Abstract: The invention relates to an in vitro method for identifying microRNAs or the target mRNAs thereof, the expression of which during the infection of cells by a virus using a cell receptor and at least one cell co-receptor for entering the cell, is specifically modified on the basis of the cell co-receptor used by the virus for its entering the cells, comprising: i) determining the microRNA expression levels in a test cell expressing a receptor, a first co-receptor and at least one other co-receptor, after infection by a first virus using the first co-receptor and by at least one other virus using another co-receptor, respectively; ii) identifying the microRNAs, the expression level of which is modulated during the infection by each of the viruses in relation to the expression level in the uninfected cells; iii) comparing the thus-identified microRNAs; iv) selecting the microRNAs, the modification of the expression level of which is specific to the use of a co-receptor; v) optionally identifying the target mR

Abstract: The present invention relates to microarrays, sets of primers and methods for determining the co-receptor usage of a virus, in particular whether HIV uses CXCR4 or CCR5 as co-receptor. The methods and compositions of the invention are based on microRNA analysis. The invention can be used to determine virus tropism in any species or organism that expresses microRNAs, particularly in human beings.

Abstract: The invention relates to an in vitro method for identifying microRNAs or the target mRNAs thereof, the expression of which during the infection of cells by a virus using a cell receptor and at least one cell co-receptor for entering the cell, is specifically modified on the basis of the cell co-receptor used by the virus for its entering the cells, comprising: i) determining the microRNA expression levels in a test cell expressing a receptor, a first co-receptor and at least one other co-receptor, after infection by a first virus using the first co-receptor and by at least one other virus using another co-receptor, respectively; ii) identifying the microRNAs, the expression level of which is modulated during the infection by each of the viruses in relation to the expression level in the uninfected cells; iii) comparing the thus-identified microRNAs; iv) selecting the microRNAs, the modification of the expression level of which is specific to the use of a co-receptor; v) optionally identifying the target mR

Abstract: The invention relates to the use of nucleic acid miRNA derived molecules for producing a drug for treating a myelogenous leukemia and to a method for identifying therapeutic agents or the efficient combination thereof for inducing the differentiation of myelogenous leukemia cells.