Embolization of the Pancreas Using Microspheres: A Proof-of-Safety Study in a Porcine Model.

INTRODUCTION: Particle embolization of the pancreas with the intent of producing tissue ischemia has not been evaluated, but could have valuable application in the oncologic realm. A pig model was used to evaluate safety and impact on pancreatic function. METHODS: Embolization of the dorsal pancreatic artery using 100-300-micron particles was performed on fourteen Yorkshire pigs. Baseline and post-embolization glucose tolerance testing and serum amylase/lipase levels were obtained. Pigs were observed for two weeks to assess for behavioral signs of pain/distress, bowel changes, and changes to intake/output. After two weeks, euthanasia and necropsy with gross and histopathologic assessment of the pancreas was performed. RESULTS: Embolization was technically successful in all pigs. All animals survived the two-week follow up without evidence of pain/distress. There were significant increases in amylase and lipase at 24- and 48-hours (p < 0.001), which normalized by two weeks. There clinically significant change in glucose tolerance testing at 2 weeks. Bowel habits were unchanged without diarrhea. At necropsy, all examined pancreases had fibrosis in the distal body and tail, without gross evidence of ongoing inflammation. On histopathologic evaluation, all pancreases demonstrated fibrosis in the embolized portions without evidence of active inflammation in treated or adjacent pancreatic tissue. CONCLUSION: Particle embolization of the pancreas was feasible and tolerated by all tested pigs with transient amylasemia, lipasemia, and mildly impaired glucose tolerance, but without clinical or histopathologic evidence of acute pancreatitis and no evident impact on pancreatic endocrine or exocrine function.

An Investigation of Cancer-Directed Surgery for Different Histologic Subtypes of Malignant Pleural Mesothelioma.

BACKGROUND: The role of cancer-directed surgery in the treatment of stage I-IIIA malignant pleural mesothelioma (MPM) by histologic subtypes remains controversial. The objective of this study was to evaluate the survival of the different histologic subtypes for stage I-IIIA MPM stratified by cancer-directed surgery and nonoperative management. RESEARCH QUESTION: How is the histologic subtype, clinical stage, and use of cancer-directed surgery for MPM associated with overall survival? STUDY DESIGN AND METHODS: Overall survival of patients with stage I-IIIA epithelioid, sarcomatoid, and biphasic MPM in the National Cancer Database from 2004 through 2017 who underwent cancer-directed surgery (ie, surgery with or without chemotherapy or radiation) or chemotherapy with or without radiation (nonoperative management) was evaluated using Kaplan-Meier analysis, multivariable Cox proportional hazards analysis, and propensity score-matched analysis. RESULTS: Of 2,285 patients with stage I-IIIA MPM who met inclusion criteria, histologic subtype was epithelioid in 71% of patients, sarcomatoid in 12% of patients, and biphasic in 17% of patients. Median survival was 20 months in the epithelioid group, 8 months in the sarcomatoid group, and 13 months in the biphasic group (P < .01). Among patients who underwent surgery, median survival was 25 months in the epithelioid group, 8 months in the sarcomatoid group, and 15 months in the biphasic group (P < .01). In multivariable Cox proportional hazards analyses, surgery was associated with improved survival in the epithelioid group (P < .01) but not in the sarcomatoid (P = .63) or biphasic (P = .21) groups. These findings were consistent in propensity score-matched analyses for each MPM histologic type. INTERPRETATION: In this national analysis, cancer-directed surgery was found to be associated with improved survival for stage I-IIIA epithelioid MPM, but not for biphasic or sarcomatoid MPM.

Fab-dimerized glycan-reactive antibodies are a structural category of natural antibodies.

Natural antibodies (Abs) can target host glycans on the surface of pathogens. We studied the evolution of glycan-reactive B cells of rhesus macaques and humans using glycosylated HIV-1 envelope (Env) as a model antigen. 2G12 is a broadly neutralizing Ab (bnAb) that targets a conserved glycan patch on Env of geographically diverse HIV-1 strains using a unique heavy-chain (VH) domain-swapped architecture that results in fragment antigen-binding (Fab) dimerization. Here, we describe HIV-1 Env Fab-dimerized glycan (FDG)-reactive bnAbs without VH-swapped domains from simian-human immunodeficiency virus (SHIV)-infected macaques. FDG Abs also recognized cell-surface glycans on diverse pathogens, including yeast and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike. FDG precursors were expanded by glycan-bearing immunogens in macaques and were abundant in HIV-1-naive humans. Moreover, FDG precursors were predominately mutated IgM+IgD+CD27+, thus suggesting that they originated from a pool of antigen-experienced IgM+ or marginal zone B cells.

