The triphibious warfare against viruses

Biosafety and immunology: An interdisciplinary field for health priority

Biosafety hazards can trigger a host immune response after infection, invasion, or contact with the host. Whether infection with a microorganism results in disease or biosafety concerns depends to a large extent on the immune status of the population. Therefore, it is essential to investigate the immunological characteristics of the host and the mechanisms of biological threats and agents to protect the host more effectively. Emerging and re-emerging infectious diseases, such as the current coronavirus disease 2019 (COVID-19) pandemic, have raised concerns regarding both biosafety and immunology worldwide. Interdisciplinary studies involved in biosafety and immunology are relevant in many fields, including the development of vaccines and other immune interventions such as monoclonal antibodies and T-cells, herd immunity (or population-level barrier immunity), immunopathology, and multispecies immunity, i.e., animals and even plants. Meanwhile, advances in immunological science and technology are occurring rapidly, resulting in important research achievements that may contribute to the recognition of emerging biosafety hazards, as well as early warning, prevention, and defense systems. This review provides an overview of the interdisciplinary field of biosafety and immunology. Close collaboration and innovative application of immunology in the field of biosafety is becoming essential for human health.

Metagenomic analysis of viromes in tissues of wild Qinghai vole from the eastern Tibetan Plateau

Rodents are natural reservoirs of diverse zoonotic viruses and widely distributed on the Tibetan Plateau. A comprehensive understanding of the virome in local rodent species could provide baseline of viral content and assist in efforts to reduce the risk for future emergence of rodent related zoonotic diseases. A total of 205 tissue and fecal samples from 41 wild Qinghai voles were collected. Metagenomic analyses were performed to outline the characteristics of the viromes, and phylogenetic analyses were used to identify the novel viral genomes. The virome distribution among five tissues (liver, lung, spleen, small intestine with content and feces) was also compared. We identified sequences related to 46 viral families. Novel viral genomes from distinct evolutionary lineages with known viruses were characterized for their genomic and evolutionary characteristics, including Hepatovirus, Hepacivirus, Rotavirus, and Picobirnavirus. Further analyses revealed that the core virome harbored by rodent internal tissues were quite different from the virome found in intestine and fecal samples. These findings provide an overview of the viromes in wild Qinghai voles, which are unique and the most common rodent species in the eastern Tibetan Plateau. A high diversity of viruses is likely present in rodent species in this area.

Avian influenza A (H7N9) virus: from low pathogenic to highly pathogenic

The avian influenza A (H7N9) virus is a zoonotic virus that is closely associated with live poultry markets. It has caused infections in humans in China since 2013. Five waves of the H7N9 influenza epidemic occurred in China between March 2013 and September 2017. H7N9 with low-pathogenicity dominated in the first four waves, whereas highly pathogenic H7N9 influenza emerged in poultry and spread to humans during the fifth wave, causing wide concern. Specialists and officials from China and other countries responded quickly, controlled the epidemic well thus far, and characterized the virus by using new technologies and surveillance tools that were made possible by their preparedness efforts. Here, we review the characteristics of the H7N9 viruses that were identified while controlling the spread of the disease. It was summarized and discussed from the perspectives of molecular epidemiology, clinical features, virulence and pathogenesis, receptor binding, T-cell responses, monoclonal antibody development, vaccine development, and disease burden. These data provide tools for minimizing the future threat of H7N9 and other emerging and re-emerging viruses, such as SARS-CoV-2.

Genomic epidemiological characteristics of dengue fever in Guangdong province, China from 2013 to 2017

Dengue fever, a mosquito-borne viral disease in humans, has been endemic in many Southeast Asian countries. Since its first outbreak in 1978 in Foshan, Guangdong province, China, dengue has been continually epidemic in recent years in Guangdong, which raised the concern whether dengue infection is endemic in Guangdong. In this study, we performed phylogenetic, recombinant, and nucleotide variation analyses of 114 complete genome sequences of dengue virus serotypes 1–4 (DENV1-4) collected from 2013 to 2017 in 18 of 21 cities of Guangdong. Phylogenetic analyses revealed that DENV sequences did not form a single cluster, indicating that dengue fever was not endemic in Guangdong, although DENV1-4 co-circulated in Guangdong. Twenty intra-serotype recombinant isolates involving DENV1-4 were detected, but no inter-serotype recombinant events were identified in this study. Additionally, the most recombinant events were detected simultaneously in the gene NS3 of DENV1-4. Nucleotide variation analyses showed that no significant intra-serotype differences were observed, whereas more significant inter-subtype differences were discovered in non-structural genes than in structural genes. Our investigation will facilitate the understanding of the current prevalent status of dengue fever in Guangdong and contribute to designing more effective preventive and control strategies for dengue infection.

In 1978, dengue fever was first reported in Guangdong province, China, and this has been continuously prevalent in Guangdong in recent years. This is responsible for the heavy burden on the control of dengue, and raises the concern about whether dengue outbreaks have become endemic in Guangdong. Previous studies based on single E gene or few full-length genome sequences were inconclusive. In this study, we sequenced 114 DENV complete genomes of DENV1-4 obtained from 2013 to 2017 in Guangdong and further analyzed the epidemiological and molecular characteristics. Phylogenetic analyses revealed that dengue fever was not endemic in Guangdong, which was indirectly supported by results of our recombination analyses. Nucleotide variation analyses indicated that purification selection shaped dengue virus population. Our investigation will facilitate the development of more effective epidemiological surveillance strategies for dengue infection.

Peptide presentation by bat MHC class I provides new insight into the antiviral immunity of bats

Bats harbor many zoonotic viruses, including highly pathogenic viruses of humans and other mammals, but they are typically asymptomatic in bats. To further understand the antiviral immunity of bats, we screened and identified a series of bat major histocompatibility complex (MHC) I Ptal-N*01:01-binding peptides derived from four different bat-borne viruses, i.e., Hendra virus (HeV), Ebola virus (EBOV), Middle East respiratory syndrome coronavirus (MERS-CoV), and H17N10 influenza-like virus. The structures of Ptal-N*01:01 display unusual peptide presentation features in that the bat-specific 3-amino acid (aa) insertion enables the tight "surface anchoring" of the P1-Asp in pocket A of bat MHC I. As the classical primary anchoring positions, the B and F pockets of Ptal-N*01:01 also show unconventional conformations, which contribute to unusual peptide motifs and distinct peptide presentation. Notably, the features of bat MHC I may be shared by MHC I from various marsupials. Our study sheds light on bat adaptive immunity and may benefit future vaccine development against bat-borne viruses of high impact on humans.

Laboratory biosafety in China: past, present, and future

The launch of the new journal, Biosafety and Health, presents me with a unique opportunity to recount the progress of laboratory biosafety (LB) in China and my contribution to this area over the past 30 years. Since the severe acute respiratory syndrome epidemic in 2003, China has constructed a primary network of high-level biosafety laboratories at different levels and established an expert team on LB. Furthermore, a series of LB management documents, including laws, regulations, standards, and guidelines, have been developed and published. This gradually maturing LB system has played a pivotal role in emerging infectious disease control and prevention, as well as in research, which in turn contributes to public health. In recent years, international collaboration between China and other countries has also been accelerated. Despite these achievements, we are still facing many challenges and opportunities in the field of LB. Sustainable LB development requires the joint efforts of the entire society and continuous international cooperation to safeguard global public health.