Neutralization potency of monoclonal antibodies recognizing dominant and subdominant epitopes on SARS-CoV-2 Spike is impacted by the B.1.1.7 variant.

Interaction of the SARS-CoV-2 Spike receptor binding domain (RBD) with the receptor ACE2 on host cells is essential for viral entry. RBD is the dominant target for neutralizing antibodies, and several neutralizing epitopes on RBD have been molecularly characterized. Analysis of circulating SARS-CoV-2 variants has revealed mutations arising in the RBD, N-terminal domain (NTD) and S2 subunits of Spike. To understand how these mutations affect Spike antigenicity, we isolated and characterized >100 monoclonal antibodies targeting epitopes on RBD, NTD, and S2 from SARS-CoV-2-infected individuals. Approximately 45% showed neutralizing activity, of which ∼20% were NTD specific. NTD-specific antibodies formed two distinct groups: the first was highly potent against infectious virus, whereas the second was less potent and displayed glycan-dependant neutralization activity. Mutations present in B.1.1.7 Spike frequently conferred neutralization resistance to NTD-specific antibodies. This work demonstrates that neutralizing antibodies targeting subdominant epitopes should be considered when investigating antigenic drift in emerging variants.

[Clinicopathological features of BAP1 mutated clear cell renal cell carcinoma].

Objective: To investigate the clinicopathological characteristics, immunophenotypes, molecular features, and differential diagnosis of BAP1 mutated clear cell renal cell carcinoma (CCRCC) for better understanding this entity. Methods: Clinical data, histological morphology, immunophenotypes and molecular characteristics of 18 BAP1 mutated CCRCC cases diagnosed at the Department of Pathology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China from January 2020 to December 2022 were analyzed. The patients were followed up. Results: There were 17 males and 1 female patients, aged from 39 to 72 years, with an average age of 56.3 years. Sixteen patients with primary CCRCC were followed up for an average of 24 months, 7 patients had metastases occurred from 4 to 22 months postoperatively. Thirteen of the 16 patients were alive at the time of the last follow-up while 3 patients died 12, 15, and 20 months after the surgery, respectively. One patient underwent retroperitoneal mass resection, but had lung metastasis 32 months after surgery. One case received cervical tumor resection and died at 22 months after the surgery. Characteristic CCRCC regions were identified in 11 of the 18 cases. The tumor cells were arranged in papillary, alveolar, and large nest patterns. Abundant lymphoid tissue, necrosis, and psammoma bodies were seen. Tumor cells showed abundant eosinophilic cytoplasm, and sometimes exhibited rhabdoid differentiation. Round eosinophilic globules were located in the cytoplasm and extracellular matrix. There were 9 cases with WHO/International Society of Urological Pathology grade 3, and 9 cases with grade 4. PAX8 (18/18), carbonic anhydrase 9 (CA9, 16/18), CD10 (18/18), and vimentin (18/18) were positive in the vast majority of tumors.TFE3 was expressed in 5 cases, with strong expression in only 1 case. Eighteen cases were all positive for P504s. Twelve cases harbored a BAP1 mutation combined with von Hippel-Lindau (VHL) mutation, and 2 cases had mutations in BAP1, VHL and PBRM1 simultaneously. SETD2 mutation was not found in any of the cases. Conclusions: BAP1 mutated CCRCC contained papillary, alveolar, and large nest patterns, eosinophilic cytoplasm, high-grade nucleoli, and collagen globules, with P504s positivity. In practical work, when encountering CCRCC containing these features, pathologists should consider the possibility of BAP1 mutations and conduct related molecular tests.

[Characteristics of serum autoantibodies in patients with lupus nephritis and tubulointerstitial damage].