A glycan cluster on the SARS-CoV-2 spike ectodomain is recognized by Fab-dimerized glycan-reactive antibodies.

The COVID-19 pandemic caused by SARS-CoV-2 has escalated into a global crisis. The spike (S) protein that mediates cell entry and membrane fusion is the current focus of vaccine and therapeutic antibody development efforts. The S protein, like many other viral fusion proteins such as HIV-1 envelope (Env) and influenza hemagglutinin, is glycosylated with both complex and high mannose glycans. Here we demonstrate binding to the SARS-CoV-2 S protein by a category of Fab-dimerized glycan-reactive (FDG) HIV-1-induced broadly neutralizing antibodies (bnAbs). A 3.1 Å resolution cryo-EM structure of the S protein ectodomain bound to glycan-dependent HIV-1 bnAb 2G12 revealed a quaternary glycan epitope on the spike S2 domain involving multiple protomers. These data reveal a new epitope on the SARS-CoV-2 spike that can be targeted for vaccine design. HIGHLIGHTS: Fab-dimerized, glycan-reactive (FDG) HIV-1 bnAbs cross-react with SARS-CoV-2 spike.3.1 Å resolution cryo-EM structure reveals quaternary S2 epitope for HIV-1 bnAb 2G12.2G12 targets glycans, at positions 709, 717 and 801, in the SARS-CoV-2 spike.Our studies suggest a common epitope for FDG antibodies centered around glycan 709.

The role of thoracoscopic pneumonectomy in the management of non-small cell lung cancer: A multicenter study.

OBJECTIVE: The objective of this study was to evaluate the impact of the video-assisted thoracoscopic (VATS) approach on the outcomes of patients who underwent pneumonectomy. METHODS: The effect of the surgical approach on perioperative complications and survival in patients who underwent pneumonectomy for nonmetastatic non-small cell lung cancer across 3 institutions (2000-2016) was assessed using multivariable logistic regression, Cox proportional hazards analysis, and propensity-score matching. Completion pneumonectomies were excluded from this study, and an "intent-to-treat" analysis was performed. RESULTS: During the study period, 359 patients met inclusion criteria and underwent pneumonectomy for nonmetastatic non-small cell lung cancer; 124 (35%) underwent pneumonectomy via VATS and 235 (65%) via thoracotomy. Perioperative mortality (VATS, 7% [n = 9] vs open, 8% [n = 19]; P = .75) and morbidity (VATS, 28% [n = 35] vs open, 28% [n = 65]; P = .91) were similar between the groups, even after multivariable adjustment. VATS showed similar 5-year survival when compared with thoracotomy in unadjusted analysis (47% [95% confidence interval (CI), 36-56] vs 33% [95% CI, 27-40]; P = .19), even after multivariable adjustment (hazard ratio, 0.76 [95% CI, 0.50-1.18]; P = .23). In a propensity score-matched analysis that balanced patient characteristics, there were no significant differences found in overall survival between the 2 groups (P = .69). CONCLUSIONS: Although the role of VATS pneumonectomy will likely become clearer as more surgeons report results, this multicenter study suggests that the VATS approach for pneumonectomy can be performed safely, with at least equivalent oncologic outcomes when compared with thoracotomy.

Functional Relevance of Improbable Antibody Mutations for HIV Broadly Neutralizing Antibody Development.

HIV-1 broadly neutralizing antibodies (bnAbs) require high levels of activation-induced cytidine deaminase (AID)-catalyzed somatic mutations for optimal neutralization potency. Probable mutations occur at sites of frequent AID activity, while improbable mutations occur where AID activity is infrequent. One bottleneck for induction of bnAbs is the evolution of viral envelopes (Envs) that can select bnAb B cell receptors (BCR) with improbable mutations. Here we define the probability of bnAb mutations and demonstrate the functional significance of key improbable mutations in three bnAb B cell lineages. We show that bnAbs are enriched for improbable mutations, which implies that their elicitation will be critical for successful vaccine induction of potent bnAb B cell lineages. We discuss a mutation-guided vaccine strategy for identification of Envs that can select B cells with BCRs that have key improbable mutations required for bnAb development.

HIV envelope V3 region mimic embodies key features of a broadly neutralizing antibody lineage epitope.

