Korean J Anat.  2001 Feb;34(1):23-32.

Regulation of homotypic aggregation of myeloma-derived cell line IM-9 by CD82

• Hahn JH
• Kim DJ

Abstract

Although reduced expression of CD82 transmembrane protein facilitates metastasis of cancer cells, little is known about its biological function. Here we have investigated the role of CD82 in B cell lymphocyte adhesion. When IM-9 cells were engaged with anti-CD82 monoclonal antibody, they formed homotypic aggregates in a short time. This adhesion was inhibited by anti-CD11a monoclonal antibody that has been known to block LFA-1-mediated cell adhesion. The cell surface expression of LFA-1 has not been changed by CD82 engagement. Homotypic aggregation was decreased in the cells in which the level of CD82 expression was low, and it was not recovered by anti-CD99 monoclonal antibody or PMA that has been known to stimulate cell adhesion. In addition, it was recovered by Mg++ treatment that induces conformational change of LFA-1 moleucles, but not by Ca++ treatment that leads to clustering of LFA-1 on the cell surface. CD82-induced cell aggregation was dramatically abrogated by addition of the phos-phatidylinositol 3-kinase (PI3-K) inhibitor LY294002 or p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580. Taken together, these results suggest that CD82 molecule may fascilitate adhesion of lymphocytes by inducing conformational change of LFA-1 to pro-adhesive structure through PI3-K or p38 MAPK signal pathway.

Keyword

CD82; IM-9 cell; B lymphocyte; Homotypic cell adhesion; LFA-1

MeSH Terms

Cell Adhesion
Cell Aggregation
Cell Line*
Lymphocyte Function-Associated Antigen-1
Lymphocytes
Neoplasm Metastasis
p38 Mitogen-Activated Protein Kinases
Protein Kinases
Signal Transduction
Lymphocyte Function-Associated Antigen-1
Protein Kinases
p38 Mitogen-Activated Protein Kinases