Beta1 integrins mediate tubule formation induced by supernatants derived from KSHV-infected cells.
OBJECTIVE
Angiogenesis is defined as the formation of new blood vessels. In a recently concluded study, we identified Kaposi's sarcoma-associated herpesvirus (KSHV)-infected cells derived from primary effusion lymphoma (PEL) to overexpress vascular endothelial growth factor (VEGF) that had the propensity to mediate tubule formation on a Matrigel, an indicator of angiogenesis. The objective of this study was to determine the receptor molecules that mediate the tubule formation induced by the supernatant derived from KSHV-infected PEL cells.


METHODS
The identity of receptor(s) that play a role in mediating tubule formation driven by PEL supernatant was determined by the classical in vitro angiogenesis assay conducted on a Matrigel.


RESULTS
RGD peptides, antibodies, and siRNA specific to beta1 integrins significantly lowered the ability of the PEL supernatants to induce tubule formation by endothelial cells. beta1 Integrins mediated tubule formation to comparable levels in endothelial cells that were incubated with supernatants derived from uninduced or TPA-induced PEL cells. Interestingly, the beta1 integrins did not seem to have a major role in cellular attachment.


CONCLUSIONS
We report for the first time a critical role for beta1 integrins in angiogenesis supported by the supernatant from KSHV-infected PEL cells.
Dyson
Ossie F
OF
Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University, Greenville, NC 27834, USA.
Bryan
Benjaman A
BA
Lambert
Phelps J
PJ
Ford
Patrick W
PW
Akula
Shaw M
SM
D001402:B-Lymphocytes / Q000821:virology; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D003094:Collagen; D017077:Culture Media, Conditioned / Q000494:pharmacology*; D004338:Drug Combinations; D042783:Endothelial Cells / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology; D006566:Herpesviridae Infections / Q000821:virology; D019288:Herpesvirus 8, Human / Q000472:pathogenicity*; D006801:Humans; D019012:Integrin beta1 / Q000378:metabolism*; D007797:Laminin; D009389:Neovascularization, Pathologic; D011509:Proteoglycans; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D017077:Culture Media, Conditioned; D004338:Drug Combinations; D019012:Integrin beta1; D007797:Laminin; D011509:Proteoglycans; D042461:Vascular Endothelial Growth Factor A; C059485:matrigel; D003094:Collagen