Method for detecting regulatory t cells using expression of folate receptor 4 as indicator, method for treating diseases using the detection method, pharmaceutical composition for immunostimulation, and method for treating diseases using the composition

Abstract

An object of the present invention is to provide a technique to distinguish between T reg cells and activated T cells in a live state. Another object of the present invention is to provide a pharmaceutical composition for immunostimulation that can reduce the number of T reg cells in vivo and effectively express the immune response of activated T cells. In the method of the present invention, T reg cells are detected from test cells containing (i) regulatory T cells and (ii) at least one type of cell selected from the group consisting of naive T cells and activated T cells, wherein expressions of folate receptor 4 on the surfaces of cells are measured and T reg cells are detected using the expressions as an indicator. The present invention uses anti-folate receptor 4 antibody or folate receptor 4-binding fragment as an active ingredient contained in a pharmaceutical composition for immunostimulation.

1 - 12 . (canceled) 
     
     
         13 . A method for treating tumors comprising administering an anti-folate receptor 4 antibody or folate receptor 4-binding fragment of the antibody. 
     
     
         14 . The method according to  claim 13 , wherein the administration is performed by intravenous injection. 
     
     
         15 . The method according to  claim 13  or  14 , wherein the folate receptor 4-binding fragment of the antibody is a Fab fragment or F(ab′)2 fragment. 
     
     
         16 . The method according to  claim 13  or  14 , wherein the anti-folate receptor 4 antibody or folate receptor 4-binding fragment is humanized or chimeric. 
     
     
         17 . The method according to  claim 13  or  14 , wherein the anti-folate receptor 4 antibody is a monoclonal antibody. 
     
     
         18 . An immunostimulation method comprising administering an anti-folate receptor 4 antibody or folate receptor 4-binding fragment of the antibody. 
     
     
         19 . The method according to  claim 18 , wherein the administration is performed by intravenous injection. 
     
     
         20 . The method according to  claim 18  or  19 , wherein the folate receptor 4-binding fragment of the antibody is a Fab fragment or F(ab′)2 fragment. 
     
     
         21 . The method according to  claim 18  or  19 , wherein the anti-folate receptor 4 antibody or folate receptor 4-binding fragment is humanized or chimeric. 
     
     
         22 . The method according to  claim 18  or  19 , wherein the anti-folate receptor 4 antibody is a monoclonal antibody.