Genetic control of the immune repertoire in nematode infections

Mammals vary considerably, both within and between species, in the way in which their innate and adaptive immune systems respond to infections. An understanding of the processes involved in such variability will not only contribute to explaining heterogeneity in susceptibility and pathology, but will also be relevant to vaccination. This will be particularly important for the new generation of vaccines that are likely to be composed of one or a few cloned or synthesized antigens. For helminth infections, this could have particular relevance to hypersensitivity responses. The adaptive immune response is fundamentally constrained by the genetic constitution of an individual, and the need to avoid reactivity to self. This will have important implications for the dynamic relationship between host defences and parasite evasion mechanisms at both physiological and evolutionary levels. In this review, Malcolm Kennedy examines the genetic control of the specificity of the immune response to nematode infections, and in particular, the role of the major histocompatibility complex.