Role of Kaposi's sarcoma cells in recruitment of circulating leukocytes: implications in pathogenesis.
OBJECTIVE
We sought to identify and characterize mechanisms of interaction between Kaposi's sarcoma cells and circulating leukocytes leading to leukocyte migration into the lesion.


METHODS
By using static and dynamic adhesion models, we measured the ability of late-stage KSY1 cells to support adhesion and transmigration of peripheral blood lymphocytes (PBL).


RESULTS
We showed that resting as well as TNF-alpha- or PMA-activated KSY1 cells supported adhesion and transmigration of PBL with a higher efficiency compared with normal endothelial cells. The LFA1/ICAM1 pathway was totally involved in PBL adhesion to resting or TNF-alpha-activated KSY1 cells and partially responsible for adhesion to PMA-activated KSY1 cells. No inhibition of adhesion was observed by blockage of the VLA4 pathway. Under flow conditions, PBL/KSY1 cell interaction was totally dependent on L-selectin.


CONCLUSIONS
Our data indicate that KS cells mimic an endothelium-like structure by regulating extravasation of lymphocytes into lesions.
Galea
P
P
Unit of Retroviruses and Associated Diseases, Parc Scientifique et Technologique de Luminy, Marseille, France.
Frances
V
V
Dou-Dameche
L
L
Sampol
J
J
Chermann
J C
JC
D002449:Cell Aggregation; D002478:Cells, Cultured; D018920:Coculture Techniques; D006801:Humans; D039041:Integrin alpha4beta1; D016023:Integrins / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000473:pathology*; D016169:Lymphocyte Function-Associated Antigen-1 / Q000378:metabolism; D016201:Receptors, Lymphocyte Homing / Q000378:metabolism; D012514:Sarcoma, Kaposi / Q000473:pathology*; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D039041:Integrin alpha4beta1; D016023:Integrins; D016169:Lymphocyte Function-Associated Antigen-1; D016201:Receptors, Lymphocyte Homing; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1