OBJECTIVE: To observe the tubulointerstitial damage (TID) in lupus nephritis (LN) and investigate the relationship between autoantibodies and TID in lupus nephritis. METHODS: This cross-sectional study was conducted in a comprehensive tertiary hospital in Peking University Shenzhen Hospital. From March 2012 to July 2021, LN patients who performed renal biopsy were enrolled in the study. Clinical, laboratory and pathology data were collected. We classified the patients into none-or-mild group and moderate-to-severe groups according to the severity of interstitial fibrosis (IF) /tubular atrophy (TA) or tubulointerstitial inflammation (TII). The t test, U test and Chi-square test were used for statistical analysis as appropriate. RESULTS: A total of 226 patients were included, of who 190 (84%) were female with a median age of 32 (26, 39) years. 89% (201/226) of the patients who pathologically proved to be proliferative LN by renal biopsy. The frequency of moderate-to-severe TII and moderate-to-severe IF/TA was 30% (67/226) and 34% (76/226) respectively. For autoantibodies, the patients with moderate-to-severe TII had a lower rate of positive serum anti-ribonucleoprotein (anti-RNP) antibodies than the patients with none-or-mild TII (34% vs. 51%), and moderate-to-severe IF/TA had a lower rate of positive anti-ribosomal P protein (anti-P) antibodies than patients with none-or-mild IF/TA (19% vs. 33%). For other clinical indicators, the patients with moderate-to-severe TII and moderate-to-severe IF/TA were more often combined with proliferative LN, hypertension and anemia than the patients with none-or-mild TII and none-or-mild IF/TA, respectively. The patients with moderate-to-severe TII had higher serum creatinine values and lower glomerular filtration rates than the patients with none-or-mild TII. The patients with moderate-to-severe IF/TA had higher serum creatinine values, and lower glomerular filtration rates than the patients with none-or-mild IF/TA. CONCLUSION: In patients with LN in Southern China, anti-RNP antibodies and anti-P antibodies may be potential protective factors for TII and IF/TA, respectively. More studies are needed to identify the risk factors of lupus patients with TID and investigate the correlation between autoantibodies and TID, which are critical for developing better preventive and therapeutic strategies to improve the survival rate of LN.

Structure-Based Classification Defines the Discrete Conformational Classes Adopted by the Arenaviral GP1.

The emergence of Old and New World arenaviruses from rodent reservoirs persistently threatens human health. The GP1 subunit of the envelope-displayed arenaviral glycoprotein spike complex (GPC) mediates host cell recognition and is an important determinant of cross-species transmission. Previous structural analyses of Old World arenaviral GP1 glycoproteins, alone and in complex with a cognate GP2 subunit, have revealed that GP1 adopts two distinct conformational states distinguished by differences in the orientations of helical regions of the molecule. Here, through comparative study of the GP1 glycoprotein architectures of Old World Loei River virus and New World Whitewater Arroyo virus, we show that these rearrangements are restricted to Old World arenaviruses and are not induced solely by the pH change that is associated with virus endosomal trafficking. Our structure-based phylogenetic analysis of arenaviral GP1s provides a blueprint for understanding the discrete structural classes adopted by these therapeutically important targets.IMPORTANCE The genetically and geographically diverse group of viruses within the family Arenaviridae includes a number of zoonotic pathogens capable of causing fatal hemorrhagic fever. The multisubunit GPC glycoprotein spike complex displayed on the arenavirus envelope is a key determinant of species tropism and a primary target of the host humoral immune response. Here, we show that the receptor-binding GP1 subcomponent of the GPC spike from Old World but not New World arenaviruses adopts a distinct, pH-independent conformation in the absence of the cognate GP2. Our analysis provides a structure-based approach to understanding the discrete conformational classes sampled by these therapeutically important targets, informing strategies to develop arenaviral glycoprotein immunogens that resemble GPC as presented on the mature virion surface.

Randomized clinical trial of continuous transversus abdominis plane block, epidural or patient-controlled analgesia for patients undergoing laparoscopic colorectal cancer surgery.

BACKGROUND: The optimal analgesia regimen after laparoscopic colorectal cancer surgery is unclear. The aim of the study was to characterize the beneficial effects of continuous transversus abdominis plane (TAP) blocks initiated before operation on outcomes following laparoscopic colorectal cancer surgery. METHODS: Patients undergoing surgery for colorectal cancer were divided randomly into three groups: combined general-TAP anaesthesia (TAP group), combined general-thoracic epidural anaesthesia (TEA group) and standard general anaesthesia (GA group). The primary endpoint was duration of hospital stay. Secondary endpoints included gastrointestinal motility, pain scores and plasma levels of cytokines. RESULTS: In total, 180 patients were randomized and 165 completed the trial. The intention-to-treat analysis showed that duration of hospital stay was significantly longer in the TEA group than in the TAP and GA groups (median 4·1 (95 per cent c.i. 3·8 to 4·3) versus 3·1 (3·0 to 3·3) and versus 3·3 (3·2 to 3·6) days respectively; both P < 0·001). Time to first flatus was earlier in the TAP group (P < 0·001). Visual analogue scale (VAS) scores during coughing were lower in the TAP and TEA groups than the GA group (P < 0·001). Raised plasma levels of vascular endothelial growth factor C, interleukin 6, adrenaline and cortisol were attenuated significantly by continuous TAP block. CONCLUSION: Continuous TAP analgesia not only improved gastrointestinal motility but also shortened duration of hospital stay. A decreased opioid requirement and attenuating surgical stress response may be potential mechanisms. Registration number: ChiCTR-TRC-1800015535 ( http://www.chictr.org.cn).

