Large cell neuroendocrine lung carcinoma: consensus statement from The British Thoracic Oncology Group and the Association of Pulmonary Pathologists.

Over the past 10 years, lung cancer clinical and translational research has been characterised by exponential progress, exemplified by the introduction of molecularly targeted therapies, immunotherapy and chemo-immunotherapy combinations to stage III and IV non-small cell lung cancer. Along with squamous and small cell lung cancers, large cell neuroendocrine carcinoma (LCNEC) now represents an area of unmet need, particularly hampered by the lack of an encompassing pathological definition that can facilitate real-world and clinical trial progress. The steps we have proposed in this article represent an iterative and rational path forward towards clinical breakthroughs that can be modelled on success in other lung cancer pathologies.

CSF Levels of Elongation Factor Tu Is Associated With Increased Mortality in Malawian Adults With Streptococcus pneumoniae Meningitis.

Background: Mortality from bacterial meningitis, predominately caused by Streptococcus pneumoniae, exceeds 50% in sub-Saharan African countries with high HIV prevalence. Underlying causes of high mortality are poorly understood. We examined the host and pathogen proteome in the CSF of adults with proven pneumococcal meningitis (PM), testing if there was an association between differentially expressed proteins and outcome. Materials/Methods: CSF proteomes were analyzed by quantitative Mass-Spectrometry. Spectra were identified using the Swissprot human and TIGR4 pneumococcal protein libraries. Proteins were quantitated and analyzed against mortality. Unique proteins in PM were identified against published normal CSF proteome. Random-Forest models were used to test for protein signatures discriminating outcome. Proteins of interest were tested for their effects on growth and neutrophil opsonophagocytic killing of S. pneumoniae. Results: CSF proteomes were available for 57 Adults with PM (median age 32 years, 60% male, 70% HIV-1 co-infected, mortality 63%). Three hundred sixty individual human and 23 pneumococcal proteins were identified. Of the human protein hits, 30% were not expressed in normal CSF, and these were strongly associated with inflammation and primarily related to neutrophil activity. No human protein signature predicted outcome. However, expression of the essential S. pneumoniae protein Elongation Factor Tu (EF-Tu) was significantly increased in CSF of non-survivors [False Discovery Rate (q) <0.001]. Expression of EF-Tu was negatively co-correlated against expression of Neutrophil defensin (r 0.4 p p < 0.002), but not against complement proteins C3 or Factor H. In vitro, addition of EF-Tu protein impaired S. pneumoniae neutrophil killing in CSF. Conclusions: Excessive S. pneumoniae EF-Tu protein in CSF was associated with reduced survival in meningitis in a high HIV prevalence population. We show EF-Tu may inhibit neutrophil mediated killing of S. pneumoniae in CSF. Further mechanistic work is required to better understand how S. pneumoniae avoids essential innate immune responses during PM through production of excess EF-Tu.

Redefining Treatment Paradigms in First-line Advanced Non-Small-Cell Lung Cancer.

Metastatic non-small-cell lung cancer is still a devastating disease; however, treatment options have diversified dramatically in the past two decades. From unselected platinum-based chemotherapy for all patients, several different treatment groups have evolved, that is, those with "druggable" targets, those with a promising immune signature, and those without any predicting factors outlined in this article. Challenge includes the intersections between these groups and the optimal treatment path. These issues will be addressed in this review.

Quantitative Proteomics of Cerebrospinal Fluid in Paediatric Pneumococcal Meningitis.