HIV-1 envelope (Env) mimetics are candidate components of prophylactic vaccines and potential therapeutics. Here we use a synthetic V3-glycopeptide ("Man9-V3") for structural studies of an HIV Env third variable loop (V3)-glycan directed, broadly neutralizing antibody (bnAb) lineage ("DH270"), to visualize the epitope on Env and to study how affinity maturation of the lineage proceeded. Unlike many previous V3 mimetics, Man9-V3 encompasses two key features of the V3 region recognized by V3-glycan bnAbs-the conserved GDIR motif and the N332 glycan. In our structure of an antibody fragment of a lineage member, DH270.6, in complex with the V3 glycopeptide, the conformation of the antibody-bound glycopeptide conforms closely to that of the corresponding segment in an intact HIV-1 Env trimer. An additional structure identifies roles for two critical mutations in the development of breadth. The results suggest a strategy for use of a V3 glycopeptide as a vaccine immunogen.

Vaccine Elicitation of High Mannose-Dependent Neutralizing Antibodies against the V3-Glycan Broadly Neutralizing Epitope in Nonhuman Primates.

Induction of broadly neutralizing antibodies (bnAbs) that target HIV-1 envelope (Env) is a goal of HIV-1 vaccine development. A bnAb target is the Env third variable loop (V3)-glycan site. To determine whether immunization could induce antibodies to the V3-glycan bnAb binding site, we repetitively immunized macaques over a 4-year period with an Env expressing V3-high mannose glycans. Env immunizations elicited plasma antibodies that neutralized HIV-1 expressing only high-mannose glycans-a characteristic shared by early bnAb B cell lineage members. A rhesus recombinant monoclonal antibody from a vaccinated macaque bound to the V3-glycan site at the same amino acids as broadly neutralizing antibodies. A structure of the antibody bound to glycan revealed that the three variable heavy-chain complementarity-determining regions formed a cavity into which glycan could insert and neutralized multiple HIV-1 isolates with high-mannose glycans. Thus, HIV-1 Env vaccination induced mannose-dependent antibodies with characteristics of V3-glycan bnAb precursors.

HIV-1 Consensus Envelope-Induced Broadly Binding Antibodies.

Antibodies that cross-react with multiple HIV-1 envelopes (Envs) are useful reagents for characterizing Env proteins and for soluble Env capture and purification assays. We previously reported 10 murine monoclonal antibodies induced by group M consensus Env, CON-6 immunization. Each demonstrated broad cross-reactivity to recombinant Envs. Here we characterized the Env epitopes to which they bind. Seven mapped to linear epitopes in gp120, five at the Env N-terminus, and two at the Env C-terminus. One antibody, 13D7, bound at the gp120 N-terminus (aa 30-42), reacted with HIV-1-infected CD4+ T cells, and when expressed in a human IgG1 backbone, mediated antibody-dependent cellular cytotoxicity. Antibody 18F11 bound at the gp120 C-terminus (aa 445-459) and reactivity was glycan dependent. Antibodies 13D7, 3B3, and 16H3 bound to 100 percent of HIV-1 Envs tested in ELISA and sodium dodecyl sulfate/polyacrylamide gel electrophoresis/western blot analysis. These data define the epitopes of monoclonal antibody reagents for characterization of recombinant Envs, one epitope of which is also expressed on the surface of HIV-1-infected CD4+ T cells.

Staged induction of HIV-1 glycan-dependent broadly neutralizing antibodies.

A preventive HIV-1 vaccine should induce HIV-1-specific broadly neutralizing antibodies (bnAbs). However, bnAbs generally require high levels of somatic hypermutation (SHM) to acquire breadth, and current vaccine strategies have not been successful in inducing bnAbs. Because bnAbs directed against a glycosylated site adjacent to the third variable loop (V3) of the HIV-1 envelope protein require limited SHM, the V3-glycan epitope is an attractive vaccine target. By studying the cooperation among multiple V3-glycan B cell lineages and their coevolution with autologous virus throughout 5 years of infection, we identify key events in the ontogeny of a V3-glycan bnAb. Two autologous neutralizing antibody lineages selected for virus escape mutations and consequently allowed initiation and affinity maturation of a V3-glycan bnAb lineage. The nucleotide substitution required to initiate the bnAb lineage occurred at a low-probability site for activation-induced cytidine deaminase activity. Cooperation of B cell lineages and an improbable mutation critical for bnAb activity defined the necessary events leading to breadth in this V3-glycan bnAb lineage. These findings may, in part, explain why initiation of V3-glycan bnAbs is rare, and suggest an immunization strategy for inducing similar V3-glycan bnAbs.