ANTECEDENTES: El régimen analgésico óptimo para los pacientes tras cirugía laparoscópica del cáncer colorrectal se desconoce. El objetivo de este estudio fue caracterizar los efectos beneficiosos del bloqueo continuo del plano transverso abdominal (transversus abdominis plane, TAP) iniciado preoperatoriamente sobre los resultados después de cirugía laparoscópica del cáncer colorrectal. MÉTODOS: Los pacientes sometidos a cirugía del cáncer colorrectal fueron divididos aleatoriamente en tres grupos: anestesia combinada general-TAP (grupo TAP), anestesia epidural combinada general-torácica (grupo TEA) y anestesia general estándar (grupo GA). El resultado primario fue la duración de la estancia hospitalaria. Los resultados secundarios incluyeron la motilidad gastrointestinal, puntuaciones de dolor y niveles plasmáticos de citocinas. RESULTADOS: En total, 180 pacientes fueron aleatorizados y 165 completaron el ensayo. El análisis por intención de tratar mostró que la duración de la estancia hospitalaria en el grupo TEA fue significativamente más larga que en el grupo TAP y GA respectivamente (4,1 (3,8-4,3) versus 3,1 (3,0-3,3) días, P < 0,001; 4,1 (3,8-4,3) versus 3,3 (3,2-3,6) días, P < 0,001). El tiempo hasta la primera eliminación de gases fue más precoz en el grupo TAP (P < 0,001). Las puntuaciones de la escala analógica visual (visual analogue scale, VAS) durante la tos en el grupo TAP y TEA fueron inferiores (P < 0,01). Los niveles elevados en plasma del factor de crecimiento endotelial C (VEGF-C), interleucina (IL)-6, epinefrina y cortisol fueron atenuados significativamente por el bloque TAP continuo. CONCLUSIÓN: La analgesia TAP continua no solo mejora la motilidad gastrointestinal, sino que también acorta la estancia hospitalaria. Una disminución en los requerimientos de opiáceos y la atenuación de la respuesta al estrés quirúrgico podrían ser mecanismos potenciales de la acción de TAP.

Results of a global, patient-based survey assessing the impact of psoriatic arthritis discussed in the context of the Psoriatic Arthritis Impact of Disease (PsAID) questionnaire.

BACKGROUND: Psoriatic arthritis (PsA) is a chronic immune-mediated inflammatory musculoskeletal disease, manifesting as peripheral arthritis, enthesitis, dactylitis, spondylitis, and skin and nail psoriasis. A core set of domains for measuring the impact of PsA has been developed, including pain, patient global assessment, physical function, health-related quality of life (HRQoL), and fatigue. To understand the impact of PsA on health domains from a patient's perspective, a global survey was developed and results reported in the context of the 12-item Psoriatic Arthritis Impact of Disease (PsAID-12) questionnaire. METHODS: An online patient-based global survey was conducted by The Harris Poll in Australia, Brazil, Canada, France, Spain, Taiwan, the UK, and the US between November 2, 2017 and March 12, 2018. Eligible patients were ≥ 18 years old with a diagnosis of PsA for > 1 year, had visited a rheumatologist/dermatologist in the past 12 months and reported using ≥ 1 synthetic/biologic disease-modifying antirheumatic drug for PsA. Patients reported on PsA severity and symptoms, and the impact of PsA on HRQoL. After survey completion, responses were aligned with PsAID health domains. Descriptive statistics and chi-square tests were conducted. RESULTS: This analysis included 1286 patients from eight countries. Most patients (97%) reported musculoskeletal symptoms relating to PsA in the past year. Common moderate/major impacts of PsA were on physical activity (78%), ability to perform certain activities (76%), work productivity (62%), and career path (57%). Skin/nail symptoms occurred in 80% of patients. Overall, 69% of patients reported that PsA had a moderate/major impact on emotional/mental wellbeing, 56% on romantic relationships/intimacy, and 44% on relationships with family and friends. Social impacts included emotional distress (58%), social shame or disapproval (32%), and ceased participation in social activities (45%). Over half of all patients experienced unusual fatigue over the past 12 months (52%). The health domains that patients reported as being impacted by PsA aligned with life impact domains of the patient-derived PsAID health domains. CONCLUSION: These results highlight the impact of PsA on multiple health domains from a patient perspective that should be considered during shared decision-making processes between healthcare providers and patients.

