Detection of Hantaan virus RNA from anti-Hantaan virus IgG seronegative rodents in an area of high endemicity in Republic of Korea.

Hantaan virus (HTNV), of the family Bunyaviridae, causes hemorrhagic fever with renal syndrome (HFRS) in humans. Although the majority of epidemiologic studies have found that rodents are seropositive for hantavirus-specific immunoglobulin, the discovery of hantavirus RNA in seronegative hosts has led to an investigation of the presence of HTNV RNA in rodents captured in HFRS endemic areas. HTNV RNA was detected in seven (3.8%) of 186 anti-HTNV IgG seronegative rodents in Republic of Korea (ROK) during 2013-2014. RT-qPCR for HTNV RNA revealed dynamic virus-host interactions of HTNV in areas of high endemicity, providing important insights into the epidemiology of hantaviruses.

Phylogeographic analysis of hemorrhagic fever with renal syndrome patients using multiplex PCR-based next generation sequencing.

Emerging and re-emerging infectious diseases caused by RNA viruses pose a critical public health threat. Next generation sequencing (NGS) is a powerful technology to define genomic sequences of the viruses. Of particular interest is the use of whole genome sequencing (WGS) to perform phylogeographic analysis, that allows the detection and tracking of the emergence of viral infections. Hantaviruses, Bunyaviridae, cause hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS) in humans. We propose to use WGS for the phylogeographic analysis of human hantavirus infections. A novel multiplex PCR-based NGS was developed to gather whole genome sequences of Hantaan virus (HTNV) from HFRS patients and rodent hosts in endemic areas. The obtained genomes were described for the spatial and temporal links between cases and their sources. Phylogenetic analyses demonstrated geographic clustering of HTNV strains from clinical specimens with the HTNV strains circulating in rodents, suggesting the most likely site and time of infection. Recombination analysis demonstrated a genome organization compatible with recombination of the HTNV S segment. The multiplex PCR-based NGS is useful and robust to acquire viral genomic sequences and may provide important ways to define the phylogeographical association and molecular evolution of hantaviruses.

Genetic Diversity and Reassortment of Hantaan Virus Tripartite RNA Genomes in Nature, the Republic of Korea.

BACKGROUND: Hantaan virus (HTNV), a negative sense tripartite RNA virus of the Family Bunyaviridae, is the most prevalent hantavirus in the Republic of Korea (ROK). It is the causative agent of Hemorrhagic Fever with Renal Syndrome (HFRS) in humans and maintained in the striped field mouse, Apodemus agrarius, the primary zoonotic host. Clinical HFRS cases have been reported commonly in HFRS-endemic areas of Gyeonggi province. Recently, the death of a member of the ROK military from Gangwon province due to HFRS prompted an investigation of the epidemiology and distribution of hantaviruses in Gangwon and Gyeonggi provinces that border the demilitarized zone separating North and South Korea. METHODOLOGY AND PRINCIPAL FINDINGS: To elucidate the geographic distribution and molecular diversity of HTNV, whole genome sequences of HTNV Large (L), Medium (M), and Small (S) segments were acquired from lung tissues of A. agrarius captured from 2003-2014. Consistent with the clinical incidence of HFRS established by the Korea Centers for Disease Control & Prevention (KCDC), the prevalence of HTNV in naturally infected mice in Gangwon province was lower than for Gyeonggi province. Whole genomic sequences of 34 HTNV strains were identified and a phylogenetic analysis showed geographic diversity of the virus in the limited areas. Reassortment analysis first suggested an occurrence of genetic exchange of HTNV genomes in nature, ROK. CONCLUSION/SIGNIFICANCE: This study is the first report to demonstrate the molecular prevalence of HTNV in Gangwon province. Whole genome sequencing of HTNV showed well-supported geographic lineages and the molecular diversity in the northern region of ROK due to a natural reassortment of HTNV genomes. These observations contribute to a better understanding of the genetic diversity and molecular evolution of hantaviruses. Also, the full-length of HTNV tripartite genomes will provide a database for phylogeographic analysis of spatial and temporal outbreaks of hantavirus infection.

Active regulator of SIRT1 cooperates with SIRT1 and facilitates suppression of p53 activity.

Human SIRT1 is an NAD+-dependent deacetylase protein that plays a role in cell death/survival, senescence, and endocrine signaling. While its substrates, including p53, have been well characterized, no direct regulators are known. We describe here a nuclear protein, active regulator of SIRT1 (AROS), which directly regulates SIRT1 function. AROS enhanced SIRT1-mediated deacetylation of p53 both in vitro and in vivo, and it inhibited p53-mediated transcriptional activity. AROS activity was abrogated by the SIRT1 inhibitors splitomicin and nicotinamide and by SIRT1 small interfering RNA (siRNA). In addition, AROS was unable to cooperate in p53 inactivation in an AROS-binding-defective SIRT1 mutant. Finally, knockdown of endogenous AROS using an antisense expression vector enhanced p21WAF1 expression and increased both the G0/G1 population and apoptosis in response to DNA damage, while AROS overexpression improved cell survival. To our knowledge, AROS is the first direct SIRT1 regulator to be identified that modulates p53-mediated growth regulation.