Capture agents and related methods and systems for detecting and/or sorting targets
Polynucleotide-encoded capture agents for target detection and in particular modular polynucleotide-capture agents comprising a target binding component, a scaffold component and an encoding component formed by standardized molecular units that can be coupled and decoupled in a controlled fashion, and related compositions methods and systems.
1. A method for sorting cells comprising:
combining a sample having a plurality of target cells with a plurality of capture agent sets, each capture agent set comprising a plurality of capture agents comprising a tetramer of an antigen-presenting MHC attached to an optimized streptavidin scaffold molecule and an encoding polynucleotide attached to the scaffold molecule, wherein the MHC specifically binds to a predetermined target cell and the encoding polynucleotide specifically binds to a complementary substrate polynucleotide and wherein each capture agent within a capture agent set binds the same target cells and binds the same complementary substrate polynucleotides;
forming target cell complexes of capture agents bound to the target cells;
combining the target cell complexes with a plurality of complementary substrate polynucleotide sets attached to a substrate; and
hybridizing the encoding polynucleotides to complementary substrate polynucleotides to sort target cell complexes.
2. The method of claim 1 , wherein each capture agent has three encoding polynucleotides attached to the scaffold molecule.
3. The method of claim 1 further comprising a plurality of sets of capture agents, wherein each set of capture agents has encoding polynucleotides orthogonal to the encoding polynucleotides of each other set of capture agents and an MHC tetramer that binds to a target cell surface antigen different from the target cell surface antigen to which the other sets of MHC tetramers bind.
4. The method of claim 3 , wherein the encoding polynucleotides of each set of capture agents encodes a restriction site different from the restriction enzyme site of the encoding polynucleotides of the other sets of capture agents.
5. The method of claim 4 , wherein substrate bound target cells complexes are combined with restriction enzymes.
6. The method of claim 1 , wherein the encoding polynucleotides are ssDNA oligomers.
7. The method of claim 1 , wherein the capture agent further comprises a labeled molecule.
8. The method of claim 7 , wherein the labeled molecule is selected from the group consisting of radioactive isotopes, fluorophores, chemiluminescent dyes, chromophores, enzymes, enzyme substrates, enzyme cofactors, enzyme inhibitors, dyes, metal ions, nanoparticles, metal sols, and ligands.
9. The method of claim 8 further comprising detecting a labeling signal.
10. The method of claim 1 , wherein the MHC is an MHC class I, II or III protein.
11. The method of claim 10 , wherein the MHC binds a T cell receptor.
12. The method of claim 1 , wherein the target cells are selected from the group consisting of CD8, CD4, CD3 and antigen specific T cells.
13. The method of claim 12 , wherein the T cell antigen is selected from the group consisting of MART-1, OVA, CMV, and tyrosinase.
14. The method of claim 1 , wherein the optimized streptavidin scaffold molecule further comprises the amino acid sequence as set forth in SEQ ID NO:2.