[Pathological changes of the spleen in ten patients with coronavirus disease 2019(COVID-19) by postmortem needle autopsy].

Objective: To study the pathological changes of the spleen in patients with COVID-19 and to analyze the relationship between the weakened immune system and splenic lesions. Methods: Postmortem needle autopsies from the spleen were carried out on 10 patients who died from COVID-19 in Wuhan. Routine hematoxylin and eosin (HE) staining was used to observe the pathological changes. The changes of lymphocytes were studied further with immunohistochemistry.RT-PCR was used to detect 2019-nCoV RNA in the spleen. In addition,the Epstein-Barr virus (EBV) was detected by in situ hybridization, and coronavirus particles were detected by transmission electron microscopy in 2 cases. Results: There were 7 males and 3 females, with an average age of 68.3 years.Of the 10 cases, 4 had cancer history and another 4 had other underlying diseases respectively.Cough, fever, malaise and dyspnea were the main clinical symptoms.The time from onset to death was 15-45 days.Ten cases patients had normal or slight increase in peripheral blood leukocyte count in the early stage of the disease, 6 cases had significant increase before death. Five patients' peripheral blood lymphocyte count decreased in the early stage of the disease, and 10 patients' peripheral blood lymphocyte count decreased significantly before the disease progressed or died. Seven cases were treated with corticosteroid (methylprednisolone ≤40 mg/d, not more than 5 days). Histopathological examination showed that the cell composition of the spleen decreased, white pulp atrophied at different levels, meanwhile lymphoid follicles decreased or absent;in addition, the ratio of red pulp to white pulp increased with varying degrees. In 7 cases, more neutrophil infiltration was found, and in 5 cases, scattered plasma cell infiltration was found. Macrophage proliferation and hemophagocytic phenomena in a few cells were found in a case. Meanwhile, necrosis and lymphocyte apoptosis were detected in 2 cases, small artery thrombosis and spleen infarction in 1 case, and fungal infection in 1 case. The results of immunohistochemistry showed that the T and B lymphocyte components of the spleen in all cases decreased in varying degrees. CD20(+) B cells were found to accumulate in the lymphoid sheath around the splenic artery in 8 cases. However, CD20 and CD21 immunostaining in 2 cases showed that the number of white pulp was almost normal, and splenic nodules were atrophic. CD3(+), CD4(+) and CD8(+)T cells were decreased. In 9 cases,CD68(+) macrophages were no significant changes in the distribution and quantity. While more CD68(+) cells were found in the medullary sinuses of 1 case (related to fungal infection). Few CD56(+) cells were found. EBV was negative by in situ hybridization. RT-PCR was used to detect the nucleic acid of 2019-nCoV. One of 10 cases was positive, 39 years old,who was the youngest patient in this group, and the other 9 cases were negative. Coronavirus particles were found in the cytoplasm of macrophage under electron microscope in 2 cases. Conclusions: The death of COVID-19 occurs mainly in the elderly, and some cases have no underlying diseases. Spleen may be one of the organs directly attacked by the virus in some patients who died from COVID-19. T and B lymphocyte in the spleen decrease in varying degrees, lymphoid follicles are atrophied, decreased or absent, and the number of NK cells do not change significantly. And the pathological changes of the spleen are not related to the use of low dose corticosteroid, which may be related to the direct attack of virus and the attack of immune system on its own tissues.

[Nomenclature correction of "incidental gallbladder cancer" and its prevention strategies].

Incidental gallbladder cancer(IGBC) originated in the West more than half a century ago.IGBC was translated and introduced into China afterwards with widespread clinical application.With the popularization of laparoscopic cholecystectomy, the trend of "abuse" of IGBC has become increasingly apparent worldwide.Many advanced gallbladder cancers have been categorized as IGBC which actually become the synonym of "missed diagnosis" . From the point of the pathology, the diagnosis of IGBC may cause delays in treatment and adversely affect the patient's prognosis.For country like China with relatively high incidences of chronic cholecystitis, cholelithiasis, and gallbladder cancer, the concept of IGBC, however, is no longer applicable to our diagnosis treat model.For improving the prognosis of gallbladder patients, it is necessary to update and rename the concept of IGBC and more attention should be paid to improve the diagnostic level of early stage tumor.

Risk factors for community-associated Clostridioides difficile infection in young children.

