Ferrets are a valuable animal model of disease, particularly for human respiratory infections such as influenza. The similarities and distribution of common sialic acid receptors between humans and ferrets position ferrets favorably as a relevant animal model. In the case of influenza research the restricted sialic acid receptors expressed in mice require viruses be mouse adapted, however, ferrets require no adaptation to be productively infected. Additionally, the similarities in the ferret and human sneeze reflex make ferrets even more applicable as a model for human transmission studies. Despite the apparent suitability of ferrets to inform and predict human responses to respiratory infections, widespread adoption of the ferret model is disadvantaged by the dearth of available reagents.
Panels of human and mouse regents have been evaluated for cross-reactivity, and while some T cell reagents have been identified, there are notable gaps in the availability of reagents of critical importance. Trusted mAbs for CD4 and CD8 have been identified, however to date no reliable reagent has been found to identify ferret CD3.
To address this deficiency we endeavored to develop a useful robust reagent for the identification of CD3 positive cells. Fc fusion constructs of ferret CD3 where cloned and expressed for murine immunization. Following significant serum titre, hybridomas were generated and screened against lymph node cells by flow cytometry. Several candidate mAbs were identified and validated as anti-CD3 reagents. We have now used these and other reagents to characterize the T cell compartment within the ferret to show functional similarities to other mammalian species. This will be an invaluable tool for analyzing the immune response in the ferret for influenza and other disease models.
This work was supported in part by the National Collaborative Research Infrastructure Strategy (NCRIS) and the Australian Research Council (ARC).