The Molecular Basis of B‐Cell and T‐Cell Development.

Abstract

All lymphohaemopoietic cells arise from common precursors. Complex regulatory processes determine committment to the different lineages. Among these, B and T lymphocytes differ from all other haemopoietic cells because they develop into clonally unique progenies through appropriate events of negative and positive selection that eliminate autoreactive and non-functional elements. Experimental approaches, skill, ingenuity and insights that are bound to either ‘immunology’ or ‘experimental hematology’ are necessary to understand the mechanisms that control the commitment of stem cells to the B- and T-cell lineage and the developmental regulations of lymphoid precursors. The purpose of this book is to organize a fast-moving field and its overwhelming amount of information that comes from the intersection of different disciplines into a comprehensive and coherent perspective. By and large the editors have succeeded in their aim by selecting as authors of the different chapters a number of high-rank scientists that include several world-leading authorities in their respective fields. The structure of the book is lucid and logical. It starts with a part on stem cell and lineage commitment models, where hard facts and their interpretations are carefully blended. It then moves to the analysis of intrinsic and extrinsic factors that regulate B and T lymphopoiesis. Next comes the part on commitment and ordered developmental progression of lymphoid lineages, followed by a number of chapters dealing with the selection processes that operate during B- and T-lymphocyte development. A final part deals with the clinical applications of the basic studies on haematolymphoid development. Two points emerge from a careful reading of this book and deserve additional comments. First, the increasing power of technology which is clearly changing the rules of the game. In the recent past lymphoid malignancies provided the only valuable source to study the early events of lymphoid differentiation and the properties of normal cells were inferred from those of the malignant ones or, at best, the malignant cell samples were used to track back to the normal situation. Now, the reverse has become true. Normal cells, irrespective of their scarcity, can be identified, purified and analysed at molecular level. So we can plan to use our knowledge of these early events occurring in normal precursors to investigate what has gone awry in leukaemic cell populations. The second comment concerns the clinical applications of the technology and the information thereby obtained by basic science studies. These investigations are of fundamental importance to understand the mechanisms of leukaemogenesis, to exploit how the immune system may reconstitute after bone marrow transplantation, to develop innovative treatments based upon the manipulations of the immune system, and also to provide a source of cells for gene therapy. A beautiful example of clinical application is the chapter by Eder and Silberstein on Placental Blood. In the next edition of this book I would expect a more expanded section on these clinical topics. Unfortunately, no one requested to review a book for a major journal feels comfortable until he has found some criticism to raise and I am no exception. Actually, the book is sometimes, for typographical reasons, not very easy to read. The chapters are very packed and the different sections within individual chapters are not always clearly demarcated. One would also like to see more schemes, figures or cartoons; surprisingly, the few which are present do not have the quality one would expect and like to see in such a book. Notwithstanding these minor details, Molecular Biology of B-cell and T-cell Development is a book that I recommend to a number of people with different scientific and clinical interests. It should be on the shelves of Immunology and Haematology Departments. Also, people ranging from molecular biologists to clinicians involved in the treatment of blood malignancies and in bone marrow transplantation should be well aware of how valuable a source of information this book is.