Cooperation Between Systemic and Mucosal Antibodies Induced by Virosomal Vaccines Targeting HIV-1 Env: Protection of Indian Rhesus Macaques Against Low-Dose Intravaginal SHIV Challenges.

A virosomal vaccine inducing systemic/mucosal anti-HIV-1 gp41 IgG/IgA had previously protected Chinese-origin rhesus macaques (RMs) against vaginal SHIVSF162P3 challenges. Here, we assessed its efficacy in Indian-origin RMs by intramuscular priming/intranasal boosting (n=12/group). Group K received virosome-P1-peptide alone (harboring the Membrane Proximal External Region), Group L combined virosome-rgp41 plus virosome-P1, and Group M placebo virosomes. Vaccination induced plasma binding but no neutralizing antibodies. Five weeks after boosting, all RMs were challenged intravaginally with low-dose SHIVSF162P3 until persistent systemic infection developed. After SHIV challenge #7, six controls were persistently infected versus only one Group L animal (vaccine efficacy 87%; P=0.0319); Group K was not protected. After a 50% SHIV dose increase starting with challenge #8, protection in Group L was lost. Plasmas/sera were analyzed for IgG phenotypes and effector functions; the former revealed that protection in Group L was significantly associated with increased binding to FcγR2/3(A/B) across several time-points, as were some IgG measurements. Vaginal washes contained low-level anti-gp41 IgGs and IgAs, representing a 1-to-5-fold excess over the SHIV inoculum's gp41 content, possibly explaining loss of protection after the increase in challenge-virus dose. Virosomal gp41-vaccine efficacy was confirmed during the initial seven SHIV challenges in Indian-origin RMs when the SHIV inoculum had at least 100-fold more HIV RNA than acutely infected men's semen. Vaccine protection by virosome-induced IgG and IgA parallels the cooperation between systemically administered IgG1 and mucosally applied dimeric IgA2 monoclonal antibodies that as single-agents provided no/low protection - but when combined, prevented mucosal SHIV transmission in all passively immunized RMs

Defense-in-depth by mucosally administered anti-HIV dimeric IgA2 and systemic IgG1 mAbs: complete protection of rhesus monkeys from mucosal SHIV challenge.

Although IgA is the most abundantly produced immunoglobulin in humans, its role in preventing HIV-1 acquisition, which occurs mostly via mucosal routes, remains unclear. In our passive mucosal immunizations of rhesus macaques (RMs), the anti-HIV-1 neutralizing monoclonal antibody (nmAb) HGN194, given either as dimeric IgA1 (dIgA1) or dIgA2 intrarectally (i.r.), protected 83% or 17% of the RMs against i.r. simian-human immunodeficiency virus (SHIV) challenge, respectively. Data from the RV144 trial implied that vaccine-induced plasma IgA counteracted the protective effector mechanisms of IgG1 with the same epitope specificity. We thus hypothesized that mucosal dIgA2 might diminish the protection provided by IgG1 mAbs targeting the same epitope. To test our hypothesis, we administered HGN194 IgG1 intravenously (i.v.) either alone or combined with i.r. HGN194 dIgA2. We enrolled SHIV-exposed, persistently aviremic RMs protected by previously administered nmAbs; RM anti-human IgG responses were undetectable. However, low-level SIV Gag-specific proliferative T-cell responses were found. These animals resemble HIV-exposed, uninfected humans, in which local and systemic cellular immune responses have been observed. HGN194 IgG1 and dIgA2 used alone and the combination of the two neutralized the challenge virus equally well in vitro. All RMs given only i.v. HGN194 IgG1 became infected. In contrast, all RMs given HGN194 IgG1+dIgA2 were completely protected against high-dose i.r. SHIV-1157ipEL-p challenge. These data imply that combining suboptimal defenses at the mucosal and systemic levels can completely prevent virus acquisition. Consequently, active vaccination should focus on defense-in-depth, a strategy that seeks to build up defensive fall-back positions well behind the fortified frontline.We thank Dr. J. Mascola for providing mAb VRC01, Dr. S.-L. Hu for providing SHIV-1157ip Env proteins, and Dr. W. Marasco for providing mAb Fm-6. We thank Dr. K. Rogers and K. Kinsley for TRIM5α genotype analysis, Dr. S. Lee for assistance in statistical analysis, V. Shanmuganathan for technical assistance, and Juan Esquivel for assistance with the preparation of the manuscript. This was work supported by the Bill and Melinda Gates Foundation Collaboration for AIDS Vaccine Discovery (CAVD) UCL-VDC Grant 38637 (R.A.W.). This project was also funded in part by NIH grants P01 AI048240, R01 AI100703 and R37 AI034266 to RMR. Base grant P51 OD011132 provided support to the Yerkes National Primate Research Center. The Southwest National Primate Research Center is supported by an NIH primate center base grant (previously NCRR grant P51 RR013986; currently Office of Research Infrastructure Programs/OD P51 OD011133).This is the accepted manuscript of a paper published in Vaccine (Sholukh AM, et al., Vaccine, 2015, 33, 2086-2095, doi:10.1016/j.vaccine.2015.02.020). The final version is available at http://dx.doi.org/10.1016/j.vaccine.2015.02.02

