Kaposi's sarcoma: breeding ground of herpesviridae - A tour de force over viral evolution (review).

After reviewing the molecular biological basis of prominent theories for the integration of viruses into the earliest forms of living matter, an account is given on the immunoevasive strategies viruses have had to acquire in order to secure their existence against the most sophisticated anti-viral defensive mechanisms evolving in their hosts. Herpes-viridae and Kaposi's sarcoma illustrate the complexity of host-virus relationship. In following the evolutionary steps of simians and hominoids to Homo, it becomes evident that: a) Epstein-Barr virus evolved in Africa and its ancestral viruses are present in cercopithecines and hominoids; b) human herpes-virus-8-related viruses are present in macaques, in S. American primates and in Homo but such isolates from the great apes are missing. Thus interspecies transfer occurred from lower monkeys to Homo but when and at what geographical location? The human retrolentiviruses also jumped species barriers: this occurred recently in Africa, from great apes (chimpanzee and bonobo) to Homo sapiens (except when HIV-2 was transferred to mankind from sooty mangabeys). The matter is further complicated by the long coevolutionary cooperative interactions between herpes- and retrolentiviruses. Of pathological entities suspected to be etiologically affected by such complex viral cooperation, the origin of Reed-Sternberg cells of Hodgkin's disease is singled out for critical analysis. In this article the senior author summarizes his own 52 years of studentship in virology.