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Influenza H7N9 virus continues to cause infections in humans and represents a significant pandemic risk. During the most recent 5th epidemic wave in 2016/17 two distinct lineages with increased human infections and wider geographical spread emerged. In preparation for any future adaptations, broadly reactive antibodies against H7N9 are required for surveillance, therapy and prophylaxis. In this study we have isolated a panel of nanobodies (Nbs) with broad reactivity across H7 influenza strains, including H7N9 strains between 2013 and 2017. We also describe Nbs capable of distinguishing between the most recent high and low pathogenicity Yangtze River Delta lineage H7N9 strains. Nanobodies were classified into 5 distinct groups based on their epitope footprint determined using yeast display and mutational scanning. The epitope footprint of Nbs capable of distinguishing high pathogenic (HP) A/Guangdong/17SF003/2016 from low pathogenic (LP) A/Hong Kong/125/2017 (H7N9) were correlated to natural sequence divergence in the head domain at lysine 164. Several Nbs binding to the head domain were capable of viral neutralisation. The potency of one nanobody NB7-14 could be increased over 1000-fold to 113 pM by linking two Nbs together. Nbs specific for distinct epitopes on H7N9 may be useful for surveillance or therapy in human or veterinary settings.

Influenza B virus (IBV) circulates in the human population and causes considerable disease burden worldwide, each year. Current IBV vaccines can struggle to mount an effective cross-reactive immune response, as strains become mismatched, due to constant antigenic changes. Additional strategies which use monoclonal antibodies, with broad reactivity, are of considerable interest, both, as diagnostics and as immunotherapeutics. Alternatives to conventional monoclonal antibodies, such as single domain antibodies (NanobodiesTM) with well-documented advantages for applications in infectious disease, have been emerging. In this study we have isolated single domain antibodies (sdAbs), specific to IBV, using alpacas immunised with recombinant hemagglutinin (HA) from two representative viruses, B/Florida/04/2006 (B/Yamagata lineage) and B/Brisbane/60/2008 (B/Victoria lineage). Using phage display, we have isolated a panel of single domain antibodies (sdAbs), with both cross-reactive and lineage-specific binding. Several sdAbs recognise whole virus antigens, corresponding to influenza B strains included in vaccines spanning over 20 years, and were capable of neutralising IBV pseudotypes corresponding to prototype strains from both lineages. Lineage-specific sdAbs recognised the head domain, whereas, sdAbs identified as cross-reactive could be classified as either head binding or stem binding. Using yeast display, we were able to correlate lineage specificity with naturally occurring sequence divergence, at residue 122 in the highly variable 120 loop of the HA1 domain. The single domain antibodies described, might have applications in IBV diagnostics, vaccine potency testing and as immunotherapeutics.

Increased exposure of the tubular epithelium to filtered protein is a proposed mechanism of progressive renal failure associated with glomerular disease, but how this protein overload translates into tubular damage remains unclear. We have examined a model of adriamycin-induced proteinuria to determine the effect of locally synthesized C3, the central proinflammatory protein of the complement cascade. C3-/- kidney isografts placed in wild-type C3+/+ mice were protected from proteinuria-associated complement activation, tubular damage, and progressive renal failure despite the presence of abundant circulating C3. The quantity of urinary protein was unaffected by the absence of C3, and thus the influence of C3 was not explained by alteration in the filtered protein load. These results suggest that local synthesis of complement from renal epithelial cells is a critical mediator of tubular damage in proteinuria-associated renal disease. Our results concur with previous findings of increased synthesis of C3 in human tubular epithelium exposed to high concentrations of protein in vitro. Because progressive renal damage in humans associates with proteinuria regardless of cause, our findings have implications for the pathogenesis and treatment of renal failure from many common causes, immunological and nonimmunological.

Although complement activation can make immune complex glomerulonephritis worse, the third complement component also can solubilize immune complexes and thus reduce the severity of disease. How C3 that is produced within the kidney contributes to this balance is unknown. This study therefore investigated the relative roles of systemic and local C3 production in a model of glomerular immune complex disease. Injection of sheep anti-glomerular basement membrane antibody into preimmunized mice resulted in accumulation of immune complexes and progressive loss of function over 14 d that was much more marked in C3-deficient (C3-/-) mice. In C3-sufficient mice that received a transplant of a C3-/- mouse kidney and in C3-/- mice with C3-sufficient mouse kidney transplants, the severity and the pattern of injury went with the complement status of the recipient. That is, mice with deficient circulating C3 developed severe glomerular immune complex disease, whereas those with a high level of circulating C3 had well-preserved glomerular structure and function. It is concluded that circulating C3 is a critical factor in reducing the glomerular accumulation of immune complexes. Local synthesis of C3 did not have a major influence on this aspect of glomerular disease.

