A bacterial toxin co-opts caspase-3 to disable active gasdermin D and limit macrophage pyroptosis

During infections, host cells are exposed to pathogen-associated molecular patterns (PAMPs) and virulence factors that stimulate multiple signaling pathways that interact additively, synergistically, or antagonistically. The net effect of such higher-order interactions is a vital determinant of the outcome of host-pathogen interactions. Here, we demonstrate one such complex interplay between bacterial exotoxin- and PAMP-induced innate immune pathways. We show that two caspases activated during enterohemorrhagic Escherichia coli (EHEC) infection by lipopolysaccharide (LPS) and Shiga toxin (Stx) interact in a functionally antagonistic manner; cytosolic LPS-activated caspase-11 cleaves full-length gasdermin D (GSDMD), generating an active pore-forming N-terminal fragment (NT-GSDMD); subsequently, caspase-3 activated by EHEC Stx cleaves the caspase-11-generated NT-GSDMD to render it nonfunctional, thereby inhibiting pyroptosis and interleukin-1β maturation. Bacteria typically subvert inflammasomes by targeting upstream components such as NLR sensors or full-length GSDMD but not active NT-GSDMD. Thus, our findings uncover a distinct immune evasion strategy where a bacterial toxin disables active NT-GSDMD by co-opting caspase-3.

NLRP inflammasomes in health and disease

NLRP inflammasomes are a group of cytosolic multiprotein oligomer pattern recognition receptors (PRRs) involved in the recognition of pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs) produced by infected cells. They regulate innate immunity by triggering a protective inflammatory response. However, despite their protective role, aberrant NLPR inflammasome activation and gain-of-function mutations in NLRP sensor proteins are involved in occurrence and enhancement of non-communicating autoimmune, auto-inflammatory, and neurodegenerative diseases. In the last few years, significant advances have been achieved in the understanding of the NLRP inflammasome physiological functions and their molecular mechanisms of activation, as well as therapeutics that target NLRP inflammasome activity in inflammatory diseases. Here, we provide the latest research progress on NLRP inflammasomes, including NLRP1, CARD8, NLRP3, NLRP6, NLRP7, NLRP2, NLRP9, NLRP10, and NLRP12 regarding their structural and assembling features, signaling transduction and molecular activation mechanisms. Importantly, we highlight the mechanisms associated with NLRP inflammasome dysregulation involved in numerous human auto-inflammatory, autoimmune, and neurodegenerative diseases. Overall, we summarize the latest discoveries in NLRP biology, their forming inflammasomes, and their role in health and diseases, and provide therapeutic strategies and perspectives for future studies about NLRP inflammasomes.

The HIV capsid mimics karyopherin engagement of FG-nucleoporins

HIV can infect non-dividing cells because the viral capsid can overcome the selective barrier of the nuclear pore complex and deliver the genome directly into the nucleus1,2. Remarkably, the intact HIV capsid is more than 1,000 times larger than the size limit prescribed by the diffusion barrier of the nuclear pore3. This barrier in the central channel of the nuclear pore is composed of intrinsically disordered nucleoporin domains enriched in phenylalanine-glycine (FG) dipeptides. Through multivalent FG interactions, cellular karyopherins and their bound cargoes solubilize in this phase to drive nucleocytoplasmic transport4. By performing an in vitro dissection of the nuclear pore complex, we show that a pocket on the surface of the HIV capsid similarly interacts with FG motifs from multiple nucleoporins and that this interaction licences capsids to penetrate FG-nucleoporin condensates. This karyopherin mimicry model addresses a key conceptual challenge for the role of the HIV capsid in nuclear entry and offers an explanation as to how an exogenous entity much larger than any known cellular cargo may be able to non-destructively breach the nuclear envelope.

An ancient defense mechanism: Conservation of gasdermin-mediated pyroptosis

The gasdermins are a family of pore-forming proteins involved in various cellular processes such as cell death and inflammation. A new study in PLOS Biology explores the evolutionary history of gasdermins across metazoans, highlighting the conservation and divergence of gasdermin E.

Structural basis for GSDMB pore formation and its targeting by IpaH7.8

Gasdermins (GSDMs) are pore-forming proteins that play critical roles in host defence through pyroptosis1,2. Among GSDMs, GSDMB is unique owing to its distinct lipid-binding profile and a lack of consensus on its pyroptotic potential3-7. Recently, GSDMB was shown to exhibit direct bactericidal activity through its pore-forming activity4. Shigella, an intracellular, human-adapted enteropathogen, evades this GSDMB-mediated host defence by secreting IpaH7.8, a virulence effector that triggers ubiquitination-dependent proteasomal degradation of GSDMB4. Here, we report the cryogenic electron microscopy structures of human GSDMB in complex with Shigella IpaH7.8 and the GSDMB pore. The structure of the GSDMB-IpaH7.8 complex identifies a motif of three negatively charged residues in GSDMB as the structural determinant recognized by IpaH7.8. Human, but not mouse, GSDMD contains this conserved motif, explaining the species specificity of IpaH7.8. The GSDMB pore structure shows the alternative splicing-regulated interdomain linker in GSDMB as a regulator of GSDMB pore formation. GSDMB isoforms with a canonical interdomain linker exhibit normal pyroptotic activity whereas other isoforms exhibit attenuated or no pyroptotic activity. Overall, this work sheds light on the molecular mechanisms of Shigella IpaH7.8 recognition and targeting of GSDMs and shows a structural determinant in GSDMB critical for its pyroptotic activity.

3D Artificial Array Interface Engineering Enabling Dendrite-Free Stable Zn Metal Anode

The ripple effect induced by uncontrollable Zn deposition is considered as the Achilles heel for developing high-performance aqueous Zn-ion batteries. For this problem, this work reports a design concept of 3D artificial array interface engineering to achieve volume stress elimination, preferred orientation growth and dendrite-free stable Zn metal anode. The mechanism of MXene array interface on modulating the growth kinetics and deposition behavior of Zn atoms were firstly disclosed on the multi-scale level, including the in-situ optical microscopy and transient simulation at the mesoscopic scale, in-situ Raman spectroscopy and in-situ X-ray diffraction at the microscopic scale, as well as density functional theory calculation at the atomic scale. As indicated by the electrochemical performance tests, such engineered electrode exhibits the comprehensive enhancements not only in the resistance of corrosion and hydrogen evolution, but also the rate capability and cyclic stability. High-rate performance (20 mA cm-2) and durable cycle lifespan (1350 h at 0.5 mA cm-2, 1500 h at 1 mA cm-2 and 800 h at 5 mA cm-2) can be realized. Moreover, the improvement of rate capability (214.1 mAh g-1 obtained at 10 A g-1) and cyclic stability also can be demonstrated in the case of 3D MXene array@Zn/VO2 battery. Beyond the previous 2D closed interface engineering, this research offers a unique 3D open array interface engineering to stabilize Zn metal anode, the controllable Zn deposition mechanism revealed is also expected to deepen the fundamental of rechargeable batteries including but not limited to aqueous Zn metal batteries.

