Method of inducing autophagy and activating toll-like receptor

Abstract

A method of inducing autophagy in a cell is achieved by contacting the cell with graphene oxide (GO) in an amount effective to induce autophagy in the cell, wherein the cell expresses at least one of TLR-4 (Toll-like receptor 4) and TLR-9 (Toll-like receptor 9). Differences between autophagy triggered by GO and other conventional agonists such as rapamycin have been observed. GO may activate autophagy in some cells that may not be triggered by rapamycin. The cell reveals no apparent apoptosis after treatment of the graphene oxide. A method of activating a Toll-like receptor in a cell is also herein provided.

What is claimed is: 
     
         1 . A method of inducing autophagy in a cell, comprising:
 contacting the cell with graphene oxide in an amount effective to induce autophagy in the cell, wherein the cell expresses at least one of TLR-4 (Toll-like receptor 4) and TLR-9 (Toll-like receptor 9).   
     
     
         2 . The method as claimed in  claim 1 , wherein the particle sizes of the graphene oxide range from 100 nm to 3 μm. 
     
     
         3 . The method as claimed in  claim 1 , wherein the particle sizes of the grapheme oxide range from 100-800 nm. 
     
     
         4 . The method as claimed in  claim 1 , wherein the concentration of the graphene oxide is greater than or equal to 5 μM. 
     
     
         5 . The method as claimed in  claim 1 , wherein the concentration of the graphene oxide is greater than or equal to 100 μM. 
     
     
         6 . The method as claimed in  claim 1 , wherein the cell is a cancer cell. 
     
     
         7 . The method as claimed in  claim 1 , wherein the cell is an ovarian cancer cell, a brain cancer cell, a prostate cancer cell, a cervical cancer cell, a lung cancer cell, a liver cancer cell or a colon cancer cell. 
     
     
         8 . The method as claimed in  claim 1 , wherein the cell is an immune cell. 
     
     
         9 . The method as claimed in  claim 8 , wherein an inflammatory response is triggered after contacting the immune cell with graphene oxide. 
     
     
         10 . The method as claimed in  claim 1 , wherein the cell is a primary immune cell. 
     
     
         11 . The method as claimed in  claim 1 , wherein autophagy of the cell is not triggered by rapamycin. 
     
     
         12 . The method as claimed in  claim 1 , wherein autophagy is induced in more than 40% of the cell. 
     
     
         13 . The method as claimed in  claim 1 , wherein autophagy is induced in essentially 80% or more of the cell. 
     
     
         14 . The method as claimed in  claim 1 , wherein the cell reveals no apparent apoptosis or necrosis after treatment of the graphene oxide. 
     
     
         15 . The method as claimed in  claim 1 , wherein the cell expresses both of TLR-4 and TLR-9. 
     
     
         16 . A method of activating a Toll-like receptor in a cell, comprising:
 contacting the cell with graphene oxide in an amount effective to activate a at least one of TLR-2 (Toll-like receptor 2), TLR-4 (Toll-like receptor 4), TLR-7 (Toll-like receptor 7) and TLR-9 (Toll-like receptor 9) in the cell, whereby at least one of TLR-2, TLR-4, TLR-7 and TLR-9 are activated in the cell.   
     
     
         17 . The method as claimed in  claim 16 , wherein the cell is an immune cell or a cancer cell. 
     
     
         18 . The method as claimed in  claim 16 , wherein TLR-4 and TLR-9 are both activated in the cell. 
     
     
         19 . A method of potentiating an antitumor immune response in a subject, comprising:
 administering an effective amount of graphene oxide to the subject.