Patent ID: 7125670

Claim:
A method of detecting the presence of activated CD4+ T-cells in a sample, comprising: contacting a sample nucleic acid molecule obtained from a sample with a polynucleotide probe under stringent hybridization conditions of about 1×SSC and 0.1% SDS at 50° C.–70° C., wherein said polynucleotide probe comprises a nucleic acid sequence comprising nucleotides 15 through 845 of SEQ ID NO: 1 or a complete complement of said nucleic acid sequence, which nucleic acid sequence encodes an ACT-4 receptor polypeptide or variant thereof that is capable of specifically binding to the extracellular domain of the ACT-4-L-h-1 ligand; and detecting hybridization between said sample nucleic acid molecule and said polynucleotide probe, wherein the detection of hybridization is diagnostic of the presence of activated CD4+ T-cells in the sample.