Background and Purpose—The risk of atherosclerosis from endotoxemia is increased in smokers. Endotoxin is a potent mediator of inflammation, and smokers have elevated plasma levels of endotoxin. The endotoxin receptor CD14 can enhance the endotoxin-neutralization capacity of plasma. A functional polymorphism in the promoter region of the CD14 gene (CD14 −159C/T) was studied to determine its impact on common carotid artery (CCA) intima-media thickness (IMT) and any interactions with environmental inflammatory stimuli.Methods—A community population (n=992; aged 50 to 65 years) underwent genotypic examination for the CD14 −159 polymorphism by restriction fragment length polymorphism analysis.Results—TheCCgenotype was associated with increased CCA IMT. The age- and sex-adjusted odds ratio for IMT above the 75th percentile was 1.63 (95% CI, 1.19 to 2.24;P=0.002) and 1.70 (95% CI, 1.18 to 2.44;P=0.004) after additional adjustment for conventional risk factors. This gene effect was found only in current smokers and ex-smokers. Multivariate analysis in this group (n=503) increased the odds ratio to 2.02 (95% CI, 1.23 to 3.34;P=0.006). No significant interactions were found in nonsmokers or with alcohol consumption.Conclusions—The CD14 −159 polymorphism is associated with increased CCA IMT in smokers from a general population. CD14 may modulate the inflammatory effects of smoking in atherogenesis.

Background and Purpose— A J-shaped relationship has been demonstrated between alcohol and both clinical cardiovascular events and carotid atherosclerosis. A similar J-shaped relationship has been found between alcohol intake and inflammatory markers. If inflammation were on the intermediate causal pathway between alcohol intake and atherosclerosis, then genetic determinants of enhanced inflammation would be expected to modify this relationship. Methods— In a large community population (n=1000; age, 50 to 65 years), we studied the effects of the interleukin-6 (IL-6)-174 polymorphism and gene-alcohol interactions on common carotid artery intima-media thickness (CCA-IMT) and carotid plaque. Results— The CC genotype was associated with significantly higher IL-6 levels; the odds ratio (OR) for IL-6 in the top quartile was 2.07 (95% CI, 1.16 to 3.72; P =0.014). Interactions were seen between genotype and alcohol consumption for both IL-6 levels and CCA-IMT. In individuals who drank >30 g/d of alcohol, the CC genotype was associated with higher IL-6 levels, elevated CCA-IMT ( P =0.001), and increased risk of carotid plaque (OR, 3.64; 95% CI, 1.15 to 11.54; P =0.028). The J-shaped relationship between alcohol intake and IMT was seen only for the CC genotype. Conclusions— These data suggest that the IL-6-174 promotor polymorphism may modulate the effects of alcohol on carotid atherosclerosis. These data support the hypothesis that inflammation forms part of the intermediate causal pathway between alcohol intake and atherosclerosis.

Background— Infection with Helicobacter pylori and Chlamydia pneumoniae is associated with coronary heart disease. We conducted an intervention study using antibiotics against these bacteria in patients with acute coronary syndromes to determine whether antibiotics reduce inflammatory markers and adverse cardiac events. Methods and Results— Patients (n=325) admitted with acute myocardial infarction or unstable angina (acute coronary syndromes) were randomized to receive a 1-week course of 1 of 3 treatment regimens: (1) placebo; (2) amoxicillin (500 mg twice daily), metronidazole (400 mg twice daily), and omeprazole (20 mg twice daily); or (3) azithromycin (500 mg once daily), metronidazole (400 mg twice daily), and omeprazole (20 mg twice daily). Serum fibrinogen, white cell count, and high-sensitivity C-reactive protein were measured at study entry and at 1, 3, and 12 months during follow-up. Cardiac death and readmission with acute coronary syndrome were considered clinical end points. Patients were followed for 1 year. C-reactive protein levels were reduced ( P =0.03) in unstable angina patients receiving amoxicillin, and fibrinogen was reduced in both patient groups receiving antibiotics ( P =0.06). There were 17 cardiac deaths and 71 readmissions with acute coronary syndrome. No difference in frequency or timing of end points was observed between the 2 antibiotic groups. At 12 weeks, there was a 36% reduction in all end points in patients receiving antibiotics compared with placebo ( P =0.02). This reduction persisted during the 1-year follow-up. Neither C pneumoniae nor H pylori antibody status was significantly related to response to treatment. Conclusions— Antibiotic treatment significantly reduced adverse cardiac events in patients with acute coronary syndromes, but the effect was independent of H pylori or C pneumoniae seropositivity.