The majority of paediatric Clostridioides difficile infections (CDI) are community-associated (CA), but few data exist regarding associated risk factors. We conducted a case-control study to evaluate CA-CDI risk factors in young children. Participants were enrolled from eight US sites during October 2014-February 2016. Case-patients were defined as children aged 1-5 years with a positive C. difficile specimen collected as an outpatient or ⩽3 days of hospital admission, who had no healthcare facility admission in the prior 12 weeks and no history of CDI. Each case-patient was matched to one control. Caregivers were interviewed regarding relevant exposures. Multivariable conditional logistic regression was performed. Of 68 pairs, 44.1% were female. More case-patients than controls had a comorbidity (33.3% vs. 12.1%; P = 0.01); recent higher-risk outpatient exposures (34.9% vs. 17.7%; P = 0.03); recent antibiotic use (54.4% vs. 19.4%; P < 0.0001); or recent exposure to a household member with diarrhoea (41.3% vs. 21.5%; P = 0.04). In multivariable analysis, antibiotic exposure in the preceding 12 weeks was significantly associated with CA-CDI (adjusted matched odds ratio, 6.25; 95% CI 2.18-17.96). Improved antibiotic prescribing might reduce CA-CDI in this population. Further evaluation of the potential role of outpatient healthcare and household exposures in C. difficile transmission is needed.

[Evaluating the impact of preoperative anemia on the prognosis of upper tract urothelial carcinoma following radical nephroureterectomy: A single-center retrospective study of 686 patients].

OBJECTIVE: To identify the effect of preoperative anemia on the prognosis of patients with upper tract urothelial carcinoma (UTUC) following radical nephroureterectomy. METHODS: Clinicopathological and prognosis data on 686 patients with UTUC who underwent RNU at Peking University First Hospital between January 2000 and December 2013 were retrospectively analyzed. Preoperative anemia was defined as hemoglobin <130 g/L in men and <120 g/L in women based on the World Health Organization classification. The Kaplan-Meier method with log-rank test was applied to estimate the effect of anemia on survival. The associations of clinicopathologic features with overall survival and cancer-specific survival were evaluated using univariate and multivariate Cox regression models. RESULTS: There were 303(44.2%, 303/686) male and 383(55.8%, 383/686) female patients, and the median age was 68 years (interquartile range: 60-74 years). In all, 320 (46.6%, 320/686) patients were anemic before surgery. The median follow-up duration was 47 months. In all, 160 (23.3%) patients died, 141 (20.6%) died of cancer and 19 (2.7%) died of other disease or accidents. Preoperative anemia was associated with gender (P=0.002), age (P<0.001), lymph node positive (P=0.026), increased tumor grade (P=0.018), concomitant carcinoma in situ (P=0.038), tumor necrosis (P=0.007) and poor renal function (P<0.001). In univariate analysis, overall mortality was correlated with pre-operative anemia (P<0.001), gender (P=0.009), hydronephrosis (P=0.024), tumor stage (P<0.001), lymph node positive (P<0.001), tumor grade (P<0.001), tumor architecture(P<0.001), sarcomatoid differentiation (P=0.013), history of ureteroscope (P=0.033) and tumor hemorrhage (P<0.001); cancer-specific mortality was correlated with preoperative anemia (P=0.001), gender (P=0.001), hydronephrosis (P=0.043), tumor stage (P<0.001), lymph node positive (P<0.001), tumor grade (P<0.001), tumor architecture (P<0.001), sarcomatoid differentiation (P=0.016), history of ureteroscope (P=0.028) and tumor hemorrhage (P=0.003). A multivariate Cox proportional hazards model indicated that preoperative anemia was an independent prognositic predictor for overall mortality (P<0.001, HR=1.861) and cancer-specific mortality (P=0.003, HR=1.688). CONCLUSION: The preoperative anemia is an independent risk factor for cancer-specific survival and overall survival. Hemoglobin levels should be considered during patient counseling and in decision-making for further therapy.

[Endoscopicretrograde cholangio-pancreatography management of long-term complications after pancreaticoduodenectomy].