Streptococcus pneumoniae is responsible for diseases causing major global public health problems, including meningitis, pneumonia and septicaemia. Despite recent advances in antimicrobial therapy, pneumococcal meningitis remains a life-threatening disease. Furthermore, long-term sequelae are a major concern for survivors. Hence, a better understanding of the processes occurring in the central nervous system is crucial to the development of more effective management strategies. We used mass spectrometry based quantitative proteomics to identify protein changes in cerebrospinal fluid from children with Streptococcus pneumoniae infection, compared with children admitted to hospital with bacterial meningitis symptoms but negative diagnosis. Samples were analysed, by label free proteomics, in two independent cohorts (cohort 1: cases (n = 8) and hospital controls (n = 4); cohort 2: cases (n = 8), hospital controls (n = 8)). Over 200 human proteins were differentially expressed in each cohort, of which 65% were common to both. Proteins involved in the immune response and exosome signalling were significantly enriched in the infected samples. For a subset of proteins derived from the proteome analysis, we corroborated the proteomics data in a third cohort (hospital controls (n = 15), healthy controls (n = 5), cases (n = 20)) by automated quantitative western blotting, with excellent agreement with our proteomics findings. Proteomics data are available via ProteomeXchange with identifier PXD004219.

An external sensing system in Plasmodium falciparum-infected erythrocytes.

BACKGROUND: A number of experiments have previously indicated that Plasmodium falciparum-infected erythrocytes (pRBC) were able to sense host environment. The basis of this ability to detect external cues is not known but in screening signalling molecules from pRBC using commercial antibodies, a 34 kDa phosphorylated molecule that possesses such ability was identified. METHODS: The pRBC were exposed to different culture conditions and proteins were extracted for 1D or 2D gel electrophoresis followed by Western blot. The localization of 34 kDa protein was examined by biochemical fractionation followed by Western blot. High-resolution mass spectrometric analysis of immune precipitants was used to identify this protein and real-time quantitative reverse transcriptase polymerase chain reaction was used for detecting mRNA expression level. RESULTS: The 34 kDa protein was called PfAB4 has immediate responses (dephosphorylation and rapid turnover) to host environmental stimuli such as serum depletion, osmolality change and cytokine addition. PfAB4 is expressed constitutively throughout the erythrocytic lifecycle with dominant expression in trophozoites 30 h post-infection. Tumour necrosis factor (TNF) treatment induced a transient detectable dephosphorylation of PfAB4 in the ItG strain (2 min after addition) and the level of expression and phosphorylation returned to normal within 1-2 h. PfAB4 localized dominantly in pRBC cytoplasm, with a transient shift to the nucleus under TNF stimulation as shown by biochemical fractionation. High-resolution mass spectrometric analysis of immune precipitants of AB4 antibodies revealed a 34 kDa PfAB4 component as a mixture of proliferating cellular nuclear antigen-1 (PCNA1) and exported protein-2 (EXP2), along with a small number of other inconsistently identified peptides. Different parasite strains have different PfAB4 expression levels, but no significant association between mRNA and PfAB4 levels was seen, indicating that the differences may be at the post-transcriptional, presumably phosphorylation, level. A triple serine phosphorylated PCNA1 peptide was identified from the PfAB4 high expression strain only, providing further evidence that the identity of PfAB4 is PCNA1 in P. falciparum. CONCLUSION: A protein element in the human malaria parasite that responds to external cues, including the pro-inflammatory cytokine TNF have been discovered. Treatment results in a transient change in phosphorylation status of the response element, which also migrates from the parasite cytoplasm to the nucleus. The response element has been identified as PfPCNA1. This sensing response could be regulated by a parasite checkpoint system and be analogous to bacterial two-component signal transduction systems.

Diagnosis of snakebite and the importance of immunological tests in venom research.

In many cases of envenoming following snake bite, the snake responsible for the accident remains unidentified; this frequently results in difficulty deciding which antivenom to administer to the systemically-envenomed victim, especially when only monospecific antivenoms are available. Normally the specific diagnosis of snake bite can be conveniently made using clinical and laboratory methods. Where clinical diagnosis depends upon the recognition of specific signs of envenoming in the patient, laboratory diagnosis is based on the changes which occur in envenomed victims including the detection of abnormalities in blood parameters, presence/absence of myoglobinuria, changes in certain enzyme levels, presence/absence of neurotoxic signs and the detection in the blood of specific venom antigens using immunologically-based techniques, such as enzyme immunoassay. It is the latter which is the main subject of this review, together with the application of techniques currently used to objectively assess the effectiveness of new and existing antivenoms, to assess first aid measures, to investigate the possible use of such methods in epidemiological studies, and to detect individual venom components. With this in mind, we have discussed in some detail how such techniques were developed and how they have helped in the treatment of envenoming particularly and in venom research in general.