The response to the 2009 A(H1N1) influenza pandemic has highlighted the need for additional strategies for intervention which preclude the prior availability of the influenza strain. Here, 18 single domain VHH antibodies against the 2009 A(H1N1) hemagglutinin (HA) have been isolated from a immune alpaca phage displayed library. These antibodies have been grouped as having either (i) non-neutralising, (ii) H1N1 restricted neutralising or (iii) broad cross-subtype neutralising activity. The ability to neutralise different viral subtypes, including highly pathogenic avian influenza (H5N1), correlated with the absence of hemagglutination inhibition activity, loss of binding to HA at acid pH and the absence of binding to the head domain containing the receptor binding site. This data supports their binding to epitopes in the HA stem region and a mechanism of action other than blocking viral attachment to cell surface receptors. After conversion of cross-neutralising antibodies R1a-B6 and R1a-A5 into a bivalent format, no significant enhancement in neutralisation activity was seen against A(H1N1) and A(H5N1) viruses. However, bivalent R1a-B6 showed an 18 fold enhancement in potency against A(H9N2) virus and, surprisingly, gained the ability to neutralise an A(H2N2) virus. This demonstrates that cross-neutralising antibodies, which make lower affinity interactions with the membrane proximal stem region of more divergent HA sub-types, can be optimised by bivalency so increasing their breadth of anti-viral activity. The broad neutralising activity and favourable characteristics, such as high stability, simple engineering into bivalent molecules and low cost production make these single domain antibodies attractive candidates for diagnostics and immunotherapy of pandemic influenza.

Large-scale studies of genomic variation could assist efforts to eliminate malaria. But there are scientific, ethical and practical challenges to carrying out such studies in developing countries, where the burden of disease is greatest. The Malaria Genomic Epidemiology Network (MalariaGEN) is now working to overcome these obstacles, using a consortial approach that brings together researchers from 21 countries. © 2008 Macmillan Publishers Limited. All rights reserved.

Background and Purpose— Smoking acts as a pro-inflammatory stimulus. Inflammation may provide a key mechanism by which smoking causes atherosclerosis. If so, then the degree to which an individual mounts an inflammatory response is likely to influence atherosclerosis severity. This study examined the impact of inflammatory gene polymorphisms and gene–smoking interactions on common carotid artery intima-media thickness (IMT), a measure of early atherosclerosis. Methods— In a community population (n=1000), mean IMT was determined using ultrasound. This population was genotyped for 6 polymorphisms in 4 inflammatory genes: IL-6-174 , IL-6-572 , and IL-6-597 ; IL-1-β-31 ; IL-1 receptor antagonist VNTR and CD14-159. Serum IL-6 levels were measured in the first 500 subjects. Genotypes/haplotypes associated with higher IL-6 levels were designated “inflammatory haplotypes.” A gene load score was calculated, in which 2 represented individuals homozygous for ≥2 inflammatory genotypes/haplotypes and 0 was homozygous for none. Results— Increasing gene load of inflammatory genotypes was associated with a linear increase in serum IL-6 levels ( P =0.018) and increased carotid artery IMT ( P =0.003). There was a significant interaction between gene load and smoking status on carotid IMT ( P for interaction=0.002). Specifically, in smokers, carriers of inflammatory haplotypes had significantly increased age- and sex-adjusted IMT ( IL-6-174C/IL-6-572G/IL-6-597A , P =0.005; IL-1-β-31T/IL-1RN*2 , P =0.04; CD14-159CC , P =0.028). Conclusions— These findings support the hypothesis that inflammation and cytokine responses provide a key mechanism by which smoking causes atherogenesis. Secondly, they highlight the importance of gene–environment, and gene–gene–environment interactions in the pathogenesis of atherosclerosis.