Objective: To investigate the feasibility and effectiveness of endoscopicretrograde cholangio-pancreatography(ERCP)in the management of long-term complications after pancreaticoduodenectomy. Methods: From January 2009 to July 2018, the clinical data of 62 patients with biliary or pancreatic long-term complications after pancreatoduodenectomy were reviewed at Department of General Surgery, and the corresponding ERCP were carried out in the multi-disciplinary cooperation.There were 39 males and 24 females.The age was 56.5 years(aging from 13 to 76 years). The time of treatment was 3 months to 20 years after pancreatoduodenectomy.The long-term biliopancreatic complications after pancreatoduodenectomy included 51 cases of biliary calculi, 42 cases of bilioenteric anastomotic stenosis with proximal bile duct dilatation, and 11 cases of pancreaticointestinal anastomosis stenosis with distal pancreatic duct dilatation.All patients received conventional duodenoscopy or single-balloon enteroscopy assisted ERCP under general anesthesia. Results: A total of 95 ERCP were performed in 62 patients, averaging 1.5 times per case.The long-term complications of cholangiopancreatic after pancreatoduodenectomy(ERCP indications) included 56 times of bile duct stones(58.9%), 45 times of bilioenteric anastomatic stricture(47.4%), 11 times of recurrent pancreatitis(11.6%), 6 cases(6.3%) of bilioenteric anastomatic foreign body, 3 times of intrahepatic bile duct stenosis(3.2%). Among the 95 times, 82 times(86.3%) achieved endoscopic endoscopy, 76 times(80.0%) were diagnosed successfully, and 72 times(75.8%) were successfully treated with ERCP.Small intestinal perforation occurred in 1 patient undergoing duodenoscopy, and then healed by surgical repair. Conclusion: Multi-disciplinary collaboration of ERCP is safe and effective in the treatment of long-term complications after pancreaticoduodenectomy, but the long-term effect still needs further clinical follow-up.

Blockade of the CXCR6 signaling inhibits growth and invasion of hepatocellular carcinoma cells through inhibition of the VEGF expression.

Chemokines have been shown to play a critical role in tumor development and progression. However, little is known about the function and molecular mechanisms of CXCR6 in multiple malignancies. In the present study, we aimed to investigate the role of CXCR6 in human hepatocellular carcinoma (HCC). The expression of CXCR6 was examined by immunohistochemical assay using a tissue microarray procedure. A loss-of-function experiment was performed to explore the effects of lentivirus-mediated CXCR6 shRNA (shCXCR6) on cell proliferation and invasive potential by MTT and Transwell assays in HCC cell line (SMMC-7721). It was found that the expression of CXCR6 protein was significantly increased in HCC tissues compared with that in adjacent non-cancerous tissues (ANCT) (63.04% vs 36.96%, P=0.019), and correlated with the lymph-vascular space invasion in HCC patients (P=0.038). Knockdown of CXCR6 repressed cell proliferation and invasion of HCC cells followed by the down-regulation of vascular endothelial growth factor (VEGF). Taken together, our findings show that high expression of CXCR6 is positively associated with distant invasion of HCC patients, and blockade of CXCR6 signaling suppresses the growth and invasion of HCC cells through inhibition of the VEGF expression, suggesting that CXCR6 may represent a promising therapeutic target for the treatment of HCC.

Contrasting Modes of New World Arenavirus Neutralization by Immunization-Elicited Monoclonal Antibodies.

Transmission of the New World hemorrhagic fever arenaviruses Junín virus (JUNV) and Machupo virus (MACV) to humans is facilitated, in part, by the interaction between the arenavirus GP1 glycoprotein and the human transferrin receptor 1 (hTfR1). We utilize a mouse model of live-attenuated immunization with envelope exchange viruses to isolate neutralizing monoclonal antibodies (NAbs) specific to JUNV GP1 and MACV GP1. Structures of two NAbs, termed JUN1 and MAC1, demonstrate that they neutralize through disruption of hTfR1 recognition. JUN1 utilizes a binding mode common to all characterized infection- and vaccine-elicited JUNV-specific NAbs, which involves mimicking hTfR1 binding through the insertion of a tyrosine into the receptor-binding site. In contrast, MAC1 undergoes a tyrosine-mediated mode of antigen recognition distinct from that used by the reported anti-JUNV NAbs and the only other characterized anti-MACV NAb. These data reveal the varied modes of GP1-specific recognition among New World arenaviruses by the antibody-mediated immune response. IMPORTANCE The GP1 subcomponent of the New World arenavirus GP is a primary target of the neutralizing antibody response, which has been shown to be effective in the prevention and treatment of infection. Here, we characterize the structural basis of the antibody-mediated immune response that arises from immunization of mice against Junín virus and Machupo virus, two rodent-borne zoonotic New World arenaviruses. We isolate a panel of GP1-specific monoclonal antibodies that recognize overlapping epitopes and exhibit neutralizing behavior, in vitro. Structural characterization of two of these antibodies indicates that antibody recognition likely interferes with GP1-mediated recognition of the transferrin receptor 1. These data provide molecular-level detail for a key region of vulnerability on the New World arenavirus surface and a blueprint for therapeutic antibody development.