Intra-specific variation in venom of the African Puff Adder (Bitis arietans): Differential expression and activity of snake venom metalloproteinases (SVMPs).

Bitis arietans is considered one of the most medically significant snakes in Africa, primarily due to a combination of its extensive geographical distribution, common occurrence and highly potent haemorrhagic and cytotoxic venom. Our investigation has revealed a remarkable degree of intra-species variation between pooled venom samples from different geographical origins across sub-Saharan Africa and Arabia, and within a group of individual specimens from the same origin in Nigeria as determined by a combination of immunological, biochemical and proteomic assays. We demonstrate significant quantitative and qualitative differences between B. arietans venom in terms of protein expression, immunogenicity and activity of snake venom metalloproteinases (SVMPs); toxins with a primary role in the haemorrhagic and tissue-necrotic pathologies suffered by envenomed victims. Specifically, we have identified a processed PII SVMP that exhibits striking inter-specimen variability.

Death following coral snake bite in the United States--first documented case (with ELISA confirmation of envenomation) in over 40 years.

We report the first documented death due to a coral snake (Micrurus species) in the United States (U.S.) in over 40 years. The victim failed to seek medical care following the bite of an eastern coral snake (Micrurus fulvius) and succumbed within hours. Post-mortem proof of envenomation was obtained using an ELISA (enzyme-linked immunosorbent assay) developed specifically for this investigation. U.S. coral snakes are briefly reviewed in terms of their venom compositions, their clinical effects, and proper pre-hospital and hospital management. The clinical significance of the impending absence of commercially available antivenom for coral snake bites in the U.S. is highlighted.

Molecular characterisation of endogenous snake venom metalloproteinase inhibitors.

Viper venoms contain one of the most potent mixtures of proteases in natural existence and yet the venom gland and proteins in this mixture are refractory to degradation. Here we demonstrate that the sub-10-kDa components of venom from two African viper species (Echis ocellatus and Cerastes cerastes cerastes) are predominantly composed of the tri-peptide pyroglutamate-lysine-tryptophan (pEKW). This tripeptide is encoded by tandemly repeating elements and, in E. ocellatus, on the same transcript as a novel, and highly unusual, poly-histidine-poly-glycine peptide (pHpG) also detected in E. ocellatus venom. The pEKW and pHpG peptides inhibit the proteolytic activity of the haemorrhagic snake venom metalloproteinase (SVMP), EoVMP-2, and the haemorrhagic activity of E. ocellatus venom. These results demonstrate that these vipers express abundant transcripts encoding tandemly repeated protease inhibitor cassettes and accumulate significant quantities of peptide inhibitors in venoms to provide a basis for attenuating the proteolytic activity of SVMPs.

Bioinformatics and multiepitope DNA immunization to design rational snake antivenom.

BACKGROUND: Snake venom is a potentially lethal and complex mixture of hundreds of functionally diverse proteins that are difficult to purify and hence difficult to characterize. These difficulties have inhibited the development of toxin-targeted therapy, and conventional antivenom is still generated from the sera of horses or sheep immunized with whole venom. Although life-saving, antivenoms contain an immunoglobulin pool of unknown antigen specificity and known redundancy, which necessitates the delivery of large volumes of heterologous immunoglobulin to the envenomed victim, thus increasing the risk of anaphylactoid and serum sickness adverse effects. Here we exploit recent molecular sequence analysis and DNA immunization tools to design more rational toxin-targeted antivenom. METHODS AND FINDINGS: We developed a novel bioinformatic strategy that identified sequences encoding immunogenic and structurally significant epitopes from an expressed sequence tag database of a venom gland cDNA library of Echis ocellatus, the most medically important viper in Africa. Focusing upon snake venom metalloproteinases (SVMPs) that are responsible for the severe and frequently lethal hemorrhage in envenomed victims, we identified seven epitopes that we predicted would be represented in all isomers of this multimeric toxin and that we engineered into a single synthetic multiepitope DNA immunogen (epitope string). We compared the specificity and toxin-neutralizing efficacy of antiserum raised against the string to antisera raised against a single SVMP toxin (or domains) or antiserum raised by conventional (whole venom) immunization protocols. The SVMP string antiserum, as predicted in silico, contained antibody specificities to numerous SVMPs in E. ocellatus venom and venoms of several other African vipers. More significantly, the antiserum cross-specifically neutralized hemorrhage induced by E. ocellatus and Cerastes cerastes cerastes venoms. CONCLUSIONS: These data provide valuable sequence and structure/function information of viper venom hemorrhagins but, more importantly, a new opportunity to design toxin-specific antivenoms-the first major conceptual change in antivenom design after more than a century of production. Furthermore, this approach may be adapted to immunotherapy design in other cases where targets are numerous, diverse, and poorly characterized such as those generated by hypermutation or antigenic variation.

