Assessing the potential pandemic risk of recent avian influenza viruses

The immune-adjunctive potential of recombinant LAB vector expressing murine IFNλ3 (MuIFNλ3) against Type A Influenza Virus (IAV) infection

BACKGROUND

The conventional means of controlling the recurring pandemics of Type A Influenza Virus (IAV) infections remain challenging primarily because of its high mutability and increasing drug resistance. As an alternative to control IAV infections, the prophylactic use of cytokines to drive immune activation of multiple antiviral host factors has been progressively recognized. Among them, Type III Interferons (IFNs) exhibit a pivotal role in inducing potent antiviral host responses by upregulating the expression of several antiviral genes, including the Interferon-Stimulated Genes (ISGs) that specifically target the virus replication machinery. To harness the immuno-adjunctive potential, we examined whether pre-treatment of IFNλ3, a Type III IFN, can activate antiviral host responses against IAV infections.

METHODS

In the present study, we bioengineered a food-grade lactic acid-producing bacteria (LAB), Lactococcus lactis (L. lactis), to express and secrete functional murine IFNλ3 (MuIFNλ3) protein in the extracellular milieu. To test the immune-protective potential of MuIFNλ3 secreted by recombinant L. lactis (rL. lactis), we used murine B16F10 cells as an in vitro model while mice (BALB/c) were used for in vivo studies.

RESULTS

Our study demonstrated that priming with MuIFNλ3 secreted by rL. lactis could upregulate the expression of several antiviral genes, including Interferon Regulatory Factors (IRFs) and ISGs, without exacerbated pulmonary or intestinal inflammatory responses. Moreover, we also showed that pre-treatment of B16F10 cells with MuIFNλ3 can confer marked immune protection against mice-adapted influenza virus, A/PR/8/1934 (H1N1) infection.

CONCLUSION

Since the primary target for IAV infections is the upper respiratory and gastrointestinal tract, immune activation without affecting the tissue homeostasis suggests the immune-adjunctive potential of IFNλ3 against IAV infections.

Choosing awareness over fear: Risk analysis and free trade support global food security

Livestock production and global trade are key components to achieving food security, but are bedfellows with the risk for emergence and spread of infectious diseases. The World Trade Organization's Agreement on the Application of Sanitary and Phytosanitary Measures outlines provisions for member countries to protect animal, plant, and public health while promoting free trade. The capacity for risk analysis equips countries to increase access to export markets, improve local animal health and food safety regarding known hazards, and build the institutional capacity to respond to unexpected events. The COVID-19 pandemic has highlighted the need to detect, report, and implement effective response measures to emerging challenges on a local and global scale, and it is crucial that these measures are implemented in a way that supports food production and trade. The use of risk analysis coupled with sound understanding of underlying system dynamics will contribute to resilient and enduring food systems.

Systematic identification of chicken type I, II and III interferon-stimulated genes

Interferon-stimulated genes (ISGs) play an important role in antiviral innate immune responses. Although many ISGs have been identified in mammals, researchers commonly recognize that many more ISGs are yet to be discovered. Current information is still very limited particularly for the systematic identification of type III ISGs. Similarly, current research on ISGs in birds is still in its infancy. The aim of this study was to systematically identify chicken type I (IFN-α), II (IFN-γ) and III (IFN-λ) ISGs and analyze their respective response elements. RNA sequencing (RNA-Seq) was employed to identify those genes with up-regulated expression following chicken IFN-α, IFN-γ and IFN-λ treatment. Two hundred and five type I ISGs, 299 type II ISGs, and 421 type III ISGs were identified in the chicken. We further searched for IFN-stimulated response elements (ISRE) and gamma-activated sequences (GAS) elements in the promoters region of ISGs. The GAS elements were common in the promoter of type II ISGs and were even detected in type I and III ISGs. However, ISRE were not commonly found in the promoters of chicken ISGs. Furthermore, we demonstrated that ISRE in chicken cells were significantly activated by IFN-α or IFN-λ treatment, and expectedly, that GAS elements were also significantly activated by IFN-γ treatment. Interestingly, we also found that GAS elements were significantly activated by IFN-λ. Our study provides a systematic library of ISGs in the chicken together with preliminary information about the transcriptional regulation of the identified ISGs.

A Review of Laboratory-Acquired Infections in the Asia-Pacific: Understanding Risk and the Need for Improved Biosafety for Veterinary and Zoonotic Diseases

A rapid review was performed to determine (1) the number and causes of reported laboratory-acquired infections (LAI) in the Asia-Pacific region; (2) their significance and threat to the community; (3) the primary risk factors associated with LAIs; (4) the consequences in the event of a LAI or pathogen escape; and (5) to make general recommendations regarding biosafety practices for diagnosis and research in the Asia-Pacific region. A search for LAI and zoonoses in the Asia-Pacific region using online search engines revealed a relatively low number of reports. Only 27 LAI reports were published between 1982 and 2016. The most common pathogens associated with LAIs were dengue virus, Arthroderma spp., Brucella spp., Mycobacterium spp., Rickettsia spp., and Shigella spp. Seventy-eight percent (21 out of 27 LAI reports) occurred in high-income countries (i.e., Australia, Japan, South Korea, Singapore, and Taiwan) where laboratories were likely to comply with international biosafety standards. Two upper-middle income countries (China (2), and Malaysia (2)) and one lower-middle income country (India (2)) reported LAI incidents. The majority of the reports (fifty-two percent (14/27)) of LAIs occurred in research laboratories. Five LAI reports were from clinical or diagnostic laboratories that are considered at the frontier for zoonotic disease detection. Governments and laboratories in the Asia-Pacific region should be encouraged to report LAI cases as it provides a useful tool to monitor unintended release of zoonotic pathogens and to further improve laboratory biosafety. Non-reporting of LAI events could pose a risk of disease transmission from infected laboratory staff to communities and the environment. The international community has an important and continuing role to play in supporting laboratories in the Asia-Pacific region to ensure that they maintain the safe working environment for the staff and their families, and the wider community.