Structure of trimeric pre-fusion rabies virus glycoprotein in complex with two protective antibodies.

Rabies virus (RABV) causes lethal encephalitis and is responsible for approximately 60,000 deaths per year. As the sole virion-surface protein, the rabies virus glycoprotein (RABV-G) mediates host-cell entry. RABV-G's pre-fusion trimeric conformation displays epitopes bound by protective neutralizing antibodies that can be induced by vaccination or passively administered for post-exposure prophylaxis. We report a 2.8-Å structure of a RABV-G trimer in the pre-fusion conformation, in complex with two neutralizing and protective monoclonal antibodies, 17C7 and 1112-1, that recognize distinct epitopes. One of these antibodies is a licensed prophylactic (17C7, Rabishield), which we show locks the protein in pre-fusion conformation. Targeted mutations can similarly stabilize RABV-G in the pre-fusion conformation, a key step toward structure-guided vaccine design. These data reveal the higher-order architecture of a key therapeutic target and the structural basis of neutralization by antibodies binding two key antigenic sites, and this will facilitate the development of improved vaccines and prophylactic antibodies.

Eosinophils are necessary for pulmonary arterial remodeling in a mouse model of eosinophilic inflammation-induced pulmonary hypertension.

There is increasing evidence that inflammation plays a pivotal role in the pathogenesis of some forms of pulmonary hypertension (PH). We recently demonstrated that deficiency of adiponectin (APN) in a mouse model of PH induced by eosinophilic inflammation increases pulmonary arterial remodeling, pulmonary pressures, and the accumulation of eosinophils in the lung. Based on these data, we hypothesized that APN deficiency exacerbates PH indirectly by increasing eosinophil recruitment. Herein, we examined the role of eosinophils in the development of inflammation-induced PH. Elimination of eosinophils in APN-deficient mice by treatment with anti-interleukin-5 antibody attenuated pulmonary arterial muscularization and PH. In addition, we observed that transgenic mice that are devoid of eosinophils also do not develop pulmonary arterial muscularization in eosinophilic inflammation-induced PH. To investigate the mechanism by which APN deficiency increased eosinophil accumulation in response to an allergic inflammatory stimulus, we measured expression levels of the eosinophil-specific chemokines in alveolar macrophages isolated from the lungs of mice with eosinophilic inflammation-induced PH. In these experiments, the levels of CCL11 and CCL24 were higher in macrophages isolated from APN-deficient mice than in macrophages from wild-type mice. Finally, we demonstrate that the extracts of eosinophil granules promoted the proliferation of pulmonary arterial smooth muscle cells in vitro. These data suggest that APN deficiency may exacerbate PH, in part, by increasing eosinophil recruitment into the lung and that eosinophils could play an important role in the pathogenesis of inflammation-induced PH. These results may have implications for the pathogenesis and treatment of PH caused by vascular inflammation.

A retrospective study of pulmonary infarction in patients with systemic lupus erythematosus from southern Taiwan.

Since large-scale reports of pulmonary infarction in systemic lupus erythematosus (SLE) are limited, a retrospective study was performed for this manifestation in 773 hospitalized patients in southern Taiwan from 1999 to 2009. Pulmonary infarction was defined as the presence of pulmonary embolism, persistent pulmonary infiltrates, and characteristic clinical symptoms. Demographic, clinical, laboratory, and radiological images data were analyzed. There were 12 patients with pulmonary embolism and 9 of them had antiphospholipid syndrome (APS). Six patients (19 to 53 years, average 38.2 ± 12.6) with 9 episodes of lung infarction were identified. All cases were APS and four episodes had coincidental venous thromboembolism. There were four episodes of bilateral infarction and seven episodes of larger central pulmonary artery embolism. Heparin therapy was routinely prescribed and thrombolytic agents were added in two episodes. Successful recovery was noted in all patients. In conclusion, there was a 0.8% incidence of pulmonary infarction in patients with SLE, all with the risk factor of APS. Differentiation between pulmonary infarction and pneumonia in lupus patients should be made; they have similar chest radiography with lung consolidation but require a different clinical approach in management. Although this report is a retrospective study with relatively small numbers of lupus patients with lung infarcts, our observation might provide beneficial information on the clinical features and radiological presentations during the disease evolution of pulmonary infarction in SLE with APS.

Impact of the B.1.1.7 variant on neutralizing monoclonal antibodies recognizing diverse epitopes on SARS-CoV-2 Spike.