Isolation and characterization of cotiaractivase, a novel low molecular weight prothrombin activator from the venom of Bothrops cotiara.

In this study, we isolated a novel prothrombin activator from the venom of Bothrops cotiara, a Brazilian lance-headed pit viper (Cotiara, Jararaca preta, Biocotiara), which we have designated "cotiaractivase" (prefix: cotiar- from B. cotiara; suffix: -activase, from prothrombin activating activity). Cotiaractivase was purified using a phenyl-Superose hydrophobic interaction column followed by a Mono-Q anion exchange column. It is a single-chain polypeptide with a molecular weight of 22,931 Da as measured by mass spectroscopy. Cotiaractivase generated active alpha-thrombin from purified human prothrombin in a Ca2+-dependent manner as assessed by S2238 chromogenic substrate assay and SDS-PAGE. Cotiaractivase cleaved prothrombin at positions Arg271-Thr272 and Arg320-Ile321, which are also cleaved by factor Xa. However, the rate of thrombin generation by cotiaractivase was approximately 60-fold less than factor Xa alone and 17 x 10(6)-fold less than the prothrombinase complex. The enzymatic activity of cotiaractivase was inhibited by the chelating agent EDTA, whereas the serine protease inhibitor PMSF had no effect on its activity, suggesting that it is a metalloproteinase. Interestingly, S2238 inhibited cotiaractivase activity non-competitively, suggesting that this toxin contains an exosite that allows it to bind prothrombin independently of its active site. Tandem mass spectrometry and N-terminal sequencing of purified cotiaractivase identified peptides that were identical to regions of the cysteine-rich and disintegrin-like domains of known snake venom metalloproteinases. Cotiaractivase is a unique low molecular weight snake venom prothrombin activator that likely belongs to the metalloproteinase family of proteins.

A novel Syk-dependent mechanism of platelet activation by the C-type lectin receptor CLEC-2.

The snake venom rhodocytin has been reported to bind to integrin alpha2beta1 and glycoprotein (GP) Ibalpha on platelets, but it is also able to induce activation independent of the 2 receptors and of GPVI. Using rhodocytin affinity chromatography, we have identified a novel C-type lectin receptor, CLEC-2, in platelets that confers signaling responses to rhodocytin when expressed in a cell line. CLEC-2 has a single tyrosine residue in a YXXL motif in its cytosolic tail, which undergoes tyrosine phosphorylation upon platelet activation by rhodocytin or an antibody to CLEC-2, but not to collagen, thrombin receptor agonist peptide (TRAP), or convulxin. Tyrosine phosphorylation of CLEC-2 and other signaling proteins by rhodocytin is inhibited by the Src family kinase inhibitor PP2. Further, activation of murine platelets by rhodocytin is abolished in the absence of Syk and PLCgamma2, and partially reduced in the absence of LAT, SLP-76, and Vav1/Vav3. These findings define a novel signaling pathway in platelets whereby activation of CLEC-2 by rhodocytin leads to tyrosine phosphorylation of its cytosolic tail, binding of Syk and initiation of downstream tyrosine phosphorylation events, and activation of PLCgamma2. CLEC-2 is the first C-type lectin receptor to be found on platelets which signals through this novel pathway.