Nexinhib20 Inhibits Neutrophil Adhesion and β2 Integrin Activation by Antagonizing Rac-1-Guanosine 5'-Triphosphate Interaction

Neutrophils are critical for mediating inflammatory responses. Inhibiting neutrophil recruitment is an attractive approach for preventing inflammatory injuries, including myocardial ischemia-reperfusion (I/R) injury, which exacerbates cardiomyocyte death after primary percutaneous coronary intervention in acute myocardial infarction. In this study, we found out that a neutrophil exocytosis inhibitor Nexinhib20 inhibits not only exocytosis but also neutrophil adhesion by limiting β2 integrin activation. Using a microfluidic chamber, we found that Nexinhib20 inhibited IL-8-induced β2 integrin-dependent human neutrophil adhesion under flow. Using a dynamic flow cytometry assay, we discovered that Nexinhib20 suppresses intracellular calcium flux and β2 integrin activation after IL-8 stimulation. Western blots of Ras-related C3 botulinum toxin substrate 1 (Rac-1)-GTP pull-down assays confirmed that Nexinhib20 inhibited Rac-1 activation in leukocytes. An in vitro competition assay showed that Nexinhib20 antagonized the binding of Rac-1 and GTP. Using a mouse model of myocardial I/R injury, Nexinhib20 administration after ischemia and before reperfusion significantly decreased neutrophil recruitment and infarct size. Our results highlight the translational potential of Nexinhib20 as a dual-functional neutrophil inhibitory drug to prevent myocardial I/R injury.

Experimental demonstration of optical stochastic cooling

Particle accelerators and storage rings have been transformative instruments of discovery, and, for many applications, innovations in particle-beam cooling have been a principal driver of that success¹. Stochastic cooling (SC), one of the most important conceptual and technological advances in this area^2–6, cools a beam through granular sampling and correction of its phase-space structure, thus bearing resemblance to a ‘Maxwell’s demon’. The extension of SC from the microwave regime up to optical frequencies and bandwidths has long been pursued, as it could increase the achievable cooling rates by three to four orders of magnitude and provide a powerful tool for future accelerators. First proposed nearly 30 years ago, optical stochastic cooling (OSC) replaces the conventional microwave elements of SC with optical-frequency analogues and is, in principle, compatible with any species of charged-particle beam^7,8. Here we describe a demonstration of OSC in a proof-of-principle experiment at the Fermi National Accelerator Laboratory’s Integrable Optics Test Accelerator^9,10. The experiment used 100-MeV electrons and a non-amplified configuration of OSC with a radiation wavelength of 950 nm, and achieved strong, simultaneous cooling of the beam in all degrees of freedom. This realization of SC at optical frequencies serves as a foundation for more advanced experiments with high-gain optical amplification, and advances opportunities for future operational OSC systems with potential benefit to a broad user community in the accelerator-based sciences.

Stochastic cooling at optical frequencies is demonstrated in an experiment at the Fermi National Accelerator Laboratory’s Integrable Optics Test Accelerator, substantially increasing the bandwidth of stochastic cooling compared with conventional systems.

Nexinhib20 inhibits neutrophil adhesion and β2 integrin activation to prevent myocardial ischemia-reperfusion injury

Primary percutaneous coronary intervention (PPCI)—a therapy intended to restore blood flow after acute myocardial infarction—can also induce myocardial ischemia-reperfusion (I/R) injury, exacerbating cardiomyocyte death. Neutrophil-mediated cardiac tissue damage contributes prominently to the process of myocardial I/R injury. Therefore, limiting neutrophil recruitment and exocytosis may prevent myocardial I/R injury after PPCI. Here, we found out that a neutrophil exocytosis inhibitor Nexinhib20 inhibits both neutrophil adhesion and exocytosis and prevents myocardial I/R injury in a mouse model. Using a microfluidic chamber, we found that Nexinhib20 inhibited interleukin 8 (IL-8)-induced β2 integrin-dependent human neutrophil adhesion under flow. Using dynamic flow cytometry assay, we discovered that Nexinhib20 suppresses intracellular calcium flux and β2 integrin activation after IL-8 stimulation. Western blots of Rac-1-GTP pull-down assay confirmed that Nexinhib20 inhibited Rac-1 activation in leukocytes. In vitro competing assay showed that Nexinhib20 antagonized the binding of Rac-1 and GTP. Using a mouse model of myocardial I/R injury, Nexinhib20 administration after ischemia and before reperfusion significantly decreased neutrophil recruitment and infarct size. Our results highlight the translational potential of Nexinhib20 as a dual-functional neutrophil inhibitory drug to prevent myocardial I/R injury.

This research was supported by grants from the National Institutes of Health, National Heart, Lung, and Blood Institute, USA (R01HL145454, R41HL156322, R44HL152710, and K99HL153678), a Career Development Award from American Heart Association (18CDA34110426), and a startup fund from UConn Health.

Emerging enterococcus pore-forming toxins with MHC/HLA-I as receptors

Enterococci are a part of human microbiota and a leading cause of multidrug resistant infections. Here, we identify a family of Enterococcus pore-forming toxins (Epxs) in E. faecalis, E. faecium, and E. hirae strains isolated across the globe. Structural studies reveal that Epxs form a branch of β-barrel pore-forming toxins with a β-barrel protrusion (designated the top domain) sitting atop the cap domain. Through a genome-wide CRISPR-Cas9 screen, we identify human leukocyte antigen class I (HLA-I) complex as a receptor for two members (Epx2 and Epx3), which preferentially recognize human HLA-I and homologous MHC-I of equine, bovine, and porcine, but not murine, origin. Interferon exposure, which stimulates MHC-I expression, sensitizes human cells and intestinal organoids to Epx2 and Epx3 toxicity. Co-culture with Epx2-harboring E. faecium damages human peripheral blood mononuclear cells and intestinal organoids, and this toxicity is neutralized by an Epx2 antibody, demonstrating the toxin-mediated virulence of Epx-carrying Enterococcus.

