Modulation of mitogen-dependent lymphocyte stimulation by hyaluronic acid

The stimulation of incorporation of [3H]-thymidine into mononuclear cells (MC) from human body by plant lectins was assessed in the presence of varying concentrations of hyaluronic acid (HA). The simultaneous addition of HA and phytohemagglutinin to MC cultures resulted in a decrease in the incorporation of radioactivity. The magnitude of the decrease was directly related to the concentration of HA added. Kinetic studies, however, indicated that the addition of HA after the initiation of DNA synthesis in the MC cultures also resulted in a decline of the rate of incorporation of radioactivity. The kinetic and analytical data suggest that DNA synthesis by MC in inflammatory arthropathies might be modulated by the HA rich microenvironment of the joint and that this modulation could also occur even if the MC were stimulated before they reached the joint tissues.