Survey and future research in immunology of infectious disease

A review by E. Lee

Immunology and Evolution of Infectious Disease. By Steven A., Frank. Princeton University Press. 2002. Paper $24.95/£17.95 ISBN 0-691-09595-7. Cloth $75.00/£52.00 ISBN 0-691-09594-9. 352 pp.

As stated in the book's introduction, it is necessary to understand multiple disciplines in order to understand immunology and evolution of infectious disease. The author provides this background by guiding the reader through basic details of molecular biology, the population-wide evolutionary race between host and parasite, and the steps in between. He also provides an in-depth summary of a biological system involving multiple spatial and temporal scales. This book is not the first of its kind: it is however, still important for two reasons. (1) The rapid rate of scientific development makes it easy for one to specialize in a single field while losing connection with others. With fewer than 300 pages, this book provides a relatively compact, yet in-depth summary of a broad and detailed array of results. (2) As an active researcher in the field, the author can provide an insider's view. Each chapter concludes with a section stating what he believes are the important questions and future directions. The final chapter is devoted to the same topic.

The book is divided into five parts. (1) Minimal background details necessary to understand the rest of book are given. (2) Molecular processes by which the host recognizes the parasite are described. A brief overview of common mechanisms by which the parasite escapes detection is also given. (3) Infection within a single host is described. Initial focus is on immunodominance, where the host recognizes the parasite with a small number of many possible epitopes. An overview is given of the dynamics of parasite recognition to illustrate selection pressures on the host as well as potential problems with immundominance for the host. The focus then shifts to the parasite, where it is explained how the parasite escapes detection within a host. The author looks at real examples of the human immunodeficiency and hepatitis C viruses to see how parasites interfere with host immunity. (4) The focus shifts from the individual host to a population of hosts. The author points out that some qualities can only be seen at the population scale. Examples are genetic variation and the distribution of immune memory profiles in the host population. Effects of host populations on the parasites are described. (5) Methods of understanding how evolution leads to antigenic variation in the parasite are described. One method is to compare immunological and phylogenetic information to determine whether the immune system is imposing stabilizing or divergent selection. Another is experimental evolution, where host properties are manipulated and the resulting evolution of parasite antigens are observed in the laboratory. Particular examples include foot-and-mouth disease, influenza and leukaemia viruses. A third method was to look at synonymous and non-synonymous mutations in natural populations to determine the degree of selection on viral amino acids.

The author effectively connects immunology and evolution whenever possible. Development of ideas is smooth and the book is for the most part, self-contained. It also provides an excellent survey, and with over 500 references, it makes a good reference guide to current developments. This makes it suitable for researchers and graduate students in related fields, as well as an excellent starting point for interdisciplinary research or topics for a graduate seminar. This book should also be of considerable interest to those studying the link between genotypes and phenotypes, or genotype–phenotype maps. Viruses are ideal for at least two reasons: (1) they are simple enough so that the interaction between viral parts and how they contribute to fitness can be effectively studied as the author explains with experimental evolution and (2) they are structurally rich enough to produce non-trivial behaviour. Recent results as well as the author's suggestions for future research may provide a glimpse into important future developments for genotype–phenotype map studies. Undergraduates and newcomers may however, experience difficulty. By the nature of the discipline, the book is very dense and difficult to read straight through. This is helped by the summaries at the beginning of each chapter, each of the five parts, and in the introduction. Another difficulty for the non-expert is that there are relatively few pictures, making it difficult to visualize many of the systems. Reference books may be helpful, especially when molecular descriptions are involved.