Adhesion Protein Protocols

Adhesion molecules are of fundamental importance in the regulation of immunity, inflammation, tissue remodeling, and embryonic development. They comprise different families of homologous proteins, such as selectins, integrins, cadherins, and immunoglobins. In addition, beyond these groups, other str- tures with adhesive properties, such as proteoglycans, occludin, and CD44, have been characterized recently. An understanding of the type and characteristics of adhesive molecules expressed by the different cell types and the possibility of manipulating their activity promises considerable clinical potential. Antibodies, small peptidic and nonpeptidic molecules, have recently been used to inhibit thrombosis by blocking platelet aggregation or inflammation through inhibition of leukocyte infiltration and adhesion. Inhibitors of adhesive molecules are used in expe- mental systems for the study of tumor growth and dissemination. Among major goals in the field are the identification of new members of the known adhesive protein families and of independent new adhesive structures. After structural characterization, even more demanding is the study of the biological activity of the new proteins, and the development of simple, rapid tests for the screening of possible inhibitors. In this regard, the production of such reagents as fragments and antibodies would help define the structurefunction relati- ship of individual proteins. Data available in the literature show the complexity of the adhesive process and how different molecular epitopes might contribute to the adhesive properties of a single structure. Finally, a new area of investi- tion is the characterization of the intracellular signaling cascade triggered by the engagement of transmembrane adhesive proteins.