Inhibition of concanavalin a‐induced proliferative responses of mouse spleen cells and rabbit Peyer's patch cells by hen egg‐white avidin

Abstract

Hen egg‐white avidin inhibited the proliferative responses of mouse spleen cells stimulated by both concanavalin A (Con A) and pokeweed mitogen. It also inhibited mitogen‐induced proliferation of rabbit Peyer's patch cells. The Con A‐induced proliferation of spleen cells was inhibited by streptavidin without α‐D‐mannose residues as well as by egg‐white avidin with α‐D‐mannose residues. Egg‐white avidin was found to bind directly to spleen cells, but it had no cytotoxic activity against spleen cells or Peyer's patch cells. Egg‐white avidin did not appear to inhibit the formation of cytokines required for Con A‐induced spleen cell proliferation or to induce the production of growth‐inhibiting cytokines. On the other hand, egg‐white avidin's inhibitory effect on Con A‐induced spleen cell proliferation decreased as the time to addition of egg‐white avidin increased, and was lowest when the protein was added after 10 h of spleen cell cultivation with Con A. Spleen cells cultured with Con A resulted in a significant reactivity with anti‐interleukin‐2 (IL‐2) receptor antibody, whereas the addition of egg‐white avidin to the culture of Con A‐stimulated spleen cells noticeably reduced the reactivity. These findings suggest that the suppression of Con A‐induced proliferation of mouse spleen cells by hen egg‐white avidin occurs, at least in part, through the inhibition of binding of IL‐2 to its receptors on Con A‐activated spleen lymphocytes because of binding of the avidin to spleen lymphocytes or through the inhibition of IL‐2 receptor expression on the spleen lymphocytes.

Keywords:

• Hen egg‐white avidin
• spleen cells
• Peyer's patch cells
• lymphocytes
• inhibition of proliferation
• IL‐2 receptor
• concanavalin A