Mimicry of an HIV broadly neutralizing antibody epitope with a synthetic glycopeptide.

A goal for an HIV-1 vaccine is to overcome virus variability by inducing broadly neutralizing antibodies (bnAbs). One key target of bnAbs is the glycan-polypeptide at the base of the envelope (Env) third variable loop (V3). We have designed and synthesized a homogeneous minimal immunogen with high-mannose glycans reflective of a native Env V3-glycan bnAb epitope (Man9-V3). V3-glycan bnAbs bound to Man9-V3 glycopeptide and native-like gp140 trimers with similar affinities. Fluorophore-labeled Man9-V3 glycopeptides bound to bnAb memory B cells and were able to be used to isolate a V3-glycan bnAb from an HIV-1-infected individual. In rhesus macaques, immunization with Man9-V3 induced V3-glycan-targeted antibodies. Thus, the Man9-V3 glycopeptide closely mimics an HIV-1 V3-glycan bnAb epitope and can be used to isolate V3-glycan bnAbs.

Long-Term Outcomes of Lobectomy for Non-Small Cell Lung Cancer After Definitive Radiation Treatment.

BACKGROUND: Salvage surgical resection for non-small cell lung cancer (NSCLC) patients initially treated with definitive chemotherapy and radiotherapy can be performed safely, but the long-term benefits are not well characterized. METHODS: Perioperative complications and long-term survival of all patients with NSCLC who received curative-intent definitive radiotherapy, with or without chemotherapy, followed by lobectomy from 1995 to 2012 were evaluated. RESULTS: During the study period, 31 patients met the inclusion criteria. Clinical stage distribution was stage I in 2 (6%), stage II in 5 (16%), stage IIIA in 15 (48%), stage IIIB in 5 (16%), stage IV in 3 (10%), and unknown in 1 (3%). The reasons surgical resection was initially not considered were: patients deemed medically inoperable (5 [16%]); extent of disease was considered unresectable (21 [68%]); small cell lung cancer misdiagnosis (1 [3%]), and unknown (4 [13%]). Definitive therapy was irradiation alone in 2 (6%), concurrent chemoradiotherapy in 28 (90%), and sequential chemoradiotherapy in 1 (3%). The median radiation dose was 60 Gy. Patients were subsequently referred for resection because of obvious local relapse, medical tolerance of surgical intervention, or posttherapy imaging suggesting residual disease. The median time from radiation to lobectomy was 17.7 weeks. There were no perioperative deaths, and morbidity occurred in 15 patients (48%). None of the 3 patients with residual pathologic nodal disease survived longer than 37 months, but the 5-year survival of pN0 patients was 36%. Patients who underwent lobectomy for obvious relapse (n = 3) also did poorly, with a median overall survival of 9 months. CONCLUSIONS: Lobectomy after definitive radiotherapy can be done safely and is associated with reasonable long-term survival, particularly when patients do not have residual nodal disease.

Toll-like receptor 7/8 (TLR7/8) and TLR9 agonists cooperate to enhance HIV-1 envelope antibody responses in rhesus macaques.

UNLABELLED: The development of a vaccine that can induce high titers of functional antibodies against HIV-1 remains a high priority. We have developed an adjuvant based on an oil-in-water emulsion that incorporates Toll-like receptor (TLR) ligands to test whether triggering multiple pathogen-associated molecular pattern receptors could enhance immunogenicity. Compared to single TLR agonists or other pairwise combinations, TLR7/8 and TLR9 agonists combined were able to elicit the highest titers of binding, neutralizing, and antibody-dependent cellular cytotoxicity-mediating antibodies against the protein immunogen, transmitted/founder HIV-1 envelope gp140 (B.63521). We further found that the combination of TLR7/8 and TLR9 agonists was associated with the release of CXCL10 (IP-10), suggesting that this adjuvant formulation may have optimally stimulated innate and adaptive immunity to elicit high titers of antibodies. IMPORTANCE: Combining TLR agonists in an adjuvant formulation resulted in higher antibody levels compared to an adjuvant without TLR agonists. Adjuvants that combine TLR agonists may be useful for enhancing antibody responses to HIV-1 vaccines.

