Principles of Cytotoxic T Lymphocyte Induction and Recognition

In this chapter I will discuss neither HIV nor its associated dementia; instead I will focus on the principles which underlie the importance of cytotoxic T lymphocytes (CTLs) in controlling viral infections and the means by which these critical antiviral effectors can be induced. Viral infections remain major causes of human morbidity and mortality. Vaccination has eradicated smallpox and has diminished the incidence of the more severe viral infections (mumps, rubella, measles and polio), at least in the “developed” countries. However, in “underdeveloped” countries the incidence of many of these diseases remains high, and the morbidity and mortality consequent upon the infections remains significant. For example, measles virus infections in the third world lead directly or indirectly to an estimated 1–2 million deaths per year. Furthermore, since the appearance of HIV the contribution of viruses to human suffering has escalated enormously, and forecasts suggest that this will increase in the years to come. At present of course there is no vaccine for HIV, and this drives much of the current effort to molecularly dissect the antiviral immune response.