ABSTRACT
This chapter focuses on some features of heat shock proteins as they are of potential relevance to the host-pathogen relationship, maintenance of host integrity, and eventual emergence of autoaggressive reactions. The heat shock proteins are paradigmatic members of this group. Parasitic microorganisms have played a tremendous role in the evolution of humans. Parasites are microbes which live at the expense of their mammalian hosts. Although some of these parasites interact with their hosts loosely, others achieve intimate contact, thus causing stable infection. Evolutionary thinking holds that the length of the epitope has not evolved arbitrarily but rather represents the outcome of a balanced process between avoidance of antiself responses on the one hand and broad covering of as many foreign entities as possible. The host immune system encounters the world of pathogenic microbes at a nonspecific and a specific level. The specific arm focuses on and improves the response initiated by the nonspecific effector system.