HIV-1 gp120 vaccine induces affinity maturation in both new and persistent antibody clonal lineages.

Most antibodies that broadly neutralize HIV-1 are highly somatically mutated in antibody clonal lineages that persist over time. Here, we describe the analysis of human antibodies induced during an HIV-1 vaccine trial (GSK PRO HIV-002) that used the clade B envelope (Env) gp120 of clone W6.1D (gp120(W6.1D)). Using dual-color antigen-specific sorting, we isolated Env-specific human monoclonal antibodies (MAbs) and studied the clonal persistence of antibodies in the setting of HIV-1 Env vaccination. We found evidence of V(H) somatic mutation induced by the vaccine but only to a modest level (3.8% ± 0.5%; range 0 to 8.2%). Analysis of 34 HIV-1-reactive MAbs recovered over four immunizations revealed evidence of both sequential recruitment of naïve B cells and restimulation of previously recruited memory B cells. These recombinant antibodies recapitulated the anti-HIV-1 activity of participant serum including pseudovirus neutralization and antibody-dependent cell-mediated cytotoxicity (ADCC). One antibody (3491) demonstrated a change in specificity following somatic mutation with binding of the inferred unmutated ancestor to a linear C2 peptide while the mutated antibody reacted only with a conformational epitope in gp120 Env. Thus, gp120(W6.1D) was strongly immunogenic but over four immunizations induced levels of affinity maturation below that of broadly neutralizing MAbs. Improved vaccination strategies will be needed to drive persistent stimulation of antibody clonal lineages to induce affinity maturation that results in highly mutated HIV-1 Env-reactive antibodies.

Characterization of turkey inducible nitric oxide synthase and identification of its expression in the intestinal epithelium following astrovirus infection.

The inducible nitric oxide synthase (iNOS) enzyme has long been recognized as a key mediator of innate immune responses to infectious diseases across the phyla. Its role in killing or inactivating bacterial, parasitic, and viral pathogens has been documented in numerous host systems. iNOS, and its innate immune mediator NO has also been described to have negative consequence on host tissues as well; therefore understanding the pathogenesis of any infectious agent which induces iNOS expression requires a better understanding of the role iNOS and NO play in that disease. Previous studies in our laboratory and others have demonstrated evidence for increased levels of iNOS and activity of its innate immune mediator NO in the intestine of turkeys infected with astrovirus. To begin to characterize the role iNOS plays in the innate immune response to astrovirus infection, we identified, characterized, developed tkiNOS specific reagents, and demonstrated that the intestinal epithelial cells induce expression of iNOS following astrovirus infection. These data are the first to our knowledge to describe the tkiNOS gene, and demonstrate that astrovirus infection induces intestinal epithelial cells to express iNOS, suggesting these cells play a key role in the antiviral response to enteric infections.

H3N2 influenza infection elicits more cross-reactive and less clonally expanded anti-hemagglutinin antibodies than influenza vaccination.

BACKGROUND: During the recent H1N1 influenza pandemic, excess morbidity and mortality was seen in young but not older adults suggesting that prior infection with influenza strains may have protected older subjects. In contrast, a history of recent seasonal trivalent vaccine in younger adults was not associated with protection. METHODS AND FINDINGS: To study hemagglutinin (HA) antibody responses in influenza immunization and infection, we have studied the day 7 plasma cell repertoires of subjects immunized with seasonal trivalent inactivated influenza vaccine (TIV) and compared them to the plasma cell repertoires of subjects experimentally infected (EI) with influenza H3N2 A/Wisconsin/67/2005. The majority of circulating plasma cells after TIV produced influenza-specific antibodies, while most plasma cells after EI produced antibodies that did not react with influenza HA. While anti-HA antibodies from TIV subjects were primarily reactive with single or few HA strains, anti-HA antibodies from EI subjects were isolated that reacted with multiple HA strains. Plasma cell-derived anti-HA antibodies from TIV subjects showed more evidence of clonal expansion compared with antibodies from EI subjects. From an H3N2-infected subject, we isolated a 4-member clonal lineage of broadly cross-reactive antibodies that bound to multiple HA subtypes and neutralized both H1N1 and H3N2 viruses. This broad reactivity was not detected in post-infection plasma suggesting this broadly reactive clonal lineage was not immunodominant in this subject. CONCLUSION: The presence of broadly reactive subdominant antibody responses in some EI subjects suggests that improved vaccine designs that make broadly reactive antibody responses immunodominant could protect against novel influenza strains.