Intracellular immunoglobulin A (icIgA) in protective immunity and vaccines.

Virus neutralization at respiratory mucosal surfaces is important in the prevention of infection. Mucosal immunity is mediated mainly by extracellular secretory immunoglobulin A (sIgA) and its role has been well studied. However, the protective role of intracellular specific IgA (icIgA) is less well defined. Initially, in vitro studies using epithelial cell lines with surface expressed polymeric immunoglobulin receptor (pIgR) in transwell culture chambers have shown that icIgA can neutralize influenza, parainfluenza, HIV, rotavirus and measles viruses. This effect appears to involve an interaction between polymeric immunoglobulin A (pIgA) and viral particles within an intracellular compartment, since IgA is transported across the polarized cell. Co-localization of specific icIgA with influenza virus in patients' (virus culture positive) respiratory epithelial cells using well-characterized antisera was initially reported in 2018. This review provides a summary of in vitro studies with icIgA on colocalization and neutralization of the above five viruses. Two other highly significant respiratory infectious agents with severe global impacts viz. SARS-2 virus (CoViD pandemic) and the intracellular bacterium-Mycobacterium tuberculosis-are discussed. Further studies will provide more detailed understanding of the mechanisms and kinetics of icIgA neutralization in relation to viral entry and early replication steps with a specific focus on mucosal infections. This will inform the design of more effective vaccines against infectious agents transmitted via the mucosal route.

Using online simulations to teach biochemistry laboratory content during COVID-19.

At the University of South Australia (UniSA), Biochemistry is a second year undergraduate course. The student cohort is diverse, with students enrolled in courses with a laboratory focus, such as Laboratory Medicine, Medical Science, Nutrition and Food Science and Pharmaceutical Science. The course is taught in a traditional manner, with weekly lectures, fortnightly tutorials and three practical sessions. In response to the growing numbers of COVID-19 cases, in mid-March the University leadership moved to cease face-to-face teaching. By this time, 58 of 96 students had completed the first two (of three) face-to-face laboratory practicals. In response to this decision, teaching of all practical based content was moved online for all students. The first question was, how do we teach practical content online? And secondly, how do we teach hands-on skills? The first question was addressed using a suite of online simulations, progressively developed since 2013. Simulations are widely used and shown to be useful as teaching aids in STEM. A total of five simulations were introduced each covering key aspects of laboratory practice, including fundamental mathematical skills, reading, and setting a pipette, basic Biochemistry assays, protein quantification, and enzyme kinetics. The second issue of teaching hands on skills was addressed once restrictions were eased. Students were invited to attend the laboratory to learn the kinesthetic skills with instructor guidance. Both approaches used proved to be highly effective and can be readily adapted not only to teaching Biochemistry, but any aspect of science education.