[SARS-CoV-2 with transcription regulatory sequence motif mutation poses a greater threat]

OBJECTIVE

To analyze the mutations in transcription regulatory sequences (TRSs) of coronaviruss (CoV) to provide the basis for exploring the patterns of SARS-CoV-2 transmission and outbreak.

METHODS

A combined evolutionary and molecular functional analysis of all sets of publicly available genomic data of viruses was performed.

RESULTS

A leader transcription regulatory sequence (TRS-L) usually comprises the first 60-70 nts of the 5' UTR in a CoV genome, and the body transcription regulatory sequences (TRS-Bs) are located immediately upstream of the genes other than ORF1a and 1b. In each CoV genome, the TRS-L and TRS-Bs share a specific consensus sequence, namely the TRS motif. Any changes of nucleotide residues in the TRS motifs are defined as TRS motif mutations. Mutations in the TRS-L or multiple TRS-Bs result in superattenuated variants. The spread of super-attenuated variants may cause an increase in asymptomatic or mild infections, prolonged incubation periods and a decreased detection rate of the viruses, thus posing new challenges to SARS-CoV-2 prevention and control. The super-attenuated variants also increase their possibility of long-term coexistence with humans. The Delta variant is significantly different from all the previous variants and may lead to a large-scale transmission. The Delta variant (B.1.617.2) with TRS motif mutation has already appeared and shown signs of spreading in Singapore, which, and even the Southeast Asia, may become the new epicenter of the next wave of SARS-CoV-2 outbreak.

CONCLUSION

TRS motif mutation will occur in all variants of SARS-CoV-2 and may result in super-attenuated variants. Only super-attenuated variants with TRS motif mutations will eventually lose the abilities of cross-species transmission and causing outbreaks.

Results of a hybrid cardiovascular rehabilitation program (in-hospital plus home) in patients with low income

Background

One of the main problems facing cardiovascular rehabilitation (CR) is patient care and adherence. However, due to the low level of economic income of the patients who are cared for in our center, the possibility of going to CR in a conventional way is very difficult since they do not have the necessary resources to cover transportation, cost of the sessions, among others.

It has been shown that the greater the number of sessions attended by the patient, the greater the reduction in cardiovascular risk, however the role of a hybrid program with a decreased number of face-to-face sessions has not been established.

Purpose

Present the results of a hybrid training program (in-hospital plus home) in a low-income population. Education through supervised sessions plus home physical training in a patient with bases for exercise can improve their adherence with better results.

Methods

A cohort of patients with heart disease who were referred to the Cardiovascular Rehabilitation program between May 2017 and February 2019 was included. The socioeconomic level was classified into 6 strata according to occupation, income, housing, economic dependents, place of origin and family health status. After risk stratification, the patients participated in a hybrid program that consisted of 6 in-hospital sessions, once a week, in which the training to be carried out at home was prescribed by means of a triptych. An exercise test was performed before and after completing the program, as well as psychological and nutritional intervention. Statistical analysis was performed using SPSS 21.0 software. All p values less than 0.05 were considered significant.

Results

In the study period, of the total number of patients discharged for heart disease from the hospital, 61% were referred to cardiovascular rehabilitation, of which only 45% (n=39) completed the program, the reasons for dropping out were multiple and the lowest socioeconomic level (1) was the most frequent (figure 1). The main referral diagnosis was ischemic heart disease in 82%. The majority of patients were men, 95%. A significant improvement was observed in load METs, maximum heart rate, heart rate recovery (figure 2).

Conclusion

The implementation of a hybrid cardiovascular rehabilitation program (in-hospital + home) was associated with an improvement in the exercise test parameters of patients who successfully completed the program.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

[Clinical efficacy and safety analysis of camrelizumab combined with apatinib as a second-line therapy for unresectable hepatocellular carcinoma: a multicenter retrospective study]

Objective: To analyze the clinical efficacy and safety of camrelizumab combined with apatinib as a second-line therapy for unresectable hepatocellular carcinoma (HCC). Methods: Ninety-four cases with mid-and advanced-stage HCC who received camrelizumab combined with apatinib as second-line treatment were enrolled. Routine blood test, blood biochemical indexes, tumor stage, tumor imaging characteristics, previous treatment strategies and other clinical data before treatment were documented. Imaging examination follow-up results and adverse reactions during treatment were followed up until the end of follow-up or loss of follow-up or death. Kaplan-Meier method was used to analyze the clinical efficacy. Results: As of the last follow-up, 94 cases with mid-and advanced-stage HCC had received camrelizumab combined with apatinib as second-line treatment. Among them, 15 cases were lost to follow-up, 31 cases died, and 48 cases survived. The overall remission rate was 31.9%. The overall disease control rate was 71.3%. The median time to disease-free progression was 6.6 months. The median time to disease progression was not yet available. The 1-year cumulative survival rate was 62.3%. Grade 3 and above adverse reactions mainly included were thrombocytopenia (7.4%), abdominal pain (4.3%), active hepatitis (4.3%), leukopenia (4.3%), diarrhea (3.2%), hand-foot syndrome (3.2%). All adverse reactions were effectively controlled. Conclusion: Camrelizumab combined with apatinib can effectively prolong the survival period of patients with mid-and advanced-stage HCC, and it is well tolerated.

Gasdermin D pore structure reveals preferential release of mature interleukin-1

As organelles of the innate immune system, inflammasomes activate caspase-1 and other inflammatory caspases that cleave gasdermin D (GSDMD). Caspase-1 also cleaves inactive precursors of the interleukin (IL)-1 family to generate mature cytokines such as IL-1β and IL-18. Cleaved GSDMD forms transmembrane pores to enable the release of IL-1 and to drive cell lysis through pyroptosis1-9. Here we report cryo-electron microscopy structures of the pore and the prepore of GSDMD. These structures reveal the different conformations of the two states, as well as extensive membrane-binding elements including a hydrophobic anchor and three positively charged patches. The GSDMD pore conduit is predominantly negatively charged. By contrast, IL-1 precursors have an acidic domain that is proteolytically removed by caspase-110. When permeabilized by GSDMD pores, unlysed liposomes release positively charged and neutral cargoes faster than negatively charged cargoes of similar sizes, and the pores favour the passage of IL-1β and IL-18 over that of their precursors. Consistent with these findings, living-but not pyroptotic-macrophages preferentially release mature IL-1β upon perforation by GSDMD. Mutation of the acidic residues of GSDMD compromises this preference, hindering intracellular retention of the precursor and secretion of the mature cytokine. The GSDMD pore therefore mediates IL-1 release by electrostatic filtering, which suggests the importance of charge in addition to size in the transport of cargoes across this large channel.

