Methods and kits for identifying effector treg cells

Abstract

The present invention relates to methods and kits for identifying effector regulatory T cells. In particular the present invention relates to use of CD15s as a biomarker for eTreg cells. The present invention also relates to a method for identifying effector Treg cells (eTreg) in a fluid sample comprising the steps of i) detecting the cell surface expression of CD4, CD25, CD127 and CD15s markers on the cell population contained in the fluid sample and ii) concluding that the cells expressing CD4, CD25, CD127 at low levels and CD15s are the effector Treg cells. The present invention also relates to a method for identifying effector Treg cells (eTreg) in a tissue sample comprising the steps of i) detecting the cell expression of CD4, CD25, Foxp3 and CD15s markers and ii) concluding that the cells expressing CD4, CD25, Foxp3 and CD15s are the effector Treg cells.

1 . A method for identifying effector Treg (eTreg) cells in a sample comprising the steps of
 i) identifying a population of Treg cells;   ii) detecting cell surface expression of CD15s in the population of Treg cells; and   iii) concluding that Treg cells expressing CD15s are the eTreg cells.   
     
     
         2 . The method of  claim 1 , wherein the sample is a fluid sample, and wherein the method of identifying a population of Treg cells comprises
 iv) detecting cell surface expression of CD127, CD4 and CD25 in the population of Treg cells; and   v) concluding that cells expressing CD127 at low levels, and expressing CD4 and CD25, are the Treg cells.   
     
     
         3 . The method according to  claim 2  wherein the fluid sample is selected from the group consisting of blood samples, PBMC samples and samples of Treg cells in suspension. 
     
     
         4 . The method of  claim 2  wherein the step of detecting is performed with a set of antibodies specific for CD4, CD25 and CD127. 
     
     
         5 . The method of  claim 2  wherein the step of detecting comprises performing flow cytometry. 
     
     
         6 . The method of  claim 1 , wherein the sample is a tissue sample, and wherein the method further comprises
 iv) detecting cell surface expression of CD4, CD25 and Foxp3 in the population of Treg cells; and   v) concluding that Treg cells expressing CD4, CD25 and Foxp3 are the eTreg cells.   
     
     
         7 . The method of  claim 6  wherein the step of detecting comprises a step of staining the tissue sample with a set of antibodies specific for CD4, CD25 and Foxp3. 
     
     
         8 . The method of  claim 6  wherein the step of detecting is performed by immunochemistry. 
     
     
         9 . The method of  claim 6  wherein the tissue sample is selected from the group consisting of tissue sections of brain, adrenal glands, colon, small intestines, stomach, heart, liver, skin, kidney, lung, pancreas, testis, ovary, prostate, uterus, thyroid and spleen. 
     
     
         10 . The method of  claim 2  which further comprises a step of detecting cell surface expression of CD45RA. 
     
     
         11 . The method of  claim 2  which further comprises a step of determining the level of eTreg cells present in the sample. 
     
     
         12 . The method of  claim 2  which further comprises a step of isolating eTreg cells from the sample. 
     
     
         13 . An isolated eTreg obtained by the method of  claim 12 . 
     
     
         14 . A pharmaceutical composition comprising a population of isolated eTreg cells identified by the method of  claim 1 . 
     
     
         15 . A method of treating a disease selected from the group consisting of autoimmune diseases, inflammatory disease, allergic disease and graft rejection in a subject in need thereof, comprising
 administering to said subject an efficient amount of isolated effector Treg (eTreg) cells identified by the method of  claim 1 .   
     
     
         16 . An in vitro method for monitoring the treatment of a disease selected from the group consisting of autoimmune diseases, inflammatory diseases and allergic diseases comprising the steps of
 i) determining the level of a population of eTreg cells in a sample obtained from the subject before the treatment by performing the method of  claim 11 ,   ii) determining the level of a population of eTreg cells in a sample obtained from the subject after the treatment by performing the method of  claim 11 ,   iii) comparing the level determined at step i) with the level determined at step ii) and   iv) concluding that the treatment is efficient when the level determined at step ii) is higher than the level determined at step i).   
     
     
         17 . An in vitro method for predicting the survival of a patient suffering from a cancer comprising the steps of
 i) determining the level of a population of eTreg cells in a sample obtained from the subject by performing the method of  claim 11 ,   ii) comparing the level determined at step i) with a reference value and   iii) concluding that the patient has a poor prognosis when the level determined at step i) is higher than the reference value.   
     
     
         18 . An in vitro method for determining whether a patient suffering from a cancer will respond to a treatment comprising the steps of
 i) determining the level of a population of eTreg cells in a sample obtained from the subject by performing the method of  claim 11 ,   ii) comparing the level determined at step i) with a reference value and   iii) concluding that the patient will significantly respond to the treatment when the level determined at step i) is lower than the reference value.   
     
     
         19 . The method of  claim 18  wherein the treatment is done with a immunotherapeutic agent. 
     
     
         20 . A kit comprising means for detecting, on a cell population, the cell surface expression of
 CD4, CD25, CD127 and CD15s markers; or   CD4, CD25, Foxp3 and CD15s markers.   
     
     
         21 . The kit of  claim 20  wherein said means are antibodies.