Role of the snake venom toxin jararhagin in proinflammatory pathogenesis: in vitro and in vivo gene expression analysis of the effects of the toxin.

To assess the indirect effects of snake venom metalloproteinases (SVMP) on host tissue local necrosis, we investigated the effect of the SVMP jararhagin on the gene expression profiles of human fibroblasts in vitro and mouse tissue in vivo. Two functional classes of up-regulated proteins, cell death and inflammatory disease were identified as being significantly populated. The changes in gene expression observed by qRT-PCR on laser microdissected mouse muscle tissue treated with jararhagin were similar with significant up-regulation of proinflammatory transcripts such as IL-1 beta, IL-6, CXCL1, CXCL2, IL-8, and apoptosis, inflammation responsive transcripts such as TNF-alpha induced protein 6. Proteolytically inactive jararhagin had no effect on the gene expression profile of fibroblasts, indicating proteolysis as the primary mechanism affecting gene expression of cells and tissues resulting in a proinflammatory, pro-apoptotic host response which likely exacerbates the local necrosis frequently observed at the site of envenoming.

Characterization of a novel protein from Proatheris superciliaris venom: proatherocytin, a 34-kDa platelet receptor PAR1 agonist.

Many toxins from viperid venoms have been characterised as powerful activators of platelets. Here, the venom from the East African Lowland viper, Proatheris superciliaris, was investigated for its effect on platelets and the coagulation system. Whole P. superciliaris venom stimulated platelet shape change and aggregation; however, the stimulation of platelet activation was unaffected by the structurally distinct Src family kinase inhibitors PP1 and PD0173952, suggesting that platelet activation was mediated by a G protein-coupled receptor. A platelet reactive 34-kDa protein was isolated from P. superciliaris venom which we have designated proatherocytin. This protein induced Src kinase-independent aggregation of both human and mouse platelets that was inhibited by the serine protease inhibitor AEBSF. Proatherocytin did not clot bovine or human fibrinogen, degrade fibrinogen or hydrolyse the serine protease substrate benzoyl-FVR-pNA. It activated human PAR1 on stably transfected rat kidney epithelial cells, whereas no activation of the trypsin receptor PAR2 was shown. Surprisingly, Edman degradation of proatherocytin revealed sequence identity with existing disintegrin-like domains of snake venom metalloproteinases. These results suggest that proatherocytin is a highly selective PAR1 agonist that also causes mouse platelet aggregation, probably through cleavage of PAR4.

Jararhagin and its multiple effects on hemostasis.

Jararhagin is a 52 kDa hemorrhagic P-III metalloproteinase isolated from the venom of the medically important Brazilian pit-viper Bothrops jararaca. It is a member of the reprolysin family of zinc metalloproteinases containing a catalytic metalloproteinase domain followed by a disintegrin-like and a cysteine-rich domain. The impact of jararhagin on hemostasis has been extensively studied using in vitro and in vivo model systems as well as in clinical studies. Jararhagin-induced hemorrhage is the result of the degradation of sub-endothelial matrix proteins leading to the disruption of the blood vessel endothelium, with accompanying disturbances in platelet function. The versatility of jararhagin is further demonstrated by its direct action on von Willebrand factor, the degradation of fibrinogen, by its inhibition of platelet adhesion to collagen and by its inability to be affected by the plasma inhibitor alpha(2)-macroglobulin. Collagen-induced platelet aggregation is inhibited by jararhagin though the binding of the molecule to the alpha(2) subunit I domain of the platelet surface alpha(2)beta(1) integrin (collagen receptor). Jararhagin also cleaves the beta(1) subunit of the same integrin, inhibiting platelet interaction and ultimately causing impairment of signal transduction. The effect of jararhagin on cell systems other than platelets is evaluated; in fibroblasts, jararhagin functions as a collagen-mimetic substrate and, in endothelial cells, it causes apoptosis and indirectly inhibits cell proliferation by release of angiostatin-like compounds. Jararhagin induces a strong pro-inflammatory response characterized by intense leukocyte accumulation at the site of the injection. Although hemorrhage and edema are a response to the direct effect of jararhagin, jararhagin-induced inflammation and necrosis are dependent on macrophages and key pro-inflammatory cytokines or their receptors. Some data also indicate that the toxin possesses anti-tumorgenic properties. Methods for inhibiting jararhagin are reviewed; this encompasses the use of synthetic peptides to the isolation of naturally occurring mammalian peptides and the development of toxin-specific antibodies through DNA immunisation and monoclonal antibody technologies. The availability of jararhagin makes it an important tool for research into the mechanisms of action of similar toxins, for insights into cellular interactions and for clinical investigations into the treatment of envenomings from B. jararaca.