Mechanism of filament formation in UPA-promoted CARD8 and NLRP1 inflammasomes

NLRP1 and CARD8 are related cytosolic sensors that upon activation form supramolecular signalling complexes known as canonical inflammasomes, resulting in caspase-1 activation, cytokine maturation and/or pyroptotic cell death. NLRP1 and CARD8 use their C-terminal (CT) fragments containing a caspase recruitment domain (CARD) and the UPA (conserved in UNC5, PIDD, and ankyrins) subdomain for self-oligomerization, which in turn form the platform to recruit the inflammasome adaptor ASC (apoptosis-associated speck-like protein containing a CARD) or caspase-1, respectively. Here, we report cryo-EM structures of NLRP1-CT and CARD8-CT assemblies, in which the respective CARDs form central helical filaments that are promoted by oligomerized, but flexibly linked, UPAs surrounding the filaments. Through biochemical and cellular approaches, we demonstrate that the UPA itself reduces the threshold needed for NLRP1-CT and CARD8-CT filament formation and signalling. Structural analyses provide insights on the mode of ASC recruitment by NLRP1-CT and the contrasting direct recruitment of caspase-1 by CARD8-CT. We also discover that subunits in the central NLRP1CARD filament dimerize with additional exterior CARDs, which roughly doubles its thickness and is unique among all known CARD filaments. Finally, we engineer and determine the structure of an ASCCARD-caspase-1CARD octamer, which suggests that ASC uses opposing surfaces for NLRP1, versus caspase-1, recruitment. Together these structures capture the architecture and specificity of the active NLRP1 and CARD8 inflammasomes in addition to key heteromeric CARD-CARD interactions governing inflammasome signalling.

Intracellular immune sensing promotes inflammation via gasdermin D-driven release of a lectin alarmin

Inflammatory caspase sensing of cytosolic lipopolysaccharide (LPS) triggers pyroptosis and the concurrent release of damage-associated molecular patterns (DAMPs). Collectively, DAMPs are key determinants that shape the aftermath of inflammatory cell death. However, the identity and function of the individual DAMPs released are poorly defined. Our proteomics study revealed that cytosolic LPS sensing triggered the release of galectin-1, a β-galactoside-binding lectin. Galectin-1 release is a common feature of inflammatory cell death, including necroptosis. In vivo studies using galectin-1-deficient mice, recombinant galectin-1 and galectin-1-neutralizing antibody showed that galectin-1 promotes inflammation and plays a detrimental role in LPS-induced lethality. Mechanistically, galectin-1 inhibition of CD45 (Ptprc) underlies its unfavorable role in endotoxin shock. Finally, we found increased galectin-1 in sera from human patients with sepsis. Overall, we uncovered galectin-1 as a bona fide DAMP released as a consequence of cytosolic LPS sensing, identifying a new outcome of inflammatory cell death.

Shiga toxin suppresses noncanonical inflammasome responses to cytosolic LPS

Inflammatory caspase-dependent cytosolic lipopolysaccharide (LPS) sensing is a critical arm of host defense against bacteria. How pathogens overcome this pathway to establish infections is largely unknown. Enterohemorrhagic Escherichia coli (EHEC) is a clinically important human pathogen causing hemorrhagic colitis and hemolytic uremic syndrome. We found that a bacteriophage-encoded virulence factor of EHEC, Shiga toxin (Stx), suppresses caspase-11-mediated activation of the cytosolic LPS sensing pathway. Stx was essential and sufficient to inhibit pyroptosis and interleukin-1 (IL-1) responses elicited specifically by cytosolic LPS. The catalytic activity of Stx was necessary for suppression of inflammasome responses. Stx impairment of inflammasome responses to cytosolic LPS occurs at the level of gasdermin D activation. Stx also suppresses inflammasome responses in vivo after LPS challenge and bacterial infection. Overall, this study assigns a previously undescribed inflammasome-subversive function to a well-known bacterial toxin, Stx, and reveals a new phage protein-based pathogen blockade of cytosolic immune surveillance.

The effect of PD-1 expression on tumor-associated macrophage in T cell lymphoma

PURPOSE

Our study aimed to explore the programmed death 1 (PD-1) expression on tumor-associated macrophage (TAM) in T cell non-Hodgkin lymphoma (T-NHL) and its relationship with lymphoma prognosis. The effect of PD-1 expression on the function of macrophages was also studied.

METHODS

Multispectral image quantitative analysis was applied for detecting PD-1 expression on macrophages in T cell lymphoma tissues. The Kaplan-Meier analysis was performed to evaluate the value of PD-1 expression of TAM in predicting the overall survival of T-NHL. PD-1 overexpression THP-1-derived macrophage was constructed and was cocultured with Jurkat cells to explore the effect of PD-1 on macrophage function.

RESULTS

In 17 T cell lymphoma cases, the 1-year overall survival rate was significantly lower in patients with higher PD-1 expression on TAMs (0.25 vs 0.86, p < 0.05). After co-cultured with Jurkat cells, classically activated (M1)-related markers on PD-1 overexpressed macrophages were significantly lower than those on controls, while the expressions of alternatively activated (M2) related markers were similar. The PD-1 overexpressed macrophages showed inhibited phagocytosis (4.42% vs 40.7%, p < 0.001) and increased IL-10 secretion (144.48 pg/ml vs 32.32 pg/ml, p < 0.001).

CONCLUSION

High PD-1 expression on TAMs in T-NHL may predict poor prognosis. The PD-1 overexpression of macrophages significantly inhibited polarization of M1 macrophages and phagocytosis, and more IL-10 was excreted. These changes may enhance the pro-tumor effects of tumor microenvironment.

FDA-approved disulfiram inhibits pyroptosis by blocking gasdermin D pore formation

Cytosolic sensing of pathogens and damage by myeloid and barrier epithelial cells assembles large complexes called inflammasomes, which activate inflammatory caspases to process cytokines (IL-1β) and gasdermin D (GSDMD). Cleaved GSDMD forms membrane pores, leading to cytokine release and inflammatory cell death (pyroptosis). Inhibiting GSDMD is an attractive strategy to curb inflammation. Here we identify disulfiram, a drug for treating alcohol addiction, as an inhibitor of pore formation by GSDMD but not other members of the GSDM family. Disulfiram blocks pyroptosis and cytokine release in cells and lipopolysaccharide-induced septic death in mice. At nanomolar concentration, disulfiram covalently modifies human/mouse Cys191/Cys192 in GSDMD to block pore formation. Disulfiram still allows IL-1β and GSDMD processing, but abrogates pore formation, thereby preventing IL-1β release and pyroptosis. The role of disulfiram in inhibiting GSDMD provides new therapeutic indications for repurposing this safe drug to counteract inflammation, which contributes to many human diseases.

