Phosphorylated dextrans
Dextrans, which have no immunoreactivity, were revealed to exert immunopotentiating activities on their chemical phosphorylation. Since phosphorylated dextrans not only function as B cell mitogens, but also activate dendritic cells and induce IL-10 and IFN-γ, they can be expected to have effects in preventing infectious diseases and colitis, and in preventing allergic diseases by maintaining the Th1/Th2 balance.
1 . An agent comprising a phosphorylated dextran as an active ingredient, and having an immunopotentiating activity.
2 . The agent of claim 1 , wherein the agent is a B cell-specific mitogen.
3 . The agent of claim 1 , wherein the immunopotentiating activity is a blastogenic activity.
4 . The agent of claim 1 , wherein the immunopotentiating activity is an activity of inducing interferon γ (IFN-γ) or interleukin 10 (IL-10).
5 . A pharmaceutical composition for preventing, improving, or treating infectious diseases, colitis, or allergic diseases, wherein the composition comprises a phosphorylated dextran as an active ingredient.
6 . A food composition for preventing or improving infectious diseases, colitis, or allergic diseases, wherein the composition comprises a phosphorylated dextran as an active ingredient.
7 . A method for immunopotentiating a cell, which comprises the step of contacting the cell with a phosphorylated dextran.
8 . The method of claim 7 , wherein the immunopotentiation is blastogenesis.
9 . The method of claim 7 , wherein the immunopotentiation is the induction of interferon γ (IFN-γ) or interleukin 10 (IL-10).
10 . The method of claim 7 , wherein the cells are derived from spleen cells or dendritic cells.
11 . A method for producing a phosphorylated dextran, which comprises the step of reacting a dextran with polyphosphoric acid in a formaldehyde solution.
12 . The method of claim 11 , wherein a dextran and polyphosphoric acid are reacted under heat.
13 . The composition of claim 5 , wherein the phosphorylated dextran is produced by a method comprising the following steps of:
(a) reacting a dextran with a phosphate buffer under heat;
(b) freeze-drying the reaction solution of step (a); and
(c) heating the freeze-dried sample of step (b) at 100-160° C. for 24 hours.
14 . The composition of claim 6 , wherein the phosphorylated dextran is produced by a method comprising the following steps of:
(a) reacting a dextran with a phosphate buffer under heat;
(b) freeze-drying the reaction solution of step (a); and
(c) heating the freeze-dried sample of step (b) at 100-160° C. for 24 hours.
15 . The method of claim 8 , wherein the cells are derived from spleen cells or dendritic cells.
16 . The method of claim 9 , wherein the cells are derived from spleen cells or dendritic cells.