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Although anucleated, blood platelets are extraordinarily
efficient cells and still the subject of fruitful investigations
in haematology, in vascular physiology, in biochemistry,
and more recently in immunology and in physiopathology
where their metabolism has been implicated
as a source of potential effector compounds. It is
challenging for cell physiologists that these blood elements
reset so strongly to environmental stimuli,
expressing a tremendous and rapid modification of their
shape and metabolism, with only their intrinsic and relatively
locked properties and without the active machinery
of the nucleus. Platelet literature already covers yards of
shelves in haematology departments, in blood centre
libraries and in atherosclerosis research laboratories. Why
produce a new book in such a well-explored area? It is to
the credit of Dr Clive Page, the series editor of The Handbook
of Immunopharma~ology, that he has focused thought
over the last decade, by his own investigations and by a
careful survey of the literature, on the involvement of
blood platelets outside their classical field of application,
and more precisely in physiopathological mechanisms of
allergy and inflammation. We have logically let him
present an introductory chapter, which summarizes,
with great precision what will be found in more detail in
the other contributions to this work.
Dr Boris Vargaftig, at the Institute Pasteur in Paris, has
contributed largely to the development of animal models
in allergic and inflammatory disorders, and is particularly
well qualified to present here, with the collaboration of
Dr Anthony Coyle, a review of such models for investigating
the potential implications of platelets in these
pathologies. The results they, and others, have obtained
with animal substitutes have thrown some light on a
possible place for platelets in the cell network of acute
inflammation or allergic reactions, and more particularly,
asthma. As already stressed above, another fascinating
aspect of platelets is the absence of a nucleus, which
strengthens the importance of the membrane and receptors
in the physiological mechanisms of thrombocyte
activation, together with the understanding of the intracellular
signalling pathways sustaining their haematological
functions. The rapidly moving knowledge in this
domain has been carefully covered by the specialists in
the matter, Dr Michael Kroll and Dr Andrew Schafer in
Houston. Although specifically centred on biochemical
mechanisms leading to aggregation, their extensive analysis
brings interesting perspectives to the potential
participation of platelets in immunological and physiopathological
processes. Their contribution is perfectly
complemented by that of Dr John McGregor, in Lyon,
which has taken into account the active role played by
adhesion molecules and membrane-bound ligands in
mediating the platelet involvement in inflammation. |