Prevalence of Cognitive Frailty Phenotypes and Associated Factors in a Community-Dwelling Elderly Population

OBJECTIVES

Cognitive frailty was notable target for the prevention of adverse health outcomes in future. The goal of this study was to use a population-based survey to investigate cognitive frailty phenotypes and potentially sociodemographic factors in elderly Chinese individuals.

DESIGN

Cross-sectional study.

SETTING

General community.

PARTICIPANTS

A total of 5328 elderly adults (aged 60 years or older, mean age 71.36 years) enrolled in the Shanghai study of health promotion for elderly individuals with frailty.

MEASUREMENTS

The 5-item FRAIL scale and the 3-item Rapid Cognitive Screen tools were used to assess physical frailty and cognitive impairment, including dementia or mild cognitive impairment (MCI). Physical frailty was diagnosed by limitations in 3 or more of the FRAIL scale domains and pre-physical frailty by 1-2 limitations. Subjective cognitive decline (SCD) and pre-MCI SCD, was diagnosed with two self-report measures based on memory and other cognitive domains in elderly adults.

RESULTS

Of the participating individuals, 97.17% (n= 5177, female 53.4%) were eligible. Notably, 9.67%, 41.61% and 35.20% of participants were MCI, SCD and pre-MCI SCD; 35.86% and 4.41% exhibited physical pre-frailty and frailty; and 19.86% and 6.30% exhibited reversible and potential reversible cognitive frailty. Logistic regression analyses indicated that physical frailty phenotypes were significantly associated with MCI with SCD, and pre-MCI with SCD. Older single females with a high education level were more likely to exhibit the reversible cognitive frailty; and younger elderly individuals with a middle education level were at lower risk for potentially reversible cognitive frailty.

CONCLUSIONS

The prevalence of pre-physical and reversible cognitive frailty was high in elderly individuals and age was the most significant risk factor for all types of frailty phenotypes. To promote the rapid screening protocol of cognitive frailty in community-dwelling elderly is important to find high-risk population, implement effective intervention, and decrease adverse prognosis.

Monitoring gasdermin pore formation in vitro

The gasdermin (GSDM) family consists of gasdermin A (GSDMA), B (GSDMB), C (GSDMC), D (GSDMD), E or DNFA5 (GSDME), and DFNB59 in human. Expressed in the skin, gastrointestinal tract, and various immune cells, GSDMs mediate homeostasis and inflammation upon activation by caspases and unknown proteases. In particular, GSDMD is activated by inflammasome-activated caspases-1/-4/-5/-11 as well as a caspase-8-mediated pathway during Yersinia infection. These caspases cleave GSDMD to release its functional N-terminal fragment (GSDMD-NT) from its auto-inhibitory C-terminal fragment (GSDMD-CT). GSDMD-NTs bind to acid lipids in mammalian cell membranes and bacterial membranes, oligomerize, and insert into the membranes to form large transmembrane pores. Consequently, cellular contents including inflammatory cytokines are released and cells can undergo pyroptosis, a highly inflammatory form of cell death. In this chapter, we summarize recent research findings and present experimental procedures to obtain pure recombinant GSDMs for biochemical studies. We highlight a liposome-based assay that yields robust fluorescence signals for characterizing GSDM activities in vitro and may be applicable to other pore-forming proteins and ion channels in general.

Abstract A132: Identification of pyroptosis inhibitors that target a reactive cysteine in gasdermin D

Inflammasomes are multiprotein signaling scaffolds that assemble in response to invasive pathogens and sterile danger signals to activate inflammatory caspases (1/4/5/11), which trigger inflammatory death (pyroptosis) and processing and release of proinflammatory cytokines. Inflammasome activation contributes to many human diseases, including inflammatory bowel disease, gout, type II diabetes, cardiovascular disease, Alzheimer’s disease, and sepsis, the often fatal response to systemic infection. The recent identification of the pore-forming protein gasdermin D (GSDMD) as the final pyroptosis executioner downstream of inflammasome activation presents an attractive drug target for these diseases. Here we show that C-23 and C-27 potently inhibit GSDMD pore formation in liposomes and inflammasome-mediated pyroptosis and IL-1β secretion in human and mouse cells. Moreover, C-23, administered at a clinically well-tolerated dose, inhibits LPS-induced septic death and IL-1β secretion in mice. Both compounds covalently modify a conserved Cys (Cys191 in human and Cys192 in mouse GSDMD) that is critical for pore formation. Inflammatory caspases employ Cys active sites, and many previously identified inhibitors of inflammatory mediators, including those against NLRP3 and NF-κB, covalently modify reactive cysteine residues. Since NLRP3 and noncanonical inflammasome activation are amplified by cellular oxidative stress, these redox-sensitive reactive cysteine residues may regulate inflammation endogenously, and compounds that covalently modify reactive cysteines may inhibit inflammation by acting at multiple steps. Indeed, both C-23 and C-27 also directly inhibit inflammatory caspases and pleiotropically suppress multiple processes in inflammation triggered by both canonical and noncanonical inflammasomes, including priming, puncta formation and caspase activation. Hence, cysteine-reactive compounds, despite their lack of specificity, may be attractive agents for reducing inflammation.

Citation Format: Jun Hu, Xing Liu, Jingxia Zhao, Shiyu Xia, Jianbin Ruan, Xuemei Luo, Justin Kim, Judy Lieberman, Hao Wu. Identification of pyroptosis inhibitors that target a reactive cysteine in gasdermin D [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A132.

