Decreased Pre-existing Ad5 Capsid and Ad35 Neutralizing Antibodies Increase HIV-1 Infection Risk in the Step Trial Independent of Vaccination

<div><h3>Background</h3><p>The Step trial raised the possibility that uncircumcised men with pre-existing Ad5 neutralizing antibodies carried an increased risk of HIV infection after vaccination. Thus, understanding Ad seropositivity in humans is important to the development of an AIDS vaccine. Here, we analyze the impact of different Ad5-specific neutralizing antibodies on immune function and clinical outcome.</p> <h3>Methods and Findings</h3><p>Ad seropositivity in the Step trial volunteers was analyzed using chimeric rAd5/35 vectors to characterize their specificity for Ad5 fiber and non-fiber external (capsid) proteins. Immune responses and HIV seropositivity were correlated with the specificity of Ad5-neutralizing antibodies. Neutralizing antibodies induced by the vaccine in Ad5 seronegative subjects were directed preferentially to Ad5 capsid proteins, although some fiber-neutralizing antibodies could be detected. Pre-vaccination Ad5 serostatus did not affect the capsid-directed response after three vaccinations. In contrast, anti-fiber antibody titers were significantly higher in volunteers who were Ad5 seropositive prior to vaccination. Those Ad5 seropositive subjects who generated anti-capsid responses showed a marked reduction in vaccine-induced CD8 responses. Unexpectedly, anti-vector immunity differed qualitatively in Ad5 seropositive participants who became HIV-1 infected compared to uninfected case controls; Ad5 seropositive participants who later acquired HIV had lower neutralizing antibodies to capsid. Moreover, Ad35 seropositivity was decreased in HIV-infected subjects compared with uninfected case controls, while seroprevalence for other serotypes including Ad14, Ad28 and Ad41 was similar in both groups.</p> <h3>Conclusions</h3><p>Together, these findings suggest that the case subjects were less immunologically responsive prior to infection. Subjects infected during the Step trial had qualitative differences in immunity that increased their risk of HIV-1 infection independent of vaccination.</p> </div

Evaluating the sensitivity and specificity of promising circulating biomarkers to diagnose liver injury in humans

Early diagnosis of drug-induced liver injury (DILI) continues to be a major hurdle during drug development and post marketing. The objective of this study was to evaluate the diagnostic performance of promising biomarkers of liver injury - glutamate dehydrogenase (GLDH), cytokeratin-18 (K18), caspase-cleaved K18 (ccK18), osteopontin (OPN), macrophage colony-stimulating factor (MCSF), MCSF receptor (MCSFR), and microRNA-122 (miR-122) in comparison to the traditional biomarker alanine aminotransferase (ALT). Biomarkers were evaluated individually and as a multivariate model in a cohort of acetaminophen overdose (n=175) subjects and were further tested in cohorts of healthy adults (n=135), patients with liver damage from various causes (n=104), and patients with damage to the muscle (n=74), kidney (n=40), gastrointestinal tract (n=37) and pancreas (n=34). In the acetaminophen cohort, a multivariate model with GLDH, K18 and miR-122 was able to detect DILI more accurately than individual biomarkers alone. Furthermore, the three-biomarker model could accurately predict patients with liver injury compared to healthy volunteers or patients with damage to muscle, pancreas, gastrointestinal tract and kidney. Expression of K18, GLDH ad miR-122 was evaluated using a database of transcriptomic profiles across multiple tissues/organs in humans and rats. K18 mRNA (Krt18) and MiR-122 were highly expressed in liver whereas GLDH mRNA (Glud1) was widely expressed. We performed a comprehensive, comparative performance assessment of seven promising biomarkers and demonstrated that a three-biomarker multivariate model can accurately detect liver injury

MOESM1 of Vaccination with recombinant adenovirus expressing peste des petits ruminants virus-F or -H proteins elicits T cell responses to epitopes that arises during PPRV infection

Additional file 1. Gating strategies for IFN-γ detection, cytotoxicity assays and CD45RO expression. (A) For IFN-γ detection, cells were selected by FSC/SSC discrimination. Gating for IFN-γ+ events was set using fluorescence minus one antibody (isotype) staining for CD4+ and CD8+ events. This gating was then maintained to measured IFN-γ+ events in stimulated cells. (B) In cytotoxicity assays, FSC/SSC discrimination was applied to gate putative live and dead cell events. Target cells labelled with the cell membrane marker PKH67 were first run on the cytometer to set up the target cell gate (PKH67+ events). Propidium iodide was used to discriminate live and dead cells. Bright PKH67+ and propidium iodide+ events were considered dead target cells. For each target cells, spontaneous and maximum cell death controls were acquired. In cytotoxicity co-culture assays, specific target cell lysis was assessed in the bright PKH67+gate. (C) For CD45RO expression, cells were first selected selected by FSC/SSC discrimination followed by CD4 or CD8 gating. Within these CD4+ or CD8+ gates, CD45RO+ gate was set using fluorescence minus one antibody (isotype) staining

A dendritic cell targeted vaccine induces long-term HIV-specific immunity within the gastrointestinal tract

Despite significant therapeutic advances for HIV-1 infected individuals, a preventative HIV-1 vaccine remains elusive. Studies focusing on early transmission events, including the observation that there is a profound loss of gastrointestinal (GI) CD4(+) Tcells during acute HIV-1 infection, highlight the importance of inducing HIV-specific immunity within the gut. Here we report on the generation of cellular and humoral immune responses in the intestines by a mucosally administered, dendritic cell (DC) targeted vaccine. Our results show that nasally delivered alpha-CD205-p24 vaccine in combination with polyICLC, induced polyfunctional immune responses within naso-pulmonary lymphoid sites that disseminated widely to systemic and mucosal (GI tract and the vaginal epithelium) sites. Qualitatively, while alpha-CD205-p24 prime-boost immunization generated CD4(+) T-cell responses, heterologous prime-boost immunization with alpha-CD205-p24 and NYVAC gag-p24 generated high levels of HIV-specific CD4(+) and CD8(+) Tcells within the GI tract. Finally, DC-targeting enhanced the amplitude and longevity of vaccine-induced immune responses in the GI tract. This is the first report of a nasally delivered, DC-targeted vaccine to generate HIV-specific immune responses in the GI tract and will potentially inform the design of preventative approaches against HIV-1 and other mucosal infectionsclos