We recently developed a novel strategy to identify transmitted HIV-1 genomes in acutely infected humans using single-genome amplification and a model of random virus evolution. Here, we used this approach to determine the molecular features of simian immunodeficiency virus (SIV) transmission in 18 experimentally infected Indian rhesus macaques. Animals were inoculated intrarectally (i.r.) or intravenously (i.v.) with stocks of SIVmac251 or SIVsmE660 that exhibited sequence diversity typical of early-chronic HIV-1 infection. 987 full-length SIV env sequences (median of 48 per animal) were determined from plasma virion RNA 1–5 wk after infection. i.r. inoculation was followed by productive infection by one or a few viruses (median 1; range 1–5) that diversified randomly with near starlike phylogeny and a Poisson distribution of mutations. Consensus viral sequences from ramp-up and peak viremia were identical to viruses found in the inocula or differed from them by only one or a few nucleotides, providing direct evidence that early plasma viral sequences coalesce to transmitted/founder viruses. i.v. infection was >2,000-fold more efficient than i.r. infection, and viruses transmitted by either route represented the full genetic spectra of the inocula. These findings identify key similarities in mucosal transmission and early diversification between SIV and HIV-1, and thus validate the SIV–macaque mucosal infection model for HIV-1 vaccine and microbicide research.

Background/Aims: Systemic inflammatory response (SIR) is widely considered as a preoperative risk factor for hepatocellular carcinoma (HCC) outcomes. The neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR), two of the prognostic indices, have been investigated in post-therapeutic recurrence and survival of HCC. Here, we quantify the prognostic value of these two biomarkers and evaluate their consistency in different HCC therapies. Methods: A systematic review of electronic database of the Web of Science, Embase, PubMed and the Cochrane Library was conducted to search for associations between the NLR and PLR in the blood and clinical outcomes of HCC. Overall survival (OS) and recurrence-free survival (RFS) were the primary outcomes, and hazard ratios (HRs) and 95% confidence intervals (95% CIs) were explored as effect measures. Subgroup analyses were performed to explore the heterogeneity of different therapies. Results: A total of 24 articles comprising 6318 patients were included in the meta-analysis. Overall, the pooled outcomes revealed that a high NLR before treatment predicted a poor OS (HR: 1.54, 95% CI: 1.34 to 1.76, p<0.001) and poor RFS (HR: 1.45, 95% CI: 1.16 to 1.82, p=0.001). Moreover, an increased PLR predicted a poor OS (HR: 1.63, 95% CI: 1.34 to 1.98, p<0.001) and earlier HCC recurrence (HR: 1.52, 95% CI: 1.21 to 1.91, p<0.001). In addition, both the NLR and PLR were identified as independent risk factors for predicting OS and RFS in HCC patients in a subgroup analysis of different treatment types, including curative or palliative therapy; however, these results were not found in the sorafenib subgroup due to limited clinical research. Conclusion: An increased NLR or PLR indicated poor outcomes for patients with HCC. The NLR and PLR may be considered as reliable and inexpensive biomarkers for making clinical decisions regarding HCC treatment.

HIV-1 mucosal transmission begins with virus or virus-infected cells moving through mucus across mucosal epithelium to infect CD4+ T cells. Although broadly neutralizing antibodies (bnAbs) are the type of HIV-1 antibodies that are most likely protective, they are not induced with current vaccine candidates. In contrast, antibodies that do not neutralize primary HIV-1 strains in the TZM-bl infection assay are readily induced by current vaccine candidates and have also been implicated as secondary correlates of decreased HIV-1 risk in the RV144 vaccine efficacy trial. Here, we have studied the capacity of anti-Env monoclonal antibodies (mAbs) against either the immunodominant region of gp41 (7B2 IgG1), the first constant region of gp120 (A32 IgG1), or the third variable loop (V3) of gp120 (CH22 IgG1) to modulate in vivo rectal mucosal transmission of a high-dose simian-human immunodeficiency virus (SHIV-BaL) in rhesus macaques. 7B2 IgG1 or A32 IgG1, each containing mutations to enhance Fc function, was administered passively to rhesus macaques but afforded no protection against productive clinical infection while the positive control antibody CH22 IgG1 prevented infection in 4 of 6 animals. Enumeration of transmitted/founder (T/F) viruses revealed that passive infusion of each of the three antibodies significantly reduced the number of T/F genomes. Thus, some antibodies that bind HIV-1 Env but fail to neutralize virus in traditional neutralization assays may limit the number of T/F viruses involved in transmission without leading to enhancement of viral infection. For one of these mAbs, gp41 mAb 7B2, we provide the first co-crystal structure in complex with a common cyclical loop motif demonstrated to be critical for infection by other retroviruses.

A novel influenza A (H7N9) virus of avian origin emerged in eastern China in the spring of 2013. This virus causes severe disease in humans, including acute and often lethal respiratory failure. As of January 2014, 275 cases of H7N9-infected patients had been reported, highlighting the urgency of identifying biomarkers for predicting disease severity and fatal outcomes. Here, we show that plasma levels of angiotensin II, a major regulatory peptide of the renin-angiotensin system, are markedly elevated in H7N9 patients and are associated with disease progression. Moreover, the sustained high levels of angiotensin II in these patients are strongly correlated with mortality. The predictive value of angiotensin II is higher than that of C-reactive protein and some clinical parameters such as the PaO 2 /FiO 2 ratio (partial pressure of arterial oxygen to the fraction of inspired oxygen). Our findings indicate that angiotensin II is a biomarker for lethality in flu infections.