Ubiquitin-Mediated Regulation of RIPK1 Kinase Activity Independent of IKK and MK2

Tumor necrosis factor (TNF) can drive inflammation, cell survival, and death. While ubiquitylation-, phosphorylation-, and nuclear factor κB (NF-κB)-dependent checkpoints suppress the cytotoxic potential of TNF, it remains unclear whether ubiquitylation can directly repress TNF-induced death. Here, we show that ubiquitylation regulates RIPK1's cytotoxic potential not only via activation of downstream kinases and NF-kB transcriptional responses, but also by directly repressing RIPK1 kinase activity via ubiquitin-dependent inactivation. We find that the ubiquitin-associated (UBA) domain of cellular inhibitor of apoptosis (cIAP)1 is required for optimal ubiquitin-lysine occupancy and K48 ubiquitylation of RIPK1. Independently of IKK and MK2, cIAP1-mediated and UBA-assisted ubiquitylation suppresses RIPK1 kinase auto-activation and, in addition, marks it for proteasomal degradation. In the absence of a functional UBA domain of cIAP1, more active RIPK1 kinase accumulates in response to TNF, causing RIPK1 kinase-mediated cell death and systemic inflammatory response syndrome. These results reveal a direct role for cIAP-mediated ubiquitylation in controlling RIPK1 kinase activity and preventing TNF-mediated cytotoxicity.

Amplification of flat laser pulse train

We present modeling and measurements of flattop amplification of a laser pulse train in a diode pumped Nd:YLF system. We establish a theoretical model, accounting for the transverse Gaussian shape of an amplified laser beam, in order to explain remaining slopes in the pulse train energy. The influence of the transverse Gaussian shape on the train's flatness has been experimentally verified. Based on the model we are able to increase the total amplification of a long train of infrared seed beam in the drive laser system at the Fermilab Accelerator Science and Technology facility. The single-pass amplifier improvements resulted in a gain of ∼7 with flat output pulse train for up to 1000 seed pulses.

Circular RNA expression profile analysis of severe acne by RNA-Seq and bioinformatics

BACKGROUND

Acne is a common chronic skin disease with a multifactorial aetiology and pathogenesis. Recently, circular RNAs (circRNAs) have been identified as a key factor in regulating gene expression through circRNA-miRNA-mRNA networks in many biological processes and human diseases. However, the circRNAs expression in patients with acne is still unknown.

OBJECTIVE

To investigate circRNA expression profile in severe acne.

METHODS

The expression profile of circRNAs in three paired lesional skin and adjacent non-lesional skin in severe acne was detected by high-throughput RNA sequencing technology and bioinformatics analysis. The candidate circRNAs were validated by PCR, Sanger sequencing and qRT-PCR in the separate group (n = 4). The circRNA-miRNA-mRNA interaction networks were predicted.

RESULTS

A total of 538 circRNAs including 271 up- and 267 downregulated circRNAs were differentially expressed in lesional skin compared with adjacent non-lesional skin in severe acne. Gene Ontology and KEGG pathway enrichment analyses revealed that the aberrantly expressed circRNAs were primarily involved in inflammatory, metabolism and immune responses. Five candidate circRNAs (circRNA_0084927, circRNA_0001073, circRNA_0005941, circRNA_0086376 and circRNA_0018168) were validated to have significant decrease in severe acne by PCR, Sanger sequencing and qRT-PCR, in agreement with the results from RNA-Seq data analysis. The five identified circRNAs were predicted to interact with 213 miRNAs and regulated target gene expression.

CONCLUSION

This study firstly showed that circRNAs were differentially expressed in severe acne and suggested that circRNAs could be used as a potential biomarker for the drug targets of acne.

The Pore-Forming Protein Gasdermin D Regulates Interleukin-1 Secretion from Living Macrophages

The interleukin-1 (IL-1) family cytokines are cytosolic proteins that exhibit inflammatory activity upon release into the extracellular space. These factors are released following various cell death processes, with pyroptosis being a common mechanism. Recently, it was recognized that phagocytes can achieve a state of hyperactivation, which is defined by their ability to secrete IL-1 while retaining viability, yet it is unclear how IL-1 can be secreted from living cells. Herein, we report that the pyroptosis regulator gasdermin D (GSDMD) was necessary for IL-1β secretion from living macrophages that have been exposed to inflammasome activators, such as bacteria and their products or host-derived oxidized lipids. Cell- and liposome-based assays demonstrated that GSDMD pores were required for IL-1β transport across an intact lipid bilayer. These findings identify a non-pyroptotic function for GSDMD, and raise the possibility that GSDMD pores represent conduits for the secretion of cytosolic cytokines under conditions of cell hyperactivation.

A phase II trial of lenalidomide plus rituximab in previously untreated follicular non-Hodgkin's lymphoma (NHL): CALGB 50803 (Alliance)

BACKGROUND

This multicenter, phase II trial tested the tolerability and efficacy of lenalidomide plus rituximab in patients with previously untreated follicular lymphoma (FL).

PATIENTS AND METHODS

Patients with grade 1-3a FL, stage 3-4 or bulky stage 2, FL international prognostic index (FLIPI) 0-2, and no prior therapy were eligible to receive rituximab 375 mg/m2 weekly during cycle 1 and day 1 of cycles 4, 6, 8, and 10, plus lenalidomide 20-25 mg on days 1-21 for twelve 28-day cycles. The primary objectives were to evaluate response rates [complete (CR) and overall] and time to progression. Secondary objectives included toxicity, response according to polymorphisms in FcgR2A and FcgR3A, and changes in circulating pro-angiogenic cells.

RESULTS

From October 2010 to September 2011, 66 patients were enrolled. Median age was 53 years, 34 were female, 15 had bulky disease, 21 were FLIPI 0-1, 43 FLIPI 2, and 2 FLIPI 3. One patient withdrew before receiving treatment. Fifty-one patients completed 12 cycles of lenalidomide. Reasons for discontinuation included withdrawal (n = 6), adverse events (n = 6), progression (n = 2). Grade 3-4 hematologic toxicity included neutropenia (21%), lymphopenia (9%), and thrombocytopenia (2%), infection (11%), and rash (8%). Grade 1-2 toxicity included fatigue (78%), diarrhea (37%), rash (32%), and febrile neutropenia in one patient. The overall response rate was 95%; the CR rate was 72% (95% confidence interval, 60% to 83%). With a median follow-up of 5 years, the 2- and 5-year progression-free survival were 86% and 70%, respectively, and the 5-year overall survival was 100%. There was no association between CR rate or PFS and FLIPI, histological grade, bulky disease, FcgR2A/FcgR3A polymorphism, or change in circulating endothelial cell/hematopoietic progenitor cell.

CONCLUSION

Lenalidomide plus rituximab was associated with low rates of grade 3-4 toxicity, yielded a CR rate and PFS similar to chemotherapy-based treatment and may represent a reasonable alternative to immunochemotherapy in previously untreated FL.

CLINICALTRIALS.GOV IDENTIFIER

NCT01145495.

