ABSTRACT
Immune defence against foot-and-mouth disease virus (FMDV) has been related to the antibody-mediated compartments affording protection in both animal models and natural hosts. Induction of the specific immune response involves the B lymphocytes recognising epitopes on the virus particle to produce specific antibody. In addition, the concomitant recognition of T lymphocyte epitopes following antigen processing and presentation in the context of MHC class II molecules is essential. This ensures stimulation of helper (Th) lymphocytes to produce the growth and differentiation factors necessary for the development of the immune response. The humoral response in sera against FMDV is well documented, with high titres of virus-specific antibody being related to protection against challenge infection. This relationship is not absolute, because animals with the same titre of specific antibody can differ in their resistance to FMDV infection. Effector immunity involves antibody concentrations, antibody affinities, and the involvement of the phagocytic system to remove the antibody/virus complexes and destroy the virus Conversely, little is known about the role of cytotoxic lymphocytes (CTL) in protection against FMDV.
In this chapter on the immunology of foot-and-mouth disease, the immune response against FMDV will be dealt with in detail, from the induction of the response to the effector defences generated. The induction will be presented from the viewpoint of the immune system and the cellular interactions involved, as well as from the viewpoint of the virus in terms of the epitopes recognised by the compartments of the immune system. Effector immunity will be presented in terms of the current evidence on the functioning of both the innate and adaptive (or specific) immune defences. Therein, the capacity of FMDV to modulate immune responses, and use cells of the immune defence for transport in the host will also be described.
