The result of a statistic analysis regarding the grant applications submitted to “Virus, Viral Infection & Host Immunity, Medical Science, National Natural Science Foundation, Code H1904” in the last ten years is presented. The purpose of the paper is to support the potential applicants in the field.
Lassa fever (LF) caused by Lassa virus (LASV) is an acute hemorrhagic zoonotic disease transmitted to humans by rodent. The disease has high mortality, and mainly endemic in West Africa. However, the imported cases have been reported in many countries worldwide. In this review, we focus on the etiology of Lassa virus, disease prevalence, clinical features, laboratory testing, treatment and prevention. In light of the global economic integration, it is recommended that the strengthening of prevention and control of Lassa fever, establishment of international strategies on prevention measures, and integration into the global system should be paid more attention.
Hepatitis B virus X protein (HBx), a 154-amino acid protein encoded by hepatitis B virus (HBV), has been implicated in the development of hepatocellular carcinoma (HCC). The aim of the present study is to establish a complete and dominant peptide sequence of HBx. A total of 13 950 HBx protein sequences were retrieved from GenBank. After excluding the non-complete ones that harbor insertions, deletions and non-methionine start amino acid, 7 126 were included in the study. Occurrence frequencies of the 20 amino acids at each position of HBx were calculated. The amino acid with the highest frequency at each position was designated as the dominant amino acid at the position and all the dominant residues constituted the complete and dominant peptide sequence of HBx. All the non-dominant amino acids were taken as the mutants. 32 hotspots with a mutation rate over 10.0% were detected. The positions 36, 42, 44, 87, 88, and 127 showed a higher polymorphism, having more than 4 kinds of mutations with a rate over 1.0%. The K130M/V131I dual mutation, regarded as a high risk factor of HBV-related HCC, showed an occurrence frequency at 34.7% in this study. The homology between the dominant sequence and each of the 7 126 HBx sequences was calculated. 50 sequences, which included 2 sequences with a homology to the dominant below 75% and 48 sequences with a homology between 76%-99%, were chosen for phylogenetic tree construction. The phylogenetic tree with the dominant HBx, 50 selected HBx and 23 reference sequences showed that the dominant HBx belonged to genotype C. This study has systematically constituted a calculated HBx peptide sequence with dominant amino acid at each position, laying the foundation for the basic and applied research on HBx.
The aim of this study is to investigate the role of human cytomegalovirus (HCMV) infection in glioma pathogenesis and its possible mechanism. Based on the previous experiments, the expressions of signal transducer and activator of transcription 3 (STAT3) and endocan in HCMV-infected U87 cells, a human glioma cell line, were detected, and the relationship among HCMV, STAT3 and endocan was analyzed. The results showed that HCMV infection induced the upregulation of endocan mRNA and protein as well as the activated STAT3 in U87 cells. On the other hand, decreased levels of endocan mRNA and protein were observed in U87-STAT3-knockdown cells by RNAi. Furthermore, downregulated levels of endocan mRNA and protein were found in U87 cells treated by ganciclovir, an anti-viral drug. Then the expression of pSTAT3 in 79 glioma specimens and 8 control brain tissues was detected by immunohistochemistry (IHC) and the relationship between pSTAT3 level and glioma grade was analyzed. Compared with the control brain samples, increased level of pSTAT3 was found in glioma specimens and the staining intensity was related to glioma grade. The results suggest that HCMV infection is involved in glioma pathogenesis via upregulating endocan expression through STAT3 signaling pathway, and further provide some new clues for the treatment of glioma.
A total of 31 representative strains of influenza A virus H3N2 subtype isolated at different time and regions in Nanjing between 2013 and 2014 through influenza pathogen monitoring system were selected for this study. The genetic distance between the vaccine strain A/Texas/50/2012 and the isolated group at nucleotide and amino acid levels were 0.010 2 and 0.012 1, respectively. The similarities of nucleotide and amino acid sequence were 97.9%-99.6% and 97.2%-99.3%, respectively. The phylogenetic analysis showed that hemagglutinin (HA) gene of 31 isolates could be divided into several groups. Three 2013 strains belonged to 3B, three 2014 strains belonged to 3C.1, two 2014 strains belonged to 3C.2b and the other 23 strains belonged to 3C.3a. Compared with the vaccine strain, the accumulated mutations on epitopes reached 24. The amino acid substitutions of N128A/T and P198S/A on HA in 31 isolates were observed. A new glycosylation site 126 NWT occurred in 7 isolates, and 45NSS and 144NNS glycosylation sites disappeared in 3 isolates. The results suggest that HA gene of H3N2 has a significant variation compared to the vaccine strain, and this may be related to the vaccine prevention program in Jiangsu Province during 2013-2014.
The present study aims to investigate the epidemiological characteristics of influenza in Shanghai children during 2013-2015, and to provide evidence-based data for influenza control and prevention. The throat swab samples were collected from the influenza-like cases at a sentinel surveillance hospital in Shanghai during 2013-2015, according to the National Influenza Surveillance Program and Influenza Virus and Experimental Technology. The samples were subjected to real-time reverse transcriptase-polymerase chain reaction (RT-PCR) for influenza virus detection. A total of 3 359 samples were collected during 2013-2015, and 540 samples were influenza virus-positive, including 105 influenza A (H1N1), 158 influenza B and 277 H3 subtype, with a positive detection rate of 16.08%. The positive rates of influenza virus were 10.02%, 19.02% and 20.81% in 2013, 2014 and 2015, respectively. The detection rate was the lowest (7.67%) in the infants younger than 1.0 year and the highest (31.83%) in the children older than 7.0 years. The results showed that the peak of influenza epidemic appeared twice in one year. The peak of detection rate of influenza B and H1N1 appeared in winter and spring (December to March), whereas the peak in July to September was caused by H3. The predominant type of influenza virus changed from H3 to H3 and B after 2013. The results suggest that the predominant subtype of influenza virus in children has changed after 2013 in this sentinel surveillance hospital, and the monitoring of influenza B should be strengthened.
The blood-brain barrier (BBB) is an important protective structure to maintain the homeostasis of the central nervous system, limiting the invasion of most pathogens in the blood. Some viruses can cross the BBB to invade the central nervous system by cellular and (or) paracellular ways, causing neurological dysfunction. The cellular ways consist of direct infection of the brain microvascular endothelial cells and transcellular pathway. The paracellular ways are composed of breaching of the tight junction between endothelial cells and the “Trojan horse” pathway. In this review, the current research progress on viral impacts on the BBB is summarized.
Varicella-zoster virus (VZV) may cause latent infection and its reactivation is associated with zoster (shingles). The mechanism behind the VZV reactivation is still unclear. Here, the experimental models developed for VZV latency study are described and the updated knowledge is summarized.
With the consecutive innovation and application of gene sequencing technology, the third generation sequencing (TGS) based on single molecule real time (SMRT) sequencing technology has demonstrated a potential in a variety of applications in basic and clinical studies, including whole genome assembly, detection of gene structure variation, epigenetic research, etc. This review mainly introduces the principle, characteristics and applications of the TGS technology, especially its applications in virus researches. This review also compares the differences between the next generation sequencing (NGS) and TGS, so as to provide a reference for application based selection for sequencing technology.