Passive immunization of macaques with polyclonal anti-SHIV IgG against a heterologous tier 2 SHIV: outcome depends on IgG dose

Background: A key goal for HIV-1 envelope immunogen design is the induction of cross-reactive neutralizing antibodies (nAbs). As AIDS vaccine recipients will not be exposed to strains exactly matching any immunogens due to multiple HIV-1 quasispecies circulating in the human population worldwide, heterologous SHIV challenges are essential for realistic vaccine efficacy testing in primates. We assessed whether polyclonal IgG, isolated from rhesus monkeys (RMs) with high-titer nAbs (termed SHIVIG), could protect RMs against the R5-tropic tier-2 SHIV-2873Nip, which was heterologous to the viruses or HIV-1 envelopes that had elicited SHIVIG. Results: SHIVIG demonstrated binding to HIV Gag, Tat, and Env of different clades and competed with the broadly neutralizing antibodies b12, VRC01, 4E10, and 17b. SHIVIG neutralized tier 1 and tier 2 viruses, including SHIV-2873Nip. NK-cell depletion decreased the neutralizing activity of SHIVIG 20-fold in PBMC assays. Although SHIVIG neutralized SHIV-2873Nip in vitro, this polyclonal IgG preparation failed to prevent acquisition after repeated intrarectal low-dose virus challenges, but at a dose of 400 mg/kg, it significantly lowered peak viremia (P = 0.001). Unexpectedly, single-genome analysis revealed a higher number of transmitted variants at the low dose of 25 mg/kg, implying increased acquisition at low SHIVIG levels. In vitro, SHIVIG demonstrated complement-mediated Ab-dependent enhancement of infection (C’-ADE) at concentrations similar to those observed in plasmas of RMs treated with 25 mg/kg of SHIVIG. Conclusion: Our primate model data suggest a dual role for polyclonal anti-HIV-1 Abs depending on plasma levels upon virus encounter

Bronchiectasis in India:results from the European Multicentre Bronchiectasis Audit and Research Collaboration (EMBARC) and Respiratory Research Network of India Registry

BACKGROUND: Bronchiectasis is a common but neglected chronic lung disease. Most epidemiological data are limited to cohorts from Europe and the USA, with few data from low-income and middle-income countries. We therefore aimed to describe the characteristics, severity of disease, microbiology, and treatment of patients with bronchiectasis in India. METHODS: The Indian bronchiectasis registry is a multicentre, prospective, observational cohort study. Adult patients ( 6518 years) with CT-confirmed bronchiectasis were enrolled from 31 centres across India. Patients with bronchiectasis due to cystic fibrosis or traction bronchiectasis associated with another respiratory disorder were excluded. Data were collected at baseline (recruitment) with follow-up visits taking place once per year. Comprehensive clinical data were collected through the European Multicentre Bronchiectasis Audit and Research Collaboration registry platform. Underlying aetiology of bronchiectasis, as well as treatment and risk factors for bronchiectasis were analysed in the Indian bronchiectasis registry. Comparisons of demographics were made with published European and US registries, and quality of care was benchmarked against the 2017 European Respiratory Society guidelines. FINDINGS: From June 1, 2015, to Sept 1, 2017, 2195 patients were enrolled. Marked differences were observed between India, Europe, and the USA. Patients in India were younger (median age 56 years [IQR 41-66] vs the European and US registries; p<0\ub70001]) and more likely to be men (1249 [56\ub79%] of 2195). Previous tuberculosis (780 [35\ub75%] of 2195) was the most frequent underlying cause of bronchiectasis and Pseudomonas aeruginosa was the most common organism in sputum culture (301 [13\ub77%]) in India. Risk factors for exacerbations included being of the male sex (adjusted incidence rate ratio 1\ub717, 95% CI 1\ub703-1\ub732; p=0\ub7015), P aeruginosa infection (1\ub729, 1\ub710-1\ub750; p=0\ub7001), a history of pulmonary tuberculosis (1\ub720, 1\ub707-1\ub734; p=0\ub7002), modified Medical Research Council Dyspnoea score (1\ub732, 1\ub725-1\ub739; p<0\ub70001), daily sputum production (1\ub716, 1\ub703-1\ub730; p=0\ub7013), and radiological severity of disease (1\ub703, 1\ub701-1\ub704; p<0\ub70001). Low adherence to guideline-recommended care was observed; only 388 patients were tested for allergic bronchopulmonary aspergillosis and 82 patients had been tested for immunoglobulins. INTERPRETATION: Patients with bronchiectasis in India have more severe disease and have distinct characteristics from those reported in other countries. This study provides a benchmark to improve quality of care for patients with bronchiectasis in India. FUNDING: EU/European Federation of Pharmaceutical Industries and Associations Innovative Medicines Initiative inhaled Antibiotics in Bronchiectasis and Cystic Fibrosis Consortium, European Respiratory Society, and the British Lung Foundation

International genome-wide meta-analysis identifies new primary biliary cirrhosis risk loci and targetable pathogenic pathways.

