletion markedly enhances interleukin-1β (IL-1β) and interleukin-18 (IL-18) production in response to the virus. EphA2^-/- mice show stronger inflammatory infiltration and enhanced inflammasome activation upon viral infection, and aggravated asthma symptoms upon ovalbumin (ova) induction. Mechanistically, EphA2 binds to NLRP3 and induces its phosphorylation at Tyr132, thereby interfering with ASC speck formation and blocking the activation of the NLRP3-inflammasome. These data demonstrate that reovirus employs EphA2 to suppress inflammasome activation in AECs and that EphA2 deficiency causes a pathological exacerbation of asthma in an ova-induced asthma model.

A novel vaccine candidate based on chimeric virus-like particle displaying multiple conserved epitope peptides induced neutralizing antibodies against EBV infection

Rationale: Epstein-Barr virus (EBV) is the causative pathogen for infectious mononucleosis and many kinds of malignancies including several lymphomas such as Hodgkin's lymphoma, Burkitt's lymphoma and NK/T cell lymphoma as well as carcinomas such as nasopharyngeal carcinoma (NPC) and EBV-associated gastric carcinoma (EBV-GC). However, to date no available prophylactic vaccine was launched to the market for clinical use.

Methods: To develop a novel vaccine candidate to prevent EBV infection and diseases, we designed chimeric virus-like particles (VLPs) based on the hepatitis B core antigen (HBc149). Various VLPs were engineered to present combinations of three peptides derived from the receptor binding domain of EBV gp350. All the chimeric virus-like particles were injected into Balb/C mice for immunogenicity evaluation. Neutralizing titer of mice sera were detected using an in vitro cell model.

Results: All chimeric HBc149 proteins self-assembled into VLPs with gp350 epitopes displayed on the surface of spherical particles. Interestingly, the different orders of the three epitopes in the chimeric proteins induced different immune responses in mice. Two constructs (149-3A and 149-3B) induced high serum titer against the receptor-binding domain of gp350. Most importantly, these two VLPs elicited neutralizing antibodies in immunized mice, which efficiently blocked EBV infection in cell culture. Competition analysis showed that sera from these mice contained antibodies to a major neutralizing epitope recognized by the strong neutralizing mAb 72A1.

Conclusion: Our data demonstrate that HBc149 chimeric VLPs provide a valuable platform to present EBV gp350 antigens and offer a robust basis for the development of peptide-based candidate vaccines against EBV.

Epstein-Barr Virus miRNA BART2-5p Promotes Metastasis of Nasopharyngeal Carcinoma by Suppressing RND3

Nasopharyngeal carcinoma is an Epstein-Barr virus (EBV)-related malignancy. Recently, we found that the EBV-encoded miRNA BART2-5p was increased in the serum of patients with preclinical nasopharyngeal carcinoma and that the copy number positively correlated with disease progression. In this study, we established its role in nasopharyngeal carcinoma progression and explored underlying mechanisms and clinical significance. BART2-5p was an independent unfavorable prognostic factor for progression-free survival and its circulating abundance positively associated with distant metastasis. Ectopic expression of BART2-5p promoted migration and invasion of EBV-negative nasopharyngeal carcinoma cells, whereas genetic downregulation of BART2-5p in EBV-positive nasopharyngeal carcinoma cells decreased aggressiveness. Mechanistically, BART2-5p targeted RND3, a negative regulator of Rho signaling. Downregulation of RND3 phenocopied the effect of BART2-5p and reconstitution of RND3 rescued the phenotype. By suppressing RND3, BART2-5p activated Rho signaling to enhance cell motility. These findings suggest a novel role for EBV miRNA BART2-5p in promoting nasopharyngeal carcinoma metastasis and its potential value as a prognostic indicator or therapeutic target. SIGNIFICANCE: This study shows that EBV-encoded BART2-5p miRNA suppresses expression of the RND3 Rho family GTPase, consequently promoting ROCK signaling, cell motility, and metastatic behavior of NPC cells.