M Cooper - Böcker

The aberrant replication pathway of foamy viruses distinguishes them from all other retroviruses. Many details have been accumulated over the past ten or so years. Most of the findings on foamy viruses were obtained by research on a single virus isolate previously called "human foamy virus", which appeared to be the first to be investigated on a molecular level. However, to the editor's knowledge, genuine human foamy viruses do not exist, but several trans-species transmissions of different simian foamy viruses from monkeys and apes to human hosts.

Marek's disease virus (MDV) is a herpesvirus which causes a lymphoproliferative disorder of the domestic chicken worldwide. This serious economical problem caused by MDV was mostly solved by development of an effective vaccine against MDV. The development of live vaccines against the disease is remarkable as it has led to the first example of a commercially available vaccine against cancer as well as against diseases caused by herpesviruses.This volume gives an overview on many aspects of MDV research and summarizes recent advances in the field. The topics include the history, biology,and molecular biology of MDV, pathogenesis, vaccinal immunity, immune response, genetic resistance and development of recombinant polyvalent vaccines. It is hoped that this volume will make an important contribution towards the control of infectious diseases.

Binding of various ligands (hormones, neurotransmitters, immunological stimuli) to membrane receptors induces the following changes: 1. Receptor redistribution (clustering, "capping") 2. Conformational changes that can be detected by fluorescent probes 3. Alteration in membrane fluidity (spin label and fluorescence polarization probes) 4. Changes in fluxes of ions and metabolites 5. Increased phospholipid turnover (especially of phosphatidyl inositol) 6. Activation of membrane-bound enzymes (adenyl cyclase, ATPase, transmethylases). Some of the early changes resulting from or associated with the binding (adsorption) of virions to the host cell membrane are of the same type. Adsorption of animal viruses to cells is the ftrst step in a chain of events resulting in the production of progeny virus on the one hand and in damage to cells and tissues on the other. In the classical studies of viral infection, cells are adsorbed with virus, usually for 60 min, and the changes induced by the virus in the host cell are recorded thereafter. In the past decade, more and more studies have been aimed at the events occurring in these ftrst 60 min of the so-called adsorption period. These studies deal with the nature of adsorption, e. g. , the ligand-receptor type of interaction between the virus and the cell membrane. Many receptors for viruses were identifted and so were the viral proteins which take part in adsorption.