Primary biliary cirrhosis (PBC) is a classical autoimmune liver disease for which effective immunomodulatory therapy is lacking. Here we perform meta-analyses of discovery data sets from genome-wide association studies of European subjects (n=2,764 cases and 10,475 controls) followed by validation genotyping in an independent cohort (n=3,716 cases and 4,261 controls). We discover and validate six previously unknown risk loci for PBC (Pcombined<5 × 10(-8)) and used pathway analysis to identify JAK-STAT/IL12/IL27 signalling and cytokine-cytokine pathways, for which relevant therapies exist

Prospective, multicentre study of screening, investigation and management of hyponatraemia after subarachnoid haemorrhage in the UK and Ireland

Background: Hyponatraemia often occurs after subarachnoid haemorrhage (SAH). However, its clinical significance and optimal management are uncertain. We audited the screening, investigation and management of hyponatraemia after SAH. Methods: We prospectively identified consecutive patients with spontaneous SAH admitted to neurosurgical units in the United Kingdom or Ireland. We reviewed medical records daily from admission to discharge, 21 days or death and extracted all measurements of serum sodium to identify hyponatraemia (&lt;135 mmol/L). Main outcomes were death/dependency at discharge or 21 days and admission duration &gt;10 days. Associations of hyponatraemia with outcome were assessed using logistic regression with adjustment for predictors of outcome after SAH and admission duration. We assessed hyponatraemia-free survival using multivariable Cox regression. Results: 175/407 (43%) patients admitted to 24 neurosurgical units developed hyponatraemia. 5976 serum sodium measurements were made. Serum osmolality, urine osmolality and urine sodium were measured in 30/166 (18%) hyponatraemic patients with complete data. The most frequently target daily fluid intake was &gt;3 L and this did not differ during hyponatraemic or non-hyponatraemic episodes. 26% (n/N=42/164) patients with hyponatraemia received sodium supplementation. 133 (35%) patients were dead or dependent within the study period and 240 (68%) patients had hospital admission for over 10 days. In the multivariable analyses, hyponatraemia was associated with less dependency (adjusted OR (aOR)=0.35 (95% CI 0.17 to 0.69)) but longer admissions (aOR=3.2 (1.8 to 5.7)). World Federation of Neurosurgical Societies grade I–III, modified Fisher 2–4 and posterior circulation aneurysms were associated with greater hazards of hyponatraemia. Conclusions: In this comprehensive multicentre prospective-adjusted analysis of patients with SAH, hyponatraemia was investigated inconsistently and, for most patients, was not associated with changes in management or clinical outcome. This work establishes a basis for the development of evidence-based SAH-specific guidance for targeted screening, investigation and management of high-risk patients to minimise the impact of hyponatraemia on admission duration and to improve consistency of patient care

Stromelysin-1 and hepatic stellate cells

This thesis examines the synthesis and secretion of stromelysin-1 in a culture model of rat HSC activation, its role in HSC proliferation and its binding to the HSC surface membrane through a high affinity binding site.Highly pure (&gt;98% characterised by Vitamin A autofluorescence) HSC were prepared by pronase/collagenase perfusion, differential centrifugation and centrifugal elutriation. By Northern analysis, stromelysin-1 mRNA was undetectable in freshly isolated HSC, peaked after 3 days and declined below the detection limit at 7 days (n=6) relative to ribosomal S14 mRNA. Released stromelysin-1 activity was characterised by zymography of serum-free HSC conditioned media (HSCCM) in the presence of enzyme inhibitors and by Western blotting. Intracellular stromelysin was demonstrated in cultured desmin-positive HSC by dual indirect immunofluorescence. Interestingly, the intensity of stromelysin expression was vividly heterogeneous with large clumps of strongly positive, rounded cells containing pleomorphic nuclei. Continued stromelysin-1 activity was seen by zymography of HSCCM harvested after 3, 7, 14 and 21 days in culture but net quantitative 14C-β-casein degradation (per &mu;g DNA) was reduced sevenfold in prolonged culture. Analysis of cell conditioned media by zymography showed that stromelysin release by HSC was downregulated by culture on a model basement membrane and was not a feature of cultured Kupffer cells, sinusoidal endothelial cells or hepatocytes.Confocal autofluorescence subtraction microscopy displayed cell surface immunofluoresence for endogenously secreted stromelysin by freshly cultured HSC.These data show that HSC synthesise and secrete stromelysin in early primary culture. I addition, expression of stromelysin-1 by cultured HSC may be important in permitting or mediation cellular proliferation in the presence of serum. Current evidence indicates this is an extracellular effect mediated by the proteinase activity of stromelysin and that hepatic stellate cells possess an as yet uncharacterised high affinity cell surface binding site for stromelysin-1.</p