Abstract P1-03-01: An international multicenter study to evaluate reproducibility of automated scoring methods for assessment of Ki67 in breast cancer

Background: The nuclear proliferation biomarker Ki67 has multiple potential roles in breast cancer, including prognosis-based decisions, but unacceptable between-laboratory variability has limited its clinical value. The International Ki67 Working Group (IKWG) has undertaken a systematic program to determine whether Ki67 immunohistochemistry can be analytically validated and standardized across laboratories. Technological advances and broader availability of devices for automated assessment of stained slides raise the possibility that these machines may improve on reproducibility of traditional pathologist-based visual Ki67 assessment.

Aims: To characterize reproducibility of automated machine-measured Ki67 expression using slides previously analyzed in the IKWG phase 3 study that evaluated reproducibility of visual Ki67 assessment.

Methods: Two sets of 30 previously stained slides containing core-cut biopsy sections of breast tumors were circulated to 14 laboratories for scanning and automated assessment of Ki67 expression. Sites were instructed to return average and maximum percentage of tumor cells positive for Ki67 for each slide, where maximum is designed to reflect “hot spot” analysis. Two laboratories returned scores from 2 operators; not all laboratories reported values for maximum Ki67 scores. Different operators were treated as distinct laboratories in analyses. Sixteen and 10 score sets were available for average and maximum Ki67 analyses, respectively, encompassing 7 unique scanner and 10 software platforms. Pre-specified analyses included evaluation of reproducibility across all laboratories as well as within a subgroup limited to those using Aperio scanners. The primary reproducibility metric was intraclass correlation coefficient between laboratories (ICC), regardless of device platform or software.

Results: Geometric means across 30 cases for 16 operators ranged from 11.06% to 38.11% with overall mean 16.75% (95% CI:14.45-19.42) for average scores. Geometric means for 10 operators ranged from 16.44% to 68.73% with overall mean 25.16% (95% CI: 18.71-33.84) for maximum scores. ICC for automated average scores across 16 operators was 0.83 (95% CI: 0.73-0.91) and ICC for maximum scores across 10 operators was 0.63 (95% CI: 0.44-0.80) although one outlier lab dramatically affected results. For the laboratories using the Aperio platform (8 score sets), ICC for automated average scores was 0.89 (95% CI; 0.81-0.96). These results are similar to ICC of 0.87 (95%CI; 0.81-0.93) reported using these same slides in the Phase 3 visual assessment reproducibility study in which observers counted 500 cells per slide (Leung et al, NPJBrCancer, in press).

Conclusions: Between-laboratory reproducibility for automated machine assessment of average Ki67 is similar to that for pathologist-based visual assessment of Ki67. However, the observed ICC was markedly numerically lower for the maximum score method compared to the average method, suggesting that the maximum score may not be useful as a reproducible measure of proliferation. Automated average scoring methods show promise for standardization of Ki67 scoring, supporting future studies to clinically validate Ki67.

Citation Format: Rimm DL, McShane LM, Leung SCY, Bai Y, Bane AL, Bartlett JMS, Bayani J, Chang MC, Dean M, Denkert C, Enwere E, Galderisi C, Gholap A, Hugh JC, Jadhav A, Kornaga E, Laurinavicius A, Levenson R, Lima J, Miller K, Pantanowitz L, Piper T, Ruan J, Srinivasan M, Virk S, Wu Y, Yang H, Hayes DF, Nielsen TO, Dowsett M. An international multicenter study to evaluate reproducibility of automated scoring methods for assessment of Ki67 in breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-03-01.

Abstract B134: Cryo-EM structure of the activated NAIP2-NLRC4 inflammasome reveals nucleated polymerization

The NLR family apoptosis inhibitory proteins (NAIPs) bind conserved bacterial ligands, such as the bacterial rod protein PrgJ, and recruit NLR family CARD-containing protein 4 (NLRC4) as the inflammasome adapter to activate innate immunity. We found that the PrgJ-NAIP2-NLRC4 inflammasome is assembled into multisubunit disk-like structures through a unidirectional adenosine triphosphatase polymerization, primed with a single PrgJ-activated NAIP2 per disk. Cryo-electron microscopy (cryo-EM) reconstruction at subnanometer resolution revealed a ∼90° hinge rotation accompanying NLRC4 activation. Unlike in the related heptameric Apaf-1 apoptosome, in which each subunit needs to be conformationally activated by its ligand before assembly, a single PrgJ-activated NAIP2 initiates NLRC4 polymerization in a domino-like reaction to promote the disk assembly. These insights reveal the mechanism of signal amplification in NAIP-NLRC4 inflammasomes.

Citation Format: Liman Zhang, Shuobing Chen, Jianbin Ruan, Liron David, Youdong Mao, Hao Wu. Cryo-EM structure of the activated NAIP2-NLRC4 inflammasome reveals nucleated polymerization [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B134.

Inflammasome-activated gasdermin D causes pyroptosis by forming membrane pores

Inflammatory caspases (caspases 1, 4, 5 and 11) are activated in response to microbial infection and danger signals. When activated, they cleave mouse and human gasdermin D (GSDMD) after Asp276 and Asp275, respectively, to generate an N-terminal cleavage product (GSDMD-NT) that triggers inflammatory death (pyroptosis) and release of inflammatory cytokines such as interleukin-1β. Cleavage removes the C-terminal fragment (GSDMD-CT), which is thought to fold back on GSDMD-NT to inhibit its activation. However, how GSDMD-NT causes cell death is unknown. Here we show that GSDMD-NT oligomerizes in membranes to form pores that are visible by electron microscopy. GSDMD-NT binds to phosphatidylinositol phosphates and phosphatidylserine (restricted to the cell membrane inner leaflet) and cardiolipin (present in the inner and outer leaflets of bacterial membranes). Mutation of four evolutionarily conserved basic residues blocks GSDMD-NT oligomerization, membrane binding, pore formation and pyroptosis. Because of its lipid-binding preferences, GSDMD-NT kills from within the cell, but does not harm neighbouring mammalian cells when it is released during pyroptosis. GSDMD-NT also kills cell-free bacteria in vitro and may have a direct bactericidal effect within the cytosol of host cells, but the importance of direct bacterial killing in controlling in vivo infection remains to be determined.

[Functional mapping of the insular and opercular cortex: A study using SEEG electrical stimulation in epileptic patients]

OBJECTIVE

Insular and opercular cortex is involved in complicated physiological function.Insular seizures involve extensive epileptic network, which results in the complex and diverse semiology.Electrical cortical stimulation(ECS) can explore the functional mapping and symptomatogenic zone.

