Reagents for cell selection and methods of use

A method of selecting a cell, comprising the steps of:

• (a) contacting a cell population with a peptide-ligand conjugate, wherein said conjugate comprises a first ligand specific for a cell in said population conjugated to a peptide capable of displacing a second ligand specific for said peptide, thereby forming a cell-conjugate complex;
• (b) contacting said peptide-ligand conjugate with said second ligand;
• and
• (c) isolating said cell-conjugate complex.

A method of enriching for a cell from a cell population, comprising the steps of:

• (a) contacting a cell population with a peptide-ligand conjugate, wherein said conjugate comprises a first ligand specific for a cell in said population conjugated to a peptide capable of displacing a second ligand specific for said peptide, thereby forming a cell-conjugate complex;
• (b) contacting said peptide-ligand conjugate with said second ligand;
• and
• (c) isolating said cell-conjugate complex.

A method of diagnosing a condition, comprising the steps of:

• (a) contacting a sample comprising a cell population with a peptide-ligand conjugate, wherein said conjugate comprises a first ligand specific for a cell in said population conjugated to a peptide capable of displacing a second ligand specific for said peptide, thereby forming a cell-conjugate complex;
• (b) contacting said peptide-ligand conjugate with said second ligand;
• (c) isolating said cell-conjugate complex;
• and
• (d) identifying said cell in said complex, wherein said cell is associated with a condition.

A peptide comprising an amino acid sequence selected from the group consisting of ACKQF (SEQ ID NO:34);

• ASKQF (SEQ ID NO:35);
• ACKRPP (SEQ ID NO:36);
• ACKQFN (SEQ ID NO:37);
• ACKQFDFC (SEQ ID NO:38);
• ACKQFNNDV (SEQ ID NO:39);
• ACKQFACKQF (SEQ ID NO:40);
• ACKQFDFCNDH (SEQ ID NO:41);
• ACKRPPVSLTCH (SEQ ID NO:42);
• ACKQLHSVSGCR (SEQ ID NO:43);
• ACKQFNNDVTCN (SEQ ID NO:44);
• ACKQFDFCNDHWSK (SEQ ID NO:45);
• ACKQFNNDVTCNKRH (SEQ ID NO:46);
• ACKQFDFCNDHWSKSQH (SEQ ID NO:47);
• ACKQFNNDVTCNAAEGDD (SEQ ID NO:48);
• KCHPNMSLKECH (SEQ ID NO:49);
• RCRRPATTPACR (SEQ ID NO:50);
• and RCRRPATTPACRACKQF (SEQ ID NO:51).

A method of selecting a cell subpopulation, comprising the steps of:

• (a) contacting a cell population with:
• a peptide-ligand conjugate, wherein said conjugate comprises a first ligand specific for a first cell in said population, said first ligand conjugated to a peptide capable of displacing a peptide-specific ligand, thereby forming a first cell-conjugate complex;
• and
• with a second ligand specific for a second cell in said population, thereby forming a second cell-second ligand complex;
• (b) contacting said peptide-ligand conjugate with said peptide-specific ligand;
• and
• (c) isolating said first cell-conjugate complex and said second cell-second ligand complex.

A method of selecting a cell, comprising the steps of:

• (a) contacting a cell population with a peptide-ligand conjugate, wherein said conjugate comprises a first ligand specific for a first cell in said population conjugated to a peptide capable of displacing a peptide-specific ligand, wherein said peptide-specific ligand binds to a second cell in said population, thereby forming a cell-conjugate complex;
• (b) contacting said peptide-ligand conjugate with said peptide-specific ligand;
• (c) contacting said cell population with a second ligand specific for said second cell, wherein said second ligand is not displaced by said peptide and binds to a distinct site from said peptide-specific ligand;
• and
• (d) isolating said cell-conjugate complex.