Crotaline snake bite in the Ecuadorian Amazon: randomised double blind comparative trial of three South American polyspecific antivenoms.

OBJECTIVE: To compare the efficacy and safety of three polyspecific antivenoms for bites by pit vipers. DESIGN: Randomised double blind comparative trial of three antivenoms. SETTING: Shell, Pastaza, southeastern Ecuador. PARTICIPANTS: 210 patients with incoagulable blood were recruited from 221 consecutive patients admitted with snake bite between January 1997 and December 2001. INTERVENTION: One of three antivenoms manufactured in Brazil, Colombia, and Ecuador, chosen for their preclinical potency against Ecuadorian venoms. MAIN OUTCOME MEASURES: Permanent restoration of blood coagulability after 6 and 24 hours. RESULTS: The snakes responsible for the bites were identified in 187 cases: 109 patients (58%) were bitten by Bothrops atrox, 68 (36%) by B bilineatus, and 10 (5%) by B taeniatus, B brazili, or Lachesis muta. Eighty seven patients (41%) received Colombian antivenom, 82 (39%) received Brazilian antivenom, but only 41 (20%) received Ecuadorian antivenom because the supply was exhausted. Two patients died, and 10 developed local necrosis. All antivenoms achieved the primary end point of permanently restoring blood coagulability by 6 or 24 hours after the start of treatment in > 40% of patients. Colombian antivenom, however, was the most effective after initial doses of 20 ml (two vials), < 70 ml, and any initial dose at both 6 and 24 hours. An initial dose of 20 ml of Colombian antivenom permanently restored blood coagulability in 64% (46/72) of patients after 6 hours (P = 0.054 compared with the other two antivenoms) and an initial dose of < 70 ml was effective at 6 hours (65%, P = 0.045) and 24 hours (99%, P = 0.06). Early anaphylactoid reactions were common (53%, 73%, and 19%, respectively, for Brazilian, Colombian, and Ecuadorian antivenoms, P < 0.0001) but only three reactions were severe and none was fatal. CONCLUSIONS: All three antivenoms can be recommended for the treatment of snakebites in this region, though the reactogenicity of Brazilian and Colombian antivenoms is a cause for concern.

Inflammatory pathogenesis of snake venom metalloproteinase-induced skin necrosis.

Local tissue damage, characterized by edema, hemorrhage and necrosis, is a common consequence of envenoming by many vipers. We have investigated the contribution of inflammatory responses induced by the venom metalloproteinase jararhagin (isolated from Bothrops jararaca venom) in the development of these lesions. Local venom effects (edema, hemorrhage and necrosis) were induced experimentally in knockout mice deficient in the TNF receptors TNFR1 or TNFR2, IL-1betaR, IL-6 and iNOS. Jararhagin-induced dermal necrosis was abolished in mice deficient in the TNF receptors TNFR1 and TNFR2, and the same activity was significantly reduced in IL-6(-/-) mice. There was no significant difference in edema and hemorrhage activities following jararhagin insult between knockout and WT strains, indicating that these local venom metalloproteinase-induced effects are independent of these pro-inflammatory mediators. The contribution of both TNF receptors and IL-6 in local tissue necrosis raises important therapeutic issues regarding the treatment of local envenoming.