Laboratory animal models to study foot-and-mouth disease: a review with emphasis on natural and vaccine-induced immunity

Abstract

Laboratory animal models have provided valuable insight into foot-and-mouth disease virus (FMDV) pathogenesis in epidemiologically important target species. While not perfect, these models have delivered an accelerated time frame to characterize the immune responses in natural hosts and a platform to evaluate therapeutics and vaccine candidates at a reduced cost. Further expansion of these models in mice has allowed access to genetic mutations not available for target species, providing a powerful and versatile experimental system to interrogate the immune response to FMDV and to target more expensive studies in natural hosts. The purpose of this review is to describe commonly used FMDV infection models in laboratory animals and to cite examples of when these models have failed or successfully provided insight relevant for target species, with an emphasis on natural and vaccine-induced immunity.

Fig. 1.

(a) Striated ventricle muscle fibres of a BALB/c mouse 1 day after IP challenge with FMDV O UKG 34/2001. FMDV capsid (green) is localized to cardiomyocytes [red, phalloidin; blue, 4′,6-diamidino-2-phenylindole (DAPI)]. (b) Pancreas of a C57BL/6 mouse 1 day after IP challenge with FMDV O UKG 34/2001. FMDV capsid (green) is detectable in the pancreas [red, insulin (islets of Langerhans); blue, DAPI]. No FMDV capsid was detected in pancreas samples at 28 or 46 days post IP challenge (data not shown). (c) Pancreas of a C57BL/6 mouse 21 days post ovalbumin IP inoculation. Routine haematoxylin and eosin (H & E) stain demonstrates the normal morphology of the pancreas: A, glandular acinar cells of the exocrine pancreas; D, interlobular duct; I, islets of Langerhans of the exocrine pancreas; S, septa of the collagenous capsule. (d) Pancreas of a C57BL/6 mouse 21 days after IP challenge with FMDV O UKG 34/2001. Routine H & E stain demonstrates the chronic pathology following FMDV infection: A, acinar cells; C, cellular infiltration; I, islets of Langerhans. Bars: (a, b) 40 µm, (c, d) 100 µm.