Immune Response Regulations in Parasitic Infections

Abstract

The yearly death toll in the major infectious diseases plaguing primarily tropical and subtropical areas of the world is estimated to be appr. 18 million (WHO, Geneva, reproduced in Science, 1992, 256:1135). These figures do not account for the enormous background of morbidity caused by these diseases and their disastrous consequences both for those directly affected and for the socioeconomic development of the countries concerned. Seen in these perspectives, it may appear surprising that only a relatively minor fraction of worldwide research in immunology during the past decades has dealt with the immunology of infection. This situation seems, however, to be changing slowly partly because of the increasing need to fight infectious diseases by immunological manipulation, i.e. with vaccines. This has led to the recognition that construction of modern vaccines requires better insights in the basic mechanisms involved in immunity to infection. Much of the research in this area has dealt with the characterization and cloning of pathogen derived antigens expected to give rise to protective immunity in the infected host. However, more recently, attention has also been given to the various factors regulating immune protection. Some of these regulations will be exemplified and discussed in the following.