Hyaluronic acid-induced lymphocyte signal transduction and HA receptor (GP85/CD44)-cytoskeleton interaction.

Abstract

The purposes of this study are to characterize the binding of hyaluronic acid (HA) to mouse T lymphoma cells, to measure changes in intracellular Ca2+ after HA binding, to elucidate the interaction between the HA receptor, GP85(CD44), and ankyrin in the membrane skeleton, and finally to correlate these events with HA receptor patching/capping and cell adhesion to HA. First, we established an in vivo assay using [3H]HA to measure the binding of HA to mouse T lymphoma cells, and found that the binding of [3H]HA to these cells is readily inhibited by the addition of anti-GP85(CD44) antibody suggesting that GP85(CD44) is the HA receptor. Next, we examined various signal transducing events that occur after HA binds to its receptor on mouse T lymphoma cells. The results of these studies indicate that the concentration of intracellular Ca2+ (as measured by Fura-2 fluorescence) begins to increase within seconds, and reaches a maximal level 5 min after the addition of HA to the cells. After this increase of intracellular Ca2+, HA induces both its receptors, GP85(CD44), to form patched/capped structures, and cell adhesion to HA-coated plates. Furthermore, we have determined that GP85(CD44) binds directly and specifically to ankyrin (Kd approximately 1.94 nM) in a saturable manner; and that ankyrin is preferentially accumulated underneath the HA-induced GP85(CD44) capped structures. The Ca2+ ionophore, ionomycin, was found to stimulate HA-induced receptor capping and adhesion while EGTA (a Ca2+ chelator), nefedipine/bepridil (Ca2+ channel blockers), W-7 (a calmodulin antagonist), and cytochalasin D (a microfilament inhibitor), but not colchicine (a microtubule disrupting agent), inhibit HA-induced receptor redistribution and adhesion to HA-coated plates. These findings strongly suggest that ankyrin plays an important role in linking the HA receptor, GP85(CD44), to the membrane-associated actomyosin contractile system during hyaluronic acid-mediated lymphocyte activation.

• Authors: L Y Bourguignon, V B Lokeshwar, X Chen, W G Kerrick
• Journal: Journal of immunology (Baltimore, Md. : 1950) (J Immunol) Vol. 151 Issue 12 Pg. 6634-44 (Dec 15 1993) ISSN: 0022-1767 [Print] United States
• PMID: 7505012 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Ankyrins
• Carrier Proteins
• Hyaluronan Receptors
• Receptors, Cell Surface
• Receptors, Lymphocyte Homing
• Hyaluronic Acid
• Calcium

Topics

• Animals
• Ankyrins (metabolism)
• Calcium (metabolism)
• Carrier Proteins (metabolism)
• Cell Adhesion
• Cell Line
• Cytoskeleton (metabolism)
• Hyaluronan Receptors
• Hyaluronic Acid (metabolism, pharmacology)
• Kinetics
• Mice
• Receptor Aggregation
• Receptors, Cell Surface (metabolism)
• Receptors, Lymphocyte Homing (metabolism)
• Signal Transduction (drug effects)
• T-Lymphocytes (drug effects, immunology, metabolism)