Teaching the laboratory assessment of neutrophil chemotaxis: a simulation-based approach for undergraduate immunology.

Neutrophils are essential cellular components of innate immunity. After injury, they migrate into tissues following chemotactic gradients to phagocytose pathogens or respond to tissue damage. This multistep process is tightly regulated, and defects at any stage can lead to increased bacterial infections. Identifying specific defects requires specialized assays, yet teaching the assessment of these functions in a laboratory setting presents challenges. At the University of South Australia, undergraduate immunology is taught to students training as laboratory medicine scientists, who must understand how to assess neutrophil function. However, demonstrating chemotaxis in the laboratory is not possible due to a lack of inverted microscopes, restricted laboratory time, and lack of patient samples with defined neutrophil defects. To address this, we developed a computer simulation replicating the under-agarose method of quantifying neutrophil chemotaxis. In the simulation, students load both "control" and "patient" samples and measure both random and directed migration toward 5 common chemoattractants. Using an in-house-defined reference range, they determine the immunological status of each sample. The simulation's impact was evaluated using a mixed-methods approach, incorporating Likert-scale questionnaires, free-text feedback, and scores from laboratory reports. Student feedback was overwhelmingly positive, with the simulation significantly enhancing their understanding of neutrophil function. All students successfully completed the report, typically achieving high grades. These findings support the use of authentic computer-based simulations as effective alternatives for teaching complex immunological techniques in resource-limited settings, offering a practical and engaging solution to challenges in traditional laboratory instruction.