METHODS

The clinical presurgical evaluation and ECS data of 20 patients whose electrode contacts were located in the insular and opercular were analyzed retrospectively.CT scan/3D MRI data fusion was performed in order to accurately identify and locate each contact and check the electrode trajectory by the MRI images performed after the electrodes were removed.ECS was applied between two contiguous contacts.Stimulation usually lasted for 5 s at 50 Hz(pulse width=0.3 ms). Depending on the area of stimulated cortex, the stimulation intensities ranged from 0.2 to 3.0 mA.The classification of the insular were anterior short gyrus, middle short gyrus, precentral gyrus, postcentral gyrus, posterior long gyrus and insular pole.The classification of the opercular were orbital, frontal, precentral, central, parietal and temporal opercular.

RESULTS

One hundred and six contacts were located in the insular and 51 responses were evoked (48.11%). Four hundred eighteen contacts were located in the insular and 132 responses were evoked (31.58%). We classified the principal responses as somatosensory, pain, auditory, oropharyngeal, speech disturbances and neurovegetative response.Somatosensory responses were mainly evoked in parietal opercular and postcentral gyrus, while pain response distributed sporadically.Auditory were only evoked in temporal opercular(transverse temporal gyri) and posterior long gyrus.Oropharyngeal symptoms were only evoked in central opercular.Speech disturbances were located in precentral and central opercular and neurovegetative responses were mainly evoked in insular pole and middle short gyrus.

CONCLUSIONS

These findings may indicate a functional specificity for the insular gyrus and opercular, which contribute to the understanding of anatomo-functional organization and the role in insular and opercular epileptic network.Moreover, it could optimize the implantation strategy for exploring these structures.

An endogenous caspase-11 ligand elicits interleukin-1 release from living dendritic cells

Dendritic cells (DCs) use pattern recognition receptors to detect microorganisms and activate protective immunity. These cells and receptors are thought to operate in an all-or-nothing manner, existing in an immunologically active or inactive state. Here, we report that encounters with microbial products and self-encoded oxidized phospholipids (oxPAPC) induce an enhanced DC activation state, which we call "hyperactive." Hyperactive DCs induce potent adaptive immune responses and are elicited by caspase-11, an enzyme that binds oxPAPC and bacterial lipopolysaccharide (LPS). oxPAPC and LPS bind caspase-11 via distinct domains and elicit different inflammasome-dependent activities. Both lipids induce caspase-11-dependent interleukin-1 release, but only LPS induces pyroptosis. The cells and receptors of the innate immune system can therefore achieve different activation states, which may permit context-dependent responses to infection.

A single domain antibody fragment that recognizes the adaptor ASC defines the role of ASC domains in inflammasome assembly

Ploegh et al. raised an alpaca single-domain antibody (VHH) against the inflammasome adaptor ASC. VHH_ASC blocks inflammasome activation in vitro and in living cells, and demonstrates a role of the ASC CARD domain in cross-linking ASC Pyrin domain filaments.

Myeloid cells assemble inflammasomes in response to infection or cell damage; cytosolic sensors activate pro–caspase-1, indirectly for the most part, via the adaptors ASC and NLRC4. This leads to secretion of proinflammatory cytokines and pyroptosis. To explore complex formation under physiological conditions, we generated an alpaca single domain antibody, VHH_ASC, which specifically recognizes the CARD of human ASC via its type II interface. VHH_ASC not only impairs ASC^CARD interactions in vitro, but also inhibits inflammasome activation in response to NLRP3, AIM2, and NAIP triggers when expressed in living cells, highlighting a role of ASC in all three types of inflammasomes. VHH_ASC leaves the Pyrin domain of ASC functional and stabilizes a filamentous intermediate of inflammasome activation. Incorporation of VHH_ASC-EGFP into these structures allowed the visualization of endogenous ASC^PYD filaments for the first time. These data revealed that cross-linking of ASC^PYD filaments via ASC^CARD mediates the assembly of ASC foci.

Clinical experience with lenalidomide alone or in combination with rituximab in indolent B-cell and mantle cell lymphomas

Lenalidomide is an oral immunomodulatory drug with significant activity in indolent B-cell and mantle cell lymphomas. Lenalidomide has a manageable safety profile whether administered as a single agent or in combination with rituximab. The combination of lenalidomide with rituximab, known as the 'R(2)' regimen, enhances efficacy over what has been shown with monotherapy and has demonstrated activity in patients considered resistant to rituximab. Tolerability of these regimens has been consistent among studies. Asymptomatic neutropenia is the most common grade 3/4 adverse event, typically managed by dose interruption, followed by dose reduction once neutrophils have recovered. Nonhematologic toxicities (e.g. fatigue) are generally low-grade, manageable with concomitant treatment, and/or lenalidomide dose modification. More frequent with R(2), immune-related symptoms such as rash and tumor flare are important to recognize as lenalidomide-associated treatment effects in patients with lymphoma who require supportive care and potential dose modifications. Severe tumor flare reactions with painful lymphadenopathy are not typically observed outside of chronic lymphocytic leukemia/small lymphocytic lymphoma. Venous thromboembolism is uncommon in lymphomas, though prophylaxis is recommended. The general safety profile, differences between lenalidomide monotherapy and R(2) treatment, and optimal strategies for managing adverse events are discussed here.

Abstracts of the 24th international isotope society (UK group) symposium: synthesis and applications of labelled compounds 2015

The 24th annual symposium of the International Isotope Society's United Kingdom Group took place at the Møller Centre, Churchill College, Cambridge, UK on Friday 6th November 2015. The meeting was attended by 77 delegates from academia and industry, the life sciences, chemical, radiochemical and scientific instrument suppliers. Delegates were welcomed by Dr Ken Lawrie (GlaxoSmithKline, UK, chair of the IIS UK group). The subsequent scientific programme consisted of oral presentations, short 'flash' presentations in association with particular posters and poster presentations. The scientific areas covered included isotopic synthesis, regulatory issues, applications of labelled compounds in imaging, isotopic separation and novel chemistry with potential implications for isotopic synthesis. Both short-lived and long-lived isotopes were represented, as were stable isotopes. The symposium was divided into a morning session chaired by Dr Rebekka Hueting (University of Oxford, UK) and afternoon sessions chaired by Dr Sofia Pascu (University of Bath, UK) and by Dr Alan Dowling (Syngenta, UK). The UK meeting concluded with remarks from Dr Ken Lawrie (GlaxoSmithKline, UK).