OBJECTIVE To investigate the effect of the functional CD14 promoter polymorphism on serum liver function tests and abnormally elevated liver function tests in a general population sample. METHODS We recruited 310 subjects at random from general practitioner lists in Surrey. A previously validated medical questionnaire was completed and a serum sample provided for estimation of liver function test and genotyping of CD14 promoter polymorphism. RESULTS The TT polymorphism was associated with significantly reduced serum levels of alanine aminotransferase 0.49 (95% confidence interval 0.26-0.93), gamma-glutamyl transferase 0.49 (95% confidence interval 0.38-0.89) and aspartate aminotransferase 0.48 (95% confidence interval 10.38-0.89). The TT polymorphism was associated with a reduced frequency of liver function test abnormalities, especially gamma-glutamyl transferase (odds ratio 0.113; 0.015-0.851). CONCLUSION The TT promoter polymorphism was associated with reduced serum levels of alanine aminotransferase, gamma-glutamyl transferase and aspartate aminotransferase in healthy patients, and a low level of liver function test abnormalities. The relationship with gamma-glutamyl transferase stands after correction for age, gender, obesity and alcohol consumption. This raises the possibility that this genotype may offer protection from the development of fatty liver disease.

Infection with Helicobacter pylori and Chlamydia pneumoniae is associated with coronary heart disease. We conducted an intervention study using antibiotics against these bacteria in patients with acute coronary syndromes to determine whether antibiotics reduce inflammatory markers and adverse cardiac events.Patients (n=325) admitted with acute myocardial infarction or unstable angina (acute coronary syndromes) were randomized to receive a 1-week course of 1 of 3 treatment regimens: (1) placebo; (2) amoxicillin (500 mg twice daily), metronidazole (400 mg twice daily), and omeprazole (20 mg twice daily); or (3) azithromycin (500 mg once daily), metronidazole (400 mg twice daily), and omeprazole (20 mg twice daily). Serum fibrinogen, white cell count, and high-sensitivity C-reactive protein were measured at study entry and at 1, 3, and 12 months during follow-up. Cardiac death and readmission with acute coronary syndrome were considered clinical end points. Patients were followed for 1 year. C-reactive protein levels were reduced (P=0.03) in unstable angina patients receiving amoxicillin, and fibrinogen was reduced in both patient groups receiving antibiotics (P=0.06). There were 17 cardiac deaths and 71 readmissions with acute coronary syndrome. No difference in frequency or timing of end points was observed between the 2 antibiotic groups. At 12 weeks, there was a 36% reduction in all end points in patients receiving antibiotics compared with placebo (P=0.02). This reduction persisted during the 1-year follow-up. Neither C pneumoniae nor H pylori antibody status was significantly related to response to treatment.Antibiotic treatment significantly reduced adverse cardiac events in patients with acute coronary syndromes, but the effect was independent of H pylori or C pneumoniae seropositivity.

OBJECTIVE—To look for the presence of the more virulent strains of Helicobacter pylori (H pylori) in men who developed ischaemic heart disease over a 10 year period and in controls. DESIGN—The Caerphilly prospective heart disease study recruited 2512 men aged 45-59 years during 1979-83. Western blot analysis or enzyme linked immunosorbent assay (ELISA) was performed on serum taken from those who subsequently died of ischaemic heart disease, or developed non-fatal myocardial infarction, to determine H pylori and Cag A status. Similar information was available on age matched controls. RESULTS—During the first decade of the study, 312 men died of ischaemic heart disease or developed non-fatal myocardial infarction. Serum was available from 172 of these (55%). There was no evidence of an association between Cag A seropositivity and incident ischaemic heart disease or ischaemic heart disease mortality, either before or after adjustment for potential confounders (adjusted odds ratios 1.18 (95% confidence interval (CI) 0.76 to 1.85) and 1.13 (95% CI 0.61 to 2.07), respectively). Further, the odds ratios for ischaemic heart disease incidence and ischaemic heart disease mortality by H pylori seropositivity did not appear to depend on the presence or absence of Cag A strains (p = 0.76 and 0.77, respectively). CONCLUSIONS—In this cohort of middle aged men, followed over a 10 year period, there is little evidence of an association between Cag A seropositivity and either incident ischaemic heart disease or ischaemic heart disease mortality. Keywords: ischaemic heart disease; epidemiology; infection; Helicobacter pylori