Expressions of very late antigen-6 and vitronectin receptor, and their interactions to laminin and vitronectin during tonsillar B-cell activation.
This study examined the expressions of a-subunits of very late antigen-6 (VLA-6; alpha 6) and vitronectin receptor (VNR; alpha V) on tonsillar B cells and interactions between those integrins and their respective ligands, laminin (LM) and vitronectin (VN). alpha 6 and alpha V were expressed on about 30 to 40% of tonsillar B cells. When purified tonsillar B cells were separated by a discontinuous Percoll gradient, the number of alpha 6- and alpha V-positive cells decreased as the cell density went down, while the number of activated cells went up. After in vitro activation of tonsillar B cells by Staphylococcus aureus Cowan I strain (SAC), the expressions of alpha 6 and alpha V and their adhesiveness to LM or VN decreased significantly. Increased proliferation of B cells was observed when tonsillar B cells were cultured with immobilized LM or VN. The results of immunohistological staining showed VLA-6, VNR, LM and VN in the follicular area. These results suggest that the expressions of VLA-6 and VNR on tonsillar B cells may be decreased during B cell activation, and the interaction between VLA-6, VNR, and LM, VN may give a costimulatory effect on B cell activation in the follicular area of the tonsil.
Ohguro
S
S
Department of Otolaryngology, Sapporo Medical University, School of Medicine, Japan.
Tsubota
H
H
D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes / Q000502:physiology*; D018122:B7-1 Antigen / Q000235:genetics*; D002448:Cell Adhesion; D002465:Cell Movement; D046508:Culture Techniques; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D007797:Laminin / Q000502:physiology*; D008024:Ligands; D014066:Palatine Tonsil / Q000382:microbiology*; D011897:Random Allocation; D016029:Receptors, Very Late Antigen / Q000502:physiology*; D013211:Staphylococcus aureus; D019096:Vitronectin / Q000502:physiology*
D000911:Antibodies, Monoclonal; D018122:B7-1 Antigen; D007797:Laminin; D008024:Ligands; D016029:Receptors, Very Late Antigen; D019096:Vitronectin