Lymphocyte trafficking research has produced extremely provoking results in the past two years. Observations dating from 1988 showed that L- selectin (GP90mel) bound to polymeric fucose-sulfates (fucoidin), polyphosphomannans, and inhibited binding of lymphocytes to high endothelial venules. This suggested a carbohydrate involvement in the interaction. In 1989, cloning and sequencing demonstrated that 3 proteins, E-Selectin (Endothelial/Leukocyte Adhesion Molecule, ELAM-1), L-Selectin, and P-Selectin (GMP140) were a series of new calcium-binding lectins (C-lectins) which played a role in leukocyte adhesion to endothelium and extravasation. A significant part of the initial interaction in the lymphocyte adhesion system appeared to be due to specific carbohydrate/lectin interaction. Sialyl-LeX, dimeric Sialyl LeX and VIM-2 have been identified as structures active in the E-selectin system participating in the first interactions between neutrophils and capillary endothelium. In 1991 it was shown that Sialyl LeA, the lactose form of Sialyl-LeX and some analog ligands were also active. There has been a large surge of research in the area primarily due to the enormous therapeutic opportunities for inflammation. Reperfusion injury plays a significant role in heart damage in myocardial infarction and in kidney and other transplantation surgery. Rheumatoid arthritis has a vast effect on human health, and other inflammatory pathologies such as psoriasis could be effected by understanding the adhesive interactive biology and be designing appropriate pharmaceuticals. In a separate development, it has been shown that sialyl LeX, dimeric sialyl LeX and related structures are probably important in metastatic cancer cell adhesion to the capillary endothelium, prophesizing applications in another important area of human biology. Other areas of carbohydrate- specific protein interactions point to a growing new area of """"""""glycobiology"""""""" where the structures of the carbohydrate ligands and their recognizing proteins have other important biological activities, such as virus and microbial host cell surface receptors, smooth muscle cell growth inhibitors and others. The area has grown in importance to the level where recombinant DNA was perhaps 10 years ago. These conferences on Cell Adhesion and Carbohydrate Ligands will be held concurrently to facilitate free and open interactions between scientists registered to attend either meeting. There will be two joint sessions on carbohydrate recognition which promise to bring together the best of current research and investigators in these areas for cross stimulation on these two exciting areas of investigation.
