was blocked modestly by most oligosaccharides at 1 
mM. IC50 values of soluble oligosaccharides deter- 
mined in competitive binding studies accurately 
predicted blocking of leukocyte adhesion to recom- 
binant E- and P-selectin-Ig and to cytokine-activated 
endothelium. L-selectin-Ig demonstrated little bind- 
ing to immobilized BSA-sLe* or BSA-sLe", precluding 
evaluation in competitive ELISAs. 
Together these results indicate that the three 
selectins have distinct carbohydrate recognition 
characteristics and that specific modifications of 
the oligosaccharides sLe" and sLe'' can result in 
higher affinity ligands for E-selectin. Moreover they 
suggest avenues for the development of novel anti- 
inflammatory therapeutic agents. 
Cell Adhesion Molecules in Lung Injury 
and Inflammation 
To assess the role of selectin-carbohydrate inter- 
actions in vivo, Dr. Bevilacqua and his colleagues 
are using murine models of acute lung injury. Intra- 
tracheal injection of lipopolysaccharides and inflam- 
matory cytokines was shown to induce leukocyte 
extravasation and movement into the airspace. Neu- 
trophils recovered in bronchoalveolar lavage fluid 
increase dramatically during the first hours postin- 
jection, peaking between 6 and 24 hours. This is 
followed by an exudation of monocytes and lym- 
phocytes that reaches a maximum between 24 and 
48 hours. In an attempt to identify potential anti- 
inflammatory agents, Dr. Bevilacqua and his col- 
leagues are evaluating selected carbohydrates. In 
preliminary studies, the tetrasaccharides sLe" and 
sLe'' given intravenously at 1 0 mg/kg blocked neu- 
trophil exudation by ~50%. In combination, sLe'' 
and sLe^ were more potent than either compound 
alone. Significant blocking activity was achieved 
with a total dose of 200 mg of oligosaccharide per 
mouse. Assuming a blood volume of 2 ml, this 
amount would yield a maximal blood concentration 
of 100 jttM. These compounds appear to be more 
effective (i.e., work at lower doses) in blocking leu- 
kocyte extravasation in vivo than they are in block- 
ing leukocyte adhesion in vitro. 
Endothelial Adhesion Molecules 
in Metastasis 
Since joining the Howard Hughes Medical Insti- 
tute, Dr. Bevilacqua and his colleagues have ex- 
panded their efforts in the study of endothelial ad- 
hesion molecules in metastasis. Their recent eff'ons 
have focused primarily on the adhesion and metasta- 
sis of colon cancer cells. Nearly all human colon 
cancer cell lines tested demonstrate enhanced bind- 
ing to cytokine-activated endothelium, a process 
that is blocked by anti-E-selectin antibodies. Simi- 
larly, these cells bind to COS cells transfected with 
recombinant E-selectin, as well as to dishes coated 
with E-selectin-Ig. One cell line, CaCo2, demon- 
strates little or no E-selectin-dependent adhesion. 
This pattern of adhesion accurately predicts the met- 
astatic potential of these tumor cell lines in a mu- 
rine model. Treatment of mice with the inflamma- 
tory cytokine interIeukin-1 results in a 3- to 10-fold 
increase in pulmonary metastatic nodules after intra- 
venous injection of all the colon cancer lines tested 
except CaCo2. Present efforts are focused on charac- 
terization of the tumor cell surface carbohydrate li- 
gands for E-selectin and evaluation of potential in- 
hibitors of metastasis. Separate studies focus on the 
interaction of cancer cells with P- and L-selectin. 
Preliminary studies on acute lung injury and the 
research on endothelial adhesion molecules in me- 
tastasis have been supported in part by funds from 
the Pew Foundation. 
Dr. Bevilacqua is also Associate Professor of Pa- 
thology and Member of Cellular and Molecular 
Medicine at the University of California, San 
Diego, and a Pew Scholar in the Biomedical 
Sciences. 
Books and Chapters of Books 
Bevilacqua, M.P., Corless, C, and Lo, S.K. 1991. 
Endothelial-leukocyte adhesion molecule- 1 
(ELAM-1): a vascular selectin that regulates in- 
flammation. In Cellular and Molecular Mecha- 
nisms of Inflammation: Vascular Adhesion Mol- 
ecules (Cochrane, C.G., and Gimbrone, M.A., Jr., 
Eds.). New York: Academic, pp 1-13- 
Article 
Bevilacqua, M., Butcher, E., Furie, B., Furie, B., 
Gallatin, M., Gimbrone, M.A., Jr., Harlan, J., Kishi- 
moto, K., Lasky, L., McEver, R., Paulsen, J., Rosen, 
S., Seed, B., Siegelman, M., Springer, T., Stoolman, 
L., Tedder, T., Varki, A., Wagner, D., Weissman, I., 
and Zimmerman, G. 1991. Selectins: a family of 
adhesion receptors. Cell 67:233. 
CELL BIOLOGY AND REGULATION 25 