The interaction of the SARS-CoV-2 Spike receptor binding domain (RBD) with the ACE2 receptor on host cells is essential for viral entry. RBD is the dominant target for neutralizing antibodies and several neutralizing epitopes on RBD have been molecularly characterized. Analysis of circulating SARS-CoV-2 variants has revealed mutations arising in the RBD, the N-terminal domain (NTD) and S2 subunits of Spike. To fully understand how these mutations affect the antigenicity of Spike, we have isolated and characterized neutralizing antibodies targeting epitopes beyond the already identified RBD epitopes. Using recombinant Spike as a sorting bait, we isolated >100 Spike-reactive monoclonal antibodies from SARS-CoV-2 infected individuals. ≈45% showed neutralizing activity of which ≈20% were NTD-specific. None of the S2-specific antibodies showed neutralizing activity. Competition ELISA revealed that NTD-specific mAbs formed two distinct groups: the first group was highly potent against infectious virus, whereas the second was less potent and displayed glycan-dependant neutralization activity. Importantly, mutations present in B.1.1.7 Spike frequently conferred resistance to neutralization by the NTD-specific neutralizing antibodies. This work demonstrates that neutralizing antibodies targeting subdominant epitopes need to be considered when investigating antigenic drift in emerging variants.

A retrospective study of catastrophic invasive fungal infections in patients with systemic lupus erythematosus from southern Taiwan.

As very few large scale publications of invasive fungal infection (IFI) have been reported in lupus patients from individual medical centers, a retrospective study was performed from 1988 to 2009 in southern Taiwan. Demographic characteristics, clinical and laboratory data, and mycological examinations were analyzed. Twenty cases with IFI were identified in 2397 patients (0.83% incidence). There were 19 females and one male with an average age of 31.8 +/- 12.6. Involved sites included eight disseminated cases, six central nervous system, four lungs, one abdomen and one soft tissue. IFI contributed to a high mortality with 10 deaths (50%), and there were no survivors for the disseminated cases and Candida-infected patients. High activity (Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) > 8) was noted in 50% of IFI episodes. The survival from IFI diagnosis to death was only 7.7 +/- 4.2 days, all in a rapid course. No statistical difference was found between survivors and non-survivors when comparing their SLEDAI. Eighty-five percent of IFI episodes under high dosages of corticosteroids therapy and 95% of patients had lupus nephritis. There was an increased risk of IFI in the lupus patients receiving high daily dosage of prednisolone therapy. Critical information from analyses of the present large series could be applied into clinical practices to reduce the morbidity and mortality in such patients.

Unraveling virus relationships by structure-based phylogenetic classification.

Delineation of the intricacies of protein function from macromolecular structure constitutes a continual obstacle in the study of cell and pathogen biology. Structure-based phylogenetic analysis has emerged as a powerful tool for addressing this challenge, allowing the detection and quantification of conserved architectural properties between proteins, including those with low or no detectable sequence homology. With a focus on viral protein structure, we highlight how a number of investigations have utilized this powerful method to infer common functionality and ancestry.

Rare coexistence of gouty and septic arthritis: a report of 14 cases.

OBJECTIVES: To analyse the characteristic features of patients with coexistence of gouty arthritis and pyarthrosis at our university hospital in southern Taiwan, an area with high prevalence of hyperuricemia and gout. METHODS: A retrospective chart review was performed for patients who had concomitant gouty and septic arthritis from July 1998 to June 2008. Clinical and laboratory data of these patients were analysed. Furthermore, a comparison was made with published cases in English literature. RESULTS: Fourteen cases with coexistence of gouty arthritis and pyarthrosis have been identified during the past 10 years. There were 13 male and 1 female, all of Han Chinese in ethnicity, with ages ranging from 45 to 85 and an average of 63.7 years. At disease presentation, there were 11 oligoarticular cases (78.6%), 2 monoarticular cases (14.3%) and 1 polyarticular case (7.1%). Ankle and knee joints were most commonly involved. Bacteriological analyses demonstrated gram-positive cocci in 12 cases, of these 10 were oxacillin-sensitive Staphylococcus aureus (71.4%). Multiple tophi deposition was noted in 13 patients (92.9%) and among them 11 patients (84.6%) had associated chronic kidney disease. CONCLUSION: Different clinical presentations and bacteriological characteristics have been identified in the present series. While the mechanisms responsible for such a coexistence remain to be elucidated, these cases underline the importance of thorough evaluation of the aspirated synovial fluid. Our report adds a novel insight into the understanding of the clinical and microbiological manifestations of such a rare concurrence of gouty and septic arthritis.